import { parseMetadata, resolveIsActive } from '@/lib/layoutConfig';
import { detectProductKind, type CompareKind } from '@/lib/compareSpecs';

export type PdpFact = { label: string; value: string };
export type PdpTrustBadge = { title: string; icon?: string };

const FACT_PRIORITY = [
  'ram',
  'storage',
  'memory',
  'color',
  'colour',
  'condition',
  'size',
  'warranty',
  'warranty_months',
];

function normalizeKey(value?: string | null): string {
  return String(value || '')
    .trim()
    .toLowerCase()
    .replace(/[\s-]+/g, '_');
}

const MISSING_SPEC_VALUES = new Set([
  'n/a',
  'na',
  'n.a',
  'n.a.',
  '-',
  '--',
  '—',
  '–',
  'none',
  'null',
  'undefined',
  'not available',
  'not applicable',
  'tbd',
  'unknown',
]);

export function isMissingSpecValue(value?: string | null): boolean {
  const trimmed = String(value ?? '').trim();
  if (!trimmed) return true;
  const compact = trimmed.toLowerCase().replace(/[_/]+/g, ' ').replace(/\s+/g, ' ').trim();
  return MISSING_SPEC_VALUES.has(compact) || MISSING_SPEC_VALUES.has(compact.replace(/\s/g, ''));
}

function prettyValue(label: string, value: string): string {
  const trimmed = value.trim();
  if (isMissingSpecValue(trimmed)) return '';
  if (normalizeKey(label) === 'color' || normalizeKey(label) === 'colour') {
    return trimmed.replace(/\b\w/g, (c) => c.toUpperCase());
  }
  return trimmed;
}

function factLabel(code: string, name?: string): string {
  const key = normalizeKey(name || code);
  const labels: Record<string, string> = {
    quality: 'Quality',
    qul: 'Quality',
    qual: 'Quality',
    memory: 'Memory',
    ram: 'RAM',
    storage: 'Storage',
    color: 'Color',
    colour: 'Color',
    clr: 'Color',
    condition: 'Condition',
    size: 'Size',
    warranty: 'Warranty',
    warranty_months: 'Warranty',
    compatible_with: 'Compatible with',
    type: 'Type',
    connector: 'Connector',
    output: 'Output',
    material: 'Material',
    processor: 'Processor',
    display: 'Display',
    connectivity: 'Connectivity',
    series: 'Series',
  };
  if (labels[key]) return labels[key];
  if (name && name.trim()) return name.trim();
  return code.replace(/[_-]+/g, ' ').replace(/\b\w/g, (c) => c.toUpperCase());
}

export function extractPdpFacts(
  product: {
    variants?: any[];
    specifications?: { label?: string; value?: string }[];
  },
  selectedVariant?: any | null,
  extraSpecs: { label: string; value: string }[] = []
): PdpFact[] {
  const variant = selectedVariant || product.variants?.[0] || null;
  const facts: PdpFact[] = [];
  const seen = new Set<string>();

  const push = (label: string, value: string) => {
    const pretty = prettyValue(label, value);
    const key = normalizeKey(label);
    if (!pretty || seen.has(key)) return;
    seen.add(key);
    facts.push({ label, value: pretty });
  };

  (variant?.attributes || []).forEach((attr: any) => {
    const key = normalizeKey(attr.attribute_code || attr.attribute_name);
    if (!FACT_PRIORITY.includes(key)) return;
    push(factLabel(attr.attribute_code || '', attr.attribute_name), String(attr.attribute_value || ''));
  });

  extraSpecs.forEach((spec) => {
    const key = normalizeKey(spec.label);
    if (!['series', 'model', 'model_reference', 'condition'].includes(key)) return;
    push(spec.label, spec.value);
  });

  (product.specifications || []).forEach((spec) => {
    const key = normalizeKey(spec.label);
    if (!['series', 'model', 'model_reference', 'condition'].includes(key)) return;
    push(String(spec.label || ''), String(spec.value || ''));
  });

  return facts.slice(0, 4);
}

const QUICK_VIEW_KIND_KEYS: Record<CompareKind | 'phone', string[]> = {
  phone: ['ram', 'storage', 'color', 'condition', 'series'],
  laptop: ['processor', 'ram', 'storage', 'display'],
  watch: ['size', 'color', 'compatible_with', 'condition'],
  case: ['compatible_with', 'color', 'material', 'condition'],
  camera: ['compatible_with', 'type', 'color', 'condition'],
  charger: ['connector', 'output', 'compatible_with', 'color'],
  protector: ['compatible_with', 'material', 'type'],
  audio: ['compatible_with', 'connectivity', 'color'],
  speaker: ['compatible_with', 'connectivity', 'color'],
  general: ['compatible_with', 'type', 'color', 'condition', 'size'],
};

const QUICK_VIEW_TYPE_LABEL: Record<CompareKind, string> = {
  audio: 'Headphones',
  speaker: 'Speaker',
  case: 'Phone case',
  camera: 'Mobile camera',
  charger: 'Charger / cable',
  phone: 'Smartphone',
  laptop: 'Laptop',
  watch: 'Smartwatch',
  protector: 'Screen protector',
  general: 'Accessory',
};

function resolveQuickViewKind(product: { device_type?: string | null; name?: string; slug?: string; full_path?: string }): CompareKind {
  const deviceType = normalizeKey(product.device_type);
  if (['mobile', 'phone', 'smartphone', 'feature_phone', 'tablet', 'ipad'].includes(deviceType)) {
    return 'phone';
  }
  if (['laptop', 'notebook', 'ultrabook'].includes(deviceType)) return 'laptop';
  if (['watch', 'smartwatch', 'wearable'].includes(deviceType)) return 'watch';
  return detectProductKind(product as any);
}

export function extractQuickViewSpecs(
  product: {
    name?: string;
    device_type?: string | null;
    variants?: any[];
    specifications?: { label?: string; value?: string }[];
    compatible_devices?: { name?: string }[];
  },
  selectedVariant?: any | null,
  extraSpecs: { label?: string; value?: string }[] = []
): PdpFact[] {
  const kind = resolveQuickViewKind(product);
  const wanted = QUICK_VIEW_KIND_KEYS[kind] || QUICK_VIEW_KIND_KEYS.general;
  const bag = new Map<string, { label: string; values: string[] }>();

  const add = (rawLabel: string, rawValue: string) => {
    const label = factLabel(rawLabel, rawLabel);
    const pretty = prettyValue(label, rawValue);
    const key = normalizeKey(label);
    if (!pretty || key === 'brand' || key === 'manufacturer') return;
    if (!bag.has(key)) bag.set(key, { label, values: [] });
    const entry = bag.get(key)!;
    if (!entry.values.some((value) => value.toLowerCase() === pretty.toLowerCase())) {
      entry.values.push(pretty);
    }
  };

  const variant = selectedVariant || product.variants?.[0] || null;
  (variant?.attributes || []).forEach((attr: any) => {
    add(attr.attribute_name || attr.attribute_code || '', String(attr.attribute_value || ''));
  });

  (product.variants || []).forEach((item: any) => {
    (item?.attributes || []).forEach((attr: any) => {
      add(attr.attribute_name || attr.attribute_code || '', String(attr.attribute_value || ''));
    });
  });

  [...extraSpecs, ...(product.specifications || [])].forEach((spec) => {
    add(String(spec.label || ''), String(spec.value || ''));
  });

  const deviceNames = (product.compatible_devices || [])
    .map((device) => String(device?.name || '').trim())
    .filter((name) => name && !isMissingSpecValue(name) && name.length > 1);
  if (deviceNames.length) {
    add('Compatible with', deviceNames.slice(0, 2).join(', '));
  }

  const forMatch = String(product.name || '').match(/\bfor\s+(.+)$/i);
  if (forMatch?.[1]) add('Compatible with', forMatch[1].replace(/\s+/g, ' ').trim());

  if (kind !== 'phone' && kind !== 'laptop' && kind !== 'general') {
    add('Type', QUICK_VIEW_TYPE_LABEL[kind]);
  }

  const facts: PdpFact[] = [];
  const used = new Set<string>();
  wanted.forEach((key) => {
    const entry = bag.get(key);
    if (!entry || used.has(key)) return;
    used.add(key);
    facts.push({
      label: entry.label,
      value: entry.values.slice(0, 3).join(', '),
    });
  });

  return facts.slice(0, 4);
}

const TRUST_DEVICE_TYPES = new Set([
  'mobile',
  'phone',
  'smartphone',
  'feature_phone',
  'laptop',
  'notebook',
  'ultrabook',
  'tablet',
  'ipad',
  'watch',
  'smartwatch',
  'wearable',
  'desktop',
  'pc',
  'computer',
  'tv',
  'television',
  'console',
  'gaming',
]);

const TRUST_CATEGORY_KEYS = new Set([
  'phones',
  'phone',
  'mobiles',
  'mobile',
  'smartphones',
  'laptops',
  'laptop',
  'notebooks',
  'tablets',
  'tablet',
  'computers',
  'wearables',
  'smart_watches',
  'smartwatches',
  'spare_parts',
  'mobile_display',
  'mobile_battery',
  'mother_board',
  'motherboard',
  'mobile_back_panel',
  'mobile_camera',
]);

const ACCESSORY_CATEGORY_KEYS = new Set([
  'accessories',
  'accessory',
  'back_covers',
  'back_cover',
  'mobile_cases',
  'mobile_case',
  'cases',
  'screen_guards',
  'screen_guard',
  'camera_lens_guards',
  'usb_c_cables',
  'charging_adapters',
  'mobile_charger',
  'charging',
  'cables',
  'earbuds',
  'headphones',
  'audio',
  'bluetooth_speaker',
]);

function categoryChainKeys(
  product: { category_id?: string; full_path?: string; category?: { slug?: string; name?: string } },
  categories: { category_id: string; parent_category_id?: string | null; slug?: string; name?: string }[] = []
): string[] {
  const keys: string[] = [];
  const byId = new Map(categories.map((cat) => [cat.category_id, cat]));
  let current = product.category_id ? byId.get(product.category_id) : undefined;
  while (current) {
    keys.push(normalizeKey(current.slug), normalizeKey(current.name));
    current = current.parent_category_id ? byId.get(current.parent_category_id) : undefined;
  }
  const firstPath = String(product.full_path || '')
    .split('/')
    .map((part) => part.trim())
    .filter(Boolean)[0];
  if (firstPath) keys.push(normalizeKey(firstPath));
  if (product.category?.slug) keys.push(normalizeKey(product.category.slug));
  if (product.category?.name) keys.push(normalizeKey(product.category.name));
  return keys.filter(Boolean);
}

export function productShowsTrustBadges(
  product: {
    device_type?: string | null;
    category_id?: string;
    full_path?: string;
    category?: { slug?: string; name?: string };
  },
  categories: { category_id: string; parent_category_id?: string | null; slug?: string; name?: string }[] = []
): boolean {
  return true;
}

const DEFAULT_HOMEPAGE_TRUST_BADGES: PdpTrustBadge[] = [
  { title: '6-Month Spare Parts Warranty', icon: 'ShieldCheck' },
  { title: 'Skilled Tech Diagnostics', icon: 'Wrench' },
  { title: 'Fast Doorstep Repairs', icon: 'Clock' },
];

export function parseTrustBadgesFromLayout(layoutData: unknown): PdpTrustBadge[] {
  const rows = Array.isArray(layoutData) ? layoutData : [];
  const section = rows.find((item: any) => {
    const region = String(item?.region || item?.metadata?.section_key || item?.type || '').toLowerCase();
    return region === 'trust_badges' || region === 'badges' || region === 'sec_trust';
  });

  if (section && resolveIsActive(section) === false) return [];

  if (section) {
    const meta = parseMetadata(section);
    const features = Array.isArray(meta.features) ? meta.features : [];
    const parsed = features
      .map((item: any) => ({
        title: String(item?.title || '').trim(),
        icon: String(item?.icon || '').trim() || undefined,
      }))
      .filter((item: PdpTrustBadge) => item.title)
      .slice(0, 3);

    if (parsed.length > 0) return parsed;
  }

  return DEFAULT_HOMEPAGE_TRUST_BADGES;
}