#!/usr/bin/env wish

set usersize [lindex $argv 0]
if {$usersize == ""} then {
  set size 5
} else {
  set size $usersize
}
set win 0

for {set i 0} {$i < $size} {incr i} {
  for {set j 0} {$j < $size} {incr j} {
    button .butr${i}c${j} -command "press $i $j" -background black -activebackground black
    grid .butr${i}c${j} -column $j -row $i
  }
}

proc rnd {n} {
  expr {int(rand()*$n)}
}

proc invert {row col} {
  global size win
  set l { {-1 0} {0 -1} {0 0} {1 0} {0 1} }
  foreach i $l {
    set r [expr $row + [lindex $i 0]]
    if {$r < 0 || $r >= $size} then {continue}
    set c [expr $col + [lindex $i 1]]
    if {$c < 0 || $c >= $size} then {continue}
    set colour [.butr${r}c${c} cget -background]
    if {$colour == "black"} then {
      .butr${r}c${c} configure -background white -activebackground white
      set win [expr $win + 1]
    } else {
      .butr${r}c${c} configure -background black -activebackground black
      set win [expr $win - 1]
    }
  }
}

proc press {row col} {
  global win
  invert $row $col
  if {$win == 0} then {
    exit
  }
}

for {set i 0} {$i < $size} {incr i} {
  for {set j 0} {$j < $size} {incr j} {
    if {[expr [rnd 1000] % 2] == 0} then {
      invert ${i} ${j}
    }
  }
}