/**
 * BiomeMusicSystem.js
 * Cross-fade background music based on biome transitions
 */

class BiomeMusicSystem {
    constructor(scene) {
        this.scene = scene;

        // Music tracks by biome
        this.biomeTracks = {
            'grassland': 'music/farm_ambient',
            'forest': 'music/forest_ambient',
            'town': 'music/town_theme',
            'combat': 'music/combat_theme',
            'night': 'music/night_theme'
        };

        // Current playing track
        this.currentTrack = null;
        this.currentBiome = null;

        // Cross-fade settings
        this.fadeDuration = 2000; // 2 seconds
        this.volume = 0.5; // Master volume

        console.log('🎵 BiomeMusicSystem initialized');
    }

    /**
     * Preload all music tracks
     */
    preload() {
        Object.entries(this.biomeTracks).forEach(([biome, track]) => {
            if (this.scene.cache.audio.exists(track)) {
                console.log(`✅ Music ready: ${track}`);
            } else {
                console.warn(`⚠️  Music missing: ${track}`);
            }
        });
    }

    /**
     * Start music for a biome
     */
    playBiomeMusic(biome) {
        // Skip if already playing this biome's music
        if (biome === this.currentBiome && this.currentTrack) {
            return;
        }

        const trackKey = this.biomeTracks[biome];

        if (!trackKey) {
            console.warn(`⚠️  No music for biome: ${biome}`);
            return;
        }

        // Check if track exists
        if (!this.scene.cache.audio.exists(trackKey)) {
            console.warn(`⚠️  Music not loaded: ${trackKey}`);
            return;
        }

        console.log(`🎵 Transitioning to: ${biome} (${trackKey})`);

        // Cross-fade to new track
        this.crossFadeTo(trackKey, biome);
    }

    /**
     * Cross-fade from current track to new track
     */
    crossFadeTo(newTrackKey, biome) {
        const oldTrack = this.currentTrack;

        // Create new track
        const newTrack = this.scene.sound.add(newTrackKey, {
            loop: true,
            volume: 0 // Start silent
        });

        newTrack.play();

        // Fade in new track
        this.scene.tweens.add({
            targets: newTrack,
            volume: this.volume,
            duration: this.fadeDuration,
            ease: 'Linear'
        });

        // Fade out old track if it exists
        if (oldTrack) {
            this.scene.tweens.add({
                targets: oldTrack,
                volume: 0,
                duration: this.fadeDuration,
                ease: 'Linear',
                onComplete: () => {
                    oldTrack.stop();
                    oldTrack.destroy();
                }
            });
        }

        // Update current track
        this.currentTrack = newTrack;
        this.currentBiome = biome;
    }

    /**
     * Stop all music
     */
    stop() {
        if (this.currentTrack) {
            this.scene.tweens.add({
                targets: this.currentTrack,
                volume: 0,
                duration: 1000,
                ease: 'Linear',
                onComplete: () => {
                    this.currentTrack.stop();
                    this.currentTrack.destroy();
                    this.currentTrack = null;
                    this.currentBiome = null;
                }
            });
        }
    }

    /**
     * Set master volume
     */
    setVolume(volume) {
        this.volume = Phaser.Math.Clamp(volume, 0, 1);

        if (this.currentTrack) {
            this.currentTrack.setVolume(this.volume);
        }
    }

    /**
     * Update called every frame
     * Checks player's current biome and switches music
     */
    update(playerX, playerY) {
        // Get current biome from biomeSystem
        if (!this.scene.biomeSystem) return;

        const gridX = Math.floor(playerX / 48);
        const gridY = Math.floor(playerY / 48);

        const biome = this.scene.biomeSystem.getBiomeAt(gridX, gridY);

        if (biome && biome !== this.currentBiome) {
            this.playBiomeMusic(biome);
        }

        // Handle night music override
        if (this.scene.timeSystem) {
            const hour = this.scene.timeSystem.currentHour || 12;

            if (hour >= 20 || hour < 6) { // Night time
                if (this.currentBiome !== 'night') {
                    this.playBiomeMusic('night');
                }
            }
        }
    }
}