const ALIEN_SPEED = 130;       // pixels/sec
const ALIEN_FIRE_RATE = 2500;  // ms between shots

export default class AlienShip {
    constructor(scene, x, y, group) {
        this.scene = scene;
        this.alive = true;

        this.sprite = scene.physics.add.sprite(x, y, 'alien');
        group.add(this.sprite);
        this.sprite.gameEntity = this;
        this.sprite.body.setAllowGravity(false);

        // Circular hitbox: texture is 64x48, use radius 20 centered at (32,24)
        this.sprite.body.setCircle(20, 12, 4);

        this.lastFired = 0;
    }

    update(time, player) {
        if (!this.alive) return;
        if (!player || !player.alive || !player.sprite.active) return;

        // Move toward player
        const dx = player.sprite.x - this.sprite.x;
        const dy = player.sprite.y - this.sprite.y;
        const dist = Math.sqrt(dx * dx + dy * dy);

        if (dist > 5) {
            this.sprite.setVelocity(
                (dx / dist) * ALIEN_SPEED,
                (dy / dist) * ALIEN_SPEED
            );
        }

        // Fire at player periodically
        if (time - this.lastFired > ALIEN_FIRE_RATE) {
            this.lastFired = time;
            const angle = Phaser.Math.RadToDeg(Math.atan2(dy, dx));
            this.scene.spawnAlienBullet(this.sprite.x, this.sprite.y, angle, this);
        }

        // Wrap around screen
        this.scene.physics.world.wrap(this.sprite, 40);
    }

    warpOut() {
        if (!this.alive) return;
        this.alive = false;
        this.sprite.body.setVelocity(0, 0);

        const scene = this.scene;
        const x = this.sprite.x;
        const y = this.sprite.y;

        // Spin and shrink the sprite into the singularity
        scene.tweens.add({
            targets: this.sprite,
            scaleX: 0,
            scaleY: 0,
            angle: this.sprite.angle + 720,
            duration: 500,
            ease: 'Cubic.In',
            onComplete: () => {
                if (this.sprite && this.sprite.active) this.sprite.destroy();
            }
        });

        // Black-hole ring effect
        const gfx = scene.add.graphics();
        const counter = { t: 0 };
        scene.tweens.add({
            targets: counter,
            t: 1,
            duration: 650,
            onUpdate: () => {
                const t = counter.t;
                gfx.clear();
                // Ring expands 0→38px over first 30%, then collapses 38→0px
                const r = t < 0.3
                    ? (t / 0.3) * 38
                    : ((1 - t) / 0.7) * 38;
                if (r < 1) return;
                const a = Math.max(0, 1 - t * 0.7);
                // Dark singularity core
                gfx.fillStyle(0x000000, a);
                gfx.fillCircle(x, y, r * 0.55);
                // Outer cyan ring
                gfx.lineStyle(3, 0x00ffff, a);
                gfx.strokeCircle(x, y, r);
                // Inner white ring
                gfx.lineStyle(1, 0xffffff, a * 0.6);
                gfx.strokeCircle(x, y, r * 0.55);
                // Rotating distortion spokes
                const off = t * Math.PI * 6;
                for (let i = 0; i < 6; i++) {
                    const ang = (i / 6) * Math.PI * 2 + off;
                    gfx.lineStyle(1, 0x88ffff, a * 0.7);
                    gfx.beginPath();
                    gfx.moveTo(x + Math.cos(ang) * r * 0.55, y + Math.sin(ang) * r * 0.55);
                    gfx.lineTo(x + Math.cos(ang) * r, y + Math.sin(ang) * r);
                    gfx.strokePath();
                }
            },
            onComplete: () => gfx.destroy()
        });
    }

    explode() {
        if (!this.alive) return;
        this.alive = false;
        this.sprite.body.setVelocity(0, 0);

        const scene = this.scene;
        const x = this.sprite.x;
        const y = this.sprite.y;

        // Brief cyan flash before implosion
        this.sprite.setTint(0x00ffff);
        scene.time.delayedCall(60, () => {
            if (this.sprite && this.sprite.active) this.sprite.clearTint();
        });

        // Phase 1 (0–400ms): sprite collapses and spins 360°
        scene.tweens.add({
            targets: this.sprite,
            scaleX: 0,
            scaleY: 0,
            angle: this.sprite.angle + 360,
            duration: 400,
            ease: 'Cubic.In',
            onComplete: () => {
                if (this.sprite && this.sprite.active) this.sprite.destroy();
            }
        });

        // Phase 2 (200–700ms): cyan shockwave ring expands and fades
        scene.time.delayedCall(200, () => {
            const gfx = scene.add.graphics();
            gfx.setDepth(5);
            const counter = { t: 0 };
            scene.tweens.add({
                targets: counter,
                t: 1,
                duration: 500,
                onUpdate: () => {
                    const t = counter.t;
                    gfx.clear();
                    const radius = t * 120;
                    if (radius < 1) return;
                    gfx.lineStyle(3, 0x00ffff, Math.max(0, 1 - t));
                    gfx.strokeCircle(x, y, radius);
                },
                onComplete: () => gfx.destroy()
            });
        });
    }

    destroy() {
        if (!this.alive) return;
        this.alive = false;
        if (this.sprite && this.sprite.active) {
            this.sprite.destroy();
        }
    }
}