/**
 * Global State Management
 * Centralized state for cart, wishlist, and user preferences
 */

(function () {
  "use strict";

  class StateManager {
    constructor() {
      this.state = {
        cart: [],
        wishlist: [],
        user: null,
        preferences: {},
      };
      this.listeners = {};
      this.init();
    }

    init() {
      this.loadFromStorage();
      this.setupStorageSync();
    }

    loadFromStorage() {
      try {
        this.state.cart = JSON.parse(localStorage.getItem("cart") || "[]");
        this.state.wishlist = JSON.parse(
          localStorage.getItem("wishlist") || "[]"
        );
        this.state.preferences = JSON.parse(
          localStorage.getItem("preferences") || "{}"
        );
      } catch (e) {
        console.error("State load error:", e);
      }
    }

    saveToStorage() {
      try {
        localStorage.setItem("cart", JSON.stringify(this.state.cart));
        localStorage.setItem("wishlist", JSON.stringify(this.state.wishlist));
        localStorage.setItem(
          "preferences",
          JSON.stringify(this.state.preferences)
        );
      } catch (e) {
        console.error("State save error:", e);
      }
    }

    setupStorageSync() {
      window.addEventListener("storage", (e) => {
        if (e.key === "cart" || e.key === "wishlist") {
          this.loadFromStorage();
          this.emit("stateChanged", { key: e.key });
        }
      });
    }

    // Cart methods
    addToCart(product, quantity = 1) {
      const existing = this._findById(this.state.cart, product.id);

      if (existing) {
        existing.quantity += quantity;
      } else {
        this.state.cart.push({
          ...product,
          quantity,
          addedAt: Date.now(),
        });
      }

      this._updateState("cart");
      return this.state.cart;
    }

    removeFromCart(productId) {
      this.state.cart = this.state.cart.filter(
        (item) => String(item.id) !== String(productId)
      );
      this._updateState("cart");
      return this.state.cart;
    }

    updateCartQuantity(productId, quantity) {
      const item = this._findById(this.state.cart, productId);
      if (item) {
        item.quantity = Math.max(0, quantity);
        if (item.quantity === 0) {
          return this.removeFromCart(productId);
        }
        this._updateState("cart");
      }
      return this.state.cart;
    }

    getCart() {
      return this.state.cart;
    }

    getCartTotal() {
      return this._calculateTotal(this.state.cart);
    }

    getCartCount() {
      return this._calculateCount(this.state.cart);
    }

    clearCart() {
      this.state.cart = [];
      this._updateState("cart");
    }

    // Wishlist methods
    addToWishlist(product) {
      const exists = this.state.wishlist.find((item) => item.id === product.id);

      if (!exists) {
        this.state.wishlist.push({
          ...product,
          addedAt: Date.now(),
        });
        this.saveToStorage();
        this.emit("wishlistUpdated", this.state.wishlist);
        return true;
      }
      return false;
    }

    removeFromWishlist(productId) {
      this.state.wishlist = this.state.wishlist.filter(
        (item) => item.id !== productId
      );
      this.saveToStorage();
      this.emit("wishlistUpdated", this.state.wishlist);
      return this.state.wishlist;
    }

    getWishlist() {
      return this.state.wishlist;
    }

    isInWishlist(productId) {
      return this.state.wishlist.some((item) => item.id === productId);
    }

    // Event system
    on(event, callback) {
      if (!this.listeners[event]) {
        this.listeners[event] = [];
      }
      this.listeners[event].push(callback);
    }

    off(event, callback) {
      if (this.listeners[event]) {
        this.listeners[event] = this.listeners[event].filter(
          (cb) => cb !== callback
        );
      }
    }

    emit(event, data) {
      if (this.listeners[event]) {
        this.listeners[event].forEach((callback) => {
          try {
            callback(data);
          } catch (e) {
            console.error(`Error in ${event} listener:`, e);
          }
        });
      }
    }

    // Helper methods
    _findById(collection, id) {
      return collection.find((item) => String(item.id) === String(id));
    }

    _updateState(type) {
      this.saveToStorage();
      this.emit(`${type}Updated`, this.state[type]);
    }

    _calculateTotal(items) {
      return items.reduce((sum, item) => {
        const price = parseFloat(item.price) || 0;
        const quantity = parseInt(item.quantity) || 0;
        return sum + price * quantity;
      }, 0);
    }

    _calculateCount(items) {
      return items.reduce((sum, item) => {
        const quantity = parseInt(item.quantity) || 0;
        return sum + quantity;
      }, 0);
    }
  }

  // Create global instance
  window.StateManager = window.StateManager || new StateManager();

  // Expose helper functions for backward compatibility
  window.addToCart = function (productId, name, price, imageurl) {
    const product = { id: productId, name, price: parseFloat(price), imageurl };
    window.StateManager.addToCart(product, 1);
    if (window.showNotification) {
      window.showNotification(`${name} added to cart!`, "success");
    }
  };

  window.addToWishlist = function (productId, name, price, imageurl) {
    const product = { id: productId, name, price: parseFloat(price), imageurl };
    const added = window.StateManager.addToWishlist(product);
    if (window.showNotification) {
      window.showNotification(
        added ? `${name} added to wishlist!` : "Already in wishlist!",
        added ? "success" : "info"
      );
    }
  };

  // Update badges on state changes
  window.StateManager.on("cartUpdated", () => {
    const badges = document.querySelectorAll(".cart-badge, #cartCount");
    const count = window.StateManager.getCartCount();
    badges.forEach((badge) => {
      if (badge) {
        badge.textContent = count;
        if (count > 0) {
          badge.classList.add("show");
        } else {
          badge.classList.remove("show");
        }
      }
    });
  });

  window.StateManager.on("wishlistUpdated", () => {
    const badges = document.querySelectorAll(".wishlist-badge, #wishlistCount");
    const count = window.StateManager.getWishlist().length;
    badges.forEach((badge) => {
      if (badge) {
        badge.textContent = count;
        if (count > 0) {
          badge.classList.add("show");
        } else {
          badge.classList.remove("show");
        }
      }
    });
  });

  // Initialize badges
  if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", () => {
      window.StateManager.emit("cartUpdated");
      window.StateManager.emit("wishlistUpdated");
    });
  } else {
    window.StateManager.emit("cartUpdated");
    window.StateManager.emit("wishlistUpdated");
  }
})();