fixed code formatting

I didn't forget this time

.gitignore

@@ -9,6 +9,3 @@
 # ignore racket compile files
 *.dep
 *.zo
-
-#ignore backup files
-*.bak

Douglas_Richardson.md

@@ -0,0 +1,149 @@
+# Hermes project report
+
+## Douglas Richardson
+### April 28, 2017
+
+# Overview
+Hermes is a multi-user chat program that allows users to setup a server, connect to it
+and communicate with all other members of the server.
+
+Hermes uses TCP pipes to tread input and output like a port. Essentially, each client sends
+information to the server and depending on the input, the server decides what to do with it
+and usually sends output back to all the other users.
+
+# Libraries Used
+The code uses two non-default libraries:
+
+```
+(require racket/gui/base)
+(require math/base)
+```
+
+* The ```racket/gui/base``` library is the primary library for the GUI.
+* the ```math/base``` is used for random number generation.
+
+# Key Code Excerpts
+
+Here is a discussion of the most essential procedures, including a description of how they embody ideas from 
+UMass Lowell's COMP.3010 Organization of Programming languages course.
+
+Five examples are shown and they are individually numbered. 
+
+## 1. Initializing the gui
+
+This line of code allows us to wrap the gui into an object.
+
+```
+(define (make-gui)
+      ...
+      (cond ((eq? command 'show) (lambda () (send main-frame show #t)))
+            ((eq? command 'get-color) get-my-color)
+            ((eq? command 'set-color) set-color)
+            ((eq? command 'prompt-color) prompt-color)
+            ((eq? command 'prompt-username) prompt-username)
+            ((eq? command 'prompt-hostname) prompt-hostname)
+            ((eq? command 'send) send-message) ;; call to show a message in a gui
+            ((eq? command 'set-name) (lambda (newname) (if (string? newname)
+                                                  (set! name newname)
+                                                  (print "Thats not good"))))
+            ; ((eq? command 'recieve-message) user-message)
+            ; ((eq? command 'get-list) listy)
+            ; ((eq? command 'set-list) update)
+            ;;Something up with that
+            ; else should assume a message and output to screen we do not want it
+            ; to fail
+            ((eq? command 'get-message) get-message)
+            (else (error "Invalid Request" command))
+            ))
+    ;;dispatch goes below that
+    dispatch)
+```
+
+This allows us to make our code simpler and lets us treat the gui like an object in it's self.
+Giving the gui commands to change it's self rather than having to remember all the commands it has.
+
+## 2. Working with lists
+
+This code is code that allows us to append a new message onto the end of the list of messages using recursion
+
+```
+(define (appendlist listoflist add-to-end)
+  (if (null? listoflist)
+      (cons add-to-end '())
+      (cons (car listoflist) (appendlist (cdr listoflist) add-to-end))))
+ ```
+      
+Normally there is a function to just append onto the end of a list, however the problem is that if we attempt to append
+a list of elements onto the end of a list, it just appends the elements onto the end of the list. For example if I had
+a list of the following '(("Doug" "Hello World!" "Purple")) 
+and wanted to append the list '("Gordon" "No one else is here Doug." "Black") The list I want back would be
+'(("Doug" "Hello World!" "Purple")("Gordon" "No one else is here Doug." "Black")) but if I use the default
+list append I get'(("Doug" "Hello World!" "Purple")"Gordon" "No one else is here Doug." "Black")
+which is no good for the gui.
+
+This follows on our idea of working with lists and using recursion to walk down a list.
+
+## 3. Re-drawing messages
+
+The following procedure is used to re-draw messages onto the canvas after a screen move or resize.
+
+```
+    (define (update-helper given-list)
+      (if (null? given-list)
+          '()
+          (if (null? (car given-list))
+              '()
+              (begin (user-message
+                      (get-username-from-list (car given-list))
+                      (get-message-from-list (car given-list))
+                      (get-color-from-list (car given-list)))
+                     (update-helper (cdr given-list))))))
+```
+
+While it doesn't actually use the map function, this is a map as for every element of a list (each element is a list of three strings)
+it runs a procedure (or in this case a set of procedures) in the order of the list.
+
+## 4. Parsing Messages
+
+This line of code is used to parse a single string message into a three string message
+
+```
+    (define (user-message-parse string-i start)
+        (define (helper str index)
+          (if (eq? (string-ref str (+ start index)) #\~) ; regexes would allow us
+                                                         ; to avoid this #\~
+              (substring str start (+ start index))
+              (helper str (+ index 1))))
+        (helper string-i 0))
+```
+
+This was used to parse a string into smaller strings. In hermes we can only send one string to each client at one time, therefore
+the three elements that the gui uses to print messages need to be compressed together. We append a ~ inbetween each of these so we can
+parse them out at the client end. 
+
+While we don't run any commands off it (saved that part for the commands we do interpret from strings) 
+it is similar to the symbolic differentaitor.
+
+## 5. Color setting
+ Here we have an example of when we use a symbolic differentiator in the gui to determine when a user wants to run a command
+ rather than input text.
+ 
+ ```
+ (define (button-do-stuff b e);b and e do nothing :/
+    (if (color-change-request? (send input get-value))
+        (set! my-color (get-color-from-input (send input get-value)))
+...
+ 
+ (define (color-change-request? given-string)
+  (if (> (string-length given-string) 7)
+      (if (equal? (substring given-string 0 6) "/color")
+          #t
+          #f)
+      #f))
+```
+
+The procedure button-do-stuff is run every time the user presses the return key or presses the send button on the gui
+and what it will do is check to see if the user typed in "/color", and if they did it sets the internal color to be 
+what the user said after that. This is part of our symbolic differentiator that allows the user to use commands
+rather than the typical use of the input (which is just to send a message to other clients)
+

Hermes/GUI.rkt

@@ -0,0 +1,354 @@
+#lang racket
+(require racket/gui/base)
+;Author:Douglas Richardson
+;Notes:Our GUI mostly deals with lists of a list of 3 strings and a number
+;although the number is always delt with locally
+;When using user-message you need to give it a list of 3 things
+;The name of the user as a string, what they said as a string,
+;and the color as a string
+
+;Object stuff
+; TODO make different objects threadable send button vs text area vs canvas
+
+(provide make-gui)
+
+; store input into a message list
+; will create closure later
+(define messages-s (make-semaphore 1))
+(define messages '())
+(define sleep-t 0.1)
+
+; (define-values (gui-in gui-out) (make-pipe #f))
+(define (make-gui)
+    ;;Create the frame/window with title "Example5", width 500 and height 700
+    (define main-frame (new frame%
+                            [label "Hermes"]
+                            [width 500]
+                            [height 700]
+                            [min-width 500]
+                            [min-height 700]
+                            ))
+    ;;Editing canvas
+    (define (do-stuff-paint paint-canvas paint-dc)
+      (do-more-stuff-paint listy paint-canvas paint-dc))
+
+    (define (do-more-stuff-paint paint-listy paint-canvas paint-dc)
+      (if (null? paint-listy)
+          '()
+          (begin
+            (re-draw-message (get-username-from-list (car paint-listy))
+                             (get-message-from-list (car paint-listy))
+                             (get-color-from-list (car paint-listy))
+                             (get-height-from-list (car paint-listy)))
+            (do-more-stuff-paint (cdr paint-listy) paint-canvas paint-dc))))
+
+    ; canvas for displaying messages with horizontal and vertical scrollbar.
+    ; on an event it calls do-stuff-paint to redraw things on the screen 
+    ; properly
+    (define read-canvas (new canvas%
+                             [parent main-frame]
+                             [paint-callback do-stuff-paint]
+                             [style '(hscroll vscroll)]
+                             [min-width 450]
+                             [min-height 690]
+                             ))
+
+    ; "send" is rackets way of doing object-oriented programming. It calls an
+    ; objects functions in this case "read-canvas" object's init-auto-scrollbars
+    (send read-canvas init-auto-scrollbars #f #f 0 0);Start with no scrollbars
+
+    ; editing area callback. Gets called when enter is pressed.
+    (define (text-field-callback callback-type other-thing)
+      (if (equal? 'text-field-enter (send other-thing get-event-type))
+          (button-do-stuff 'irrelevant 'not-used)
+          '()))
+
+    ; Create a horizontal panel to house the send button and text-field
+    (define hpanel (new horizontal-panel%
+                        [parent main-frame]
+                        [min-width 450]
+                        [min-height 10]
+                        [alignment (list 'left 'center)]))
+    
+    ; creates the editing area as part of the parent "main-frame" define above.
+    ; initially labelled "Username:"
+    ; NOTE: we pad label with additional spaces so we don't have to recompute
+    ; the window dimensions to fit the new label (the actual username)
+    ; TODO make label setable
+    (define input (new text-field%
+                       [parent hpanel]
+                       [label "username  "] 
+                       [callback text-field-callback]
+                       ))
+
+    ; It's a callback function activated when the send button is pressed in the
+    ; GUI. It is also called manually when textfield receives an enter key
+    (define (button-do-stuff b e);b and e do nothing :/
+        (if (color-change-request? (send input get-value))
+            (set! my-color (get-color-from-input (send input get-value)))
+            (if (< 0 (string-length (send input get-value)))
+              (begin 
+                ; (send-message (send input get-value) my-color);;
+                (semaphore-wait messages-s)
+                (set! messages (append messages (list (send input get-value))))
+                (semaphore-post messages-s)
+                ; (open-input-string )
+                )
+                '()))
+        (send input set-value "")
+        )
+
+    ; retrieves a message user inputed to the text field
+    (define (get-message)
+      (semaphore-wait messages-s)
+      (define one-message 
+        (if (not (null? messages))
+          (begin 
+            ;(define msg (car messages))
+            (car messages)
+            ;(set! messages (cdr messages))
+            )
+          '()))
+      (semaphore-post messages-s)
+
+      (if (not (string? one-message))
+        (begin 
+          (sleep sleep-t) ; so we don't burn cpu cycles
+          (get-message))
+        (begin
+          (semaphore-wait messages-s)
+          (set! messages (cdr messages))
+          (semaphore-post messages-s)
+          one-message)))
+    ; creates the send button 
+    (define send-button (new button%
+                             [parent hpanel]
+                             [label "Send"]
+                             [callback button-do-stuff]))
+
+
+    (send input focus) ; move focus to text-field
+
+    ; get-dc retrieves the canvas' device context. From racket docs. A dc object
+    ; is a drawing context for drawing graphics and text. It represents output 
+    ; devices in a generic way.
+    ; Specifically the line below retrieves our canvas device context object.
+    (define dc (send read-canvas get-dc))
+    (send dc set-scale 1 1) ; set scaling config of output display to 1 to 1
+                            ; no scalling
+    (send dc set-text-foreground "black") ; color of text that gets drawn on the
+                                          ; canvas with "draw-text"
+    ; (send dc set-smoothing 'aligned)
+    ;;messaging stuff
+
+    ; could convert below to regexes
+    (define (user-message-parse string-i start)
+        (define (helper str index)
+          (if (eq? (string-ref str (+ start index)) #\~) ; regexes would allow us
+                                                         ; to avoid this #\~
+              (substring str start (+ start index))
+              (helper str (+ index 1))))
+        (helper string-i 0))
+
+    
+    ;; draws a user input to the screen
+    (define (user-message user-input)
+        (define username (user-message-parse user-input 0))
+        (define input (user-message-parse user-input  (+ 1 (string-length username))))
+        (define color (substring user-input (+ 2 (string-length username) (string-length input))))
+        (send dc set-text-foreground color) ; set dc's text color to user
+                                            ; provided
+        ; (send dc draw-text (string-append username ":" input) 0 height)
+        (send dc draw-text input 0 height)  ;; just print message to string
+
+        (set! listy (appendlist listy (list username input color height)))
+        (set! height (+ height 15)) ; 15 is space between messages
+        ; redraw overly long text on gui
+        (set! min-v-size (+ min-v-size 15))
+        (if (> (* 20 (string-length input)) min-h-size)
+            (set! min-h-size (* 20 (string-length input)))
+            '())
+        (send read-canvas init-auto-scrollbars min-h-size min-v-size 0 1)
+        )
+    ;;Add a function that parces input from a string-i and extracts elements
+
+    ; actually gets called to send input to the screen. user-message is in effect
+    ; its helper. It uses "~" to delimit the different components of message
+    (define (send-message input color)
+      (user-message (string-append name "~" input "~" color)))
+    
+    ;; draws messages to the screen canvas as text
+    (define (re-draw-message username input color in-height)
+        (send dc set-text-foreground color)
+        ; (send dc draw-text (string-append username ":" input) 0 in-height)
+        (send dc draw-text input 0 in-height)
+        )
+
+    ; used when redrawing the screen along with its helper.
+    (define (update given-list)
+      (set! listy '())
+      (set! height 0)
+      (update-helper given-list))
+
+    (define (update-helper given-list)
+      (if (null? given-list)
+          '()
+          (if (null? (car given-list))
+              '()
+              (begin (user-message
+                      (get-username-from-list (car given-list))
+                      (get-message-from-list (car given-list))
+                      (get-color-from-list (car given-list)))
+                     (update-helper (cdr given-list))))))
+    
+    ;;Variables go below functions
+    ; for interfacing with outside elements
+    (define gui-input-in-s '())
+    (define gui-input-out-s '())
+    (define gui-input-in '())
+    (define gui-input-out '())
+
+    (define name "Me")
+    (define min-h-size 80)
+    (define min-v-size 30)
+    ;(define listy (list (list "Server" "Connected" "Red" 0))) ; initializes
+    (define listy '())
+      ; listy with first message to be drawn on screen
+    ; wrap in closure
+    (define my-color "black") ; default color of the text messages if none
+                              ; specified
+    ; associated methods to prompt for color, get color and set color
+    (define (set-color new-color)
+      (set! my-color new-color))
+  
+    (define (get-my-color)
+      my-color)
+  
+    ; TODO loop to make sure you get right user input
+    ; not really needed as user can set in window
+    (define (prompt-color)
+        (define returned (get-text-from-user "Color set-up" "Please enter color for text"
+                      main-frame "black" (list 'disallow-invalid)
+                      #:validate
+                      (lambda (input)
+                        (if (and (string? input) (<= (string-length input) 10)
+                                 (>= (string-length input) 3))
+                            #t
+                            #f))))
+      (set! my-color returned)
+      returned)
+    (define height 0) ; determines starting height
+    ; TODO create height variable that stores the height/space between messages
+
+     ;; prompt user for username
+    ;; could randomly assign a user
+    ;; after calling get-text set it as new label of text-field
+    ; TODO there is a pattern here could wrap all this into resusable prompt funciton
+    ; 
+    (define (prompt-username)
+          (define returned (get-text-from-user "Username set-up" "Please enter a username"
+                    main-frame "user" (list 'disallow-invalid)
+                    #:validate
+                    (lambda (input)
+                      (if (and (string? input) (<= (string-length input) 10)
+                                (>= (string-length input) 2))
+                          #t
+                          #f))))
+      (send input set-label returned)
+      returned)
+
+    (define (prompt-hostname)
+          (define returned (get-text-from-user "Hostname set-up" "Please enter a hostname"
+                    main-frame "67.186.191.81" (list 'disallow-invalid)
+                    #:validate
+                    (lambda (input)
+                      (if (and (string? input) (<= (string-length input) 50)
+                                (>= (string-length input) 2))
+                          #t
+                          #f))))
+      ; (send input set-label returned)
+      returned)
+
+
+
+    ;;dispatch goes below that
+    ;; TODO get username function maybe
+    (define (dispatch command)
+      ; show gui should return the users the name as well as its first message
+      ; to be called
+      (cond ((eq? command 'show) (lambda () (send main-frame show #t)))
+            ((eq? command 'get-color) get-my-color)
+            ((eq? command 'set-color) set-color)
+            ((eq? command 'prompt-color) prompt-color)
+            ((eq? command 'prompt-username) prompt-username)
+            ((eq? command 'prompt-hostname) prompt-hostname)
+            ((eq? command 'send) send-message) ;; call to show a message in a gui
+            ((eq? command 'set-name) (lambda (newname) (if (string? newname)
+                                                  (set! name newname)
+                                                  (print "Thats not good"))))
+            ; ((eq? command 'recieve-message) user-message)
+            ; ((eq? command 'get-list) listy)
+            ; ((eq? command 'set-list) update)
+            ;;Something up with that
+            ; else should assume a message and output to screen we do not want it
+            ; to fail
+            ((eq? command 'get-message) get-message)
+            (else (error "Invalid Request" command))
+            ))
+    ;;dispatch goes below that
+    dispatch)
+
+
+;This one displays information
+
+
+
+
+
+;Initilize scrolling
+
+;Then we need to find out if we need them or not.
+
+;Listy is going to be a list of lists of strings
+;each element in listy will contain three strings
+;the username the message they said and the color they used
+;The the height the message should display at
+
+; listoflist is listy here, and add-to-end is what gets appended to the end
+; really expensive operation but its important for Doug to showcase some opl
+; concepts
+(define (appendlist listoflist add-to-end)
+  (if (null? listoflist)
+      (cons add-to-end '())
+      (cons (car listoflist) (appendlist (cdr listoflist) add-to-end))))
+
+(define (get-username-from-list in-list)
+  (car in-list))
+
+(define (get-message-from-list in-list)
+  (car (cdr in-list)))
+
+(define (get-color-from-list in-list)
+  (car (cdr (cdr in-list))))
+
+(define (get-height-from-list in-list)
+  (car (cdr (cdr (cdr in-list)))))
+
+
+
+; did user request for color change /
+(define (color-change-request? given-string)
+  (if (> (string-length given-string) 7)
+      (if (equal? (substring given-string 0 6) "/color")
+          #t
+          #f)
+      #f))
+
+; we should use regexes for this.
+(define (get-color-from-input given-string)
+  (substring given-string 7))
+;(define thing1 (make-gui))
+;(define thing2 (make-gui))
+; (define hermes-gui (make-gui))
+; ((hermes-gui 'show))
+

Hermes/Hermes_Gui1.3.rkt

@@ -1,233 +0,0 @@
-#lang racket
-(require racket/gui/base)
-;Author:Douglas Richardson
-;Notes:Our GUI mostly deals with lists of a list of 3 strings and a number
-;although the number is always delt with locally
-;When using user-message you need to give it a list of 3 things
-;The name of the user as a string, what they said as a string,
-;and the color as a string
-
-;Object stuff
-
-(provide make-gui)
-
-(define (make-gui)
-  (begin
-    (displayln "Makin...");;eat this note
-    ;;Create the frame
-    (define main-frame (new frame%
-                            [label "Hermes"]
-                            [width 500]
-                            [height 700]
-                            ))
-    ;;Editing canvas
-    (define (do-stuff-paint paint-canvas paint-dc)
-      (do-more-stuff-paint listy paint-canvas paint-dc))
-
-    (define (do-more-stuff-paint paint-listy paint-canvas paint-dc)
-      (if (null? paint-listy)
-          '()
-          (begin
-            (re-draw-message (get-username-from-list (car paint-listy))
-                             (get-message-from-list (car paint-listy))
-                             (get-color-from-list (car paint-listy))
-                             (get-height-from-list (car paint-listy)))
-            (do-more-stuff-paint (cdr paint-listy) paint-canvas paint-dc))))
-
-    (define read-canvas (new canvas%
-                             [parent main-frame]
-                             [paint-callback do-stuff-paint]
-                             [style '(hscroll vscroll)]
-                             ))
-
-    (send read-canvas init-auto-scrollbars #f #f 0 0);Start with no scrollbars
-    ;;text-field stuff
-    (define (text-feild-callback callback-type other-thing)
-      (if (equal? 'text-field-enter (send other-thing get-event-type))
-          (button-do-stuff 'irrelevant 'not-used)
-          '()))
-    
-    (define input (new text-field%
-                       [parent main-frame]
-                       [label "Username:"]
-                       [callback text-feild-callback]
-                       ))
-    ;;button stuff
-    (define (button-do-stuff b e);b and e do nothing :/
-      (begin
-        (define given-input (send input get-value))
-        (if (string? given-input)
-            (if (color-change-request? given-input)
-                (set! my-color (get-color-from-input given-input))
-                (if (quit-request? given-input)
-                    (write "quit" the-output-port)
-                    (if (< 0 (string-length-safe given-input))
-                        (send-message (send input get-value) my-color);;
-                        '())))
-        '())
-        (send input set-value "")))
-    
-    (define send-button (new button%
-                             [parent main-frame]
-                             [label "Send"]
-                             [callback button-do-stuff]))
-    ;;I forget what these do but don't move them
-    (define dc (send read-canvas get-dc))
-    (send dc set-scale 1 1)
-    (send dc set-text-foreground "black")
-    ;;messaging stuff
-
-    (define (user-message-parse string start)
-      (define (helper str index)
-        (if (string? string)
-            (if (>= (+ start index) (string-length-safe string))
-                (display string);;Something went wrong
-                (if (eq? (string-ref str (+ start index)) #\~)
-                    (substring-s str start (+ start index))
-                    (helper str (+ index 1))))
-            '()))
-      (helper string start))
-      
-    (define (user-message onetrueinput)
-      (display "Godit!");;eat this note
-      (displayln onetrueinput);;eat this note
-      (if (not (string=? onetrueinput ""))
-          (let();;This is kind of stupid but whatever it works.
-            (define username (user-message-parse onetrueinput 0))
-            (define user-input (user-message-parse onetrueinput  (+ 1(string-length-safe username))))
-            (define color (substring-s onetrueinput (+ 2 (string-length-safe username) (string-length-safe user-input)) (string-length-safe onetrueinput)))
-            (send dc set-text-foreground color)
-            (send dc draw-text (string-append username ":" user-input) 0 height)
-            (set! listy (appendlist listy (list username user-input color height)))
-            (set! height (+ height 15))
-            (set! min-v-size (+ min-v-size 15))
-            (if (> (* 20 (string-length-safe user-input)) min-h-size)
-                (set! min-h-size (* 20 (string-length-safe user-input)))
-                '())
-            (send read-canvas init-auto-scrollbars min-h-size min-v-size 0 1))
-          '()))
-    ;;Add a function that parces input from a string and extracts elements
-
-    (define the-output-port (open-output-string))
-    
-    ;;This probably won't change...
-    (define (send-message input color)
-      (write (string-append name "~" input "~" color) the-output-port))
-    ;;Although re-draw is kind of misleading, it is just print the whole
-    ;;list of strings to the screen
-    (define (re-draw-message username input color in-height)
-      (begin
-        (displayln "Fixy!");eat this note
-        (send dc set-text-foreground color)
-        (send dc draw-text (string-append username ":" input) 0 in-height)
-        ))
-
-    (define (update given-list)
-      (begin (set! listy '())
-             (set! height 0)
-             (update-helper given-list)))
-
-    (define (update-helper given-list)
-      (if (null? given-list)
-          '()
-          (if (null? (car given-list))
-              '()
-              (begin (user-message
-                      (get-username-from-list (car given-list))
-                      (get-message-from-list (car given-list))
-                      (get-color-from-list (car given-list)))
-                     (update-helper (cdr given-list))))))
-    
-    ;;Variables go below functions
-    (define name "Me")
-    (define min-h-size 80)
-    (define min-v-size 30)
-    (define listy (list (list "Server" "Connected" "Red" 0)))
-    (define my-color "black")
-    (define height 15)
-    ;;dispatch goes below that
-    (define (dispatch command)
-      (cond ((eq? command 'show) (send main-frame show #t))
-            ((eq? command 'close)(send main-frame show #f))
-            ((eq? command 'send) send-message)
-            ((eq? command 'set-name) (lambda (newname) (if (string? newname)
-                                                  (set! name newname)
-                                                  (print "Thats not good"))))
-            ((eq? command 'recieve-message) user-message)
-            ;((eq? command 'get-list) listy)
-            ;((eq? command 'set-list) update)
-            ((eq? command 'get-output-port) the-output-port)
-            ;;Something up with that
-            (else (error "Invalid Request" command))
-            ))
-    ;;dispatch goes below that
-    dispatch))
-
-
-;This one displays information
-
-
-
-
-;Initilize scrolling
-
-;Then we need to find out if we need them or not.
-
-;Listy is going to be a list of lists of strings
-;each element in listy will contain three strings
-;the username the message they said and the color they used
-;The the height the message should display at
-
-
-(define (appendlist listoflist add-to-end)
-  (if (null? listoflist)
-      (cons add-to-end '())
-      (cons (car listoflist) (appendlist (cdr listoflist) add-to-end))))
-
-(define (get-username-from-list in-list)
-  (car in-list))
-
-(define (get-message-from-list in-list)
-  (car (cdr in-list)))
-
-(define (get-color-from-list in-list)
-  (car (cdr (cdr in-list))))
-
-(define (get-height-from-list in-list)
-  (car (cdr (cdr (cdr in-list)))))
-
-(define (get-color-from-input input)
-  (substring-s input 6 (string-length-safe input)))
-
-
-
-;this one is a crap version of justpressing the enter key
-(define (color-change-request? given-string)
-  (if (> (string-length-safe given-string) 7)
-      (if (equal? (substring-s given-string 0 6) "/color")
-          #t
-          #f)
-      #f))
-
-
-(define (quit-request? given-string)
-  (if (>= (string-length-safe given-string) 5)
-      (if (equal? (substring-s given-string 0 5) "/quit")
-          #t
-          #f)
-      #f))
-
-(define (string-length-safe string)
-  (if (string? string)
-      (string-length string)
-      0))
-
-(define (substring-s string start end)
-  (if (<= start end)
-      (if (<= end (string-length-safe string))
-          (substring string start end)
-          "")
-      ""))
-;(define thing1 (make-gui))
-;(define thing2 (make-gui))
-

Hermes/README.md

@@ -0,0 +1,34 @@
+# Hermes - the code
+## Installation
+
+The only pre-requisite is to have a recent version of Drracket, then go ahead
+and launch an instance of Drracket running server.rkt and one or more
+instances running client.rkt.
+
+## Using Hermes
+
+### General
+
+The clients can run on the same computer with the server, or you can run the
+server alone in another compute on the internet. As long as you have the
+server's public ip address, the port its listening on(must port forward on home
+network!), and the server allows communication through that port in the firewall
+you are good to go.
+
+### Clients
+
+In the clients follow the prompts to set you up. Type in messages to send to
+other clients. You may try connecting to server instance running locally
+"localhost" or have an ip-address for a hermes server running elsewhere.
+
+#### Commands
+* Change color of your messages with /color color. Default is black.
+* You can list users in chat with /list users. 
+* You can get the count of users with /list count. 
+* If you want to send a message to a particular user, do /whisper username message in chat.
+* If you want to leave chat, type /quit. 
+
+### Server
+
+You can stop the server by typing in (stop-server) in the interactive window.
+It's really important you do this to free up the ports.

Hermes/TODO

@@ -1,7 +1,6 @@
 FEATURES
-5. parser in the client side should do something similar (/color, /quit)
+need to pass color settings between users
 16. plain tcp -> ssl based 
-17. fix breaks for improper disconnects from clients
 18. Add topics after project completion
 ** regexes to parse strings for different formats -related to 5
 ** align code better for readability
@@ -15,3 +14,5 @@ additionally save user details and prompt user to use defaults or create
 new ones
 10. authentication for databases - to avoid dependencies this is left out
 ** whispers aren't currently logged - its on purpose
+automated test sets for networking and client code
+encryption over SSL using root certificates

Hermes/client.rkt

@@ -1,6 +1,10 @@
 #lang racket
+; Author: Ibrahim Mkusa
+; About: code that enables communication with the client. It uses GUI code
+; authored by Doug-Richardson
 
-(require "modules/general.rkt" "Hermes_Gui1.3.rkt")
+
+(require "modules/general.rkt" "GUI.rkt")
 (require math/base) ;; for random number generation
 ;; TODO clean up string message output and alignment
 ;; TODO close ports after done
@@ -10,13 +14,20 @@
 ;; notes: output may need to be aligned and formatted nicely
 
 
-; we will  prompt for these in the gui
+(define hermes-gui (make-gui)) ;; our gui
-(define host3 "localhost")
+((hermes-gui 'show))
+;(sleep 0.25)
+
+
+; (define host3 "localhost")
+(define hostname ((hermes-gui 'prompt-hostname))) 
 (define port-num 4321)
 (define sleep-t 0.1)
 
+(define hermes-gui-s (make-semaphore 1))
+
 ; we won't need this. Just me being overzealous
-(define hermes-conf (open-output-file "./hermes_client.conf" #:exists'append))
+(define hermes-conf (open-output-file "./hermes_client.conf" #:exists 'append))
 (define hermes-conf-s (make-semaphore 1))
 
 (define convs-out (open-output-file "./convs_client.out" #:exists 'append))
@@ -25,24 +36,24 @@
 (define error-out (open-output-file "./error_client.out" #:exists 'append))
 (define error-out-s (make-semaphore 1))
 
-(define gui (make-gui))
+; custodian for client connections. Define at top level since a function needs
-; custodian for client connections
+; to see it
 (define main-client-cust (make-custodian))
 ; make connection to server
 (define (client port-no)
   (parameterize ([current-custodian main-client-cust])
     ;; connect to server at port 8080
-    (define-values (in out) (tcp-connect host3 port-no)) ;; define values
+    
+    ;; TODO catch error here
+    (define-values (in out) (tcp-connect hostname port-no)) ;; define values
     ;; binds to multiple values akin to unpacking tuples in python
 
-    ; store username to a file for later retrieval along with relevent
+    ;; TODO could store theses info in a file for retrieval later
-    ; info used for authentication with server
+    (define username ((hermes-gui 'prompt-username)))
-    (displayln "What's your name?")
+    ((hermes-gui 'prompt-color))
-    (define username (read-line))
+
-    ((gui 'set-name) username)
-    (gui 'show)
     ;send the username to the server (username in out)
-    ;(displayln username out)
+    (displayln username out)
     (flush-output out)
 
     (define a (thread
@@ -60,45 +71,55 @@
                     (sleep sleep-t)
                     (loop)))))
     (displayln-safe "Now waiting for sender thread." error-out-s error-out)
-    (thread-wait t) ;; returns prompt back to drracket
+    ; (thread-wait t) ;; returns prompt back to drracket
+    )
+
+  (lambda ()
     (displayln-safe "Closing client ports." error-out-s error-out)
-    (close-input-port in)
+    ;(close-input-port in)
-    (close-output-port out)
+    ;(close-output-port out)
-    (gui 'close))
+    (custodian-shutdown-all main-client-cust)))
-    (custodian-shutdown-all main-client-cust))
+
 
 ;; sends a message to the server
 (define (send-messages username out)
   ; get current time
-  ;(define date-today (seconds->date (current-seconds) #t))
+  (define date-today (seconds->date (current-seconds) #t))
   ;TODO pad the second if its only 1 character
-  ;(define date-print (string-append (number->string (date-hour date-today))
+  (define date-print (string-append (pad-date (number->string (date-hour date-today)))
-   ;                                 ":"
+                                    ":"
-    ;                                (number->string (date-minute date-today))
+                                    (pad-date (number->string (date-minute date-today)))
-     ;                               ":"
+                                    ":"
-      ;                              (number->string (date-second date-today))
+                                    (pad-date (number->string (date-second date-today)))
-       ;                             " | "))
+                                    " | "))
   ;; read, quits when user types in "quit"
+  ;; TODO read from GUI instead
   ;(define input (read-line))
-  (define input (get-output-string (gui 'get-output-port)))
+  ;(semaphore-wait hermes-gui-s)
-  ; TODO /quit instead of quit
+  (define input ((hermes-gui 'get-message)))
-  (cond ((string=? input "quit")
+  ;(semaphore-post hermes-gui-s)
-             ;(displayln (string-append date-print username " signing out. See ya!") out)
+  
+  ; /color color is appended to input to specify the color the message should
+  ; be displayed in
+  (cond ((string=? input "/quit")
+             (displayln (string-append date-print username " signing out. See ya!"
+                                       " /color " ((hermes-gui 'get-color))) out)
              (flush-output out)
              (close-output-port error-out)
              (close-output-port convs-out)
+             ;(custodian-shutdown-all main-client-cust)
              (exit)))
   
-  ;(displayln (string-append date-print username ": " input) out)
+  (displayln (string-append date-print username ": " input
-  (if (not (null? input))
+                            " /color " ((hermes-gui 'get-color))) out)
-      (if (not (equal? input ""))
-      ((let()
-        (displayln input);;eat this note
-        (displayln input out)))
-      '())
-      '())
   (flush-output out))
 
+; a wrap around to call ((hermes-gui 'send) zzz yyy) without complaints from
+; drracket
+(define send-to-gui
+  (lambda (message color)
+    ((hermes-gui 'send) message color)))
+
 ; receives input from server and displays it to stdout
 (define (receive-messages in)
   ; retrieve a message from server
@@ -106,18 +127,29 @@
   
   (cond [(eof-object? evt)
          (displayln-safe "Server connection closed." error-out-s error-out)
-         (custodian-shutdown-all main-client-cust)
+         (exit)
+         ;(custodian-shutdown-all main-client-cust)
          ;(exit)
          ]
         [(string? evt)
-         ;(displayln-safe evt convs-out-s convs-out)] ; could time stamp here or to send message
+            (displayln-safe evt convs-out-s convs-out)
-         (if (not (equal? evt ""))
+            (define evt-matched
-         ((gui 'recieve-message) evt)
+              (regexp-match #px"(.*)\\s+/color\\s+(\\w+).*"
-         '())]
+                            evt))
+            ; TODO set color to current client if the message is from him
+            ; otherwise set it to the remote
+            ;(semaphore-wait hermes-gui-s)
+            ;(send-to-gui evt ((hermes-gui 'get-color)))
+            
+            ; extracts the message and color from received message
+            (send-to-gui (cadr evt-matched) (caddr evt-matched))
+            ;(semaphore-post hermes-gui-s)
+            ] ; could time stamp here or to send message
         [else
-          (displayln-safe
+          (displayln-safe (string-append "Nothing received from server for 2 minutes.") convs-out-s convs-out)]))
-           (string-append "Nothing received from server for 2 minutes.")
-           convs-out-s convs-out)]))
 
 (displayln-safe "Starting client." error-out-s error-out)
 (define stop-client (client 4321))
+;(define stop-client (client 4321))
+; we will  prompt for these in the gui
+

Hermes/logs/conversations_server.txt

@@ -0,0 +1,78 @@
+Number of users in chat: 1 /color blue
+Number of users in chat: 2 /color blue
+18:15:50 | Ibrahim: hello /color violet
+18:15:29 | Doug: fsdfdsfads /color red
+18:16:08 | Doug signing out. See ya! /color red
+18:16:01 | Ibrahim signing out. See ya! /color violet
+Number of users in chat: 1 /color blue
+18:21:58 | Ibrahim signing out. See ya! /color blue
+Number of users in chat: 1 /color blue
+18:24:14 | Doug signing out. See ya! /color black
+Number of users in chat: 1 /color blue
+11:12:05 | Ibrahim signing out. See ya! /color black
+Number of users in chat: 1 /color blue
+11:12:39 | user signing out. See ya! /color green
+Number of users in chat: 1 /color blue
+Number of users in chat: 2 /color blue
+11:16:51 | Doug: whats going on? /color blue
+11:16:41 | Ibrahim: I am alright /color green
+11:17:26 | Ibrahim: heheheh /color red
+11:17:35 | Ibrahim signing out. See ya! /color red
+11:17:50 | Doug signing out. See ya! /color blue
+Number of users in chat: 1 /color blue
+Number of users in chat: 2 /color blue
+12:02:59 | Doug: Yo /color black
+12:05:27 | Ibrahim signing out. See ya! /color green
+Number of users in chat: 2 /color blue
+12:07:31 | Ibrahi: hello /color blue
+12:07:51 | Ibrahi: how are you, Doug? /color blue
+12:03:40 | Doug: Doing well thanks /color black
+12:09:09 | Doug: Hello there /color black
+12:09:57 | Doug: Hello /color purple
+12:09:08 | Ibrahi: What's up fellaz /color blue
+12:13:57 | Ibrahi: hello /color blue
+12:16:04 | Ibrahi: hello dou /color red
+12:11:44 | Doug: say whatever we want /color purple
+12:18:14 | Doug: now im eco friendly /color green
+12:18:48 | Doug: /listusers /color green
+12:16:42 | Ibrahi signing out. See ya! /color red
+Number of users in chat: 1 /color blue
+Number of users in chat: 2 /color blue
+12:20:18 | Jill: Doesnt matter /color Blue
+12:20:28 | Jill: Does this woirk /color magenta
+12:21:26 | Jill: /list user /color magenta
+Number of users in chat: 2 /color blue
+12:22:01 | Mongol: hello /color green
+Number of users in chat: 3 /color blue
+12:24:20 | Bob: hello /color cyan
+12:21:57 | Jill: Nothing /color raddish
+12:24:32 | Jill: no way /color gold
+12:24:46 | Jill: does this work? /color silver
+12:24:57 | Jill: waht /color bronze
+12:25:18 | Jill: maybe? /color terquoise
+12:25:33 | Jill: this one cant work /color peach
+12:25:48 | Jill: yeah /color violet
+12:26:15 | Jill: hep /color purple
+12:26:25 | Jill: what /color indego
+12:26:53 | Jill: so like this /color indigo
+12:22:06 | Mongol: i'm rolling /color gold
+12:27:07 | Jill: orange /color orange
+12:27:32 | Jill: type stuff /color orange
+12:32:13 | Jill: now its red /color red
+12:34:14 | Jill: What /color red
+12:35:35 | Jill: something /color red
+12:36:21 | Jill: anything else /color red
+12:36:26 | Jill: now its blue /color blue
+12:27:27 | Mongol: hello world /color gold
+12:41:47 | Mongol: hello /color green
+12:37:19 | Jill: anything in here /color blue
+12:43:22 | Jill: i can do that /color silver
+12:27:58 | Bob signing out. See ya! /color cyan
+Number of users in chat: 3 /color blue
+12:44:10 | Julian: hohoho /color red
+12:43:36 | Jill: something /color black
+12:44:50 | Jill: say something else /color pink
+12:45:21 | Jill: works better /color purple
+12:45:55 | Jill signing out. See ya! /color purple
+12:42:05 | Mongol signing out. See ya! /color green
+12:44:19 | Julian signing out. See ya! /color red

Hermes/logs/error_server.txt

@@ -0,0 +1,28 @@
+Starting up the listener.
+Listener successfully started.
+Server process started.
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Goodbye, shutting down all services
+Starting up the listener.
+Listener successfully started.
+Server process started.
+Connection closed. EOF received
+Connection closed. EOF received
+Goodbye, shutting down all services
+Starting up the listener.
+Listener successfully started.
+Server process started.
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Connection closed. EOF received
+Goodbye, shutting down all services

Hermes/modules/general.rkt

@@ -1,6 +1,6 @@
 #lang racket
 
-(provide displayln-safe)
+(provide displayln-safe pad-date)
 ;; Several threads may want to print to stdout, so  lets make things civil
 ; constant always available
 (define stdout (make-semaphore 1))
@@ -22,3 +22,8 @@
             (displayln a-string)
             (semaphore-post stdout)])))
 
+; adds padding to dates
+(define (pad-date date-element)
+  (if (> (string-length date-element) 1)
+    date-element
+    (string-append "0" date-element)))

Hermes/server.rkt

@@ -1,11 +1,15 @@
 #lang racket
+; Author: Ibrahim Mkusa
+; About: code that powers Hermes server
 
-(require "modules/general.rkt")
+
+(require "modules/general.rkt") ;; common function(s)
 (require math/base) ;; for random number generation
 
 
-(define welcome-message "Welcome to Hermes coms. Type your message below")
+;; server messages in blue
-(define successful-connection-m "Successfully connected to a client. Sending client a welcome message.")
+(define welcome-message "Welcome to Hermes coms. Type your message below /color blue ")
+(define successful-connection-m "Successfully connected to a client. Sending client a welcome message. /color blue ")
 
 (define sleep-t 0.1)
 
@@ -53,17 +57,16 @@
            [(eq? m 'remove-ports) remove-ports]
            [(eq? m 'add) add]))
    dispatch)
+; "instantiate" to track the connections
 (define c-connections (make-connections '()))
 ; a semaphore to control acess to c-connections
 (define connections-s (make-semaphore 1)) ;; control access to connections
 
-; Track received messages in a closure
+; Track received messages in a closure. Initialy messages is '()
 (define (make-messages messages)
   (define (add message)
-    (if (string=? message "")
+    (set! messages (append messages (list message)))
-        messages
+    messages)
-    ((set! messages (append messages (list message)))
-    messages)))
   (define (mes-list)
     messages)
   (define (remove-top)
@@ -74,6 +77,7 @@
           [(eq? m 'mes-list) mes-list]
           [(eq? m 'remove-top) remove-top]))
   dispatch)
+; "instantiate" a make-message variable to track our messages
 (define c-messages (make-messages '()))
 ; semaphore to control access to c-messages
 (define messages-s (make-semaphore 1))  ;; control access to messages
@@ -83,9 +87,12 @@
 (define convs-out (open-output-file "./conversations_server.txt" #:exists 'append))
 (define error-out-s (make-semaphore 1))
 (define convs-out-s (make-semaphore 1))
-; TODO finish logging all error related messages to 
+
+; Main server code wrapped in a function
 (define (serve port-no)
+  ; custodian manages resources put under its domain
   (define main-cust (make-custodian))
+  ; "parameterize" puts resources under the domain of created custodian
   (parameterize ([current-custodian main-cust])
     (define listener (tcp-listen port-no 5 #t))
     (define (loop)
@@ -96,7 +103,7 @@
     (displayln-safe "Listener successfully started." error-out-s error-out)
     ;; Create a thread whose job is to simply call broadcast iteratively
     (thread (lambda ()
-              (displayln-safe "Broadcast thread started!\n")
+              (displayln-safe "Broadcast thread started!")
               (let loopb []
                 (sleep sleep-t)  ;; wait 0.5 secs before beginning to broadcast
                 (broadcast)
@@ -116,8 +123,7 @@
   (parameterize ([current-custodian cust])
     (define-values (in out) (tcp-accept listener))
 
-    ;TODO retrive user name for client here
+    ; TODO do some error checking
-    ; do some error checking
     (define username-evt (sync (read-line-evt in 'linefeed)))
     
 
@@ -128,10 +134,11 @@
     (semaphore-post c-count-s)
 
     (displayln-safe successful-connection-m)
-    ;(displayln welcome-message out)
+    (displayln welcome-message out)
     ;; print to server log and client
-    (define print-no-users (string-append "Server~Number of users in chat: "
+    (define print-no-users (string-append "Number of users in chat: "
-                                          (number->string ((c-count 'current-count))) "~Red"))
+                                          (number->string ((c-count 'current-count)))
+                                          " /color blue"))
     (displayln print-no-users out)
     (displayln-safe print-no-users convs-out-s convs-out)
     (flush-output out)
@@ -150,7 +157,7 @@
               (displayln-safe (string-append
                                 "Started a thread to kill hanging "
                                 "connecting threads"))
-              (sleep 1360)
+              (sleep 7200) ; kills clients threads after a while could refresh this on new message
               (custodian-shutdown-all cust)))))
 
 ; whisper selector for the username and message
@@ -184,33 +191,38 @@
            (define list-count  (regexp-match #px"(.*)/list\\s+count\\s*" evt-t0)) ;; is client asking for number of logged in users
            (define list-users (regexp-match #px"(.*)/list\\s+users\\s*" evt-t0)) ;; user names
            ; do something whether it was a message, a whisper, request for number of users and so on
+
+           
            (cond [whisper
                   (semaphore-wait connections-s)
                   ; get output port for user
+                  ; this might be null
                   (define that-user-ports
-                    (first (filter
+                    (filter
                      (lambda (ports)
                        (if (string=? (whisper-to whisper) (get-username ports))
                            #t
                            #f))
-                     ((c-connections 'cons-list)))))
+                     ((c-connections 'cons-list))))
                   ; try to send that user the whisper
-                  (if (port-closed? (get-output-port that-user-ports))
+                  (if (and (null? that-user-ports)
+                           #t) ; #t is placeholder for further checks
                       (begin
-                        (displayln "Server~User is unavailable~red" out)
+                        (displayln "User is unavailable. /color blue" out)
                         (flush-output out))
                       (begin
-                        (displayln (string-append (whisper-info whisper) (whisper-message whisper))
+                        (displayln (string-append "(whisper) "
-                                   (get-output-port that-user-ports))
+                                    (whisper-info whisper) (whisper-message whisper))
-                        (flush-output (get-output-port that-user-ports))))
+                                   (get-output-port (car that-user-ports)))
+                        (flush-output (get-output-port (car that-user-ports)))))
                   (semaphore-post connections-s)]
                  [list-count
                   ;;should put a semaphore on connections
                   (semaphore-wait c-count-s)
                   (semaphore-wait connections-s)
-                  (define no-of-users (string-append "Server~Number of users in chat: "
+                  (define no-of-users (string-append "Number of users in chat: "
                                           (number->string ((c-count 'current-count)))
-                                          "~red"))
+                                          " /color blue"))
                   (displayln no-of-users out)
                   (flush-output out)
                   (semaphore-post connections-s)
@@ -219,17 +231,15 @@
                  [list-users
                   (semaphore-wait connections-s)
                   ; map over connections sending the username to the client
-                  (displayln "Server~Here is a list of users in chat.~red" out)
+                  (displayln "Here is a list of users in chat. /color blue" out)
                   (map
                    (lambda (ports)
-                     (displayln (string-append
+                     (displayln (string-append (get-username ports) " /color blue") out))
-                                 "Server~"
-                                 (get-username ports)
-                                 "~red")out))
                    ((c-connections 'cons-list)))
                   (flush-output out)
                   (semaphore-post connections-s)]
                  [else
+                  ; Its an ordinarly message
                   ; (displayln-safe evt-t0) debug purposes
                   (semaphore-wait messages-s)
                   ; evaluate it .
@@ -245,7 +255,7 @@
               ; (sleep 1)
               (loop)))))
 
-; extracts output port from a list pair of input and output port
+; extracts output port from a list pair of username, input and output port
 (define (get-output-port ports)
   (caddr ports))
 
@@ -264,22 +274,21 @@
   (lambda ()
     (semaphore-wait messages-s)
     (cond [(not (null? ((c-messages 'mes-list))))
-        (begin (map
+        (map
-                (lambda (ports)
+            (lambda (ports)
-                  (if (not (port-closed? (get-output-port ports)))
+              (if (not (port-closed? (get-output-port ports)))
-                    (begin 
+                (begin 
-                        (displayln (first ((c-messages 'mes-list)))
+                    (displayln (first ((c-messages 'mes-list))) (get-output-port ports))
-                                   (get-output-port ports))
+                    (flush-output (get-output-port ports)))
-                        (flush-output (get-output-port ports)))
+                (displayln-safe "Failed to broadcast. Port not open." error-out-s error-out)))
-                    (displayln-safe "Failed to broadcast. Port not open." error-out-s error-out)))
+            ((c-connections 'cons-list)))
-                ((c-connections 'cons-list)))
+        (displayln-safe (first ((c-messages 'mes-list))) convs-out-s convs-out)
-               (displayln-safe (first ((c-messages 'mes-list))) convs-out-s convs-out)
+        ;; remove top message from "queue" after broadcasting
-               ;; remove top message
+        ((c-messages 'remove-top))
-               (displayln (null? ((c-messages 'mes-list))));;eat this note
+        ; debugging displayln below
-               (displayln ((c-messages 'mes-list)));;eat this note
+        ; (displayln "Message broadcasted")
-               ((c-messages 'remove-top))
+        ]) ; end of cond
-               (displayln "Message broadcasted"))])
     (semaphore-post messages-s)))
 
 (define stop-server (serve 4321)) ;; start server then close with stop
-(displayln-safe "Server process started\n" error-out-s error-out)
+(displayln-safe "Server process started." error-out-s error-out)

IBRAHIM_MKUSA.md

@@ -0,0 +1,226 @@
+# Hermes - A chat server and client written in Racket
+
+## Ibrahim Mkusa
+### April 30, 2017
+
+# Overview
+Hermes is a chat server and client written in Racket. One can run the Hermes
+server on any machine that is internet accessible. The Hermes clients then
+connect to the server from anywhere on the internet. It's inspired by chat
+systems and clients like irc.
+
+The goal in building Hermes was to expose myself to several concepts integral to
+systems like networking, synchronization, and multitasking.
+
+
+# Libraries Used
+Most libraries and utilities used are part of base Drracket installation and
+therefore do not need to be imported.
+
+The date and time modules were used for various time related queries.
+The tcp module was used for communication via Transmission Control Protocol.
+Concurrency and synchronization modules that provide threads, and semaphores
+were also used.
+
+Below are libraries that were not part of base system:
+
+```
+(require racket/gui/base)
+(require math/base)
+```
+
+* The ```racket/gui/base``` library used to build graphical user interface.
+* The ```math/base``` library was used for testing purposes. It was used to
+generated random numbers.
+
+# Key Code Excerpts
+
+Here is a discussion of the most essential procedures, including a description of how they embody ideas from 
+UMass Lowell's COMP.3010 Organization of Programming languages course.
+
+Five examples are shown and they are individually numbered. 
+
+## 1. Tracking client connections using an object and closures.
+
+The following code defines and creates a global object, ```make-connections```
+that abstracts client connections. It also creates a semaphore to control access
+to ```make-connections``` object.
+
+```
+(define (make-connections connections)
+  (define (null-cons?)
+    (null? connections))
+   (define (add username in out)
+    (set! connections (append connections (list (list username in out))))
+    connections)
+   (define (cons-list)
+     connections)
+   (define (remove-ports in out)
+     (set! connections
+       (filter 
+         (lambda (ports)
+           (if (and (eq? in (get-input-port ports))
+                    (eq? out (get-output-port ports)))
+             #f
+             #t))
+         connections)))
+   (define (dispatch m)
+     (cond [(eq? m 'null-cons) null-cons?]
+           [(eq? m 'cons-list) cons-list]
+           [(eq? m 'remove-ports) remove-ports]
+           [(eq? m 'add) add]))
+   dispatch)
+
+(define c-connections (make-connections '()))
+
+(define connections-s (make-semaphore 1)) ;; control access to connections
+ ```
+
+ When the tcp-listener accepts a connection from a client, the associated input
+ output ports along with username  are added as an entry in ```make-connections``` via ```add``` function.
+ External functions can operate on the connections by securing the semaphore,
+ and then calling ```cons-list``` to expose the underlying list of connections.
+ ```remove-ports``` method is also available to remove input output ports from
+ managed connections.
+
+
+ 
+ 
+## 2. Tracking received messages via objects and closures.
+
+The code below manages broadcast messages from one client to the rest. It wraps
+a list of strings inside an object that has functions similar to ```make-connections``` for
+exposing and manipulating the list from external functions. The code creates
+```make-messages``` global object and a semaphore to control access to it from
+various threads of execution.
+
+```
+(define (make-messages messages)
+  (define (add message)
+    (set! messages (append messages (list message)))
+    messages)
+  (define (mes-list)
+    messages)
+  (define (remove-top)
+    (set! messages (rest messages))
+    messages)
+  (define (dispatch m)
+    (cond [(eq? m 'add) add]
+          [(eq? m 'mes-list) mes-list]
+          [(eq? m 'remove-top) remove-top]))
+  dispatch)
+
+(define c-messages (make-messages '()))
+
+(define messages-s (make-semaphore 1))  ;; control access to messages
+```
+
+## 3. Using map to broadcast messages from client to clients
+
+The ```broadcast``` function is called repeatedly in a loop to extract a message
+from ```make-messages``` object, and send it to every other client. It uses the
+```make-connections``` objects to extract output port of a client. The ```map```
+routine is called on every client in the connections object to send it
+a message.
+
+```
+(define broadcast
+  (lambda ()
+    (semaphore-wait messages-s)
+    (cond [(not (null? ((c-messages 'mes-list))))
+        (map
+            (lambda (ports)
+              (if (not (port-closed? (get-output-port ports)))
+                (begin 
+                    (displayln (first ((c-messages 'mes-list))) (get-output-port ports))
+                    (flush-output (get-output-port ports)))
+                (displayln-safe "Failed to broadcast. Port not open." error-out-s error-out)))
+            ((c-connections 'cons-list)))
+        (displayln-safe (first ((c-messages 'mes-list))) convs-out-s convs-out)
+        ;; remove top message from "queue" after broadcasting
+        ((c-messages 'remove-top))
+        ; debugging displayln below
+        ; (displayln "Message broadcasted")
+        ]) ; end of cond
+    (semaphore-post messages-s)))
+```
+After the message is send, the message is removed from the "queue" via the
+```remove-top```.
+
+The code snippet below creates a thread that iteratively calls ```broadcast```
+every interval, where interval(in secs) is defined by ```sleep-t```.
+
+```sleep``` is very important for making Hermes behave gracefully
+in a system. Without it, it would be called at the rate derived from cpu clock
+rate. This raises cpu temperatures substantially, and make cause a pre-mature
+system shutdown.
+
+```
+(thread (lambda ()
+              (displayln-safe "Broadcast thread started!")
+              (let loopb []
+                (sleep sleep-t)  ;; wait 0.2 ~ 0.5 secs before beginning to broadcast
+                (broadcast)
+                (loopb))))
+```
+
+## 4. Filtering a List of connections to find recipient of a whisper
+
+I implemented a whisper functionality, where a user can whisper to any user in
+the chat room. The whisper message is only sent to specified user. To implement
+this i used ```filter``` over the connections, where the predicate tested whether the
+current list item matched that of a specific user.
+
+```
+(define whisper (regexp-match #px"(.*)/whisper\\s+(\\w+)\\s+(.*)" evt-t0))
+
+[whisper
+                  (semaphore-wait connections-s)
+                  ; get output port for user
+                  ; this might be null
+                  (define that-user-ports
+                    (filter
+                     (lambda (ports)
+                       (if (string=? (whisper-to whisper) (get-username ports))
+                           #t
+                           #f))
+                     ((c-connections 'cons-list))))
+                  ; try to send that user the whisper
+                  (if (and (null? that-user-ports)
+                           #t) ; #t is placeholder for further checks
+                      (begin
+                        (displayln "User is unavailable. /color blue" out)
+                        (flush-output out))
+                      (begin
+                        (displayln (string-append "(whisper) "
+                                    (whisper-info whisper) (whisper-message whisper))
+                                   (get-output-port (car that-user-ports)))
+                        (flush-output (get-output-port (car that-user-ports)))))
+                  (semaphore-post connections-s)]
+```
+
+The snippet above is part of cond statement that tests contents of input from
+clients to determine what the client is trying wants/trying to do. The top-line
+is using regexes to determine whether the received message is a whisper or not.
+
+
+
+## 5. Selectors for dealing with content of a whisper from clients
+
+Below are are three selectors that help abstract the contents of a whisper
+message.
+
+```
+(define (whisper-info exp)
+  (cadr exp))
+
+(define (whisper-to exp)
+  (caddr exp))
+
+(define (whisper-message exp)
+  (cadddr exp))
+```
+
+```whisper-info``` retrieves the date-time and username info.
+```whisper-to``` retrieves the username of the intented recipient of a whisper.
+```whisper-message``` retrieves the actual whisper.

README.md

@@ -1,59 +1,67 @@
 # Hermes
 
+![example](https://github.com/oplS17projects/Hermes/blob/master/ext/Test_Figure.png)
+
+
 ### Statement
 Hermes is a multi-client chat program akin to IRC written in  Racket. Building
-Hermes is interesting as it exposes us to various design problems namely networking,
+Hermes was interesting as it exposed us to various design problems namely networking,
-synchronization, scheduling, and GUI design.
+synchronization, scheduling, GUI design, and component design.
 
 ### Analysis
 > Will you use data abstraction? How?
 
-TCP communication will be abstracted away, so that we deal with Hermes
+TCP communication has been abstracted away, so that we deal with Hermes
 definition of a message.
-We will try to encrypt the messages passed around. The encryption will be
-abstracted away, so we only have to think about it once during implementation.
 
 > Will you use recursion? How?
 
-The  server will continually loop waiting for connections from clients.
+The  server continually loops waiting for connections from clients. The clients
-The GUI will continually loop to handle input from the user, and to and fro
+are always on standby to receive input.
-the server.
+The GUI continually loops to handle input from the user, 
+as well as to keep the canvas it writes the messages on updated.
 
 > Will you use map/filter/reduce? How?
 
-Map will be used for dealing with input area of clients, and iterating over a list
+Map was used for dealing with input area of clients, and iterating over a list
-of open ports to send messages.
+of open ports to send messages. Filter was used to find the recipient of
+a whisper.
 
 > Will you use object-orientation? How?
 
-Keeping count of the number of clients will require an object of some sort.
+Keeping count of the number of clients required working with objects that are able to
-With procedures to increment and decrement the number of users.
+increment and decrement the number of users. We handled a list of connection
+ports, messages similarly.
+We also keep the GUI in an object so the many moving parts of the
+user interface are packaged in one place.
 
 > Will you use functional approaches to processing your data? How?
 
 The communication part of Hermes is over tcp which uses a lot of functional
 approaches e.g. you start a listener which you can call tcp-accept on.
 The result of tcp accept are two pairs of ports which we can then bind to some
-variables.
+variables. Functional approaches are exemplied in most of the code base.
 
 > Will you use state-modification approaches? How? (If so, this should be encapsulated within objects. `set!` pretty much should only exist inside an object.)
 
-State-modification will be used e.g. keeping count of logged in users requires
+State-modification was used e.g. keeping count of logged in users requires
-state modification via set! to maintain the true user account.
+state modification via set! to maintain the true user account, managing the list
+of open connections and messages required state-modification.
+The user interface also needs a few states that it needs to keep up to date.
 
 > Will you build an expression evaluator, like we did in the symbolic differentatior and the metacircular evaluator?
 
-Users will type their input into a text field from the GUI. We will retrieve
+We allowed the use of a few commands through the user interface. The most notable ones
-the command and evaluate it to see if its a message, or a command to change
+are the /whisper to send private messages to a user, /list count and /list users
-GUI state. We will do something that resembles the metacircular evaluator.
+to  view user statistics , and the /color command to allow
-
+the user to change the color of their text.
 
 ### Deliverable and Demonstration
 There are two big deliverables for this project. Code for the server
 , and the clients which not only has code for interacting with Hermes,
 but also a GUI for interactivity with a user. 
 
-We plan to demonstrate Hermes by running the server code on a remote machine.
+We are going to  demonstrate Hermes by running the server code on a remote machine.
 We will connect to the server via our PCs running client code. We will ssh into
 the remote machine to see the server running. Since Hermes is a multichat anyone
 can join in the demonstration by connecting their computers to the remote
@@ -62,29 +70,24 @@ machine!
 
 
 ### Evaluation of Results
-Evaluating Hermes is very simple. Can at least two clients hold a meaningful
+Evaluating Hermes  was very simple. Can at least two clients hold a meaningful
 conversation remotely? If Client A speaks at 11:01 am, and client B does so at
 11:01 plus a few seconds, Hermes has to convey  this state correctly. Is the GUI
-intuitive for current irc users?  When we can successfully answer this questions
+intuitive for current irc users?  We successfully met these questions, and more.
-satisfactorily we would have met our goals.
 
 
 ## Architecture Diagram
 
-#### Preliminary design
+#### Completed design
 ![Architecture](https://github.com/oplS17projects/Hermes/blob/master/ext/arch_diagram.png)
 
 
-#### The Game plan
-![Diagram](https://github.com/oplS17projects/Hermes/blob/master/ext/architecture_diagram.png)
-
-
 ## Schedule
-The first step in our project will be to setup a system to get data from one machine to another. What data exactly isn't directly important and the other machine doesn't really need to display it in a pretty manner, it just needs to relay that it has recieved the correct information.
+The first step in our project was to setup a system to get data from one machine to another. What data exactly wasn't directly important and the other machine didn't really need to display it in a pretty manner, it just needed to relay that it has recieved the correct information.
 
-Next we need to create a user interface that looks nice. Some way to control the connection and display information in a convient and readable format.
+Next we needed to create a user interface that looked nice. Some way to control the connection and display information in a convient and readable format.
 
-After we have finished the user interface and connecting the machines, we will need to merge them together and begin expanding the utility if time permits.
+After we finished the user interface and connecting the machines, we needed to merge them together and begin expanding the utility if time permits.
 
 ### First Milestone (Sun Apr 9)
 Get two different machines to relay information meaningfully.
@@ -92,21 +95,20 @@ Get two different machines to relay information meaningfully.
 ### Second Milestone (Sun Apr 16)
 Get a GUI that looks professional and uses the correct format.
 
-### Public Presentation (Mon Apr 24, Wed Apr 26, or Fri Apr 28 [your date to be determined later])
+### Public Presentation (Mon Apr 24)
 Merging the GUI and information relay together into one program. If time permits we also plan on adding additional features.
 
 ## Group Responsibilities
 
 ### Douglas Richardson @Doug-Richardson
-Will write the GUI code. This should allow the user to access different
+I have written the code for the GUI. 
-aspects of our program in a clean easy to use interface. Most of
+It presents the user with a simple readable format for displaying the information
-how the program responds to user input will be filtered through the gui.
+that the server provides. For the most part the program only interacts with the user
-If time permits I will also be writing code to encrypt and decrypt the information
+through the GUI.
-going from the server to the clients. 
 
 ### Ibrahim Mkusa @iskm
-Will write the networking code i.e. code that allows communication between
+I wrote the networking code i.e. code that allows communication between
-clients through server. I will also write scheduling code responsible for queueing
+clients through server. I wrote scheduling code responsible for queueing
-fairly and orderly the client messages and broadcasting to the rest of connected
+fairly the client messages and broadcasting to the rest of connected
-clients. If time permits, i will also be responsible for authenticating users
+clients. I also implemented the logic for handling /list, /whisper commands,
-via a backend database. 
+dialogs for gui code and related utilities.