// The Files library: a user's done files, the folders they sit in, and the file itself
// (backend `routes/files.py`). A library file is a done download job, so it is typed as one.
import { req, uploadReq } from "./core";
import type { DownloadJob } from "./downloads";

// "source": filled by where a file came from (YouTube, Plex, a site, uploads); "own": made by the user;
// "hub": the one folder the user swaps files with their hub machine through (made by its token).
export type FolderKind = "source" | "own" | "hub";

export interface FileFolder {
  id: number;
  kind: FolderKind;
  // A source folder's origin — `youtube`, `plex`, `upload`, `site:<host>` — which the client names
  // in the reader's language; null on an own folder.
  source_key: string | null;
  name: string | null; // an own folder's name; null on a source folder
  retention_days: number | null; // null = kept until deleted
  count: number; // its done files
  size_bytes: number;
  created_at: string | null;
  // A live public link opens it: whatever is moved in is shown to whoever holds the link.
  has_link: boolean;
}

// The most files one list answers with (backend `routes/files.py` MAX_LIST, held equal by
// files.contract.test.ts): a list this long may be missing older files, so the page asks the
// server to search and sort it rather than doing either on the rows it got.
export const FILES_LIST_CAP = 500;

export type FileSort = "added" | "name" | "size";
export const FILE_SORTS: readonly FileSort[] = ["added", "name", "size"];
export type FileOrder = "asc" | "desc";

export interface FileListParams {
  folderId?: number | null; // one folder's files; absent = every file
  q?: string;
  sort?: FileSort;
  order?: FileOrder;
  shared?: boolean; // the files others shared with me instead of mine
}

export interface LibraryFile extends DownloadJob {
  // When it was shared with me (the "added" of a shared file); null on my own.
  shared_at?: string | null;
  // Where it came from — its source folder's key (`youtube`, `site:<host>`, …), wherever it sits now.
  source_key: string;
}

// Set by the server on a text preview cut at its size cap (`routes/files.py` TRUNCATED_HEADER).
const PREVIEW_TRUNCATED_HEADER = "X-Preview-Truncated";

export interface FilePreviewText {
  text: string;
  truncated: boolean;
}

// What a PATCH may change. Presence decides: a null / "" text falls back to the system value.
export interface FilePatch {
  name?: string | null;
  uploader?: string | null;
  uploader_url?: string | null;
  extra_links?: string[];
  folder_id?: number;
  kept?: boolean;
}

export interface StorageUsage {
  footprint_bytes: number;
  active_jobs: number;
  running_jobs: number;
  max_bytes: number;
  max_concurrent: number;
  max_jobs: number;
  unlimited: boolean;
  // The per-file cap on an upload, so the dialog can refuse an over-cap file before spending the
  // user's bandwidth on it. Not the same thing as `max_bytes`, which is the whole library
  // footprint: this one is a single request's ceiling and is enforced twice server-side anyway.
  upload_max_bytes: number;
}

/** The list's query string — exported for the contract test that holds its names to the route's. */
export function listQuery(p: FileListParams): string {
  const q = new URLSearchParams();
  if (p.shared) q.set("scope", "shared");
  else if (p.folderId != null) q.set("folder_id", String(p.folderId));
  if (p.q?.trim()) q.set("q", p.q.trim());
  if (p.sort) q.set("sort", p.sort);
  if (p.order) q.set("order", p.order);
  const s = q.toString();
  return s ? `?${s}` : "";
}

// What a folder PATCH may change. Presence decides: `retention_days: null` = keep its files forever.
export interface FolderPatch {
  name?: string; // an own folder's only
  retention_days?: number | null;
}

export const filesApi = {
  fileFolders: (): Promise<FileFolder[]> => req("/api/files/folders"),
  createFolder: (name: string): Promise<FileFolder> =>
    req("/api/files/folders", { method: "POST", body: JSON.stringify({ name }) }),
  updateFolder: (id: number, patch: FolderPatch): Promise<FileFolder> =>
    req(`/api/files/folders/${id}`, { method: "PATCH", body: JSON.stringify(patch) }),
  // An own folder only; its files go back to the folders they came from.
  deleteFolder: (id: number): Promise<{ ok: true; deleted: number; files_moved: number }> =>
    req(`/api/files/folders/${id}`, { method: "DELETE" }),
  files: (p: FileListParams = {}): Promise<LibraryFile[]> => req(`/api/files${listQuery(p)}`),
  filesUsage: (): Promise<StorageUsage> => req("/api/files/usage"),
  updateFile: (id: number, patch: FilePatch): Promise<DownloadJob> =>
    req(`/api/files/${id}`, { method: "PATCH", body: JSON.stringify(patch) }),
  deleteFile: (id: number): Promise<{ ok: true; deleted: number }> =>
    req(`/api/files/${id}`, { method: "DELETE" }),
  // Drop a file someone shared with me from my list (only my grant goes, not their file).
  removeSharedFile: (id: number): Promise<{ ok: true; removed: number }> =>
    req(`/api/files/shared/${id}`, { method: "DELETE" }),
  // Put a local file in the library. Sent via XHR rather than `req` so the dialog can show upload
  // progress; any file type is accepted (media gets the full function set, a generic file is
  // download-only). Returns the job the ingest creates: `done`, or `queued` while the worker
  // converts media no phone could play as it is (`downloads/upload.py`).
  // The body IS the file, and the names ride as headers. Not a style choice: a multipart part is a
  // DECLARED body, which FastAPI reads and spools BEFORE the route's `current_user` dependency runs
  // — so with that shape an unauthenticated caller could make the server write the whole per-file
  // allowance to temp. Headers are latin-1 on the wire, hence `encodeURIComponent`; the server
  // percent-decodes them. Content-Type is left to the browser (the File's own type). No folder =
  // the Uploads folder.
  uploadFile: (
    file: File,
    opts: {
      displayName?: string;
      folderId?: number | null;
      onProgress?: (pct: number) => void;
      signal?: AbortSignal;
    } = {},
  ): Promise<DownloadJob> => {
    const headers: Record<string, string> = {
      "X-Upload-Filename": encodeURIComponent(file.name || "upload"),
    };
    if (opts.displayName) headers["X-Upload-Display-Name"] = encodeURIComponent(opts.displayName);
    if (opts.folderId != null) headers["X-Upload-Folder"] = String(opts.folderId);
    return uploadReq<DownloadJob>("/api/files/upload", file, {
      onProgress: opts.onProgress,
      signal: opts.signal,
      headers,
    });
  },
  // The file itself, for a plain <a> navigation.
  fileUrl: (id: number): string => `/api/files/${id}/file`,
  // The viewer's copy of an image or a PDF (`/preview`, sandboxed): an <img> / <iframe> source.
  previewUrl: (id: number): string => `/api/files/${id}/preview`,
  // A text file's head as text, and whether the server cut it there. Quiet: the viewer says why.
  previewText: async (id: number): Promise<FilePreviewText> => {
    const r = await req<Response>(`/api/files/${id}/preview`, {}, { raw: true, quiet: true });
    return { text: await r.text(), truncated: r.headers.get(PREVIEW_TRUNCATED_HEADER) === "1" };
  },
};