import { Vector3 } from "three";
import BezierEasing from "bezier-easing";
import Stats from "stats.js";

const stats = new Stats();
stats.showPanel(0);
document.body.appendChild(stats.dom);

export const easeIn = BezierEasing(0.5, 0.16, 0.74, 0.38);
export const easeOut = BezierEasing(0, 0, 0.58, 1);

const enterDuration = 3000;
const exitDuration = 5000;
const margin = 55;
class El {
  constructor(seed) {
    const { data, row, wall, key, index } = seed;
    const { imgWidth, blockWidth, imgHeight, sphere } = wall;
    const { ratio, y } = row;
    let x = index * blockWidth + blockWidth / 2 - ratio * blockWidth;
    const point = new Vector3(x, y, 0);
    const targetPoint = new Vector3(x, y, 0);
    const spherePoint = sphere ? sphere.point : null;
    let scale = 1;
    if (sphere && point.distanceTo(spherePoint) < sphere.displacement) {
      const direction = point.clone().sub(spherePoint);
      const displacementAmount = sphere.displacement - direction.length();
      scale = ((1 - displacementAmount / sphere.displacement) / 1) * 0.3 + 0.7;
      direction.setLength(displacementAmount);
      direction.add(point);
      point.lerp(direction, 0.725);
    }
    if (point.distanceTo(targetPoint) > 0.01) {
      point.lerp(targetPoint, 0.27);
    }
    const top = point.y - imgHeight / 2;
    const left = point.x - imgWidth / 2;
    const { urlSmall } = data;
    const style = {
      width: `${imgWidth}px`,
      height: `${imgHeight}px`,
      top: `${top}px`,
      left: `${left}px`,
      backgroundImage: `url(${urlSmall})`,
      transform: `scale(${scale})`,
      opcaity: scale,
      zIndex: wall.rowNum - Math.floor(Math.abs(wall.rowNum / 2 - row.index)),
    };
    Object.assign(this, { seed, data, style, key, point });
  }
  update() {}
}

class Row {
  q = [];
  est;
  fst;
  t1;
  t2;
  constructor({ wall, index }) {
    const initY =
      wall.marginTop + index * wall.blockHeight + wall.blockHeight / 2;
    const offsetY = initY - wall.containerHeight - wall.blockHeight;
    Object.assign(this, {
      wall,
      minSize: wall.colNum + 2,
      index,
      ratio: Math.random(),
      initY,
      y: offsetY,
      offsetY,
    });
  }
  get size() {
    return this.q.length;
  }
  init() {
    while (this.size < this.minSize) {
      this.push();
    }
  }
  push() {
    const { wall } = this;
    const data = wall.getNext();
    const key = wall.getKey();
    const seed = {
      data,
      row: this,
      wall,
      key,
      index: this.q.length,
    };
    const el = new El(seed);
    this.wall.elMap.set(key, el);
    this.q.push(el);
  }
  shift() {
    const el = this.q.shift();
    this.wall.elMap.delete(el.key);
  }
  update() {
    this.q.forEach((el) => {
      this.wall.elMap.set(el.key, new El(el.seed));
    });
  }
  enter(now) {
    if (!this.est) {
      this.est = now;
    } else {
      this.y =
        this.offsetY +
        (this.wall.containerHeight + this.wall.blockHeight) *
          easeOut((now - this.est) / enterDuration);
    }
    this.update();
  }
  exit(now) {
    if (!this.fst) {
      this.fst = now;
    } else {
      this.y =
        this.initY +
        this.wall.containerHeight * easeIn((now - this.fst) / exitDuration);
    }
    this.update();
  }
  nextFrame(ratioSpeed) {
    this.ratio += ratioSpeed;
    if (this.ratio > 1) {
      this.shift();
      this.push();
      this.q.forEach((el) => {
        el.seed.index--;
      });
      this.ratio -= 1;
    }
    this.update();
  }
}
export default class Wall {
  #rafID = null;
  #lastTime;
  entering = false;
  exiting = false;
  rows = [];
  key = 0;
  time = 0;
  index = 0;
  maxDeltaTime = 1 / 30;
  constructor({
    items,
    imgWidth,
    imgHeight,
    containerWidth,
    containerHeight,
    speed,
    onListChange,
  }) {
    const blockWidth = imgWidth + margin;
    const blockHeight = imgHeight + margin;
    const colNum = Math.floor(containerWidth / blockWidth) + 1;
    const rowNum = Math.floor(containerHeight / blockHeight);
    const elNum = items.length;
    const ratioSpeed = speed / (containerWidth / colNum);
    const marginTop = (containerHeight - rowNum * blockHeight) / 2;
    const elMap = new Map();
    Object.assign(this, {
      items,
      colNum,
      rowNum,
      elNum,
      imgWidth,
      imgHeight,
      containerWidth,
      containerHeight,
      ratioSpeed,
      blockWidth,
      blockHeight,
      marginTop,
      elMap,
      onListChange,
    });
  }
  getNext() {
    const { items } = this;
    const next = items[this.index];
    this.index++;
    if (this.index === items.length) this.index = 0;
    return next;
  }
  async init() {
    const { rowNum } = this;
    for (let i = 0; i < rowNum; i++) {
      const row = new Row({ wall: this, index: i });
      row.init();
      this.rows.push(row);
    }
    this.#rafID = window.requestAnimationFrame(this.animate);
    this.isRunning = true;
    this.entering = true;
    await new Promise((resolve) => {
      setTimeout(() => {
        this.entering = false;
        resolve();
      }, enterDuration);
    });
    return this;
  }
  animate = () => {
    stats.begin();
    if (!this.isRunning) return;
    const now = performance.now();
    const dt = Math.min(this.maxDeltaTime, (now - this.#lastTime) / 1000);
    this.rows.forEach((row) =>
      this.entering
        ? row.enter(now)
        : this.exiting
        ? row.exit(now)
        : row.nextFrame(this.ratioSpeed)
    );
    this.getList();
    this.time += dt;
    this.#lastTime = now;
    this.#rafID = window.requestAnimationFrame(this.animate);
    stats.end();
  };
  async dispose() {
    if (this.#rafID === null) return;
    this.exiting = true;
    await new Promise((resolve) => {
      setTimeout(() => {
        this.exiting = false;
        window.cancelAnimationFrame(this.#rafID);
        this.#rafID = null;
        this.isRunning = false;
        resolve();
      }, exitDuration + 500);
    });
    return this;
  }
  getKey() {
    this.key++;
    return this.key;
  }
  getList() {
    if (this.onListChange) this.onListChange(Array.from(this.elMap.entries()));
  }
  attachSphere(sphere) {
    this.sphere = sphere;
  }
}