/*
 * Kakuro Solver in Copris
 * by Naoyuki Tamura
 * http://bach.istc.kobe-u.ac.jp/copris/puzzles/kakuro/
 */
package kakuro

import jp.kobe_u.copris._
import jp.kobe_u.copris.dsl._
import puzzle._

case class Kakuro(m: Int, n: Int, board: Seq[Seq[String]]) extends BoardPuzzle {
  def isBlank(cell: Cell) = at(cell) == "-"
  def isHint(cell: Cell) = at(cell).matches("""\d+\\\d+""")
  def hint(cell: Cell) = {
    val s = at(cell).split("""\\""").map(_.toInt)
    (s(0),s(1))
  }
  def block(cell: Cell, dij: Cell): Seq[Cell] =
    if (! isCell(cell) || ! isBlank(cell)) Seq.empty
    else cell +: block(move(cell, dij), dij)
  val blocks: Set[(Int,Seq[Cell])] = {
    val rowBlocks = 
      for (cell <- cells; if isHint(cell); (rsum,csum) = hint(cell); if rsum > 0)
      yield (rsum, block(move(cell, (1,0)), (1,0)))
    val colBlocks = 
      for (cell <- cells; if isHint(cell); (rsum,csum) = hint(cell); if csum > 0)
      yield (csum, block(move(cell, (0,1)), (0,1)))
    rowBlocks.toSet ++ colBlocks.toSet
  }
  def show(sol: Map[Cell,Int]) {
    for (i <- 0 until m) {
      for (j <- 0 until n; cell = (i,j)) {
	if (isBlank(cell)) print("   " + sol(cell) + "   ")
	else {
	  val (rsum,csum) = hint(cell)
	  print("[%2d\\%-2d]".format(rsum, csum))
	}
      }
      println
    }
  }
}

object Solver extends BoardPuzzleSolver[Kakuro] {
  val name = "kakuro.Solver"

  def puzzleFactory(m: Int, n: Int, board: Seq[Seq[String]]) =
    Kakuro(m, n, board)

  def define = {
    for (cell <- puzzle.cells; if puzzle.isBlank(cell))
      int('x(cell), 1, 9)
    for ((sum,block) <- puzzle.blocks) {
      val xs = block.map(cell => 'x(cell))
      add(Add(xs) === sum)
      add(Alldifferent(xs))
    }
  }

  def showSolution {
    val sol = {
      for (cell <- puzzle.cells; if puzzle.isBlank(cell))
      yield cell -> solution('x(cell))
    }.toMap
    if (quiet == 0) {
      println("Solution = " + sol)
      println("Size = " + sol.size)
      puzzle.show(sol)
    }
  }
}