/**
 * Typed API functions for Fotos (GerbilPhoto). (FEAT-6)
 *
 * Contract (FEAT-1b Phase 2, Pam):
 *   GET    /gerbils/{id}/photos  -> [{id, fileName, caption, sortOrder, url}]
 *   POST   /gerbils/{id}/photos  -> multipart, Feld 'file' (+ optional 'caption')
 *   DELETE /photos/{id}
 * Erstes Foto nach sortOrder = Profilfoto.
 *
 * Der Upload geht NICHT über api.post (das setzt Content-Type: application/json);
 * bei FormData muss der Browser den multipart-Boundary-Header selbst setzen.
 */
import { API_BASE_URL, ApiError, api } from './client'
import { de } from '../strings/de'

export interface GerbilPhoto {
  id: string
  fileName: string
  caption: string | null
  sortOrder: number
  /** Absoluter oder API-relativer Pfad zur Bilddatei. */
  url: string
}

export function listGerbilPhotos(gerbilId: string): Promise<GerbilPhoto[]> {
  return api.get<GerbilPhoto[]>(`/gerbils/${gerbilId}/photos`)
}

export async function uploadGerbilPhoto(
  gerbilId: string,
  file: File,
  caption: string | null,
): Promise<GerbilPhoto> {
  const form = new FormData()
  form.append('file', file)
  if (caption) form.append('caption', caption)

  let response: Response
  try {
    response = await fetch(`${API_BASE_URL}/gerbils/${gerbilId}/photos`, {
      method: 'POST',
      body: form,
    })
  } catch {
    throw new ApiError(de.api.errors.network, null)
  }
  if (!response.ok) {
    const message =
      response.status === 404
        ? de.api.errors.notFound
        : response.status >= 500
          ? de.api.errors.server
          : de.api.errors.unknown
    throw new ApiError(message, response.status)
  }
  return (await response.json()) as GerbilPhoto
}

export function deleteGerbilPhoto(photoId: string): Promise<void> {
  return api.delete(`/photos/${photoId}`)
}

/** Bild-URL auflösen: API liefert ggf. einen API-relativen Pfad. */
export function photoSrc(photo: GerbilPhoto): string {
  return photo.url.startsWith('http') ? photo.url : `${API_BASE_URL}${photo.url}`
}

/** Profilfoto = erstes Foto nach sortOrder (null, wenn keine Fotos). */
export function profilePhoto(photos: GerbilPhoto[]): GerbilPhoto | null {
  if (photos.length === 0) return null
  return [...photos].sort((a, b) => a.sortOrder - b.sortOrder)[0]
}