import { HttpService } from "@ribajs/core";
import { EventDispatcher } from "@ribajs/events";
import { isObject, clone, getNumber } from "@ribajs/utils/src/type.js";
import { PQueue } from "./p-queue.service.js"; // https://github.com/sindresorhus/p-queue

import {
  ShopifyCartLineItem,
  ShopifyCartUpdateProperty,
  ShopifyCartAddError,
  ShopifyCartObject,
  ShopifyCustomerAddress,
  ShopifyShippingRates,
  ShopifyShippingRate,
  ShopifyShippingRatesNormalized,
} from "../interfaces/index.js";

export interface ShopifyCartRequestOptions {
  triggerOnStart: boolean;
  triggerOnComplete: boolean;
  triggerOnChange: boolean;
}

export class ShopifyCartService {
  public static queue = new PQueue({ concurrency: 1 });

  public static cart: ShopifyCartObject | null = null;

  public static shopifyCartEventDispatcher = new EventDispatcher("ShopifyCart");

  /**
   * Use this method to force an update of the shopping cart object, e.g. if the shopping cart was updated outside Riba.
   * @param options
   */
  public static async updateExtern(
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ) {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }

    const newCart = await this.refresh();
    const oldCart = this.cart;
    this.cart = newCart;

    if (options.triggerOnChange) {
      if (
        oldCart?.total_price !== newCart?.total_price ||
        oldCart?.item_count !== oldCart?.item_count
      ) {
        this.triggerOnChange(this.cart);
      }
    }

    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
  }

  /**
   * Use this to add a variant to the cart.
   * @param id Variant id
   * @param quantity Quantity
   * @param properties Additional properties
   * @return Response if successful, the JSON of the line item associated with the added variant.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#add-to-cart
   */
  public static async add(
    id: number,
    quantity = 1,
    properties = {},
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartLineItem | ShopifyCartAddError> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(async () => {
      const body: any = { id, quantity };
      if (Object.keys(properties).length !== 0) {
        body.properties = properties;
      }
      const lineItemRes = await HttpService.post<
        ShopifyCartLineItem | ShopifyCartAddError
      >(this.CART_POST_ADD_URL, body, "json");

      if (lineItemRes.status >= 400) {
        throw lineItemRes.body as ShopifyCartAddError;
      }

      const lineItem = lineItemRes.body;

      // Force update cart object
      const cartRes = await HttpService.get<ShopifyCartObject>(
        this.CART_GET_URL,
        {},
        "json",
      );

      if (cartRes.status >= 400) {
        throw lineItemRes.body as ShopifyCartAddError;
      }

      const cart = cartRes.body;
      if (options.triggerOnChange) {
        this.triggerOnChange(cart);
      }
      this.triggerAdd(id, quantity, properties);
      return lineItem; // return original response
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  public static async refresh(): Promise<ShopifyCartObject> {
    const cartRes = await HttpService.get<ShopifyCartObject>(
      this.CART_GET_URL,
      {},
      "json",
    );

    let cart: ShopifyCartObject;

    if (typeof cartRes.body === "string") {
      cart = JSON.parse(cartRes.body);
    } else {
      cart = cartRes.body;
    }

    return cart;
  }

  public static _get(): Promise<ShopifyCartObject> {
    if (ShopifyCartService.cart !== null) {
      return new Promise((resolve /*, reject*/) => {
        setTimeout(() => {
          if (ShopifyCartService.cart !== null) {
            return resolve(ShopifyCartService.cart);
          } else {
            return this._get();
          }
        }, 0);
      });
    }
    return ShopifyCartService.refresh();
  }

  /**
   * Use this to get the cart as JSON.
   * @param data
   * @return The JSON of the cart.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#get-cart
   */
  public static get(
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(() => {
      return this._get();
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  /**
   * Use this to change cart attributes, the cart note, and quantities of line items in the cart.
   * @param id Variant ID
   * @param quantity Quantity
   * @param properties Additional properties
   * @return Response The JSON of the cart.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#update-cart
   */
  public static update(
    id: number | number,
    quantity: number,
    properties = {},
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue
      .add(() => {
        const body: any = { id, quantity };
        if (Object.keys(properties).length !== 0) {
          body.properties = properties;
        }
        return HttpService.post(this.CART_POST_UPDATE_URL, body, "form");
      })
      // because type is form we need to parse the json response by self
      .then((cart: string) => {
        return JSON.parse(cart);
      })
      .then((cart: ShopifyCartObject) => {
        if (options.triggerOnChange) {
          this.triggerOnChange(cart);
        }
        return cart;
      });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  /**
   * Use this to change cart attributes, the cart note, and quantities of line items in the cart.
   * @param id Variant ID
   * @param quantity Quantity
   * @param properties Additional properties
   * @return Response The JSON of the cart.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#update-cart
   */
  public static updates(
    updates: ShopifyCartUpdateProperty | Array<number>,
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue
      .add(() => {
        return HttpService.post(
          this.CART_POST_UPDATE_URL,
          {
            updates,
          },
          "form",
        );
      })
      // because type is form we need to parse the json response by self
      .then((cart: string) => {
        return JSON.parse(cart);
      })
      .then((cart: ShopifyCartObject) => {
        if (options.triggerOnChange) {
          this.triggerOnChange(cart);
        }
        return cart;
      });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  /**
   * This call sets the quantity of an item already in the cart.
   *
   * Although /cart/update.js and /cart/change.js may seem like they accomplish the same function,
   * they truly are quite different. The /cart/update.js controller allows updates to several items
   * at once, including items that may not yet be in the cart (it will add them), and it also allows
   * updates of cart attributes and the cart note. The /cart/change.js controller is only able to
   * update the quantity of one item at a time, and that item must be in the cart already. If the
   * item is not in the cart, /cart/change.js will not add it and it will then return a 404 error.
   * Whereas the /cart/update.js controller updates no quantity when any of the requested update
   * cannot be met, the /cart/change.js controller, on the other hand, will adjust the quantity to
   * add all items in stock if what is requested is greater than what's available. Use your browser's
   * JavaScript console to test things out if you're not sure about the behavior of the different request URLs.
   *
   * @param id Variant ID
   * @param quantity Quantity
   * @param properties Additional properties
   * @return Response The JSON of the cart.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#change-cart
   */
  public static async change(
    id: number | number,
    quantity: number,
    properties = {},
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(async () => {
      const body: any = { id, quantity };
      if (Object.keys(properties).length !== 0) {
        body.properties = properties;
      }

      const cartRes = await HttpService.post<ShopifyCartObject | string>(
        this.CART_POST_CHANGE_URL,
        body,
        "form",
      );

      let cart: ShopifyCartObject;

      // Because type is form we need to parse the json response by self
      if (typeof cartRes.body === "string") {
        cart = JSON.parse(cartRes.body);
      } else {
        cart = cartRes.body;
      }

      if (options.triggerOnChange) {
        this.triggerOnChange(cart);
      }

      return cart;
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  /**
   * If you use Line Item Properties you may end up with several items in the cart that share the same variant ID.
   * How do you update the quantity of an item in the cart that has specific line item properties?
   * Once you have identified the 1-based index of the item in the cart, you can use the line property instead of id.
   * @param line -based index of the item in the cart
   * @param quantity Quantity
   * @param properties Additional properties
   * @return Response The JSON of the cart.
   */
  public static async changeLine(
    line: string | number,
    quantity: number,
    properties = {},
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(async () => {
      const body: any = { line, quantity };
      if (Object.keys(properties).length !== 0) {
        body.properties = properties;
      }
      const cartRes = await HttpService.post<ShopifyCartObject | string>(
        this.CART_POST_CHANGE_URL,
        body,
        "form",
      );

      let cart: ShopifyCartObject;

      // Because type is form we need to parse the json response by self
      if (typeof cartRes.body === "string") {
        cart = JSON.parse(cartRes.body);
      } else {
        cart = cartRes.body;
      }

      if (options.triggerOnChange) {
        this.triggerOnChange(cart);
      }

      return cart;
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise as Promise<ShopifyCartObject>;
  }

  /**
   * This call sets all quantities of all line items in the cart to zero.
   * @return The JSON of an empty cart. This does not remove cart attributes nor the cart note.
   * @return Response The JSON of an empty cart. This does not remove cart attributes nor the cart note.
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#clear-cart
   */
  public static async clear(
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyCartObject> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(async () => {
      const cartRes = await HttpService.post<ShopifyCartObject>(
        this.CART_POST_CLEAR_URL,
        {},
        "form",
      );
      let cart: ShopifyCartObject;

      // Because type is form we need to parse the json response by self
      if (typeof cartRes.body === "string") {
        cart = JSON.parse(cartRes.body);
      } else {
        cart = cartRes.body;
      }

      if (options.triggerOnChange) {
        this.triggerOnChange(cart);
      }

      return cart;
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  public static async _getShippingRates(
    shippingAddress: ShopifyCustomerAddress,
    normalize = true,
  ): Promise<ShopifyShippingRates | ShopifyShippingRatesNormalized> {
    const res = await HttpService.get<{ shipping_rates: ShopifyShippingRates }>(
      this.CART_GET_SHIPPING_RATES_URL,
      { shipping_address: shippingAddress },
      "json",
    );

    const shippingRates = res.body;

    if (isObject(shippingRates) && isObject(shippingRates.shipping_rates)) {
      if (normalize) {
        return this.normalizeShippingRates(shippingRates.shipping_rates);
      }
      return shippingRates.shipping_rates as ShopifyShippingRates;
    } else {
      throw new Error(
        "shipping_rates property not found: " + JSON.stringify(shippingRates),
      );
    }
  }

  /**
   * Get estimated shipping rates.
   * @param shippingAddress TODO: /cart/shipping_rates.json?shipping_address[zip]=K1N 5T2&shipping_address[country]=Canada&shipping_address[province]=Ontario
   * @see https://help.shopify.com/en/themes/development/getting-started/using-ajax-api#get-shipping-rates
   */
  public static getShippingRates(
    shippingAddress: ShopifyCustomerAddress,
    normalize = true,
    options: ShopifyCartRequestOptions = this.requestOptionDefaults,
  ): Promise<ShopifyShippingRates | ShopifyShippingRatesNormalized> {
    if (options.triggerOnStart) {
      this.triggerOnStart();
    }
    const promise = this.queue.add(() => {
      return this._getShippingRates(shippingAddress, normalize);
    });
    if (options.triggerOnComplete) {
      this.triggerOnComplete();
    }
    return promise;
  }

  protected static CART_POST_ADD_URL = "/cart/add.js";

  protected static CART_GET_URL = "/cart.js";

  protected static CART_POST_UPDATE_URL = "/cart/update.js";

  protected static CART_POST_CHANGE_URL = "/cart/change.js";

  protected static CART_POST_CLEAR_URL = "/cart/clear.js";

  protected static CART_GET_SHIPPING_RATES_URL = "/cart/shipping_rates.json";

  protected static requestOptionDefaults = {
    triggerOnStart: true,
    triggerOnComplete: true,
    triggerOnChange: true,
  };

  protected static waitForComplete = false;

  /**
   * Trigger `ShopifyCart:request:complete`, if queue is already pending no noting (in this case we already looking for onIdle)
   */
  protected static triggerOnComplete() {
    if (!this.waitForComplete) {
      this.waitForComplete = true;
      return this.queue.onIdle().then(() => {
        ShopifyCartService.shopifyCartEventDispatcher.trigger(
          "ShopifyCart:request:complete",
          this.cart,
        );
        this.waitForComplete = false;
      });
    }
  }

  /**
   * TODO check if cart values are changed
   * @param cart The cart object
   */
  protected static triggerOnChange(cart: ShopifyCartObject) {
    this.cart = cart;
    ShopifyCartService.shopifyCartEventDispatcher.trigger(
      "ShopifyCart:request:changed",
      this.cart,
    );
  }

  /**
   * Trigger `ShopifyCart:request:start`, if not already triggered
   */
  protected static triggerOnStart() {
    if (this.queue.pending > 0) {
      return;
    }
    ShopifyCartService.shopifyCartEventDispatcher.trigger(
      "ShopifyCart:request:start",
    );
  }

  /**
   * Trigger `ShopifyCart:add`
   */
  protected static triggerAdd(id: number, quantity: number, properties: any) {
    ShopifyCartService.shopifyCartEventDispatcher.trigger("ShopifyCart:add", {
      id,
      quantity,
      properties,
    });
  }

  protected static normalizeShippingRates(
    shippingRates: ShopifyShippingRates,
  ): ShopifyShippingRatesNormalized {
    const normalized = new Array<any>(shippingRates.length);
    for (const i in shippingRates) {
      if (shippingRates[i]) {
        const shippingRate = shippingRates[i];
        normalized[i] = clone<ShopifyShippingRate>(false, shippingRate);
        if (normalized[i] && normalized[i].price) {
          normalized[i].price = getNumber(normalized[i].price);
          if (normalized[i].price) {
            normalized[i].price *= 100;
          } else {
            console.warn(`Can't parse "${normalized[i].price}" to number`);
          }
        } else {
          console.warn(`price property not defined`, normalized[i]);
        }
      }
    }
    return normalized as ShopifyShippingRatesNormalized;
  }
}