'use strict';

const CHANNELS = ['sms', 'email', 'bot'];

const ENV_KEYS = {
  sms: 'SMS_ENABLED',
  email: 'EMAIL_ENABLED',
  bot: 'BOT_ENABLED'
};

const DB_KEYS = {
  sms: 'smsEnabled',
  email: 'emailEnabled',
  bot: 'botEnabled'
};

const toBoolean = (value, fallback = false) => {
  if (typeof value === 'boolean') return value;
  if (value === undefined || value === null || value === '') return fallback;
  if (typeof value === 'number') return value !== 0;
  const normalized = String(value).trim().toLowerCase();
  if (['true', '1', 'yes', 'on'].includes(normalized)) return true;
  if (['false', '0', 'no', 'off'].includes(normalized)) return false;
  return fallback;
};

const isEnvChannelEnabled = (channel, envConfig = {}) => {
  const key = ENV_KEYS[channel];
  if (!key) return false;
  return toBoolean(envConfig[key], false);
};

const isDbChannelEnabled = (channel, stored = {}) => {
  const key = DB_KEYS[channel];
  if (!key) return false;
  const value = stored == null ? undefined : stored[key];
  if (value === undefined || value === null || value === '') return true;
  return toBoolean(value, true);
};

const isChannelEnabled = (channel, { env = {}, db = {} } = {}) => {
  return isEnvChannelEnabled(channel, env) && isDbChannelEnabled(channel, db);
};

const toPublicMessaging = (stored = {}, envConfig = {}) => {
  const messaging = {};
  const env = {};
  CHANNELS.forEach((channel) => {
    messaging[DB_KEYS[channel]] = isDbChannelEnabled(channel, stored);
    env[DB_KEYS[channel]] = isEnvChannelEnabled(channel, envConfig);
  });
  messaging.env = env;
  return messaging;
};

const parseIncomingMessaging = (body = {}) => {
  const source = body.messaging && typeof body.messaging === 'object'
    ? body.messaging
    : body;
  const result = {};
  let hasAny = false;

  CHANNELS.forEach((channel) => {
    const key = DB_KEYS[channel];
    if (!Object.prototype.hasOwnProperty.call(source, key) || source[key] === undefined) {
      return;
    }
    result[key] = toBoolean(source[key], true);
    hasAny = true;
  });

  return hasAny ? result : null;
};

module.exports = {
  CHANNELS,
  ENV_KEYS,
  DB_KEYS,
  toBoolean,
  isEnvChannelEnabled,
  isDbChannelEnabled,
  isChannelEnabled,
  toPublicMessaging,
  parseIncomingMessaging
};