// Piece square tables.
package engine

import "github.com/noahklein/dragon"

func init() {
	initPieceSquare()
}

var MGPawnTable = [64]int16{
	0, 0, 0, 0, 0, 0, 0, 0,
	98, 134, 61, 95, 68, 126, 34, -11,
	-6, 7, 26, 31, 65, 56, 25, -20,
	-14, 13, 6, 21, 23, 12, 17, -23,
	-27, -2, -5, 12, 17, 6, 10, -25,
	-26, -4, -4, -10, 3, 3, 33, -12,
	-35, -1, -20, -23, -15, 24, 38, -22,
	0, 0, 0, 0, 0, 0, 0, 0,
}

var EGPawnTable = [64]int16{
	0, 0, 0, 0, 0, 0, 0, 0,
	178, 173, 158, 134, 147, 132, 165, 187,
	94, 100, 85, 67, 56, 53, 82, 84,
	32, 24, 13, 5, -2, 4, 17, 17,
	13, 9, -3, -7, -7, -8, 3, -1,
	4, 7, -6, 1, 0, -5, -1, -8,
	13, 8, 8, 10, 13, 0, 2, -7,
	0, 0, 0, 0, 0, 0, 0, 0,
}

var MGKnightTable = [64]int16{
	-167, -89, -34, -49, 61, -97, -15, -107,
	-73, -41, 72, 36, 23, 62, 7, -17,
	-47, 60, 37, 65, 84, 129, 73, 44,
	-9, 17, 19, 53, 37, 69, 18, 22,
	-13, 4, 16, 13, 28, 19, 21, -8,
	-23, -9, 12, 10, 19, 17, 25, -16,
	-29, -53, -12, -3, -1, 18, -14, -19,
	-105, -21, -58, -33, -17, -28, -19, -23,
}

var EGKnightTable = [64]int16{
	-58, -38, -13, -28, -31, -27, -63, -99,
	-25, -8, -25, -2, -9, -25, -24, -52,
	-24, -20, 10, 9, -1, -9, -19, -41,
	-17, 3, 22, 22, 22, 11, 8, -18,
	-18, -6, 16, 25, 16, 17, 4, -18,
	-23, -3, -1, 15, 10, -3, -20, -22,
	-42, -20, -10, -5, -2, -20, -23, -44,
	-29, -51, -23, -15, -22, -18, -50, -64,
}

var MGBishopTable = [64]int16{
	-29, 4, -82, -37, -25, -42, 7, -8,
	-26, 16, -18, -13, 30, 59, 18, -47,
	-16, 37, 43, 40, 35, 50, 37, -2,
	-4, 5, 19, 50, 37, 37, 7, -2,
	-6, 13, 13, 26, 34, 12, 10, 4,
	0, 15, 15, 15, 14, 27, 18, 10,
	4, 15, 16, 0, 7, 21, 33, 1,
	-33, -3, -14, -21, -13, -12, -39, -21,
}

var EGBishopTable = [64]int16{
	-14, -21, -11, -8, -7, -9, -17, -24,
	-8, -4, 7, -12, -3, -13, -4, -14,
	2, -8, 0, -1, -2, 6, 0, 4,
	-3, 9, 12, 9, 14, 10, 3, 2,
	-6, 3, 13, 19, 7, 10, -3, -9,
	-12, -3, 8, 10, 13, 3, -7, -15,
	-14, -18, -7, -1, 4, -9, -15, -27,
	-23, -9, -23, -5, -9, -16, -5, -17,
}

var MGRookTable = [64]int16{
	32, 42, 32, 51, 63, 9, 31, 43,
	27, 32, 58, 62, 80, 67, 26, 44,
	-5, 19, 26, 36, 17, 45, 61, 16,
	-24, -11, 7, 26, 24, 35, -8, -20,
	-36, -26, -12, -1, 9, -7, 6, -23,
	-45, -25, -16, -17, 3, 0, -5, -33,
	-44, -16, -20, -9, -1, 11, -6, -71,
	-19, -13, 1, 17, 16, 7, -37, -26,
}

var EGRookTable = [64]int16{
	13, 10, 18, 15, 12, 12, 8, 5,
	11, 13, 13, 11, -3, 3, 8, 3,
	7, 7, 7, 5, 4, -3, -5, -3,
	4, 3, 13, 1, 2, 1, -1, 2,
	3, 5, 8, 4, -5, -6, -8, -11,
	-4, 0, -5, -1, -7, -12, -8, -16,
	-6, -6, 0, 2, -9, -9, -11, -3,
	-9, 2, 3, -1, -5, -13, 4, -20,
}

var MGQueenTable = [64]int16{
	-28, 0, 29, 12, 59, 44, 43, 45,
	-24, -39, -5, 1, -16, 57, 28, 54,
	-13, -17, 7, 8, 29, 56, 47, 57,
	-27, -27, -16, -16, -1, 17, -2, 1,
	-9, -26, -9, -10, -2, -4, 3, -3,
	-14, 2, -11, -2, -5, 2, 14, 5,
	-35, -8, 11, 2, 8, 15, -3, 1,
	-1, -18, -9, 10, -15, -25, -31, -50,
}

var EGQueenTable = [64]int16{
	-9, 22, 22, 27, 27, 19, 10, 20,
	-17, 20, 32, 41, 58, 25, 30, 0,
	-20, 6, 9, 49, 47, 35, 19, 9,
	3, 22, 24, 45, 57, 40, 57, 36,
	-18, 28, 19, 47, 31, 34, 39, 23,
	-16, -27, 15, 6, 9, 17, 10, 5,
	-22, -23, -30, -16, -16, -23, -36, -32,
	-33, -28, -22, -43, -5, -32, -20, -41,
}

var MGKingTable = [64]int16{
	-65, 23, 16, -15, -56, -34, 2, 13,
	29, -1, -20, -7, -8, -4, -38, -29,
	-9, 24, 2, -16, -20, 6, 22, -22,
	-17, -20, -12, -27, -30, -25, -14, -36,
	-49, -1, -27, -39, -46, -44, -33, -51,
	-14, -14, -22, -46, -44, -30, -15, -27,
	1, 7, -8, -64, -43, -16, 9, 8,
	-15, 36, 12, -54, 8, -28, 24, 14,
}

var EGKingTable = [64]int16{
	-74, -35, -18, -18, -11, 15, 4, -17,
	-12, 17, 14, 17, 17, 38, 23, 11,
	10, 17, 23, 15, 20, 45, 44, 13,
	-8, 22, 24, 27, 26, 33, 26, 3,
	-18, -4, 21, 24, 27, 23, 9, -11,
	-19, -3, 11, 21, 23, 16, 7, -9,
	-27, -11, 4, 13, 14, 4, -5, -17,
	-53, -34, -21, -11, -28, -14, -24, -43,
}

type GamePhase uint8

const (
	MiddleGame GamePhase = iota
	EndGame
)

type Color uint8

const (
	White Color = iota
	Black
	Empty
)

// There are 12 piece-color combinations:
// wp = 0, bp = 1
// wN = 2, bN = 3
// ...
var (
	MidGameTable = [12][64]int16{}
	EndGameTable = [12][64]int16{}
)

func initPieceSquare() {
	mgTable := [6][64]int16{
		MGPawnTable,
		MGKnightTable,
		MGBishopTable,
		MGRookTable,
		MGQueenTable,
		MGKingTable,
	}
	egTable := [6][64]int16{
		EGPawnTable,
		EGKnightTable,
		EGBishopTable,
		EGRookTable,
		MGQueenTable,
		EGKingTable,
	}

	for piece := dragon.Pawn; piece <= dragon.King; piece++ {
		for sq := uint8(0); sq < 64; sq++ {
			pc := pieceColor(piece, true)
			// White
			MidGameTable[pc][sq] = mgTable[piece-1][Flip(sq)]
			EndGameTable[pc][sq] = egTable[piece-1][Flip(sq)]
			// Black
			MidGameTable[pc+1][sq] = mgTable[piece-1][sq]
			EndGameTable[pc+1][sq] = egTable[piece-1][sq]
		}
	}
}

func pieceColor(piece int, isWhite bool) int {
	if isWhite {
		return 2 * (piece - 1)
	}
	return 2*(piece-1) + 1
}

func Flip(square uint8) uint8 {
	return square ^ 56
}
