Omok (Connect 5)

globals [current-color last-piece]

to setup
  clear-all
  ask patches [
    set pcolor white
  ]
  draw-grid
  set current-color red
  reset-ticks
end 

to go
  if place-tile [
    user-message (word whos-turn " wins!")
    stop
  ]
end 

to draw-grid
  create-turtles 1 [
    set size 0.75
    setxy min-pxcor min-pycor
    facexy xcor max-pycor
    set color gray
    pen-down
    repeat 15 [
      fd 15
      rt 90
      fd 1
      rt 270
    ]
    bk 1
    rt 90
    repeat 15 [
      fd 15
      rt 90
      fd 1
      rt 270
    ]
    die
  ]
end 

to-report place-tile
  let will-end false
  if (mouse-inside? and
    mouse-down? and
    [count turtles-here] of patch round mouse-xcor round mouse-ycor < 1 ) [
    create-turtles 1 [
      setxy round mouse-xcor round mouse-ycor
      set shape "circle"
      set size 0.75
      set color current-color
      set last-piece who

      if player-win? current-color [set will-end true]
    ]
    if will-end [report will-end]
    ifelse current-color = red [set current-color blue] [set current-color red]
  ]

  report will-end
end 

to-report player-win? [player-color]
  let num-in-row 1
  set num-in-row search-north num-in-row player-color
  set num-in-row search-south num-in-row player-color
  if num-in-row = 5 [report true]

  set num-in-row 1
  set num-in-row search-east num-in-row player-color
  set num-in-row search-west num-in-row player-color
  if num-in-row = 5 [report true]

  set num-in-row 1
  set num-in-row search-north-east num-in-row player-color
  set num-in-row search-south-west num-in-row player-color
  if num-in-row = 5 [report true]

  set num-in-row 1
  set num-in-row search-north-west num-in-row player-color
  set num-in-row search-south-east num-in-row player-color
  if num-in-row = 5 [report true]

  report false
end 

to-report search-north [num-in-row player-color]
  ask patch-at-heading-and-distance 0 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-north (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-south [num-in-row player-color]
  ask patch-at-heading-and-distance 180 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-south (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-east [num-in-row player-color]
  ask patch-at-heading-and-distance 90 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-east (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-west [num-in-row player-color]
  ask patch-at-heading-and-distance 270 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-west (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-north-east [num-in-row player-color]
  ask patch-at-heading-and-distance 45 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-north-east (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-north-west [num-in-row player-color]
  ask patch-at-heading-and-distance 315 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-north-west (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-south-east [num-in-row player-color]
  ask patch-at-heading-and-distance 135 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-south-east (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report search-south-west [num-in-row player-color]
  ask patch-at-heading-and-distance 225 1 [
    if any? turtles-here with [ color = player-color ] [
      set num-in-row search-south-west (num-in-row + 1) player-color
    ]
  ]
  report num-in-row
end 

to-report whos-turn
  ifelse current-color = red [report "Red"] [report "Blue"]
end 

to undo
  ifelse last-piece != -1 [
    ifelse current-color = red [set current-color blue] [set current-color red]
    ask turtle last-piece [ die ]
    set last-piece -1
  ] [
    user-message "Sorry, I can only undo once per round."
  ]
end