project process4

breed [fishes fish]
breed [predators predator]
breed [boats boat]
breed [detritus detritu]

turtles-own [ age  flockmates  nearest-neighbor energy]
patches-own [seagrass]

to draw-island
  if mouse-down?     ;; reports true or false to indicate whether mouse button is down
    [
      ;; mouse-xcor and mouse-ycor report the position of the mouse --
      ;; note that they report the precise position of the mouse,
      ;; so you might get a decimal number like 12.3, but "patch"
      ;; automatically rounds to the nearest patch
      ask patch mouse-xcor mouse-ycor
        [ set pcolor red ]
    ]
end 

to setup
  clear-all
  ask patches [  
    set seagrass random-float 10.0
    set pcolor scale-color blue seagrass 0 20
  ]
  
  create-fishes number-of-fish [  
    setxy random-xcor random-ycor
    set color red
    set shape "fish"  
    set age random 3
    set energy random 20
  ]
  
  create-detritus 50 [  
    setxy random-xcor random-ycor
    set color green
    set shape "molecule hydrogen"    
    set energy random 10
  ]
  
  create-predators number-of-predator [ 
    setxy random-xcor random-ycor
    set color yellow
    set shape "shark"
    set age random 5
    set energy random 60
    set size 2 ;; increase their size so they are a little easier to see
  ]
  if human-involoved?
  [ create-boats 10 [  
    setxy random-xcor random-ycor
    set color white
    set shape "boat"  
    set size 2
  ]]
  reset-ticks
end 

to go
  if not any? turtles [  
    stop
  ]
  
  ask fishes [
    ifelse flock? [
      flock
      ;; avoid
      fd 1
      set age age + 1
      set energy energy - 1
  
    ]
    [ avoid
      let walls patches in-radius 1 with [pcolor = red]
  ifelse any? walls 
  [
    move]
  [forward 1  ]
      set age age + 1
      set energy energy - 2
    ]
    check-fish-dead
    eat-seagrass
    fish-reproduce
  ]
  
  ask detritus[
    move
  ]
  
   
  ask predators [
    chase
    eat-fish
    predator-reproduce
    check-if-dead
    set age age + 1
  ]
  
  
  if human-involoved?
  [
    ask boats [
      move
      
      fishing
    ]
  ]
  
  regrow-seagrass
  tick  
  my-update-plots
end 

to flock  ;; turtle procedure
  find-flockmates
  if any? flockmates
    [ find-nearest-neighbor
      ifelse distance nearest-neighbor < 0.75
        [ separate ]
        [ align
          cohere ] ]
end 

to find-flockmates  ;; turtle procedure
  set flockmates other turtles in-radius 3
end 

to find-nearest-neighbor ;; turtle procedure
  set nearest-neighbor min-one-of flockmates [distance myself]
end 

to separate  ;; turtle procedure
  turn-away ([heading] of nearest-neighbor) 3.50
end 

to align  ;; turtle procedure
  turn-towards average-flockmate-heading 5
end 

to cohere  ;; turtle procedure
  turn-towards average-heading-towards-flockmates 5.75
end 

to turn-towards [new-heading max-turn]  ;; turtle procedure
  turn-at-most (subtract-headings new-heading heading) max-turn
end 

to turn-away [new-heading max-turn]  ;; turtle procedure
  turn-at-most (subtract-headings heading new-heading) max-turn
end 

to turn-at-most [turn max-turn]  ;; turtle procedure
  ifelse abs turn > max-turn
    [ ifelse turn > 0
      [ rt max-turn ]
      [ lt max-turn ] ]
    [ rt turn ]
end 

to-report average-flockmate-heading  ;; turtle procedure
                                     ;; We can't just average the heading variables here.
                                     ;; For example, the average of 1 and 359 should be 0,
                                     ;; not 180.  So we have to use trigonometry.
  let x-component sum [dx] of flockmates
  let y-component sum [dy] of flockmates
  ifelse x-component = 0 and y-component = 0
    [ report heading ]
    [ report atan x-component y-component ]
end 

to-report average-heading-towards-flockmates  ;; turtle procedure
                                              ;; "towards myself" gives us the heading from the other turtle
                                              ;; to me, but we want the heading from me to the other turtle,
                                              ;; so we add 180
  let x-component mean [sin (towards myself + 180)] of flockmates
  let y-component mean [cos (towards myself + 180)] of flockmates
  ifelse x-component = 0 and y-component = 0
    [ report heading ]
    [ report atan x-component y-component ]
end 

to avoid ;; android procedure
  let candidates patches in-radius 1 with [ not any? predators ]
  ifelse any? candidates
    [ face one-of candidates ]
    [ rt (random 4) * 90 ]
end 

to chase 
  ifelse any? fishes in-radius 3
    [ let candidates one-of fishes in-radius 3
      let walls patches in-radius 1 with [pcolor = red]
      
    
        face candidates
        ifelse any? walls 
       [ move]
      [fd ratio-speed-fishwolves
      set energy energy - 3]]
    [ if random 100 < predator-fight-percent
      [fight ]]
end 

to fight
  ifelse any? predators in-radius 1
  
  [let candidates one-of predators in-radius 1  
    set energy energy - 4
    face candidates
    let walls patches in-radius 1 with [pcolor = red]
  ifelse any? walls 
  [
    move]
  [forward 1  ]
    ask candidates [ die ]
    
  ]
  [ move
    set energy energy - 2]
end 

to eat-seagrass
  if ( seagrass >= 1) [
    set seagrass seagrass - 1
    set pcolor scale-color blue seagrass 0 20
  ] 
end 

to eat-fish
  if any? fishes in-radius 2 [ 
    ask fishes in-radius 2 [     
      die
    ]
    set energy energy + 10
  ]
end 

to fishing
  if random 100 < 70
    [
      ifelse any? predators-here [
        let target one-of predators
        ask target [
          die
        ]]
      [ ask fishes in-radius 3 [
        die
      ]
      ]
    ]
end 

to fish-reproduce
  if random 100 < fish-reproduce-percent [
    if age > 3 [
      hatch fish-hatch-number [ set age 0  set energy random 10]
      
      die
      ask detritus [hatch 1]
    ]
  ]
end 

to predator-reproduce
  if random 100 < predator-reproduce-percent and energy > 20[
    hatch 1 [ set age 0]
    set energy energy - 20
  ]
end 

to check-if-dead
  if age > 8 or energy < 1 [
    die
    ask detritus [hatch 2]
  ]
end 

to check-fish-dead
  if energy < 1 [
    die
  ]
end 

to regrow-seagrass
  ask patches with [pcolor = blue][
    set seagrass seagrass + 0.1
    if seagrass > 10 [
      set seagrass 10
    ]
    set pcolor scale-color blue seagrass 0 20
  ]
end 

to my-update-plots
  set-current-plot-pen "fish"
  plot count fishes
  set-current-plot-pen "shark"
  plot count predators * 10 ;; scaling factor so plot looks nice
  set-current-plot-pen "seagrass"
  plot sum [seagrass] of patches / 50 ;; scaling factor so plot looks nice end
end 

to boat-move
  rt random 360
  forward 2
end 

to move
  rt random 360
  let walls patches in-radius 1 with [pcolor = red]
  ifelse any? walls 
  [
    move]
  [forward 1  ]
end