package tetris

import "github.com/charmbracelet/lipgloss"

// pieceType identifies a tetromino (0–6).
type pieceType int

const (
	pieceI pieceType = iota
	pieceO
	pieceT
	pieceS
	pieceZ
	pieceJ
	pieceL
)

const numPieceTypes = 7

// Standard Tetris colors.
var pieceColors = [numPieceTypes]lipgloss.Color{
	lipgloss.Color("#00FFFF"), // I — cyan
	lipgloss.Color("#FFFF00"), // O — yellow
	lipgloss.Color("#AA00FF"), // T — purple
	lipgloss.Color("#00FF00"), // S — green
	lipgloss.Color("#FF0000"), // Z — red
	lipgloss.Color("#0000FF"), // J — blue
	lipgloss.Color("#FF8800"), // L — orange
}

// Each piece has 4 rotations, each rotation is a list of (row, col) offsets
// relative to the piece origin.
type rotation [4][2]int

var pieces = [numPieceTypes][4]rotation{
	// I
	{
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{0, 2}, [2]int{0, 3}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{2, 0}, [2]int{3, 0}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{0, 2}, [2]int{0, 3}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{2, 0}, [2]int{3, 0}},
	},
	// O
	{
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}},
	},
	// T
	{
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{0, 2}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{2, 0}, [2]int{1, 1}},
		{[2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}, [2]int{1, 2}},
		{[2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}, [2]int{2, 1}},
	},
	// S
	{
		{[2]int{0, 1}, [2]int{0, 2}, [2]int{1, 0}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{1, 1}, [2]int{2, 1}},
		{[2]int{0, 1}, [2]int{0, 2}, [2]int{1, 0}, [2]int{1, 1}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{1, 1}, [2]int{2, 1}},
	},
	// Z
	{
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 1}, [2]int{1, 2}},
		{[2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}, [2]int{2, 0}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 1}, [2]int{1, 2}},
		{[2]int{0, 1}, [2]int{1, 0}, [2]int{1, 1}, [2]int{2, 0}},
	},
	// J
	{
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{1, 1}, [2]int{1, 2}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 0}, [2]int{2, 0}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{0, 2}, [2]int{1, 2}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{2, 0}, [2]int{2, 1}},
	},
	// L
	{
		{[2]int{0, 2}, [2]int{1, 0}, [2]int{1, 1}, [2]int{1, 2}},
		{[2]int{0, 0}, [2]int{1, 0}, [2]int{2, 0}, [2]int{2, 1}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{0, 2}, [2]int{1, 0}},
		{[2]int{0, 0}, [2]int{0, 1}, [2]int{1, 1}, [2]int{2, 1}},
	},
}

// spawnCol returns the starting column for a piece, centering it on the board.
func spawnCol(pt pieceType, rot int) int {
	shape := pieces[pt][rot]
	minC, maxC := shape[0][1], shape[0][1]
	for _, off := range shape {
		if off[1] < minC {
			minC = off[1]
		}
		if off[1] > maxC {
			maxC = off[1]
		}
	}
	width := maxC - minC + 1
	return (boardCols - width) / 2
}