/**
 * Turns the rows the playlist and follow services read from `playlists` into
 * the {@link Playlist} the API sends.
 *
 * @module
 */

import type { SQLOutputValue } from "node:sqlite";
import type { Playlist } from "../../shared/playlist.ts";

/**
 * Returned by the playlist and follow services' `SELECT`s on `playlists`,
 * which join the owner's name as `owner_username`. A query may add the
 * `dump_count` and `last_dump_at` columns (`VISIBLE_DUMP_FIGURES`), which
 * {@link playlistRowToApi} carries over when present.
 */
export interface PlaylistRow {
  id: string;
  user_id: string;
  title: string;
  /** Unique among its owner's playlists, and set on every row since 0021. */
  slug: string;
  owner_username: string;
  description: string | null;
  is_public: number;
  created_at: string;
  updated_at: string | null;
  image_mime: string | null;
  [key: string]: SQLOutputValue;
}

/** Checks whether a row `node:sqlite` returned is a {@link PlaylistRow}. */
export function isPlaylistRow(
  obj: unknown,
): obj is PlaylistRow {
  return !!obj && typeof obj === "object" &&
    "id" in obj && typeof obj.id === "string" &&
    "user_id" in obj && typeof obj.user_id === "string" &&
    "title" in obj && typeof obj.title === "string" &&
    "slug" in obj && typeof obj.slug === "string" &&
    "owner_username" in obj && typeof obj.owner_username === "string" &&
    "description" in obj &&
    (typeof obj.description === "string" || obj.description === null) &&
    "is_public" in obj && typeof obj.is_public === "number" &&
    "created_at" in obj && typeof obj.created_at === "string" &&
    "updated_at" in obj &&
    (typeof obj.updated_at === "string" || obj.updated_at === null) &&
    "image_mime" in obj &&
    (typeof obj.image_mime === "string" || obj.image_mime === null);
}

/** Converts `row` to the {@link Playlist} the playlist routes send. */
export function playlistRowToApi(row: PlaylistRow): Playlist {
  return {
    id: row.id,
    userId: row.user_id,
    title: row.title,
    slug: row.slug,
    description: row.description ?? undefined,
    isPublic: Boolean(row.is_public),
    createdAt: new Date(row.created_at),
    updatedAt: row.updated_at ? new Date(row.updated_at) : undefined,
    imageMime: row.image_mime ?? undefined,
    dumpCount: typeof row.dump_count === "number" ? row.dump_count : undefined,
    lastDumpAt: typeof row.last_dump_at === "string"
      ? new Date(row.last_dump_at)
      : undefined,
    ownerUsername: row.owner_username,
  };
}