import { mkdirSync } from "node:fs";
import { dirname } from "node:path";
import Database from "better-sqlite3";
import { SQLITE_PATH } from "./config.js";

mkdirSync(dirname(SQLITE_PATH), { recursive: true });

const db = new Database(SQLITE_PATH);
db.pragma("journal_mode = WAL");
db.pragma("foreign_keys = ON");
db.pragma("busy_timeout = 5000");

db.exec(`
  CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    google_sub TEXT NOT NULL UNIQUE,
    email TEXT NOT NULL,
    name TEXT,
    picture TEXT,
    created_at TEXT NOT NULL DEFAULT (datetime('now'))
  );

  CREATE TABLE IF NOT EXISTS oauth_tokens (
    user_id INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
    access_token TEXT NOT NULL,
    refresh_token TEXT,
    expiry INTEGER NOT NULL
  );

  CREATE TABLE IF NOT EXISTS watch_state (
    user_id INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
    history_id TEXT NOT NULL,
    expiration INTEGER NOT NULL
  );
`);

const getUserByIdStmt = db.prepare(`SELECT * FROM users WHERE id = ?`);
const getUserByEmailStmt = db.prepare(
  `SELECT * FROM users WHERE LOWER(email) = LOWER(?)`,
);
const getTokensStmt = db.prepare(`SELECT * FROM oauth_tokens WHERE user_id = ?`);
const listUsersWithTokensStmt = db.prepare(`
  SELECT u.*
  FROM users u
  INNER JOIN oauth_tokens t ON t.user_id = u.id
`);
const saveTokensStmt = db.prepare(`
  INSERT INTO oauth_tokens (user_id, access_token, refresh_token, expiry)
  VALUES (@userId, @accessToken, @refreshToken, @expiry)
  ON CONFLICT(user_id) DO UPDATE SET
    access_token = excluded.access_token,
    refresh_token = COALESCE(excluded.refresh_token, oauth_tokens.refresh_token),
    expiry = excluded.expiry
`);
const getWatchStateStmt = db.prepare(
  `SELECT * FROM watch_state WHERE user_id = ?`,
);
const saveWatchStateStmt = db.prepare(`
  INSERT INTO watch_state (user_id, history_id, expiration)
  VALUES (@userId, @historyId, @expiration)
  ON CONFLICT(user_id) DO UPDATE SET
    history_id = excluded.history_id,
    expiration = excluded.expiration
`);

export function getUserById(id) {
  return getUserByIdStmt.get(id) || null;
}

export function getUserByEmail(email) {
  if (!email) return null;
  return getUserByEmailStmt.get(email) || null;
}

export function getTokens(userId) {
  return getTokensStmt.get(userId) || null;
}

export function listUsersWithTokens() {
  return listUsersWithTokensStmt.all();
}

export function saveTokens(userId, { accessToken, refreshToken, expiry }) {
  saveTokensStmt.run({
    userId,
    accessToken,
    refreshToken: refreshToken || null,
    expiry,
  });
}

export function getWatchState(userId) {
  return getWatchStateStmt.get(userId) || null;
}

export function saveWatchState(userId, { historyId, expiration }) {
  saveWatchStateStmt.run({
    userId,
    historyId: String(historyId),
    expiration: Number(expiration),
  });
}