/**
 * Reads and writes each user's settings in `user_settings`. The users routes
 * answer `GET` and `PATCH /api/users/me/settings` with it, and the digests read
 * their readers' choices from the same table.
 *
 * @module
 */

import { db } from "../db/connection.ts";
import {
  DEFAULT_SETTINGS,
  type UpdateSettingsRequest,
  type UserSettings,
} from "../../shared/settings.ts";
import { isUserSettingsRow, settingsRowToApi } from "../model/settings.ts";

/** Returns the settings of user `userId`, the defaults if they changed none. */
export function getSettings(userId: string): UserSettings {
  const row = db.prepare(
    `SELECT user_id, style, color_scheme, digest_weekly, digest_monthly, updated_at
       FROM user_settings WHERE user_id = ?;`,
  ).get(userId);
  return isUserSettingsRow(row)
    ? settingsRowToApi(row)
    : { ...DEFAULT_SETTINGS };
}

/**
 * Applies `patch` to the settings of user `userId` and returns them all. The
 * settings it leaves out keep their value.
 */
export function updateSettings(
  userId: string,
  patch: UpdateSettingsRequest,
): UserSettings {
  const next = { ...getSettings(userId), ...patch };
  db.prepare(
    `INSERT INTO user_settings
       (user_id, style, color_scheme, digest_weekly, digest_monthly, updated_at)
     VALUES (?, ?, ?, ?, ?, ?)
     ON CONFLICT (user_id) DO UPDATE SET
       style = excluded.style,
       color_scheme = excluded.color_scheme,
       digest_weekly = excluded.digest_weekly,
       digest_monthly = excluded.digest_monthly,
       updated_at = excluded.updated_at;`,
  ).run(
    userId,
    next.style,
    next.colorScheme,
    next.digestWeekly ? 1 : 0,
    next.digestMonthly ? 1 : 0,
    new Date().toISOString(),
  );
  return next;
}