// Typed client for the Vellum HTTP API. Every response shape here mirrors a
// Go handler; keep them in sync when endpoints change.

export interface User {
  id: number
  username: string
  display_name: string
  is_admin: boolean
  created_at: string
}

export interface Library {
  id: number
  name: string
  kind: string
  root_path: string
  created_at: string
}

export interface MediaType {
  Kind: string
  Name: string
  Extensions: string[]
}

export interface Item {
  id: number
  library_id: number
  kind: string
  path: string
  title: string
  year: number
  added_at: string
  missing?: boolean
}

export interface Progress {
  item_id: number
  file_id: number
  kind: string
  position: number
  duration: number
  percent: number
  finished: boolean
  updated_at: string
}

export interface EbookMetadata {
  title: string
  authors: string[] | null
  language: string
  identifier: string
  publisher: string
  date: string
  description: string
  spine_length: number
}

export class ApiError extends Error {
  status: number
  constructor(status: number, message: string) {
    super(message)
    this.status = status
    this.name = 'ApiError'
  }
}

async function request<T>(method: string, path: string, body?: unknown): Promise<T> {
  const res = await fetch(path, {
    method,
    credentials: 'same-origin',
    headers: body === undefined ? undefined : { 'Content-Type': 'application/json' },
    body: body === undefined ? undefined : JSON.stringify(body),
  })

  if (res.status === 204) return undefined as T

  const text = await res.text()
  let parsed: unknown = undefined
  if (text) {
    try {
      parsed = JSON.parse(text)
    } catch {
      // Fall through to the status-based error below.
    }
  }

  if (!res.ok) {
    const message =
      parsed && typeof parsed === 'object' && 'error' in parsed
        ? String((parsed as { error: unknown }).error)
        : `request failed (${res.status})`
    throw new ApiError(res.status, message)
  }
  return parsed as T
}

export const api = {
  login: (username: string, password: string) =>
    request<{ user: User; expires_in: number }>('POST', '/api/v1/auth/login', { username, password }),

  logout: () => request<{ status: string }>('POST', '/api/v1/auth/logout'),

  me: () => request<{ user: User; visible_libraries: number[] }>('GET', '/api/v1/auth/me'),

  changePassword: (current_password: string, new_password: string) =>
    request<{ status: string }>('POST', '/api/v1/auth/password', { current_password, new_password }),

  mediaTypes: () => request<{ media_types: MediaType[] }>('GET', '/api/v1/media-types'),

  libraries: () => request<{ libraries: Library[] }>('GET', '/api/v1/libraries'),

  library: (id: number) =>
    request<{ library: Library; item_count: number; reachable: boolean }>('GET', `/api/v1/libraries/${id}`),

  createLibrary: (name: string, kind: string, root_path: string) =>
    request<{ library: Library }>('POST', '/api/v1/libraries', { name, kind, root_path }),

  deleteLibrary: (id: number) => request<void>('DELETE', `/api/v1/libraries/${id}`),

  scanLibrary: (id: number) =>
    request<{ queued: number; job_id: number }>('POST', `/api/v1/libraries/${id}/scan`),

  // ── playback engines ──
  engines: () => request<{ engines: EngineSupport[] }>('GET', '/api/v1/playback/engines'),

  resolvePlayback: (itemId: number, engines: string[]) =>
    request<PlaybackResolution>('POST', '/api/v1/playback/resolve', {
      item_id: itemId,
      engines,
    }),

  // ── missing files ──
  missing: (libraryId?: number) => {
    const q = libraryId ? `?library_id=${libraryId}` : ''
    return request<{ items: MissingEntry[]; total: number }>('GET', `/api/v1/missing${q}`)
  },

  purgeMissing: (libraryId: number) =>
    request<{ purged: number }>('POST', `/api/v1/libraries/${libraryId}/purge`),

  scanStatus: (id: number) =>
    request<{
      state: 'queued' | 'running' | 'done' | 'failed' | 'idle'
      result?: {
        scanned: number
        added: number
        updated: number
        restored: number
        missing: number
        unchanged: number
        duration_ms: number
        errors?: string[]
      }
      error?: string
    }>('GET', `/api/v1/libraries/${id}/scan/status`),

  enrichLibrary: (id: number) =>
    request<{ queued: number }>('POST', `/api/v1/libraries/${id}/enrich`),

  itemMetadata: (id: number) =>
    request<{
      item_id: number
      provider_ids: { provider: string; external_id: string }[]
      fetch_history: { provider: string; status: string; detail: string; fetched_at: string }[]
    }>('GET', `/api/v1/items/${id}/metadata`),

  items: (libraryId: number, limit = 200) =>
    request<{ items: Item[]; limit: number }>('GET', `/api/v1/libraries/${libraryId}/items?limit=${limit}`),

  item: (id: number) => request<ItemDetail>('GET', `/api/v1/items/${id}`),

  home: () => request<Home>('GET', '/api/v1/home'),

  recordView: (id: number) =>
    request<{ item_id: number; views: number }>('POST', `/api/v1/items/${id}/view`),

  game: (id: number) =>
    request<{
      item_id: number
      platform: string
      core: string
      playable: boolean
      saves: { slot: string; size: number; updated_at: string }[]
    }>('GET', `/api/v1/items/${id}/game`),

  saveUrl: (id: number, slot = 'default') => `/api/v1/items/${id}/saves/${slot}`,

  deleteSave: (id: number, slot = 'default') =>
    request<void>('DELETE', `/api/v1/items/${id}/saves/${slot}`),

  listItems: (opts: { kind?: string; libraryId?: number; limit?: number; offset?: number } = {}) => {
    const p = new URLSearchParams()
    if (opts.kind) p.set('kind', opts.kind)
    if (opts.libraryId) p.set('library_id', String(opts.libraryId))
    if (opts.limit) p.set('limit', String(opts.limit))
    if (opts.offset) p.set('offset', String(opts.offset))
    return request<{ items: Item[]; total: number; offset: number; limit: number }>(
      'GET',
      `/api/v1/items?${p.toString()}`,
    )
  },

  ebook: (id: number) => request<{ metadata: EbookMetadata }>('GET', `/api/v1/items/${id}/ebook`),

  pages: (id: number) =>
    request<{ pages: { index: number; name: string }[]; count: number }>('GET', `/api/v1/items/${id}/pages`),

  pageUrl: (id: number, page: number) => `/api/v1/items/${id}/pages/${page}`,

  coverUrl: (id: number) => `/api/v1/items/${id}/cover`,

  fileUrl: (id: number) => `/api/v1/items/${id}/file`,

  fileUrlById: (id: number, fileId: number) => `/api/v1/items/${id}/files/${fileId}`,

  progress: (id: number) => request<{ progress: Progress | null }>('GET', `/api/v1/items/${id}/progress`),

  putProgress: (
    id: number,
    p: { file_id?: number; position?: number; duration?: number; percent?: number; finished?: boolean },
  ) => request<{ progress: Progress }>('PUT', `/api/v1/items/${id}/progress`, p),

  recent: () => request<{ progress: Progress[] }>('GET', '/api/v1/progress/recent'),

  search: (q: string) =>
    request<{ results: SearchResult[]; query: string }>('GET', `/api/v1/search?q=${encodeURIComponent(q)}`),

  users: () => request<{ users: User[] }>('GET', '/api/v1/users'),

  createUser: (username: string, password: string, display_name: string, is_admin: boolean) =>
    request<{ user: User }>('POST', '/api/v1/users', { username, password, display_name, is_admin }),

  userGrants: (userId: number) =>
    request<{ grants: { library_id: number; can_read: boolean; can_download: boolean }[] }>(
      'GET',
      `/api/v1/users/${userId}/grants`,
    ),

  putGrant: (userId: number, libraryId: number, canRead: boolean, canDownload: boolean) =>
    request<{ user_id: number; library_id: number; can_read: boolean; can_download: boolean }>(
      'PUT',
      `/api/v1/users/${userId}/grants/${libraryId}`,
      { can_read: canRead, can_download: canDownload },
    ),

  deleteGrant: (userId: number, libraryId: number) =>
    request<void>('DELETE', `/api/v1/users/${userId}/grants/${libraryId}`),
}

export interface SearchResult {
  id: number
  library_id: number
  kind: string
  path: string
  title: string
}

export interface ShelfItem {
  id: number
  library_id: number
  kind: string
  title: string
  percent: number
  file_id: number
  views: number
  updated_at: string
}

export interface Suggestion {
  id: number
  library_id: number
  kind: string
  title: string
  year: number
  reason: string
}

export interface Home {
  continue: ShelfItem[] | null
  most_viewed: ShelfItem[] | null
  suggestions: Suggestion[] | null
  recent: ShelfItem[] | null
  explore: ShelfItem[] | null
  counts_by_kind: Record<string, number>
  library_count: number
  total_items: number
}

// MediaFile carries the ffprobe facts about one file on disk.
//
// The codec fields are what make "direct play only" workable: playability is a
// property of the CLIENT, not the file, so the server reports what is in the
// file and each client decides for itself. An empty vcodec means there is no
// video track (audio, or a comic).
export interface MediaFile {
  id: number
  path: string
  size: number
  container: string
  missing: boolean
  duration_ms: number
  /** ffprobe codec name, e.g. "h264", "hevc", "vp9", "av1". "" when absent. */
  vcodec: string
  /** ffprobe codec name, e.g. "aac", "opus", "flac", "mp3". "" when absent. */
  acodec: string
  width: number
  height: number
}

export interface ItemDetail {
  item: Item
  files: MediaFile[]
  has_cover: boolean
  authors: string[] | null
  progress?: Progress
}

// ── playback engines ────────────────────────────────────────────────────
// Playability is a property of the CLIENT, so a client declares the engines it
// has and the server matches them against the file's codec facts. A browser
// offers "html5"; a native client offers "mpv", "vlc", "mdk" as well.
export interface EngineSupport {
  id: string
  name: string
  kind: 'browser' | 'native'
  /** Lowercase container extensions it can open, e.g. "mkv". */
  containers: string[]
  /** Video codec names it can decode, e.g. "h264", "hevc". */
  vcodecs: string[]
  /** Audio codec names it can decode. */
  acodecs: string[]
}

export interface PlaybackResolution {
  playable: boolean
  /** The engine that should play it, or null when nothing can. */
  engine: string | null
  /** Machine-readable cause when not playable, e.g. "vcodec:hevc". */
  reason: string
  /** Human text for the UI. Empty when playable. */
  message: string
}

// ── missing files ───────────────────────────────────────────────────────
// A scan never deletes: a file that vanishes is marked missing so its progress
// survives a temporarily unmounted drive. Nothing is removed until an admin
// explicitly purges, which is what these two calls are for.
export interface MissingEntry {
  item_id: number
  file_id: number
  library_id: number
  kind: string
  title: string
  path: string
  /** When the file was first seen missing, RFC3339. */
  missing_since: string
}

export interface ScanResult {
  library_id: number
  scanned: number
  added: number
  updated: number
  restored: number
  missing: number
  unchanged: number
  duration_ms: number
  errors?: string[]
}