"use strict";
const { getDb } = require("./db");
const { naturalCompare } = require("./util");

/* ==================== songs ==================== */
function getSongByFile(file) {
  return getDb().prepare("SELECT * FROM songs WHERE file = ?").get(file);
}
function getSongById(id) {
  return getDb().prepare("SELECT * FROM songs WHERE id = ?").get(id);
}
function getAllSongs() {
  const rows = getDb().prepare("SELECT * FROM songs").all();
  return rows.sort((a, b) => naturalCompare(a.file, b.file));
}
function upsertSong(s) {
  const d = getDb();
  const ex = getSongByFile(s.file);
  if (ex) {
    d.prepare(
      `UPDATE songs SET name=?, artist=?, cover=?, duration=?, file_size=? WHERE file=?`
    ).run(
      s.name != null ? s.name : ex.name,
      s.artist != null ? s.artist : ex.artist,
      s.cover != null ? s.cover : ex.cover,
      s.duration != null ? s.duration : ex.duration,
      s.file_size != null ? s.file_size : ex.file_size,
      s.file
    );
    return getSongByFile(s.file);
  }
  d.prepare(
    `INSERT INTO songs (file, name, artist, cover, duration, file_size, heat, cache_status, created_at)
     VALUES (?, ?, ?, ?, ?, ?, 0, 'pending', ?)`
  ).run(
    s.file,
    s.name || "",
    s.artist || "",
    s.cover || "",
    s.duration != null ? s.duration : null,
    s.file_size || 0,
    Date.now()
  );
  return getSongByFile(s.file);
}
function updateSong(file, fields) {
  const keys = Object.keys(fields);
  if (!keys.length) return;
  const set = keys.map((k) => `${k}=?`).join(", ");
  getDb()
    .prepare(`UPDATE songs SET ${set} WHERE file=?`)
    .run(...keys.map((k) => fields[k]), file);
}
function deleteSongByFile(file) {
  return getDb().prepare("DELETE FROM songs WHERE file = ?").run(file);
}
function setCacheStatus(file, status) {
  getDb().prepare("UPDATE songs SET cache_status=? WHERE file=?").run(status, file);
}
function incrementHeat(file) {
  getDb().prepare("UPDATE songs SET heat = heat + 1 WHERE file=?").run(file);
  return getSongByFile(file)?.heat || 0;
}

/* ==================== streams ==================== */
function createStream(id, name) {
  getDb()
    .prepare(
      "INSERT INTO streams (id, name, enabled, current_pos, media_seq, created_at) VALUES (?, ?, 1, 0, 0, ?)"
    )
    .run(id, name || id, Date.now());
  return getStream(id);
}
function listStreams() {
  return getDb().prepare("SELECT * FROM streams ORDER BY created_at ASC").all();
}
function getStream(id) {
  return getDb().prepare("SELECT * FROM streams WHERE id = ?").get(id);
}
function deleteStream(id) {
  return getDb().prepare("DELETE FROM streams WHERE id = ?").run(id);
}
function setStreamState(id, fields) {
  const keys = Object.keys(fields);
  if (!keys.length) return;
  const set = keys.map((k) => `${k}=?`).join(", ");
  getDb()
    .prepare(`UPDATE streams SET ${set} WHERE id=?`)
    .run(...keys.map((k) => fields[k]), id);
}
function setStreamEnabled(id, enabled) {
  setStreamState(id, { enabled: enabled ? 1 : 0 });
}

/* ==================== stream_playlist ==================== */
function getPlaylistRows(streamId) {
  return getDb()
    .prepare(
      `SELECT sp.id AS entry_id, sp.position, s.*
       FROM stream_playlist sp JOIN songs s ON s.id = sp.song_id
       WHERE sp.stream_id = ? ORDER BY sp.position ASC`
    )
    .all(streamId);
}
function playlistCount(streamId) {
  return getDb()
    .prepare("SELECT COUNT(*) c FROM stream_playlist WHERE stream_id=?")
    .get(streamId).c;
}
function addToPlaylist(streamId, songId) {
  const d = getDb();
  const max =
    d.prepare("SELECT COALESCE(MAX(position),-1) m FROM stream_playlist WHERE stream_id=?")
      .get(streamId).m + 1;
  d.prepare(
    "INSERT INTO stream_playlist (stream_id, song_id, position) VALUES (?, ?, ?)"
  ).run(streamId, songId, max);
}
function removePlaylistEntry(streamId, entryId) {
  const d = getDb();
  const row = d.prepare("SELECT position FROM stream_playlist WHERE id=? AND stream_id=?").get(entryId, streamId);
  if (!row) return false;
  d.prepare("DELETE FROM stream_playlist WHERE id=?").run(entryId);
  d.prepare("UPDATE stream_playlist SET position = position - 1 WHERE stream_id=? AND position > ?")
    .run(streamId, row.position);
  return true;
}
function setPlaylistOrder(streamId, entryIds) {
  const d = getDb();
  const stmt = d.prepare("UPDATE stream_playlist SET position=? WHERE id=? AND stream_id=?");
  const tx = d.transaction((ids) => {
    ids.forEach((id, i) => stmt.run(i, id, streamId));
  });
  tx(entryIds);
}
function clearPlaylist(streamId) {
  getDb().prepare("DELETE FROM stream_playlist WHERE stream_id=?").run(streamId);
}

/* ==================== sessions ==================== */
function createSession(token, expiresAt) {
  getDb()
    .prepare("INSERT INTO sessions (token, created_at, expires_at) VALUES (?, ?, ?)")
    .run(token, Date.now(), expiresAt);
}
function getSession(token) {
  const s = getDb().prepare("SELECT * FROM sessions WHERE token=?").get(token);
  if (!s) return null;
  if (s.expires_at < Date.now()) {
    deleteSession(token);
    return null;
  }
  return s;
}
function deleteSession(token) {
  getDb().prepare("DELETE FROM sessions WHERE token=?").run(token);
}
function purgeExpiredSessions() {
  return getDb().prepare("DELETE FROM sessions WHERE expires_at < ?").run(Date.now()).changes;
}

/* ==================== settings ==================== */
function getSetting(key, def = null) {
  const r = getDb().prepare("SELECT value FROM settings WHERE key=?").get(key);
  if (!r) return def;
  try {
    return JSON.parse(r.value);
  } catch (_) {
    return r.value;
  }
}
function setSetting(key, value) {
  getDb()
    .prepare(
      "INSERT INTO settings (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value=excluded.value"
    )
    .run(key, JSON.stringify(value));
}

module.exports = {
  getSongByFile, getSongById, getAllSongs, upsertSong, updateSong,
  deleteSongByFile, setCacheStatus, incrementHeat,
  createStream, listStreams, getStream, deleteStream, setStreamState, setStreamEnabled,
  getPlaylistRows, playlistCount, addToPlaylist, removePlaylistEntry,
  setPlaylistOrder, clearPlaylist,
  createSession, getSession, deleteSession, purgeExpiredSessions,
  getSetting, setSetting,
};