globals [
  destination_x ;; used to compute x location of current agent by go method
  destination_y ;; used to compute y location of current agent by go method
  ;; class_width ;; from interface
  ;; class_height ;; from interface
  ;; class_size ;; from interface
  class_width_offset
  class_height_offset
  done_so_far
]

to setup
  clear-all
  set-default-shape turtles "person"
  crt 1 [
    set color green
    setxy 0 -15
  ]
  set class_width_offset  -1 * ( class_width / 2 ) + 1
  set class_height_offset  -1 * ( class_height / 2 ) + 1
  set done_so_far  0
end

to go
  if done_so_far >= class_size [ stop ]
  find_seat
  set done_so_far done_so_far + 1
  crt 1 [
    set color white
    setxy destination_x  destination_y
  ]
  tick
end

to find_seat_1
  set destination_x ( class_width_offset + random class_width )
  set destination_y ( class_height_offset + random class_height )
end

to find_seat_2
  let x_index 0
  let y_index 0
  let patch_empty 1
  loop [
    set destination_x class_width_offset + x_index
    set destination_y class_height_offset + y_index
    set patch_empty 1
    ask patch destination_x destination_y [
      if any? turtles-here [
        set patch_empty 0
      ]
    ]
    if patch_empty = 1 [
      stop
    ]
    set x_index x_index + 1
    if x_index >= class_width [
      set x_index 0
      set y_index y_index + 1
      if y_index >= class_height [
        ask patch  10 -15 [
          set plabel-color yellow
          set plabel "CLASS TOO BIG"
        ]
        stop
      ]
    ]
  ]
end

to find_seat
  let x_index 0
  let y_index 0
  let best_x 0
  let best_y 0
  let best_score -1000
  let curr_x 0
  let curr_y 0
  let curr_score -1000
  loop [
    set curr_x class_width_offset + x_index
    set curr_y class_height_offset + y_index
    set curr_score compute_score  curr_x curr_y 
    if ( curr_score > best_score ) [
      set best_score curr_score
      set best_x curr_x
      set best_y curr_y
    ]
    set x_index x_index + 1
    if x_index >= class_width [
      set x_index 0
      set y_index y_index + 1
      if y_index >= class_height [
        ifelse best_score = -1000 [
          ask patch  10 -15 [
            set plabel-color yellow
            set plabel "CLASS TOO BIG"
          ]
          stop
        ]
        [
          set destination_x best_x
          set destination_y best_y
          stop
        ]
      ]
    ]
  ]
end

to-report compute_score_1 [ x_value y_value ]
  ;; same result as find_seat_2
  let patch_empty 1
  ask patch x_value y_value [
      if any? turtles-here [
        set patch_empty 0
      ]
  ]
  if patch_empty = 0 [
      report -1000
  ]
  report 0
end

to-report compute_score [ x_value y_value ]
  let patch_empty 1
  ask patch x_value y_value [
      if any? turtles-here [
        set patch_empty 0
      ]
  ]
  if patch_empty = 0 [
      report -1000
  ]
  ask patch x_value ( y_value - 1 ) [
      if any? turtles-here [
        set patch_empty 0
      ]
  ]
  if patch_empty = 0 [
    report -500
  ]
  report 0
end