import { type ClassValue, clsx } from 'clsx';
import { twMerge } from 'tailwind-merge';

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

/** Coerce API money fields (number | "199.00" | null) to a finite number. */
export function parseMoney(value: unknown): number {
  if (typeof value === 'number') return Number.isFinite(value) ? value : 0;
  if (typeof value === 'string') {
    const cleaned = value.trim().replace(/,/g, '');
    if (!cleaned) return 0;
    const n = Number(cleaned);
    return Number.isFinite(n) ? n : 0;
  }
  return 0;
}

export type CatalogPriceInfo = {
  price: number;
  priceMax?: number;
  oldPrice?: number;
  discount?: number;
};

/**
 * Resolve display price from either full ProductResponse (variants)
 * or list ProductCardResponse (top-level price / compare_price).
 */
export function getCatalogPriceInfo(product: {
  price?: unknown;
  compare_price?: unknown;
  discount_percent?: unknown;
  variants?: Array<{ price?: unknown; compare_price?: unknown }> | null;
}): CatalogPriceInfo {
  const variants = product.variants || [];
  const prices = variants.map((v) => parseMoney(v.price)).filter((n) => n > 0);
  const compares = variants
    .map((v) => parseMoney(v.compare_price))
    .filter((n) => n > 0);

  let price = prices.length ? Math.min(...prices) : 0;
  const priceMax = prices.length > 1 ? Math.max(...prices) : undefined;
  let oldPrice = compares.length ? Math.max(...compares) : undefined;

  // List/card endpoints expose price on the product, not variants
  if (!price) price = parseMoney(product.price);
  if (!oldPrice) {
    const compare = parseMoney(product.compare_price);
    if (compare > 0) oldPrice = compare;
  }

  let discount: number | undefined;
  if (price && oldPrice && oldPrice > price) {
    discount = Math.round(((oldPrice - price) / oldPrice) * 100);
  } else {
    const pct = parseMoney(product.discount_percent);
    if (pct > 0) discount = Math.round(pct);
  }

  return {
    price,
    priceMax: priceMax && priceMax > price ? priceMax : undefined,
    oldPrice: oldPrice && oldPrice > price ? oldPrice : undefined,
    discount,
  };
}

export function formatCatalogPriceLabel(product: {
  price?: unknown;
  compare_price?: unknown;
  variants?: Array<{ price?: unknown; compare_price?: unknown }> | null;
}): string {
  const { price, priceMax } = getCatalogPriceInfo(product);
  if (!price) return formatCurrency(0);
  if (priceMax && priceMax > price) {
    return `${formatCurrency(price)} – ${formatCurrency(priceMax)}`;
  }
  return formatCurrency(price);
}

export function formatCurrency(amount: number | string, currency = 'INR'): string {
  return new Intl.NumberFormat('en-IN', {
    style: 'currency',
    currency: 'INR',
    maximumFractionDigits: 2,
  }).format(parseMoney(amount));
}

export function getImageUrl(path?: string | null | unknown): string {
  let resolvedPath: string;
  if (typeof path === 'string') {
    resolvedPath = path;
  } else if (path && typeof path === 'object') {
    const obj = path as Record<string, unknown>;
    resolvedPath = String(obj.image_url ?? obj.url ?? obj.src ?? '');
  } else {
    return '/images/placeholder-product.webp';
  }

  if (!resolvedPath || resolvedPath === 'null' || resolvedPath === 'undefined') {
    return '/images/placeholder-product.webp';
  }

  const trimmed = resolvedPath.trim();
  if (!trimmed) return '/images/placeholder-product.webp';

  if (
    trimmed.startsWith('http://') ||
    trimmed.startsWith('https://') ||
    trimmed.startsWith('data:') ||
    trimmed.startsWith('blob:')
  ) {
    return trimmed;
  }

  let cleanPath = trimmed.startsWith('/') ? trimmed : `/${trimmed}`;

  // Local storefront static assets (e.g. /images/placeholder-product.webp, /icons/...)
  if (
    cleanPath.startsWith('/images/') ||
    cleanPath.startsWith('/icons/') ||
    cleanPath.startsWith('/assets/') ||
    cleanPath.startsWith('/_next/')
  ) {
    return cleanPath;
  }

  // Normalize relative upload paths (/uploads/product/..., product/..., uploads/product/...)
  if (cleanPath.startsWith('/product/')) {
    cleanPath = `/uploads${cleanPath}`;
  } else if (!cleanPath.startsWith('/uploads/')) {
    const withoutLeadingSlash = cleanPath.replace(/^\//, '');
    if (withoutLeadingSlash.startsWith('uploads/')) {
      cleanPath = `/${withoutLeadingSlash}`;
    } else if (withoutLeadingSlash.startsWith('product/')) {
      cleanPath = `/uploads/${withoutLeadingSlash}`;
    }
  }

  const backendUrl =
    process.env.NEXT_PUBLIC_API_URL || 'https://ifixkartbe.trionixsolution.com';

  return `${backendUrl.replace(/\/$/, '')}${cleanPath}`;
}