import { readFile, readdir } from "fs/promises";
import { join } from "path";
import type { 
  OilForConcernPage,
  OilForConcernContent,
  OilsTaxonomyData,
  ConcernsTaxonomyData,
  OilTaxonomy,
  ConcernTaxonomy,
  LocalizedString,
  LocalizedSEOKeywords,
} from "./types";

const DATA_DIR = join(process.cwd(), "data");
const TAXONOMY_DIR = join(DATA_DIR, "taxonomy");
const CONTENT_DIR = join(DATA_DIR, "content", "oil-for-concern");

let oilsTaxonomyCache: OilsTaxonomyData | null = null;
let concernsTaxonomyCache: ConcernsTaxonomyData | null = null;

export function getLocalizedString(
  localized: { sr: string; en: string; de: string; fr: string },
  locale: string
): string {
  return localized[locale as keyof typeof localized] || localized.en;
}

export function getLocalizedArray(
  localized: { sr: string[]; en: string[]; de: string[]; fr: string[] },
  locale: string
): string[] {
  return localized[locale as keyof typeof localized] || localized.en;
}

export function getLocalizedKeywords(
  seoKeywords: LocalizedSEOKeywords,
  locale: string
): string[] {
  const keywords = seoKeywords[locale as keyof LocalizedSEOKeywords] || seoKeywords.en;
  return [...keywords.primary, ...keywords.secondary, ...keywords.longTail];
}

async function getOilsTaxonomy(): Promise<OilsTaxonomyData> {
  if (oilsTaxonomyCache) return oilsTaxonomyCache;
  
  const filePath = join(TAXONOMY_DIR, "oils.json");
  const content = await readFile(filePath, "utf-8");
  oilsTaxonomyCache = JSON.parse(content) as OilsTaxonomyData;
  return oilsTaxonomyCache;
}

async function getConcernsTaxonomy(): Promise<ConcernsTaxonomyData> {
  if (concernsTaxonomyCache) return concernsTaxonomyCache;
  
  const filePath = join(TAXONOMY_DIR, "concerns.json");
  const content = await readFile(filePath, "utf-8");
  concernsTaxonomyCache = JSON.parse(content) as ConcernsTaxonomyData;
  return concernsTaxonomyCache;
}

async function getOilForConcernContent(oilId: string, concernId: string): Promise<OilForConcernContent | null> {
  try {
    const filePath = join(CONTENT_DIR, `${oilId}-${concernId}.json`);
    const content = await readFile(filePath, "utf-8");
    return JSON.parse(content) as OilForConcernContent;
  } catch (error) {
    return null;
  }
}

function generatePageSlug(oilSlug: string, concernSlug: string, locale: string): string {
  if (locale === "sr") {
    return `${oilSlug}-za-${concernSlug}`;
  }
  return `${oilSlug}-for-${concernSlug}`;
}

function generateLocalizedSlugs(oil: OilTaxonomy, concern: ConcernTaxonomy): LocalizedString {
  return {
    sr: generatePageSlug(oil.slug.sr, concern.slug.sr, "sr"),
    en: generatePageSlug(oil.slug.en, concern.slug.en, "en"),
    de: generatePageSlug(oil.slug.de, concern.slug.de, "de"),
    fr: generatePageSlug(oil.slug.fr, concern.slug.fr, "fr"),
  };
}

function generatePageTitle(oil: OilTaxonomy, concern: ConcernTaxonomy): LocalizedString {
  return {
    sr: `Najbolje ${oil.name.sr.toLowerCase()} za ${concern.name.sr.toLowerCase()}`,
    en: `Best ${oil.name.en} for ${concern.name.en}`,
    de: `Bestes ${oil.name.de} für ${concern.name.de}`,
    fr: `Meilleure ${oil.name.fr.toLowerCase()} pour ${concern.name.fr.toLowerCase()}`,
  };
}

function generateMetaTitle(oil: OilTaxonomy, concern: ConcernTaxonomy): LocalizedString {
  return {
    sr: `Najbolje ${oil.name.sr.toLowerCase()} za ${concern.name.sr.toLowerCase()} | Prirodno rešenje | ManoonOils`,
    en: `Best ${oil.name.en} for ${concern.name.en} | Natural Solution | ManoonOils`,
    de: `Bestes ${oil.name.de} für ${concern.name.de} | Natürliche Lösung | ManoonOils`,
    fr: `Meilleure ${oil.name.fr.toLowerCase()} pour ${concern.name.fr.toLowerCase()} | Solution naturelle | ManoonOils`,
  };
}

function generateMetaDescription(oil: OilTaxonomy, concern: ConcernTaxonomy): LocalizedString {
  return {
    sr: `Otkrijte zašto je ${oil.name.sr.toLowerCase()} efikasno za ${concern.name.sr.toLowerCase()}. ${oil.shortDescription.sr}`,
    en: `Discover why ${oil.name.en} is effective for ${concern.name.en}. ${oil.shortDescription.en}`,
    de: `Entdecken Sie, warum ${oil.name.de} effektiv für ${concern.name.de} ist. ${oil.shortDescription.de}`,
    fr: `Découvrez pourquoi ${oil.name.fr} est efficace pour ${concern.name.fr}. ${oil.shortDescription.fr}`,
  };
}

async function buildOilForConcernPage(
  oil: OilTaxonomy,
  concern: ConcernTaxonomy,
  content: OilForConcernContent
): Promise<OilForConcernPage> {
  const localizedSlugs = generateLocalizedSlugs(oil, concern);
  const pageTitle = generatePageTitle(oil, concern);
  const metaTitle = generateMetaTitle(oil, concern);
  const metaDescription = generateMetaDescription(oil, concern);
  
  return {
    slug: localizedSlugs.en,
    localizedSlugs,
    oilSlug: oil.slug.en,
    concernSlug: concern.slug.en,
    oilId: oil.id,
    concernId: concern.id,
    pageTitle,
    metaTitle,
    metaDescription,
    oilName: oil.name,
    concernName: concern.name,
    whyThisWorks: content.content.whyThisWorks,
    keyBenefits: content.content.keyBenefits,
    howToApply: content.content.howToApply,
    expectedResults: content.content.expectedResults,
    timeframe: content.content.timeframe,
    complementaryIngredients: content.metadata.complementaryIngredients,
    productsToShow: content.metadata.productsToShow,
    customerResults: content.metadata.customerResults,
    faqs: content.metadata.faqs,
    seoKeywords: content.metadata.seoKeywords,
    relatedPages: content.metadata.relatedPages,
  };
}

export async function getAllOilForConcernPages(): Promise<OilForConcernPage[]> {
  const [oilsTaxonomy, concernsTaxonomy] = await Promise.all([
    getOilsTaxonomy(),
    getConcernsTaxonomy(),
  ]);
  
  const pages: OilForConcernPage[] = [];
  
  for (const oil of Object.values(oilsTaxonomy.oils)) {
    for (const concernId of oil.concerns) {
      const concern = concernsTaxonomy.concerns[concernId];
      if (!concern) continue;
      
      const content = await getOilForConcernContent(oil.id, concernId);
      if (!content) continue;
      
      const page = await buildOilForConcernPage(oil, concern, content);
      pages.push(page);
    }
  }
  
  return pages;
}

export async function getOilForConcernPageBySlug(slug: string, locale: string): Promise<OilForConcernPage | null> {
  const pages = await getAllOilForConcernPages();
  return pages.find(page => 
    page.localizedSlugs[locale as "sr" | "en" | "de" | "fr"] === slug
  ) || null;
}

export async function getAllSolutionSlugs(): Promise<Array<{ locale: string; slug: string }>> {
  const pages = await getAllOilForConcernPages();
  const result: Array<{ locale: string; slug: string }> = [];
  
  for (const page of pages) {
    for (const locale of ["sr", "en", "de", "fr"] as const) {
      result.push({
        locale,
        slug: page.localizedSlugs[locale]
      });
    }
  }
  
  return result;
}

export async function getOilForConcernPage(slug: string): Promise<OilForConcernPage | null> {
  return getOilForConcernPageBySlug(slug, "en");
}

export async function getAllOilForConcernSlugs(): Promise<string[]> {
  const pages = await getAllOilForConcernPages();
  return pages.map(page => page.slug);
}

export async function getAllOils(): Promise<OilTaxonomy[]> {
  const taxonomy = await getOilsTaxonomy();
  return Object.values(taxonomy.oils);
}

export async function getAllConcerns(): Promise<ConcernTaxonomy[]> {
  const taxonomy = await getConcernsTaxonomy();
  return Object.values(taxonomy.concerns);
}

export async function getOilById(id: string): Promise<OilTaxonomy | null> {
  const taxonomy = await getOilsTaxonomy();
  return taxonomy.oils[id] || null;
}

export async function getConcernById(id: string): Promise<ConcernTaxonomy | null> {
  const taxonomy = await getConcernsTaxonomy();
  return taxonomy.concerns[id] || null;
}

export async function getPagesByOil(oilId: string): Promise<OilForConcernPage[]> {
  const pages = await getAllOilForConcernPages();
  return pages.filter(page => page.oilId === oilId);
}

export async function getPagesByConcern(concernId: string): Promise<OilForConcernPage[]> {
  const pages = await getAllOilForConcernPages();
  return pages.filter(page => page.concernId === concernId);
}