const std = @import("std");
const rl = @import("raylib");
const g = @import("game.zig");

test {
    _ = g;
}

pub fn main() !void {
    const allocator = std.heap.page_allocator;
    const scaleFactor = 30;

    var game = try g.Game.create(allocator);
    defer game.deinit();

    const screenWidth = (game.playFieldSize[0] + 1) * scaleFactor;
    const screenHeight = (game.playFieldSize[1] + 1) * scaleFactor;
    rl.initWindow(screenWidth, screenHeight, "Snake");
    defer rl.closeWindow();
    rl.setTargetFPS(60);

    const tickInterval: f32 = 0.5;
    const fastTickInterval: f32 = tickInterval / 3.0;
    var timer: f32 = 0;
    var isFast = false;

    while (!rl.windowShouldClose()) {
        const deltaTime = rl.getFrameTime();
        timer += deltaTime;

        if (game.state == g.State.running) {
            if (rl.isKeyPressed(.up)) game.setDirection(g.Direction.up);
            if (rl.isKeyPressed(.down)) game.setDirection(g.Direction.down);
            if (rl.isKeyPressed(.right)) game.setDirection(g.Direction.right);
            if (rl.isKeyPressed(.left)) game.setDirection(g.Direction.left);
            if (rl.isKeyDown(.s)) {
                if (!isFast) {
                    isFast = true;
                    timer = 0;
                }
            } else {
                isFast = false;
            }
            const interval = if (isFast) fastTickInterval else tickInterval;
            if (timer >= interval) {
                timer -= interval;
                try game.tick();
            }
        } else {
            if (rl.isKeyPressed(.r)) {
                game.deinit();
                game = try g.Game.create(allocator);
                timer = 0;
                isFast = false;
            }
        }

        render(game, scaleFactor, screenWidth, screenHeight);
    }
}

fn render(game: g.Game, scaleFactor: comptime_int, screenWidth: i32, screenHeight: i32) void {
    rl.beginDrawing();
    defer rl.endDrawing();

    rl.clearBackground(.white);

    const fieldWidth = game.playFieldSize[0] * scaleFactor + scaleFactor;
    const fieldHeight = game.playFieldSize[1] * scaleFactor + scaleFactor;

    // Border
    rl.drawRectangle(0, 0, fieldWidth, scaleFactor, .black); // top
    rl.drawRectangle(0, 0, scaleFactor, fieldHeight, .black); // left
    rl.drawRectangle(0, game.playFieldSize[1] * scaleFactor, fieldWidth, scaleFactor, .black); // bottom
    rl.drawRectangle(game.playFieldSize[0] * scaleFactor, 0, scaleFactor, fieldHeight, .black); // right

    // Food
    rl.drawRectangle(game.food[0] * scaleFactor, game.food[1] * scaleFactor, scaleFactor, scaleFactor, .red);

    // Snake
    for (game.body.items, 0..) |part, i| {
        const color: rl.Color = if (i == 0) .green else .dark_green;
        rl.drawRectangle(part[0] * scaleFactor, part[1] * scaleFactor, scaleFactor, scaleFactor, color);
    }

    // Score in top border
    var scoreBuf: [32]u8 = undefined;
    const scoreText = std.fmt.bufPrintZ(&scoreBuf, "Score: {d}", .{game.score()}) catch unreachable;
    rl.drawText(scoreText, scaleFactor + 5, 6, 18, .white);

    // Game over / win overlays
    const bigFontSize = 50;
    const smallFontSize = 22;
    const restartText = "Press R to restart";
    const restartTextWidth = rl.measureText(restartText, smallFontSize);
    const cx = @divTrunc(screenWidth, 2);
    const cy = @divTrunc(screenHeight, 2);

    if (game.state == g.State.lost) {
        const text = "Game Over!";
        const tw = rl.measureText(text, bigFontSize);
        rl.drawText(text, cx - @divTrunc(tw, 2), cy - @divTrunc(bigFontSize, 2), bigFontSize, .dark_gray);
        rl.drawText(restartText, cx - @divTrunc(restartTextWidth, 2), cy + @divTrunc(bigFontSize, 2) + 8, smallFontSize, .dark_gray);
    }
    if (game.state == g.State.won) {
        const text = "You Win!";
        const tw = rl.measureText(text, bigFontSize);
        rl.drawText(text, cx - @divTrunc(tw, 2), cy - @divTrunc(bigFontSize, 2), bigFontSize, .dark_gray);
        rl.drawText(restartText, cx - @divTrunc(restartTextWidth, 2), cy + @divTrunc(bigFontSize, 2) + 8, smallFontSize, .dark_gray);
    }
}