class CollectionSystem {
    constructor(scene) {
        this.scene = scene;
        this.unlockedItems = new Set();

        // Database of Collectables
        this.items = {
            // Resources
            'wood': { name: 'Wood', desc: 'Basic building material.', category: 'Resource' },
            'stone': { name: 'Stone', desc: 'Hard rock for walls.', category: 'Resource' },
            'ore_gold': { name: 'Gold Ore', desc: 'Shiny ore found underground.', category: 'Resource' },
            'gold_bar': { name: 'Gold Bar', desc: 'Refined gold ingot.', category: 'Resource' },

            // Crops
            'seeds': { name: 'Seeds', desc: 'Mystery seeds.', category: 'Farming' },
            'wheat': { name: 'Wheat', desc: 'Staple grain.', category: 'Farming' },
            'corn': { name: 'Corn', desc: 'Tall growing crop.', category: 'Farming' },

            // Rare
            'item_bone': { name: 'Bone', desc: 'Remains of a zombie.', category: 'Rare' },
            'item_scrap': { name: 'Scrap Metal', desc: 'Old machinery parts.', category: 'Rare' },
            'item_chip': { name: 'Microchip', desc: 'High-tech component.', category: 'Rare' },
            'coin_gold': { name: 'Gold Coin', desc: 'Currency of the new world.', category: 'Rare' },
            'artefact_old': { name: 'Ancient Pot', desc: 'A relict from the past.', category: 'Archaeology' },

            // Nature
            'flower_red': { name: 'Red Flower', desc: 'Beautiful bloom.', category: 'Nature' },
            'flower_yellow': { name: 'Yellow Flower', desc: 'Bright bloom.', category: 'Nature' },
            'flower_blue': { name: 'Blue Flower', desc: 'Rare blue bloom.', category: 'Nature' },
            'mushroom_red': { name: 'Red Mushroom', desc: 'Looks poisonous.', category: 'Nature' },
            'mushroom_brown': { name: 'Brown Mushroom', desc: 'Edible fungus.', category: 'Nature' }
        };
    }

    unlock(itemId) {
        if (!this.items[itemId]) return; // Not a collectable

        if (!this.unlockedItems.has(itemId)) {
            this.unlockedItems.add(itemId);
            console.log(`📖 Collection Unlocked: ${itemId}`);

            // Notification
            this.scene.events.emit('show-floating-text', {
                x: this.scene.player.sprite.x,
                y: this.scene.player.sprite.y - 80,
                text: `New Collection Entry!`,
                color: '#FFD700'
            });

            if (this.scene.soundManager && typeof this.scene.soundManager.playSuccess === 'function') {
                this.scene.soundManager.playSuccess();
            } else if (this.scene.soundManager && typeof this.scene.soundManager.playHarvest === 'function') {
                this.scene.soundManager.playHarvest(); // Fallback to harvest sound
            }
        }
    }

    has(itemId) {
        return this.unlockedItems.has(itemId);
    }

    getProgress() {
        const total = Object.keys(this.items).length;
        const unlocked = this.unlockedItems.size;
        return { unlocked, total, percent: (unlocked / total) * 100 };
    }

    // Save/Load Logic
    toJSON() {
        return Array.from(this.unlockedItems);
    }

    load(data) {
        if (Array.isArray(data)) {
            this.unlockedItems = new Set(data);
        }
    }
}