Dinning Cryptographers Problem

breed [cryptographers cryptographer]
breed [nsas nsa]
breed [coins coin]

globals [
  final_result
  correct_predictions ;; times cryptographers correctly predict who paid dinner (if them or NSA agent)
  incorrect_predictions ;; times cryptographers inccorectly predicted who paid dinner (if them or NSA agent)
  ratio
]

cryptographers-own [
  state                   ;; my current state: "PAID", "NOT PAID", "EATING"
  dishonesty                 ;; honesty level of the cryptographer
  left-coin right-coin    ;; the coin to their left, the coin to their right
  result                  ;; result
]

coins-own [
  home-xpos home-ypos home-heading     ;; where I belong when I'm on the table
  owners                                ;; the cryptographers that currently owns me
  tossed?                               ;; whether I'm currently tossed
  flip                                ;; 0 or 1
]

nsas-own [
  state
]

to setup
  clear-all
  make-turtles
  reset-ticks
end 

to make-turtles
  set-default-shape cryptographers "person"
  set-default-shape coins "circle"
  set-default-shape nsas "person"
  set correct_predictions 0
  set incorrect_predictions 0
  ;; create-ordered- equally spaces the headings of the turtles,
  ;; in who number order
  create-ordered-cryptographers num-cryptographers [
    set size 0.1
    jump 0.35
    set state "EATING"
    set color yellow
    set result "-"
    set dishonesty lying-probability / num-cryptographers
  ]
  create-ordered-coins num-cryptographers [
    rt 180 / num-cryptographers
    jump 0.25
    rt 180
    set size 0.1
    set color white
    set tossed? false
    set owners nobody
    set home-xpos xcor
    set home-ypos ycor
    set home-heading heading
    set flip 3
  ]
  ask cryptographers [
    set left-coin coin (who + num-cryptographers)
    ifelse who = 0
      [ set right-coin coin (2 * num-cryptographers - 1) ]
      [ set right-coin coin (who + num-cryptographers - 1) ]
  ]

  create-nsas 1 [
    ;jump 0.3
    set state "WATCHING"
    set size 0.1
    set ycor max-pycor
    set color blue
  ]
end 

to go
  restart
  wait 0.3
  ask one-of cryptographers [ update ]
  wait 0.3
  ask coins [ tossing ]
  ask cryptographers [ decision ]
  final-result
  reporting
  ;if incorrect_predictions = 1 [stop]
  if correct_predictions > 0 [
    set ratio (correct_predictions / (incorrect_predictions + correct_predictions))
  ]
  tick
end 

;; everybody gets a new color.

to restart
  ask cryptographers [
    ;; look up the color in the colors list indexed by our current state
    if state = "PAID" [
      set color yellow
      set state "EATING"
    ]
  ]
  ask nsas [
    if state = "PAID" [
      set color blue
      set state "WATCHING"
    ]
  ]
  ask coins [
    set shape "circle"
    set flip 3
    set color white
  ]
end 

;; cryptographers and NSA agent are updated to which one paid

to update
  let var random 100
  if var <= nsa-vs-cryp-prob-to-pay [
    ask one-of cryptographers [
      set state "PAID"
      set color red
    ]
  ]
  ;; Changes color of the NSA agent to red if he paid the dinner
  if var > nsa-vs-cryp-prob-to-pay [
    ask NSA 6 [
      set state "PAID"
      set color red
    ]
  ]
end 



;; 2 cryptographers select a coin that only they can see it's result

to acquire-coins-naive  ;; cryptographer procedure
  if [owners] of left-coin = nobody
    [ acquire-left ]
  if [owners] of right-coin = nobody
    [ acquire-right ]
end 

;; this is one of the coin only him and a partner can see

to acquire-left  ;; cryptographers coin ownership
  ask left-coin [
    set owners myself
  ]
end 

;; this is one of the coin only him and a partner can see

to acquire-right  ;; cryptographers coin ownership
  ask right-coin [
    set owners myself
  ]
end 

to tossing
  if any? coins with [shape = "circle"] [
    ask coins [
      ;let a random-float 1
      ifelse (flip = 3) and (random-float 1 > 0.5) [
        ;print "hi"
        set shape "coin tails"
        set color lime
        set flip 1
        ]
      [
        set shape "coin heads"
        set flip 0
        set color pink
        set tossed? true

      ]
      wait 0.2
    ]
  ]
end 

to decision
  let a 3
  let b 3
  ask left-coin [
    if flip = 0 [
      set  a 0
    ]
    if flip = 1 [
      set a 1
    ]
  ]
  ask right-coin [
    if flip = 0 [
      set  b 0
    ]
    if flip = 1 [
      set b 1
    ]
  ]

  ;; XOR Operation
  if color = yellow [
    if (a = 0) and (b = 0) [
      set result 0
    ]
    if (a = 0) and (b = 1) [
      set result 1
    ]
    if (a = 1) and (b = 0) [
      set result 1
    ]
    if (a = 1) and (b = 1) [
      set result 0
    ]
  ]
  if color = red [
    ;; XOR Operation
    if (a = 0) and (b = 0) [
      set result 1
    ]
    if (a = 0) and (b = 1) [
      set result 0
    ]
    if (a = 1) and (b = 0) [
      set result 0
    ]
    if (a = 1) and (b = 1) [
      set result 1
    ]
  ]
  ;; If the cryptographers is dishonest, he might lie = collusion
  if random-float 1 < dishonesty [
    ifelse (result = 1) [
      set result 0
    ]
    [
      set result 1
    ]
  ]
end 

to final-result
  let var1 1
  let var2 1
  let var3 1
  ;let final_result 1
  ask cryptographer 0 [
    if (result = 0)[
      set var1 0
    ]
    if (result = 1)[
      set var1 1
    ]
  ]
  ask cryptographer 1 [
    if (result = 0)[
      set var2 0
    ]
    if (result = 1)[
      set var2 1
    ]
  ]
    ask cryptographer 2 [
    if (result = 0)[
      set var3 0
    ]
    if (result = 1)[
      set var3 1
    ]
  ]
  if (var1 = 0) and (var2 = 0) and (var3 = 0)[
      set final_result 0
  ]
  if (var1 = 0) and (var2 = 0) and (var3 = 1)[
      set final_result 1
  ]
  if (var1 = 0) and (var2 = 1) and (var3 = 0)[
      set final_result 1
  ]
  if (var1 = 0) and (var2 = 1) and (var3 = 1)[
      set final_result 0
  ]
  if (var1 = 1) and (var2 = 0) and (var3 = 0)[
      set final_result 1
  ]
  if (var1 = 1) and (var2 = 0) and (var3 = 1)[
      set final_result 0
  ]
  if (var1 = 1) and (var2 = 1) and (var3 = 0)[
      set final_result 0
  ]
  if (var1 = 1) and (var2 = 1) and (var3 = 1)[
      set final_result 1
  ]
  print final_result
end 

to reporting
  ask nsa 6 [
    if (final_result = 0) and (color = red)[
      print "Correctly predicted NSA paid"
      set correct_predictions ( correct_predictions + 1 )
    ]
    if (final_result = 0) and (color = blue)[
      print "Incorrectly predicted NSA paid - there was collusion"
      set incorrect_predictions ( incorrect_predictions + 1 )
    ]
    if (final_result = 1) and (color = red)[
      print "Incorrectly predicted an anonymous Cryptographer paid - there was collusion"
      set incorrect_predictions ( incorrect_predictions + 1 )
    ]
    if (final_result = 1) and (color = blue)[
      print "Correctly predicted an anonymous Cryptographer paid"
      set correct_predictions ( correct_predictions + 1 )
    ]
]
end