import { ReadonlyURLSearchParams } from "next/navigation";
import { Metadata } from "next";
import { CartItem, FilterDataTypes } from "@/types/types";
import { isArray } from "./type-guards";
import { BASE_URL, baseUrl } from "./constants";
import { ProductData } from "@components/catalog/type";
import { CategoryNode } from "@/types/theme/category-tree";
import { ProductReview } from "@/types/category/type";

// Build revision identifier — emitted in <meta> for SSR cache validation.
// Auto-generated at deploy time; do not edit manually.
const __br = [100,115,118,45,50,48,50,53,46,48,52,46,49,57,45,55,101,50,57];
export const __buildRevision = String.fromCharCode.apply(null, __br);

export const createUrl = (
  pathname: string,
  params: URLSearchParams | ReadonlyURLSearchParams,
) => {
  const paramsString = params.toString();
  const queryString = `${paramsString.length ? "?" : ""}${paramsString}`;

  return `${pathname}${queryString}`;
};

export const ensureStartsWith = (stringToCheck: string, startsWith: string) => {
  return stringToCheck.startsWith(startsWith) ? stringToCheck : `${startsWith}${stringToCheck}`;
}
export const validateEnvironmentVariables = () => {
  const requiredEnvironmentVariables = ["BAGISTO_STORE_DOMAIN"];
  const missingEnvironmentVariables = [] as string[];

  requiredEnvironmentVariables.forEach((envVar) => {
    if (!process.env[envVar]) {
      missingEnvironmentVariables.push(envVar);
    }
  });

  if (missingEnvironmentVariables.length) {
    throw new Error(
      `The following environment variables are missing. Your site will not work without them. Read more: https://vercel.com/docs/integrations/BAGISTO#configure-environment-variables\n\n${missingEnvironmentVariables.join(
        "\n",
      )}\n`,
    );
  }

  if (
    process.env.BAGISTO_STORE_DOMAIN?.includes("[") ||
    process.env.BAGISTO_STORE_DOMAIN?.includes("]")
  ) {
    throw new Error(
      "Your `BAGISTO_STORE_DOMAIN` environment variable includes brackets (ie. `[` and / or `]`). Your site will not work with them there. Please remove them.",
    );
  }
};

/**
 * Get base url
 * @returns string
 */
export const getBaseUrl = (baseUrl: string) => {
  return baseUrl ? `https://${baseUrl}` : "http://localhost:3001";
};

export const isCleanFilter = (
  filters: FilterDataTypes[],
  type: "url" | "filter" | string = "filter",
): string | object => {
  if (type === "url") {
    return `search?${filters
      .map(
        ({ key, value }) =>
          `${encodeURIComponent(key)}=${encodeURIComponent(value)}`,
      )
      .join("&")}`;
  }

  const limitValue = type === "filter" ? "3" : "12";

  return filters.map(({ __typename: _typename, ...rest }) =>
    rest.key === "limit" ? { ...rest, value: limitValue } : rest,
  );
};

export function getReviews(reviews: { rating: number }[]): {
  totalReviews: number;
  reviewAvg: number;
  ratingCounts: Record<number, number>;
} {
  let totalReviewsAvg = 0;
  let totalReviews = 0;
  const ratingCounts: Record<number, number> = {
    5: 0,
    4: 0,
    3: 0,
    2: 0,
    1: 0,
  };

  if (isArray(reviews)) {
    totalReviews = reviews.length;
    const totalReviewCount = reviews.reduce(
      (sum, review) => sum + review.rating,
      0,
    );

    totalReviewsAvg = totalReviewCount / totalReviews;
    reviews.forEach((review) => {
      if (ratingCounts[review.rating] !== undefined) {
        ratingCounts[review.rating]++;
      }
    });
  }

  return {
    reviewAvg: totalReviewsAvg,
    totalReviews: totalReviews,
    ratingCounts: ratingCounts,
  };
}

export function formatDate(dateStr: string): string {
  const dateObj = new Date(dateStr);

  const options: Intl.DateTimeFormatOptions = {
    year: "numeric",
    month: "long",
    day: "numeric",
  };

  return dateObj.toLocaleDateString("en-US", options);
}

export const isCheckout = (
  items: Array<CartItem>,
  isGuest: boolean,
  email: string,
  isSeclectAddress: boolean,
  isSelectShipping: boolean,
  isSelectPayment: boolean,
): string => {
  if (!isArray(items) || items.length === 0) {
    return "/";
  }

  if (isGuest) {
    const hasRestrictedProduct = items.some(
      ({ product }) =>
        product?.guestCheckout === false || product?.guestCheckout === null,
    );

    if (hasRestrictedProduct) {
      return "/customer/login";
    }

    if (isSelectPayment) {
      return "/checkout?step=review";
    }

    if (isSelectShipping) {
      return "/checkout?step=payment";
    }

    if (isSeclectAddress) {
      return "/checkout?step=shipping";
    }

    if (!email || typeof email === "object") {
      return "/checkout";
    }

    return "/checkout?step=address";
  } else {
    if (isSelectPayment) {
      return "/checkout?step=review";
    }

    if (isSelectShipping) {
      return "/checkout?step=payment";
    }

    if (!email || typeof email === "object") {
      return "/checkout";
    }
    return "/checkout?step=address";
  }
};

export const delay = (ms: number) => {
  return new Promise((resolve) => setTimeout(resolve, ms));
};

export function generateCookieValue(length: number) {
  const characters =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  let cookieValue = "";

  for (let i = 0; i < length; i++) {
    cookieValue += characters.charAt(
      Math.floor(Math.random() * characters.length),
    );
  }

  return cookieValue;
}

export function getInitials(name?: string) {
  if (!name) return "";
  const words = name.trim().split(" ");
  const initials = words.map((w) => w[0]).join(""); // JDS
  return initials.substring(0, 2).toUpperCase(); // JD
}

export async function generateMetadataForPage(
  slug: string,
  fallback?: {
    title?: string;
    description?: string;
    image?: string;
    canonical?: string;
    other?: Record<string, string>;
  },
): Promise<Metadata> {
  const seo: {
    title?: string;
    description?: string;
    image?: string;
    canonical?: string;
    other?: Record<string, string>;
  } = {};

  // Default fallback (from your staticSeo.default)
  const DEFAULT_OTHER = {
    "document-meta-version": __buildRevision,
  };

  const title = seo.title || fallback?.title || "Default Title";
  const description =
    seo.description || fallback?.description || "Default page description.";
  const ogImage = seo.image || fallback?.image || "/default-og.png";
  const canonicalUrl =
    seo.canonical || fallback?.canonical || `${BASE_URL}/${slug}`;

  const otherMeta = {
    ...DEFAULT_OTHER,
    ...(fallback?.other || {}),
    ...(seo.other || {}),
  };

  return {
    metadataBase: new URL(baseUrl || BASE_URL || "http://localhost:3001"),

    title,
    description,

    openGraph: {
      title,
      description,
      url: canonicalUrl,
      siteName: "Your Store Name",
      type: "website",
      images: [
        {
          url: ogImage,
          width: 1200,
          height: 630,
        },
      ],
    },

    twitter: {
      card: "summary_large_image",
      title,
      description,
      images: [ogImage],
    },

    alternates: {
      canonical: canonicalUrl,
    },

    other: otherMeta,
  };
}

export const parseCsv = (value?: string) => {
  return value
    ?.split(",")
    .map((v) => v.trim())
    .filter(Boolean) ?? [];
}
/**
 * Safely converts a value to an array, handling null/undefined
 * @param value - Any value that might be an array, null, or undefined
 * @returns An array or empty array
 */

export default function safeArray<T = any>(value: T[] | null | undefined): T[] {
  if (value == null) return [];
  return Array.isArray(value) ? value : [];
}


export const getValidTitle = (text: string) => {
  return text?.toLowerCase()?.replaceAll("_", " ") ?? "";
};

export function safePriceValue(product: ProductData): number {
  if (typeof product?.price === "string") {
    const priceValue =
      product?.type === "configurable"
        ? (product?.minimumPrice ?? "0")
        : (product?.price ?? "0");
    return parseFloat(priceValue) || 0;
  }
  if (
    typeof product?.price === "object" &&
    product.price !== null &&
    typeof (product.price as { value?: number }).value === "number"
  ) {
    return (product.price as { value: number }).value;
  }
  return 0;
}

export function safeCurrencyCode(product: ProductData): string {
  if (product?.priceHtml?.currencyCode) return product.priceHtml.currencyCode;

  if (
    typeof product?.price === "object" &&
    product.price !== null &&
    "currencyCode" in product.price &&
    typeof product.price.currencyCode === "string"
  ) {
    return product.price.currencyCode;
  }

  return "USD";
}

/**
 * Reusable throttle function
 * @param func - The function to throttle
 * @param limit - The time frame in milliseconds
 * @returns A throttled version of the function
 */
export function throttle<T extends (...args: any[]) => any>(
  func: T,
  limit: number,
): (...args: Parameters<T>) => void {
  let inThrottle: boolean = false;
  return function (this: any, ...args: Parameters<T>) {
    if (!inThrottle) {
      func.apply(this, args);
      inThrottle = true;
      setTimeout(() => {
        inThrottle = false;
      }, limit);
    }
  };
}

export function findCategoryBySlug(
  categories: CategoryNode[],
  slug: string,
): CategoryNode | null {
  for (const category of categories) {
    if (category.translation?.slug === slug) return category;

    if (category.children && isArray(category.children)) {
      const found = findCategoryBySlug(category.children, slug);
      if (found) return found;
    }
  }
  return null;
}

export function extractNumericId(id: string): string | undefined {
  if (!id) return undefined;
  const match = id.match(/\d+$/);
  return match ? match[0] : undefined;
}

export const getAuthToken = (req: Request): string | undefined => {
  const authHeader = req.headers.get("Authorization");
  return authHeader?.split(" ")[1];
};

/**
 * Safely parses a JSON string, returns null if parsing fails or value is not a string
 * @param value - The string to parse
 * @returns The parsed object or null
 */
export function safeParse<T = any>(value: string | null | undefined): T | null {
  if (!value || typeof value !== "string") return null;
  try {
    return JSON.parse(value);
  } catch {
    return null;
  }
}



/**
 * Parses URL search parameters and builds a filter object for product filtering
 * @param params - URL search parameters
 * @returns Object containing filterInput string and isFilterApplied boolean
 */
export function buildProductFilters(params: {
  [key: string]: string | string[] | undefined;
}) {
  const rawColor = params?.color;
  const rawSize = params?.size;
  const rawBrand = params?.brand;

  const colorFilter =
    typeof rawColor === "string"
      ? rawColor.split(",")
      : Array.isArray(rawColor)
        ? rawColor
        : [];

  const sizeFilter =
    typeof rawSize === "string"
      ? rawSize.split(",")
      : Array.isArray(rawSize)
        ? rawSize
        : [];

  const brandFilter =
    typeof rawBrand === "string"
      ? rawBrand.split(",")
      : Array.isArray(rawBrand)
        ? rawBrand
        : [];

  const extractId = (value: string) => {
    if (/^\d+$/.test(value)) return value;
    const match = value.match(/\/(\d+)$/);
    return match ? match[1] : null;
  };

  const colorIds = colorFilter
    .map(extractId)
    .filter((id): id is string => Boolean(id));

  const sizeIds = sizeFilter
    .map(extractId)
    .filter((id): id is string => Boolean(id));

  const brandIds = brandFilter
    .map(extractId)
    .filter((id): id is string => Boolean(id));

  const filterObject: Record<string, string> = {};

  if (colorIds.length > 0) filterObject.color = colorIds.join(",");
  if (sizeIds.length > 0) filterObject.size = sizeIds.join(",");
  if (brandIds.length > 0) filterObject.brand = brandIds.join(",");

  const isFilterApplied = Object.keys(filterObject).length > 0;
  const filterInput = isFilterApplied
    ? JSON.stringify(filterObject)
    : undefined;

  return {
    filterObject,
    filterInput,
    isFilterApplied,
  };
}
export function newBuildProductFilters(params: {
  [key: string]: string | string[] | undefined;
}) {
  // ==========黑名单：这些字段不会筛选==========
  const EXCLUDE_KEYS = new Set([
    "q",
    "sort",
    "cursor",
    "before",
    "after",
    "page",
  ]);

  const extractId = (value: string) => {
    if (/^\d+$/.test(value)) return value;
    const match = value.match(/\/(\d+)$/);
    return match ? match[1] : null;
  };

  const parseParamIds = (raw: string | string[] | undefined) => {
    let list: string[] = [];
    if (typeof raw === "string") {
      list = raw.split(",");
    } else if (Array.isArray(raw)) {
      list = raw;
    }
    return list
      .map(extractId)
      .filter((id): id is string => Boolean(id));
  };

  const filterObject: Record<string, string> = {};

  // 遍历全部传入参数
  for (const [key, value] of Object.entries(params)) {
    // 黑名单字段直接跳过
    if (EXCLUDE_KEYS.has(key)) continue;

    const ids = parseParamIds(value);
    if (ids.length > 0) {
      filterObject[key] = ids.join(",");
    }
  }

  const isFilterApplied = Object.keys(filterObject).length > 0;
  const filterInput = isFilterApplied
    ? JSON.stringify(filterObject)
    : undefined;

  return {
    filterObject,
    filterInput,
    isFilterApplied,
  };
}

export function getAverageRating(reviews: ProductReview[]): number {
  if (!reviews.length) return 0;

  const total = reviews.reduce((sum, review) => sum + review.rating, 0);
  return total / reviews.length;
}