/**
 * Service API pour interagir avec le cache d'images de couvertures
 */

export interface CacheMetadata {
  origin_url?: string;
  [key: string]: unknown;
}

export interface CacheEntry {
  pk: string;
  id: string | null;
  collection?: string | null;
  hits: number;
  last_used: string | null;
  metadata?: CacheMetadata | null;
}

export interface AddImageRequest {
  url: string;
}

export interface AddImageResponse {
  pk: string;
  url: string;
  message: string;
}

export interface ApiError {
  error: string;
  message: string;
}

export interface DownloadStatus {
  pk: string;
  finished: boolean;
  current_size?: number;
  expected_size?: number;
  transformed_size?: number;
}

/**
 * Liste toutes les images en cache
 */
export async function listImages(): Promise<CacheEntry[]> {
  const response = await fetch("/api/covers");
  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to fetch images");
  }
  return response.json();
}

/**
 * Récupère les informations d'une image spécifique
 */
export async function getImageInfo(pk: string): Promise<CacheEntry> {
  const response = await fetch(`/api/covers/${pk}`);
  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to fetch image info");
  }
  return response.json();
}

/**
 * Ajoute une nouvelle image au cache depuis une URL
 */
export async function addImage(url: string): Promise<AddImageResponse> {
  const response = await fetch("/api/covers", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ url }),
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to add image");
  }
  return response.json();
}

/**
 * Supprime une image du cache
 */
export async function deleteImage(pk: string): Promise<void> {
  const response = await fetch(`/api/covers/${pk}`, {
    method: "DELETE",
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to delete image");
  }
}

/**
 * Purge complètement le cache
 */
export async function purgeCache(): Promise<void> {
  const response = await fetch("/api/covers", {
    method: "DELETE",
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to purge cache");
  }
}

/**
 * Consolide le cache (re-télécharge les images manquantes)
 */
export async function consolidateCache(): Promise<void> {
  const response = await fetch("/api/covers/consolidate", {
    method: "POST",
  });

  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to consolidate cache");
  }
}

/**
 * Récupère le statut du téléchargement d'une image
 */
export async function getDownloadStatus(pk: string): Promise<DownloadStatus> {
  const response = await fetch(`/api/covers/${pk}/status`);
  if (!response.ok) {
    const error: ApiError = await response.json();
    throw new Error(error.message || "Failed to get download status");
  }
  return response.json();
}

/**
 * Attend que le téléchargement d'une image soit terminé
 *
 * @param pk - Clé primaire de l'image
 * @param maxWaitMs - Temps maximum d'attente en millisecondes (défaut: 30000)
 * @param pollIntervalMs - Intervalle entre les vérifications en millisecondes (défaut: 500)
 */
export async function waitForDownload(
  pk: string,
  maxWaitMs: number = 30000,
  pollIntervalMs: number = 500
): Promise<void> {
  const startTime = Date.now();

  while (Date.now() - startTime < maxWaitMs) {
    try {
      const status = await getDownloadStatus(pk);
      if (status.finished) {
        return; // Téléchargement terminé
      }
    } catch (error) {
      // Si l'API retourne une erreur, on continue d'attendre
      console.warn(`Error checking download status for ${pk}:`, error);
    }

    // Attendre avant la prochaine vérification
    await new Promise(resolve => setTimeout(resolve, pollIntervalMs));
  }

  // Timeout atteint, on lance une dernière vérification
  const finalStatus = await getDownloadStatus(pk);
  if (!finalStatus.finished) {
    console.warn(`Download timeout for ${pk}, but continuing anyway`);
  }
}

/**
 * Génère l'URL pour afficher une image
 */
export function getOriginUrl(entry: CacheEntry): string | undefined {
  const metadata = entry.metadata;
  if (metadata && typeof metadata === "object") {
    const origin = (metadata as { origin_url?: unknown }).origin_url;
    if (typeof origin === "string" && origin.trim().length > 0) {
      return origin;
    }
  }
  return undefined;
}

export function getImageUrl(pk: string, size?: number): string {
  if (size) {
    return `/covers/image/${pk}/${size}`;
  }
  return `/covers/image/${pk}`;
}