import { GameObject } from '../engine/GameObject.js';
import { Vector2D } from '../engine/Vector2D.js';

export class Zombie extends GameObject {
  constructor(
    x,
    y,
    target,
    {
      container,
      viewport,
      speed = 110,
      size = 24,
      color = [0.15, 0.65, 0.2, 1],
      health = 1,
      knockback = 260,
      knockbackDamping = 10,
      scoreValue = 1,
      emergeTime = 0,
      onDeath = null,
    } = {},
  ) {
    super(x, y);
    this.target = target;
    this.container = container;
    this.viewport = viewport;
    this.speed = speed;
    this.size = size;
    this.baseColor = [...color];
    this.health = health;
    this.maxHealth = health;
    this.knockback = knockback;
    this.knockbackDamping = knockbackDamping;
    this.scoreValue = scoreValue;
    this.onDeath = onDeath;
    this._hitKnockback = new Vector2D(0, 0);
    this._flash = 0;
    this._time = 0;
    this._broken = Math.random() * Math.PI * 2;
    this._emergeTotal = emergeTime;
    this._emerge = emergeTime;
    this.width = size;
    this.height = size;
  }

  die() {
    if (this.onDeath) {
      this.onDeath(this);
    }
    this.remove(this.container);
  }

  hit(impulse, damage = 1) {
    this.health -= damage;
    this._hitKnockback = impulse.mulS(this.knockback);
    this._flash = 0.08;
    return this.health <= 0;
  }

  update(dt) {
    this._time += dt;
    if (this._updateEmerge(dt)) return;
    const delta = this.target.pos.subV(this.pos);
    const distance = delta.length();
    let chaseVelocity = new Vector2D(0, 0);
    if (distance > 1) {
      chaseVelocity = delta.divS(distance).mulS(this.speed);
    }

    this.velocity = chaseVelocity.addV(this._hitKnockback);
    super.update(dt);

    this._hitKnockback = this._hitKnockback.mulS(Math.max(0, 1 - dt * this.knockbackDamping));
    this._flash = Math.max(0, this._flash - dt);
  }

  _updateEmerge(dt) {
    if (this._emerge <= 0) return false;
    this._emerge -= dt;
    if (this._emerge <= 0) {
      this._emerge = 0;
      if (this._onEmergenceComplete) this._onEmergenceComplete();
    }
    return true;
  }

  _emergeSize() {
    if (this._emerge > 0 && this._emergeTotal > 0) {
      return 0.3 + 0.7 * (1 - this._emerge / this._emergeTotal);
    }
    return 1;
  }

  _drawEmerge(renderer) {
    if (this._emerge <= 0) return;
    const gear = 1 - this._emerge / this._emergeTotal;
    renderer.setBlendMode('additive');
    const g = this.size * (3.4 - gear * 1.4);
    renderer.drawTexture(
      renderer.glowTexture,
      this.pos.x - g / 2,
      this.pos.y - g / 2,
      g,
      g,
      [this.baseColor[0], this.baseColor[1], this.baseColor[2], 0.5 * (1 - gear)],
    );
    renderer.setBlendMode('normal');
  }

  draw(renderer) {
    this.width = this.size;
    this.height = this.size;

    let color = this.baseColor;
    if (this._flash > 0) {
      color = [1, 1, 1, 1];
    } else if (this.maxHealth > 1) {
      const hpRatio = this.health / this.maxHealth;
      color = [
        this.baseColor[0] + (1 - this.baseColor[0]) * (1 - hpRatio),
        this.baseColor[1] * hpRatio,
        this.baseColor[2] * hpRatio,
        1,
      ];
    }

    if (this.maxHealth > 1) {
      this._drawJuggernaut(renderer, color);
      return;
    }

    this._drawEmerge(renderer);
    const s = this.size * this._emergeSize();
    const lean = s <= 16;
    const facing = Math.atan2(
      this.target.pos.y - this.pos.y,
      this.target.pos.x - this.pos.x,
    );
    const cosF = Math.cos(facing);
    const sinF = Math.sin(facing);
    const walk = Math.sin(this._time * (lean ? 14 : 10) + this._broken);

    const shade = [color[0] * 0.6, color[1] * 0.6, color[2] * 0.6, 1];
    const shadeDark = [color[0] * 0.38, color[1] * 0.38, color[2] * 0.38, 1];
    const light = [
      Math.min(1, color[0] + 0.25),
      Math.min(1, color[1] + 0.25),
      Math.min(1, color[2] + 0.25),
      1,
    ];

    const drawLimb = (ax, ay, bx, by, thickness, limbColor) => {
      const len = Math.hypot(bx - ax, by - ay);
      if (len < 1) return;
      renderer.drawTexture(
        renderer.whiteTexture,
        (ax + bx) / 2 - len / 2,
        (ay + by) / 2 - thickness / 2,
        len,
        thickness,
        limbColor,
        Math.atan2(by - ay, bx - ax),
      );
    };

    if (!lean) {
      renderer.drawTexture(
        renderer.whiteTexture,
        this.pos.x - s * 0.62,
        this.pos.y - s * 0.5 + s * 0.06,
        s * 1.24,
        s * 0.92,
        [0, 0, 0, 0.35],
      );
    }

    const legLen = s * (lean ? 0.32 : 0.4);
    const legSpread = s * 0.22;
    const hipX = this.pos.x - cosF * s * 0.18;
    const hipY = this.pos.y - sinF * s * 0.18;
    for (let i = 0; i < 2; i += 1) {
      const sign = i === 0 ? 1 : -1;
      const step = sign * walk * s * (lean ? 0.3 : 0.18);
      const footX = hipX + cosF * legLen - sinF * legSpread * sign + cosF * step;
      const footY = hipY + sinF * legLen + cosF * legSpread * sign + sinF * step;
      drawLimb(hipX, hipY, footX, footY, s * 0.15, shadeDark);
    }

    const torsoW = s * (lean ? 0.5 : 0.62);
    const torsoH = s * (lean ? 0.46 : 0.55);
    renderer.drawTexture(
      renderer.whiteTexture,
      this.pos.x - torsoW / 2,
      this.pos.y - torsoH / 2,
      torsoW,
      torsoH,
      color,
    );

    const armLen = s * 0.5;
    const armSpread = s * 0.27;
    for (let i = 0; i < 2; i += 1) {
      const sign = i === 0 ? 1 : -1;
      const shX = this.pos.x - sinF * armSpread * sign;
      const shY = this.pos.y + cosF * armSpread * sign - s * 0.02;
      const reach = 1 + walk * 0.1;
      const handX = shX + cosF * armLen * reach;
      const handY = shY + sinF * armLen * reach;
      drawLimb(shX, shY, handX, handY, s * 0.17, shade);
    }

    const headSize = s * (lean ? 0.4 : 0.44);
    const headX = this.pos.x;
    const headY = this.pos.y - s * (lean ? 0.34 : 0.4) + walk * s * 0.03;
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - headSize / 2,
      headY - headSize / 2,
      headSize,
      headSize,
      light,
    );

    const eyeSize = headSize * 0.2;
    const eyeSpread = headSize * 0.24;
    const look = lean ? 0.1 : 0.04;
    const eyeY = headY + sinF * headSize * look;
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - eyeSize / 2 - sinF * eyeSpread,
      eyeY - eyeSize / 2 + cosF * eyeSpread,
      eyeSize,
      eyeSize,
      [0.05, 0.05, 0.05, 1],
    );
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - eyeSize / 2 + sinF * eyeSpread,
      eyeY - eyeSize / 2 - cosF * eyeSpread,
      eyeSize,
      eyeSize,
      [0.05, 0.05, 0.05, 1],
    );
  }

  _drawJuggernaut(renderer, color) {
    const s = this.size;
    const facing = Math.atan2(
      this.target.pos.y - this.pos.y,
      this.target.pos.x - this.pos.x,
    );
    const cosF = Math.cos(facing);
    const sinF = Math.sin(facing);
    const walk = Math.sin(this._time * 5 + this._broken);

    const shade = [color[0] * 0.6, color[1] * 0.6, color[2] * 0.6, 1];
    const shadeDark = [color[0] * 0.38, color[1] * 0.38, color[2] * 0.38, 1];
    const light = [
      Math.min(1, color[0] + 0.25),
      Math.min(1, color[1] + 0.25),
      Math.min(1, color[2] + 0.25),
      1,
    ];
    const mix = (a, b, t) => a + (b - a) * t;

    renderer.drawTexture(
      renderer.whiteTexture,
      this.pos.x - s * 0.78,
      this.pos.y - s * 0.55 + s * 0.08,
      s * 1.56,
      s * 1.14,
      [0, 0, 0, 0.35],
    );

    const footSize = s * 0.16;
    const footBaseY = this.pos.y + s * 0.46;
    for (let i = 0; i < 2; i += 1) {
      const sign = i === 0 ? 1 : -1;
      const stepX = -sinF * s * 0.2 * sign + cosF * walk * s * 0.06 * sign;
      const stepY = cosF * s * 0.2 * sign + sinF * walk * s * 0.06 * sign;
      renderer.drawTexture(
        renderer.whiteTexture,
        this.pos.x + stepX - footSize / 2,
        footBaseY + stepY - footSize / 2,
        footSize,
        footSize,
        shadeDark,
      );
    }

    const shellW = s * 1.0;
    const shellH = s * 0.95;
    const bottomY = this.pos.y + s * 0.4;
    const topY = this.pos.y - s * 0.5;
    const layers = 6;
    for (let i = 0; i < layers; i += 1) {
      const u = i / (layers - 1);
      const w = shellW * (1 - u * 0.66);
      const h = (shellH / layers) * 1.4;
      const cy = bottomY - u * (bottomY - topY) + walk * s * 0.02;
      renderer.drawTexture(
        renderer.whiteTexture,
        this.pos.x - w / 2,
        cy - h / 2,
        w,
        h,
        [
          mix(shadeDark[0], light[0], u),
          mix(shadeDark[1], light[1], u),
          mix(shadeDark[2], light[2], u),
          1,
        ],
      );
    }

    for (let i = 0; i < 3; i += 1) {
      const rx = this.pos.x + (i - 1) * s * 0.16;
      renderer.drawTexture(
        renderer.whiteTexture,
        rx - s * 0.045,
        topY + s * 0.04,
        s * 0.09,
        shellH * 0.9,
        shadeDark,
      );
    }

    const rivet = s * 0.055;
    renderer.drawTexture(
      renderer.whiteTexture,
      this.pos.x - s * 0.44,
      bottomY - rivet * 0.4,
      rivet,
      rivet,
      shadeDark,
    );
    renderer.drawTexture(
      renderer.whiteTexture,
      this.pos.x + s * 0.44 - rivet,
      bottomY - rivet * 0.4,
      rivet,
      rivet,
      shadeDark,
    );

    const headSize = s * 0.24;
    const headX = this.pos.x + cosF * s * 0.52;
    const headY = this.pos.y + sinF * s * 0.52;
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - headSize / 2,
      headY - headSize / 2,
      headSize,
      headSize,
      light,
    );

    const eyeSize = headSize * 0.22;
    const eyeSpread = headSize * 0.3;
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - eyeSize / 2 - sinF * eyeSpread,
      headY - eyeSize / 2 + cosF * eyeSpread,
      eyeSize,
      eyeSize,
      [0.05, 0.05, 0.05, 1],
    );
    renderer.drawTexture(
      renderer.whiteTexture,
      headX - eyeSize / 2 + sinF * eyeSpread,
      headY - eyeSize / 2 - cosF * eyeSpread,
      eyeSize,
      eyeSize,
      [0.05, 0.05, 0.05, 1],
    );
  }
}