// ============================================================
// CORE TYPES
// ============================================================

/**
 * Change frequency values per the sitemap protocol specification.
 * Note: Google ignores changefreq, but other search engines may use it.
 */
export type TChangeFreq =
  | 'always'
  | 'hourly'
  | 'daily'
  | 'weekly'
  | 'monthly'
  | 'yearly'
  | 'never';

/** Supported output formats */
export type TOutputFormat = 'xml' | 'txt' | 'json';

// ============================================================
// URL ENTRY — the core unit of a sitemap
// ============================================================

/**
 * A single URL entry in a sitemap, supporting all standard extensions.
 */
export interface ISitemapUrl {
  /** Absolute URL of the page (required, max 2048 chars) */
  loc: string;
  /** Last modification date — accepts Date, ISO string, or Unix timestamp (ms) */
  lastmod?: Date | string | number;
  /** How frequently the page changes */
  changefreq?: TChangeFreq;
  /** Priority relative to other URLs on your site, 0.0 to 1.0 */
  priority?: number;
  /** Image sitemap extension entries */
  images?: ISitemapImage[];
  /** Video sitemap extension entries */
  videos?: ISitemapVideo[];
  /** News sitemap extension */
  news?: ISitemapNews;
  /** Alternate language versions (hreflang) */
  alternates?: ISitemapAlternate[];
}

// ============================================================
// SITEMAP EXTENSIONS
// ============================================================

export interface ISitemapImage {
  /** URL of the image (required) */
  loc: string;
  /** Caption for the image */
  caption?: string;
  /** Title of the image */
  title?: string;
  /** Geographic location (e.g. "New York, USA") */
  geoLocation?: string;
  /** URL to the image license */
  licenseUrl?: string;
}

export interface ISitemapVideo {
  /** URL to the video thumbnail (required) */
  thumbnailLoc: string;
  /** Title of the video (required) */
  title: string;
  /** Description of the video, max 2048 chars (required) */
  description: string;
  /** URL of the actual video media file */
  contentLoc?: string;
  /** URL of the embeddable player — at least one of contentLoc or playerLoc required */
  playerLoc?: string;
  /** Duration in seconds (1–28800) */
  duration?: number;
  /** Rating 0.0 to 5.0 */
  rating?: number;
  /** Number of views */
  viewCount?: number;
  /** Publication date */
  publicationDate?: Date | string;
  /** Whether the video is family friendly (default true) */
  familyFriendly?: boolean;
  /** Tags for the video (max 32) */
  tags?: string[];
  /** Whether this is a live stream */
  live?: boolean;
  /** Whether a subscription is required to view */
  requiresSubscription?: boolean;
}

export interface ISitemapNews {
  /** Publication information */
  publication: {
    /** Publication name (e.g. "The New York Times") */
    name: string;
    /** Language code (ISO 639, e.g. "en", "de", "zh-cn") */
    language: string;
  };
  /** Publication date of the article */
  publicationDate: Date | string | number;
  /** Article title */
  title: string;
  /** Keywords (array or comma-separated string) */
  keywords?: string[] | string;
}

export interface ISitemapAlternate {
  /** Language code (ISO 639) or 'x-default' for the default version */
  hreflang: string;
  /** URL for this language version */
  href: string;
}

// ============================================================
// SITEMAP INDEX
// ============================================================

export interface ISitemapIndexEntry {
  /** URL to the sitemap file */
  loc: string;
  /** Last modification date of the referenced sitemap */
  lastmod?: Date | string | number;
}

// ============================================================
// CONFIGURATION
// ============================================================

export interface ISitemapOptions {
  /** Base URL for the website (used to resolve relative URLs and for auto-split filenames) */
  baseUrl?: string;
  /** XSL stylesheet URL for browser-viewable sitemaps */
  xslUrl?: string;
  /** Default changefreq for URLs that don't specify one */
  defaultChangeFreq?: TChangeFreq;
  /** Default priority for URLs that don't specify one (0.0–1.0) */
  defaultPriority?: number;
  /** Whether to pretty-print XML output (default: true) */
  prettyPrint?: boolean;
  /** Maximum URLs per sitemap file before auto-splitting (default: 50000, max: 50000) */
  maxUrlsPerSitemap?: number;
  /** Enable gzip compression for toGzipBuffer() */
  gzip?: boolean;
  /** Whether to validate URLs and fields (default: true) */
  validate?: boolean;
}

export interface INewsSitemapOptions extends ISitemapOptions {
  /** Publication name — required for news sitemaps */
  publicationName: string;
  /** Publication language (default: 'en') */
  publicationLanguage?: string;
}

export interface IFeedImportOptions {
  /** Publication name for news sitemap mapping */
  publicationName?: string;
  /** Publication language for news sitemap mapping */
  publicationLanguage?: string;
  /** Only include items newer than this date */
  newerThan?: Date | number;
  /** Maximum number of items to import */
  limit?: number;
  /** Custom mapping function from feed item to sitemap URL (return null to skip) */
  mapItem?: (item: IFeedItem) => ISitemapUrl | null;
}

/** Shape of a parsed RSS/Atom feed item */
export interface IFeedItem {
  title?: string;
  link?: string;
  pubDate?: string;
  author?: string;
  content?: string;
  contentSnippet?: string;
  isoDate?: string;
  id?: string;
  categories?: string[];
  enclosure?: {
    url?: string;
    type?: string;
    length?: string;
  };
  [key: string]: any;
}

// ============================================================
// YAML CONFIG
// ============================================================

/**
 * Enhanced YAML configuration format for defining sitemaps declaratively.
 * Supports per-frequency URL groups, default settings, and feed imports.
 */
export interface ISitemapYamlConfig {
  /** Base URL to prepend to relative paths */
  baseUrl?: string;
  /** Default values for all URLs */
  defaults?: {
    changefreq?: TChangeFreq;
    priority?: number;
  };
  /** URL groups organized by change frequency */
  urls?: { [K in TChangeFreq]?: string[] };
  /** RSS/Atom feeds to import */
  feeds?: Array<{
    url: string;
    type: 'news' | 'standard';
    publicationName?: string;
    publicationLanguage?: string;
  }>;
}

// ============================================================
// PARSED SITEMAP (bidirectional)
// ============================================================

export interface IParsedSitemap {
  /** Whether this is a urlset or a sitemap index */
  type: 'urlset' | 'sitemapindex';
  /** Parsed URL entries (populated when type is 'urlset') */
  urls: ISitemapUrl[];
  /** Parsed index entries (populated when type is 'sitemapindex') */
  sitemaps: ISitemapIndexEntry[];
}

// ============================================================
// VALIDATION
// ============================================================

export interface IValidationError {
  field: string;
  message: string;
  url?: string;
}

export interface IValidationWarning {
  field: string;
  message: string;
  url?: string;
}

export interface IValidationResult {
  valid: boolean;
  errors: IValidationError[];
  warnings: IValidationWarning[];
  stats: ISitemapStats;
}

// ============================================================
// STATISTICS
// ============================================================

export interface ISitemapStats {
  urlCount: number;
  imageCount: number;
  videoCount: number;
  newsCount: number;
  alternateCount: number;
  estimatedSizeBytes: number;
  needsIndex: boolean;
}

// ============================================================
// AUTO-SPLIT OUTPUT
// ============================================================

export interface ISitemapSet {
  /** Whether the URL count exceeded maxUrlsPerSitemap */
  needsIndex: boolean;
  /** The sitemap index XML (null if all URLs fit in one sitemap) */
  indexXml: string | null;
  /** Individual sitemap chunks */
  sitemaps: Array<{ filename: string; xml: string }>;
}