package components

import (
	"fmt"

	"github.com/ryanhamamura/games/snake"
)

func cellSizeForGrid(width, height int) int {
	maxDim := width
	if height > maxDim {
		maxDim = height
	}
	switch {
	case maxDim <= 15:
		return 28
	case maxDim <= 20:
		return 24
	case maxDim <= 30:
		return 20
	case maxDim <= 40:
		return 16
	default:
		return 14
	}
}

type cellInfo struct {
	snakeIdx int // -1 = empty, -2 = food
	isHead   bool
}

templ Board(sg *snake.SnakeGame) {
	<div
		id="snake-board"
		class="snake-board"
		if sg.State != nil && (sg.Status == snake.StatusInProgress || sg.Status == snake.StatusFinished) {
			style={ fmt.Sprintf("grid-template-columns:repeat(%d,1fr);", sg.State.Width) }
		}
	>
		if sg.State != nil && (sg.Status == snake.StatusInProgress || sg.Status == snake.StatusFinished) {
			@boardCells(sg)
		}
	</div>
}

templ boardCells(sg *snake.SnakeGame) {
	{{ state := sg.State }}
	{{ grid := buildGrid(state) }}
	{{ cellSize := cellSizeForGrid(state.Width, state.Height) }}
	for y := 0; y < state.Height; y++ {
		<div class="snake-row">
			for x := 0; x < state.Width; x++ {
				{{ ci := grid[y][x] }}
				if ci.snakeIdx == -2 {
					<div class="snake-cell snake-food" style={ fmt.Sprintf("width:%dpx;height:%dpx;", cellSize, cellSize) }></div>
				} else if ci.snakeIdx >= 0 {
					{{ s := state.Snakes[ci.snakeIdx] }}
					{{ bg := snakeColor(ci.snakeIdx) }}
					if ci.isHead {
						if s.Alive {
							<div class="snake-cell snake-head" style={ fmt.Sprintf("width:%dpx;height:%dpx;background:%s;box-shadow:0 0 8px %s;", cellSize, cellSize, bg, bg) }></div>
						} else {
							<div class="snake-cell snake-head snake-dead" style={ fmt.Sprintf("width:%dpx;height:%dpx;background:%s;box-shadow:0 0 8px %s;", cellSize, cellSize, bg, bg) }></div>
						}
					} else {
						if s.Alive {
							<div class="snake-cell snake-body" style={ fmt.Sprintf("width:%dpx;height:%dpx;background:%s;", cellSize, cellSize, bg) }></div>
						} else {
							<div class="snake-cell snake-body snake-dead" style={ fmt.Sprintf("width:%dpx;height:%dpx;background:%s;", cellSize, cellSize, bg) }></div>
						}
					}
				} else {
					<div class="snake-cell" style={ fmt.Sprintf("width:%dpx;height:%dpx;", cellSize, cellSize) }></div>
				}
			}
		</div>
	}
}

func buildGrid(state *snake.GameState) [][]cellInfo {
	grid := make([][]cellInfo, state.Height)
	for y := 0; y < state.Height; y++ {
		grid[y] = make([]cellInfo, state.Width)
		for x := 0; x < state.Width; x++ {
			grid[y][x] = cellInfo{snakeIdx: -1}
		}
	}
	for fi := range state.Food {
		f := state.Food[fi]
		if f.X >= 0 && f.X < state.Width && f.Y >= 0 && f.Y < state.Height {
			grid[f.Y][f.X] = cellInfo{snakeIdx: -2}
		}
	}
	for si, s := range state.Snakes {
		if s == nil {
			continue
		}
		for bi, bp := range s.Body {
			if bp.X >= 0 && bp.X < state.Width && bp.Y >= 0 && bp.Y < state.Height {
				grid[bp.Y][bp.X] = cellInfo{snakeIdx: si, isHead: bi == 0}
			}
		}
	}
	return grid
}

func snakeColor(idx int) string {
	if idx >= 0 && idx < len(snake.SnakeColors) {
		return snake.SnakeColors[idx]
	}
	return "#666"
}