/**
 * NPCShopSystem.js
 * ================
 * KRVAVA ŽETEV - NPC Trading & Shop System (Phase 38)
 * 
 * Features:
 * - 4 NPC shop types (Blacksmith, Baker, Trader, Healer)
 * - Shop UI with buy/sell
 * - Dynamic pricing
 * - Stock management
 * - Relationship discounts
 * 
 * @author NovaFarma Team
 * @date 2025-12-23
 */

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

        // Shop registry
        this.shops = new Map();
        this.currentShop = null;

        // Shop UI
        this.shopContainer = null;
        this.isShopOpen = false;

        // Player inventory reference
        this.playerInventory = null;
        this.playerZlatniki = 0;

        console.log('🛒 NPCShopSystem initialized');

        // Register all shops
        this.registerShops();

        // Create shop UI
        this.createShopUI();
    }

    /**
     * Register all NPC shops
     */
    registerShops() {
        const shops = [
            {
                id: 'blacksmith',
                name: 'Kovač (Blacksmith)',
                npc: 'Ivan the Blacksmith',
                icon: '⚒️',
                location: { x: 200, y: 200 },
                inventory: [
                    // Tools
                    { id: 'iron_axe', name: 'Iron Axe', price: 200, stock: 5, category: 'tools', locked: true },
                    { id: 'iron_pickaxe', name: 'Iron Pickaxe', price: 200, stock: 5, category: 'tools', locked: true },
                    { id: 'iron_hoe', name: 'Iron Hoe', price: 150, stock: 5, category: 'tools', locked: true },
                    { id: 'watering_can', name: 'Watering Can', price: 100, stock: 10, category: 'tools' },

                    // Weapons
                    { id: 'iron_sword', name: 'Iron Sword', price: 500, stock: 3, category: 'weapons', locked: true },
                    { id: 'steel_sword', name: 'Steel Sword', price: 1000, stock: 2, category: 'weapons', locked: true },
                    { id: 'crossbow', name: 'Crossbow', price: 800, stock: 2, category: 'weapons', locked: true },


                    // Armor
                    { id: 'leather_armor', name: 'Leather Armor', price: 300, stock: 5, category: 'armor' },
                    { id: 'iron_armor', name: 'Iron Armor', price: 800, stock: 3, category: 'armor' }
                ],
                buyback: ['iron_ore', 'steel_bar', 'scrap_metal']
            },
            {
                id: 'baker',
                name: 'Pekarica (Baker)',
                npc: 'Maria the Baker',
                icon: '🍞',
                location: { x: 250, y: 200 },
                inventory: [
                    // Food
                    { id: 'bread', name: 'Bread', price: 10, stock: 50, category: 'food' },
                    { id: 'cheese', name: 'Cheese', price: 20, stock: 30, category: 'food' },
                    { id: 'apple_pie', name: 'Apple Pie', price: 50, stock: 20, category: 'food' },
                    { id: 'cake', name: 'Cake', price: 100, stock: 10, category: 'food' },

                    // Recipes
                    { id: 'recipe_cookies', name: 'Cookie Recipe', price: 200, stock: 1, category: 'recipes' },
                    { id: 'recipe_pizza', name: 'Pizza Recipe', price: 300, stock: 1, category: 'recipes' },

                    // Ingredients
                    { id: 'flour', name: 'Flour', price: 15, stock: 100, category: 'ingredients' },
                    { id: 'sugar', name: 'Sugar', price: 20, stock: 80, category: 'ingredients' },
                    { id: 'yeast', name: 'Yeast', price: 10, stock: 50, category: 'ingredients' }
                ],
                buyback: ['wheat', 'milk', 'eggs', 'berries']
            },
            {
                id: 'trader',
                name: 'Trgovec (General Trader)',
                npc: 'Gregor the Trader',
                icon: '💰',
                location: { x: 300, y: 200 },
                inventory: [
                    // Seeds
                    { id: 'wheat_seeds', name: 'Wheat Seeds', price: 5, stock: 200, category: 'seeds' },
                    { id: 'corn_seeds', name: 'Corn Seeds', price: 8, stock: 150, category: 'seeds' },
                    { id: 'tomato_seeds', name: 'Tomato Seeds', price: 10, stock: 100, category: 'seeds' },
                    { id: 'strawberry_seeds', name: 'Strawberry Seeds', price: 15, stock: 80, category: 'seeds' },
                    { id: 'cannabis_seeds', name: 'Cannabis Seeds', price: 20, stock: 50, category: 'seeds' },

                    // Materials
                    { id: 'wood', name: 'Wood', price: 10, stock: 500, category: 'materials' },
                    { id: 'stone', name: 'Stone', price: 15, stock: 300, category: 'materials' },
                    { id: 'clay', name: 'Clay', price: 20, stock: 200, category: 'materials' },

                    // Special
                    { id: 'saddle', name: 'Saddle', price: 500, stock: 2, category: 'special' },
                    { id: 'bouquet', name: 'Bouquet', price: 100, stock: 10, category: 'special' },
                    { id: 'mermaid_pendant', name: 'Mermaid Pendant', price: 5000, stock: 1, category: 'special' }
                ],
                buyback: ['crops', 'foraged_items', 'fish']
            },
            {
                id: 'healer',
                name: 'Zdravnik (Healer)',
                npc: 'Dr. Ana Kovač',
                icon: '⚕️',
                location: { x: 350, y: 200 },
                inventory: [
                    // Potions
                    { id: 'health_potion', name: 'Health Potion', price: 50, stock: 50, category: 'potions' },
                    { id: 'stamina_potion', name: 'Stamina Potion', price: 40, stock: 50, category: 'potions' },
                    { id: 'antidote', name: 'Antidote', price: 30, stock: 30, category: 'potions' },
                    { id: 'cure_infection', name: 'Cure Infection', price: 200, stock: 10, category: 'potions' },

                    // Research
                    { id: 'cure_research_1', name: 'Cure Research Notes I', price: 1000, stock: 1, category: 'research' },
                    { id: 'cure_research_2', name: 'Cure Research Notes II', price: 2000, stock: 1, category: 'research' },

                    // Medical supplies
                    { id: 'bandage', name: 'Bandage', price: 15, stock: 100, category: 'medical' },
                    { id: 'medicine', name: 'Medicine', price: 80, stock: 30, category: 'medical' }
                ],
                buyback: ['herbs', 'mushrooms', 'zombie_samples', 'cannabis', 'cannabis_buds']
            }
        ];

        shops.forEach(shop => this.shops.set(shop.id, shop));

        console.log(`✅ Registered ${this.shops.size} NPC shops`);
    }

    /**
     * Create shop UI
     */
    createShopUI() {
        const width = this.scene.cameras.main.width;
        const height = this.scene.cameras.main.height;

        // Main container
        this.shopContainer = this.scene.add.container(width / 2, height / 2);
        this.shopContainer.setScrollFactor(0);
        this.shopContainer.setDepth(10000);
        this.shopContainer.setVisible(false);

        // Background
        const bg = this.scene.add.rectangle(0, 0, 900, 600, 0x1a1a1a, 0.95);
        bg.setStrokeStyle(3, 0xFFD700);
        this.shopContainer.add(bg);

        // Title (will be updated)
        this.shopTitle = this.scene.add.text(0, -280, '🛒 SHOP', {
            fontSize: '32px',
            fontFamily: 'Arial',
            color: '#FFD700',
            fontStyle: 'bold'
        });
        this.shopTitle.setOrigin(0.5);
        this.shopContainer.add(this.shopTitle);

        // Close button
        const closeBtn = this.scene.add.text(430, -280, '❌', {
            fontSize: '24px',
            cursor: 'pointer'
        });
        closeBtn.setInteractive();
        closeBtn.on('pointerdown', () => this.closeShop());
        this.shopContainer.add(closeBtn);

        // Player money display
        this.moneyText = this.scene.add.text(-430, -250, '💰 0 Zlatniki', {
            fontSize: '18px',
            fontFamily: 'Arial',
            color: '#FFD700'
        });
        this.shopContainer.add(this.moneyText);

        // Category tabs
        this.createCategoryTabs();

        // Item list container
        this.itemListContainer = this.scene.add.container(0, 0);
        this.shopContainer.add(this.itemListContainer);

        console.log('✅ Shop UI created');
    }

    /**
     * Create category tabs
     */
    createCategoryTabs() {
        const categories = ['all', 'tools', 'weapons', 'food', 'seeds', 'potions'];
        const tabWidth = 120;
        const startX = -400;
        const y = -200;

        categories.forEach((category, index) => {
            const tab = this.scene.add.rectangle(
                startX + (index * tabWidth),
                y,
                110, 40,
                0x2d2d2d
            );
            tab.setStrokeStyle(2, 0x666666);
            tab.setInteractive();
            tab.on('pointerdown', () => this.filterByCategory(category));

            const label = this.scene.add.text(
                startX + (index * tabWidth),
                y,
                category.toUpperCase(),
                {
                    fontSize: '14px',
                    fontFamily: 'Arial',
                    color: '#ffffff'
                }
            );
            label.setOrigin(0.5);

            this.shopContainer.add(tab);
            this.shopContainer.add(label);
        });
    }

    /**
     * Open shop
     */
    openShop(shopId) {
        const shop = this.shops.get(shopId);
        if (!shop) {
            console.error(`Shop ${shopId} not found!`);
            return false;
        }

        this.currentShop = shop;
        this.isShopOpen = true;

        // Update title
        this.shopTitle.setText(`${shop.icon} ${shop.name}`);

        // Update money
        this.updateMoneyDisplay();

        // Display items
        this.displayShopItems(shop.inventory);

        // Show container
        this.shopContainer.setVisible(true);

        console.log(`🛒 Opened ${shop.name}`);

        return true;
    }

    /**
     * Close shop
     */
    closeShop() {
        this.isShopOpen = false;
        this.currentShop = null;
        this.shopContainer.setVisible(false);

        console.log('🛒 Shop closed');
    }

    /**
     * Display shop items
     */
    displayShopItems(items, filter = 'all') {
        // Clear previous items
        this.itemListContainer.removeAll(true);

        // Filter items
        let filteredItems = items;
        if (filter !== 'all') {
            filteredItems = items.filter(item => item.category === filter);
        }

        // Display items (max 10 visible, scrollable)
        const itemHeight = 50;
        const startY = -150;

        filteredItems.slice(0, 10).forEach((item, index) => {
            const y = startY + (index * itemHeight);

            // Item background
            const itemBg = this.scene.add.rectangle(-400, y, 850, 45, 0x2d2d2d, 0.8);
            itemBg.setStrokeStyle(1, 0x444444);
            this.itemListContainer.add(itemBg);

            // Item name
            const nameText = this.scene.add.text(-380, y - 10, item.name, {
                fontSize: '16px',
                fontFamily: 'Arial',
                color: '#ffffff'
            });
            this.itemListContainer.add(nameText);

            // Stock
            const stockText = this.scene.add.text(-380, y + 10, `Stock: ${item.stock}`, {
                fontSize: '12px',
                fontFamily: 'Arial',
                color: '#888888'
            });
            this.itemListContainer.add(stockText);

            // Price
            const priceText = this.scene.add.text(200, y, `${item.price} Ž`, {
                fontSize: '18px',
                fontFamily: 'Arial',
                color: '#FFD700',
                fontStyle: 'bold'
            });
            priceText.setOrigin(0.5);
            this.itemListContainer.add(priceText);

            // Buy button
            const isLocked = item.locked && !this.isShopRestored(this.currentShop.id);
            const buyColor = isLocked ? 0x666666 : 0x228B22;
            const buyBtn = this.scene.add.rectangle(350, y, 100, 35, buyColor);
            buyBtn.setStrokeStyle(2, isLocked ? 0x999999 : 0x32CD32);
            buyBtn.setInteractive();
            buyBtn.on('pointerdown', () => {
                if (isLocked) {
                    this.showNotification({
                        title: 'Shop Ruined',
                        text: `Restore the shop to unlock this item!`,
                        icon: '🏚️'
                    });
                } else {
                    this.buyItem(item);
                }
            });
            this.itemListContainer.add(buyBtn);

            const buyText = this.scene.add.text(350, y, isLocked ? 'LOCKED' : 'BUY', {
                fontSize: '14px',
                fontFamily: 'Arial',
                color: '#ffffff',
                fontStyle: 'bold'
            });
            buyText.setOrigin(0.5);
            this.itemListContainer.add(buyText);
        });
    }

    isShopRestored(shopId) {
        if (!this.scene.townRestorationSystem) return true; // Fallback if system missing

        // Map shopId to buildingId
        const mapping = {
            'blacksmith': 'jakob_shop', // or whichever ID correctly matches TownRestorationSystem
            'baker': 'lena_bakery',
            'healer': 'dr_chen_clinic'
        };

        const buildingId = mapping[shopId];
        if (!buildingId) return true; // General trader is always open

        const building = this.scene.townRestorationSystem.buildings.get(buildingId);
        return building ? building.isRestored : false;
    }


    /**
     * Filter by category
     */
    filterByCategory(category) {
        if (!this.currentShop) return;
        this.displayShopItems(this.currentShop.inventory, category);
    }

    /**
     * Buy item
     */
    buyItem(item) {
        // Check stock
        if (item.stock <= 0) {
            this.showNotification({
                title: 'Out of Stock',
                text: `${item.name} is out of stock!`,
                icon: '📦'
            });
            return false;
        }

        // Calculate price with relationship discount
        const finalPrice = this.calculatePrice(item.price);

        // Check if player can afford
        if (this.playerZlatniki < finalPrice) {
            this.showNotification({
                title: 'Not Enough Money',
                text: `Need ${finalPrice}Ž to buy ${item.name}!`,
                icon: '💰'
            });
            return false;
        }

        // Purchase!
        this.playerZlatniki -= finalPrice;
        item.stock--;

        // TODO: Add item to player inventory
        console.log(`✅ Purchased: ${item.name} for ${finalPrice}Ž`);

        // Update UI
        this.updateMoneyDisplay();
        this.displayShopItems(this.currentShop.inventory);

        this.showNotification({
            title: 'Purchase Complete!',
            text: `Bought ${item.name} for ${finalPrice}Ž!`,
            icon: '✅'
        });

        return true;
    }

    /**
     * Calculate price with discounts
     */
    calculatePrice(basePrice) {
        // TODO: Apply relationship discounts
        // For now, return base price
        return basePrice;
    }

    /**
     * Update money display
     */
    updateMoneyDisplay() {
        this.moneyText.setText(`💰 ${this.playerZlatniki} Zlatniki`);
    }

    /**
     * Set player money
     */
    setPlayerMoney(amount) {
        this.playerZlatniki = amount;
        this.updateMoneyDisplay();
    }

    /**
     * Get shop info
     */
    getShopInfo(shopId) {
        return this.shops.get(shopId);
    }

    /**
     * Get all shops
     */
    getAllShops() {
        return Array.from(this.shops.values());
    }

    /**
     * Restock shop
     */
    restockShop(shopId) {
        const shop = this.shops.get(shopId);
        if (!shop) return false;

        shop.inventory.forEach(item => {
            item.stock = Math.min(item.stock + 5, 100); // Restock +5, max 100
        });

        console.log(`📦 ${shop.name} restocked!`);
        return true;
    }

    /**
     * Helper: Show notification
     */
    showNotification(notification) {
        console.log(`📢 ${notification.icon} ${notification.title}: ${notification.text}`);

        const ui = this.scene.scene.get('UIScene');
        if (ui && ui.showNotification) {
            ui.showNotification(notification);
        }
    }
}