import init, {
    World,
    Pane,
    FullTile,
    Signal,
    available_tiles,
} from "/stackline-wasm/pkg/stackline_wasm.js";

let promises = [];
promises.push(init());

const canvas = document.getElementById("main-canvas");
const ctx = canvas.getContext("2d");

let font = new FontFace("Stackline Classic", "url(\"/font/StacklineClassic-Medium.otf\")");
promises.push(font.load());
await Promise.all(promises);

font = await font.loaded;
document.fonts.add(font);

let world = World.deserialize(await (await fetch("/stackline/tests/other/prime.json")).json());
world.init();

// let world = World.new();
let cx = 0;
let cy = 0;
let zoom = 1;
let grid = true;

let click_x = 0, click_y = 0;
let mouse_x = 0, mouse_y = 0;
let mouse_down = false;
let hovered = false;
let selected = null;

let running = null;

let tile = world.get(4, 0);
tile.signal = new Signal();
tile.state = "Active";
world.set(4, 0, tile);

// let pane = Pane.empty(5, 5);
// world.set_pane("main", pane);

// let available = available_tiles();
// console.log(available);
// for (let n = 0; n < available.length; n++) {
//     world.set(
//         n % 5,
//         ~~(n / 5),
//         new FullTile(available[n])
//     );
// }

console.log(world.toString());
console.log(world.serialize());

resize();
window.addEventListener("resize", resize);
window.requestAnimationFrame(loop);

function draw() {
    let zoom_factor = Math.ceil(Math.pow(2, zoom));
    let tile_size = 10 * zoom_factor;
    ctx.fillStyle = "#202027";
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    function stroke_rect(x, y, width, height) {
        ctx.lineWidth = zoom_factor;
        ctx.strokeRect(
            Math.round(x * tile_size + cx + canvas.width / 2) - zoom_factor * 1.5,
            Math.round(y * tile_size + cy + canvas.height / 2) - zoom_factor * 1.5,
            Math.round(width * tile_size) + zoom_factor * 2,
            Math.round(height * tile_size) + zoom_factor * 2,
        );
    }

    function fill_rect(x, y, width, height) {
        ctx.fillRect(
            Math.round(x * tile_size + cx + canvas.width / 2) - zoom_factor * 1,
            Math.round(y * tile_size + cy + canvas.height / 2) - zoom_factor * 1,
            Math.round(width * tile_size) + zoom_factor * 1,
            Math.round(height * tile_size) + zoom_factor * 1,
        );
    }

    let panes = [];

    for (let name of world.panes()) {
        let pane = world.get_pane(name);

        panes.push({
            x: pane.x,
            y: pane.y,
            width: pane.width,
            height: pane.height
        });

        ctx.strokeStyle = "rgba(128, 128, 128, 0.5)";
        stroke_rect(
            pane.x,
            pane.y,
            pane.width,
            pane.height,
        );

        pane.free();
    }

    let from_y = Math.floor((-cy - canvas.height / 2) / tile_size);
    let to_y = Math.ceil((-cy + canvas.height / 2) / tile_size);
    let from_x = Math.floor((-cx - canvas.width / 2) / tile_size);
    let to_x = Math.ceil((-cx + canvas.width / 2) / tile_size);

    let width = to_x - from_x + 1;
    let height = to_y - from_y + 1;

    // TODO: memoize
    let chars = world.draw(-from_x, -from_y, width, height);
    ctx.textAlign = "left";
    ctx.textBaseline = "top";
    ctx.font = `${tile_size}px Stackline Classic`;

    for (let y = from_y; y <= to_y; y++) {
        for (let x = from_x; x <= to_x; x++) {
            let x2 = x * tile_size + cx + canvas.width / 2;
            let y2 = y * tile_size + cy + canvas.height / 2;

            let index = 3 * (width * (y - from_y) + x - from_x);

            let ch = String.fromCharCode(chars[index]);
            if (ch !== " ") {
                let fg = to_color(chars[index + 1]);
                let bg = chars[index + 2] === 0 ? null : to_color(chars[index + 2]);

                if (bg) {
                    ctx.fillStyle = `rgba(${bg.join(",")})`;
                    ctx.fillRect(
                        Math.round(x2),
                        Math.round(y2),
                        Math.round(x2 + tile_size) - Math.round(x2),
                        Math.round(y2 + tile_size) - Math.round(y2),
                    );
                }
                ctx.fillStyle = `rgba(${fg.join(",")})`;
                ctx.fillText(
                    ch,
                    Math.round(x2),
                    Math.round(y2),
                );
            } else if (grid) {
                // Draw grid
                let inside = false;

                for (let pane of panes) {
                    if (x >= pane.x && x < pane.x + pane.width && y >= pane.y && y < pane.y + pane.height) {
                        inside = true;
                        break;
                    }
                }

                if (inside || width < 100 && height < 100) {
                    ctx.fillStyle = inside ? "#404040" : "#303030";

                    ctx.fillRect(
                        Math.round(x2 + tile_size / 2) - zoom_factor,
                        Math.round(y2 + tile_size / 2) - zoom_factor,
                        zoom_factor,
                        zoom_factor
                    );
                }
            }
        }
    }

    if (hovered) {
        let [x, y] = get_hovered();

        ctx.strokeStyle = "rgba(230, 255, 230, 0.2)";
        ctx.fillStyle = "rgba(230, 255, 230, 0.07)";
        stroke_rect(x, y, 1, 1);
        fill_rect(x, y, 1, 1);
    }
}

function resize() {
    canvas.width = canvas.clientWidth;
    canvas.height = canvas.clientHeight;

    draw();
}

function loop() {
    draw();
    window.requestAnimationFrame(loop);
}

canvas.addEventListener("mousedown", (evt) => {
    click_x = mouse_x = evt.clientX;
    click_y = mouse_y = evt.clientY;
    mouse_down = true;
});

canvas.addEventListener("mousemove", (evt) => {
    hovered = true;

    if (mouse_down) {
        // TODO: numerically stable solution
        cx += evt.clientX - mouse_x;
        cy += evt.clientY - mouse_y;
    }

    mouse_x = evt.clientX;
    mouse_y = evt.clientY;
});

canvas.addEventListener("mouseup", (evt) => {
    mouse_down = false;

    let dist = Math.sqrt((mouse_x - click_x) ** 2 + (mouse_y - click_y) ** 2);
    if (dist < 10) {
        selected = get_hovered();
    }
});

canvas.addEventListener("mouseenter", (evt) => {
    hovered = true;
});

canvas.addEventListener("mouseleave", (evt) => {
    mouse_down = false;
    hovered = false;
});

canvas.addEventListener("wheel", (event) => {
    const ZOOM_STRENGTH = -0.005;
    let old_zoom = zoom;
    zoom += event.deltaY * ZOOM_STRENGTH;
    zoom = Math.min(Math.max(zoom, 0.0), 4.0);

    let delta = Math.ceil(Math.pow(2, zoom)) / Math.ceil(Math.pow(2, old_zoom));
    cx *= delta;
    cy *= delta;
});

window.addEventListener("keydown", (event) => {
    if (hovered) {
        if (event.code === "Space") {
            if (running !== null) {
                clearInterval(running);
                running = null;
            } else if (event.shiftKey) {
                world.init();
                running = setInterval(() => {
                    world.step();
                }, 100);
            } else {
                world.init();
                world.step();
            }
        } else if (event.code === "KeyG") {
            grid = !grid;
        }
    }
});

function get_hovered() {
    let zoom_factor = Math.ceil(Math.pow(2, zoom));
    let tile_size = 10 * zoom_factor;

    let x = Math.floor((mouse_x - canvas.width / 2 - cx) / tile_size);
    let y = Math.floor((mouse_y - canvas.height / 2 - cy) / tile_size);

    return [x, y];
}

function to_color(num) {
    let alpha = (num >> 24) & 0xff;
    let red = (num >> 16) & 0xff;
    let green = (num >> 8) & 0xff;
    let blue = num & 0xff;

    return [red, green, blue, alpha];
}