import {bird} from "./bird.js";
import {ffnet} from "./ffnet.js";
import {pipe} from "./pipe.js";
import {population} from "./population.js"

const _GRAVITY = 900;
const _TERMINAL_VELOCITY = 400;
const _MAX_UPWARDS_VELOCITY = -300;
const _UPWARDS_ACCELERATION = -450;
const _PIPE_SPACING_X = 250;
const _PIPE_SPACING_Y = 100;
const _TREADMILL_SPEED = -125;

const _CONFIG_WIDTH = 960;
const _CONFIG_HEIGHT = 540;
const _GROUND_Y = _CONFIG_HEIGHT;
const _BIRD_POS_X = 50;


class FlappyBirdGame {
  constructor() {
    this._game = this._CreateGame();
    this._previousFrame = null;
    this._gameOver = true;

    this._statsText1 = null;
    this._statsText2 = null;
    this._gameOverText = null;
    this._pipes = [];
    this._birds = [];

    this._InitPopulations();
  }

  _InitPopulations() {
    const NN_DEF1 = [
        {size: 7},
        {size: 5, activation: ffnet.relu},
        {size: 1, activation: ffnet.sigmoid}
    ];

    const NN_DEF2 = [
        {size: 7},
        {size: 9, activation: ffnet.relu},
        {size: 1, activation: ffnet.sigmoid}
    ];

    const NN_DEF3 = [
        {size: 7},
        {size: 9, activation: ffnet.relu},
        {size: 9, activation: ffnet.relu},
        {size: 1, activation: ffnet.sigmoid}
    ];

    this._populations = [
      this._CreatePopulation(100, NN_DEF1, 0xFF0000),
      this._CreatePopulation(100, NN_DEF2, 0x0000FF),
      this._CreatePopulation(100, NN_DEF3, 0x00FF00),
    ];
  }

  _CreatePopulation(sz, shapes, colour) {
    const t = new ffnet.FFNeuralNetwork(shapes);

    const params = {
      population_size: sz,
      genotype: {
        size: t.toArray().length,
      },
      mutation: {
        magnitude: 0.1,
        odds: 0.1,
        decay: 0,
      },
      breed: {
        selectionCutoff: 0.2,
        immortalityCutoff: 0.05,
        childrenPercentage: 0.5,
      },
      shapes: shapes,
      tint: colour,
    };

    return new population.Population(params);
  }

  _Destroy() {
    for (let b of this._birds) {
      b.Destroy();
    }
    for (let p of this._pipes) {
      p.Destroy();
    }
    this._statsText1.destroy();
    this._statsText2.destroy();
    if (this._gameOverText !== null) {
      this._gameOverText.destroy();
    }
    this._birds = [];
    this._pipes = [];
    this._previousFrame = null;
  }

  _Init() {
    for (let i = 0; i < 5; i+=1) {
      this._pipes.push(
          new pipe.PipePairObject({
            scene: this._scene,
            x: 500 + i * _PIPE_SPACING_X,
            spacing: _PIPE_SPACING_Y,
            speed: _TREADMILL_SPEED,
            config_height: _CONFIG_HEIGHT
          }));
    }

    this._gameOver = false;
    this._stats = {
      alive: 0,
      score: 0,
    };

    const style = {
      font: "40px Roboto",
      fill: "#FFFFFF",
      align: "right",
      fixedWidth: 210,
      shadow: {
        offsetX: 2,
        offsetY: 2,
        color: "#000",
        blur: 2,
        fill: true
      }
    };
    this._statsText1 = this._scene.add.text(0, 0, '', style);

    style.align = 'left';
    this._statsText2 = this._scene.add.text(
        this._statsText1.width + 10, 0, '', style);

    this._birds = [];
    for (let curPop of this._populations) {
      curPop.Step();

      this._birds.push(...curPop._population.map(
          p => new bird.FlappyBird_NeuralNet(
              {
                scene: this._scene,
                pop_entity: p,
                pop_params: curPop._params,
                x: _BIRD_POS_X,
                config_width: _CONFIG_WIDTH,
                config_height: _CONFIG_HEIGHT,
                max_upwards_velocity: _MAX_UPWARDS_VELOCITY,
                terminal_velocity: _TERMINAL_VELOCITY,
                treadmill_speed: _TREADMILL_SPEED,
                acceleration: _UPWARDS_ACCELERATION,
                gravity: _GRAVITY
              })));
    }
  }

  _CreateGame() {
    const self = this;
    const config = {
        type: Phaser.AUTO,
        scene: {
            preload: function() { self._OnPreload(this); },
            create: function() { self._OnCreate(this); },
            update: function() { self._OnUpdate(this); },
        },
        scale: {
          mode: Phaser.Scale.FIT,
          autoCenter: Phaser.Scale.CENTER_BOTH,
          treadmill_speed: _TREADMILL_SPEED,
          width: _CONFIG_WIDTH,
          height: _CONFIG_HEIGHT,
        }
    };

    return new Phaser.Game(config);
  }

  _OnPreload(scene) {
    this._scene = scene;
    this._scene.load.image('sky', 'assets/sky.png');
    this._scene.load.image('bird', 'assets/bird.png');
    this._scene.load.image('bird-colour', 'assets/bird-colour.png');
    this._scene.load.image('pipe', 'assets/pipe.png');
  }

  _OnCreate(scene) {
    const s = this._scene.add.image(0, 0, 'sky');
    s.displayOriginX = 0;
    s.displayOriginY = 0;
    s.displayWidth = _CONFIG_WIDTH;
    s.displayHeight = _CONFIG_HEIGHT;

    this._keys = {
      up: this._scene.input.keyboard.addKey(Phaser.Input.Keyboard.KeyCodes.UP),
      f: this._scene.input.keyboard.addKey('F'),
      r: this._scene.input.keyboard.addKey('R'),
    }

    this._keys.f.on('down', function () {
      if (this._scene.scale.isFullscreen) {
        this._scene.scale.stopFullscreen();
      } else {
        this._scene.scale.startFullscreen();
      }
    }, this);

    this._keys.r.on('down', function () {
      this._Destroy();
      this._Init();
    }, this);

    this._Init();
  }

  _OnUpdate(scene) {
    if (this._gameOver) {
      this._DrawStats();
      return;
    }

    const currentFrame = scene.time.now;
    if (this._previousFrame == null) {
      this._previousFrame = currentFrame;
    }

    const timeElapsedInS = Math.min(
        (currentFrame - this._previousFrame) / 1000.0, 1.0 / 30.0);

    this._UpdateBirds(timeElapsedInS);
    this._UpdatePipes(timeElapsedInS);
    this._CheckGameOver();
    this._DrawStats();

    this._previousFrame = currentFrame;
  }

  _CheckGameOver() {
    const results = this._birds.map(b => this._IsBirdOutOfBounds(b));

    this._stats.alive = results.reduce((t, r) => (r ? t: t + 1), 0);

    if (results.every(b => b)) {
      this._GameOver();
    }
  }

  _IsBirdOutOfBounds(bird) {
    const birdAABB = bird.Bounds;
    birdAABB.top += 10;
    birdAABB.bottom -= 10;
    birdAABB.left += 10;
    birdAABB.right -= 10;

    if (bird.Dead) {
      return true;
    }

    if (birdAABB.bottom >= _GROUND_Y || birdAABB.top <= 0) {
      bird.Dead = true;
      return true;
    }

    for (const p of this._pipes) {
      if (p.Intersects(birdAABB)) {
        bird.Dead = true;
        return true;
      }
    }
    return false;
  }

  _GetNearestPipes() {
    let index = 0;
    if (this._pipes[0].X + this._pipes[0].Width <= _BIRD_POS_X) {
      index = 1;
    }
    return this._pipes.slice(index, 2);
  }

  _UpdateBirds(timeElapsed) {
    const params = {
        timeElapsed: timeElapsed,
        keys: {up: Phaser.Input.Keyboard.JustDown(this._keys.up)},
        nearestPipes: this._GetNearestPipes(),
    };

    for (let b of this._birds) {
      b.Update(params);
    }
  }

  _UpdatePipes(timeElapsed) {
    const oldPipeX = this._pipes[0].X + this._pipes[0].Width;

    for (const p of this._pipes) {
      p.Update(timeElapsed);
    }

    const newPipeX = this._pipes[0].X + this._pipes[0].Width;

    if (oldPipeX > _BIRD_POS_X && newPipeX <= _BIRD_POS_X) {
      this._stats.score += 1;
    }

    if ((this._pipes[0].X + this._pipes[0].Width) <= 0) {
      const p = this._pipes.shift();
      p.Reset(this._pipes[this._pipes.length - 1].X + _PIPE_SPACING_X);
      this._pipes.push(p);
    }
  }

  _GameOver() {
    const text = "GAME OVER";
    const style = {
      font: "100px Roboto",
      fill: "#FFFFFF",
      align: "center",
      fixedWidth: _CONFIG_WIDTH,
      shadow: {
        offsetX: 2,
        offsetY: 2,
        color: "#000",
        blur: 2,
        fill: true
      }
    };

    this._gameOverText = this._scene.add.text(
        0, _CONFIG_HEIGHT * 0.25, text, style);
    this._gameOver = true;

    setTimeout(() => {
      this._Destroy();
      this._Init();
    }, 2000);
  }

  _DrawStats() {
    function _Line(t, s) {
      return t + ': ' + s + '\n';
    }

    const text1 = 'Generation:\n' + 'Score:\n' + 'Alive:\n';
    this._statsText1.text = text1;

    const text2 = (
        this._populations[0]._generations + '\n' +
        this._stats.score + '\n' +
        this._stats.alive + '\n');
    this._statsText2.text = text2;
  }
}

const _GAME = new FlappyBirdGame();