const { client: gqlClient } = require("../graphql-client/graphql-client");
const { GET_JOB_WATCHERS, GET_NOTIFICATION_ASSOCIATIONS } = require("../graphql-client/queries");
const { dispatchEmailsToQueue } = require("./queues/emailQueue");
const { dispatchAppsToQueue } = require("./queues/appQueue");
const { dispatchFcmsToQueue } = require("./queues/fcmQueue");

/**
 * Default channel preferences to fall back on if a recipient doesn't have specific preferences set for a scenario.
 * @type {Readonly<{app: boolean, email: boolean, fcm: boolean}>}
 */
const DEFAULT_CHANNEL_PREFERENCES = Object.freeze({
  app: false,
  email: false,
  fcm: false
});

/**
 * Normalizes channel preferences for a recipient based on their specific preferences for a scenario, falling back to
 * default preferences if not set.
 * @param preferences
 * @param fallbackPreferences
 * @returns {{app, email, fcm}}
 */
const normalizeChannelPreferences = (preferences, fallbackPreferences = DEFAULT_CHANNEL_PREFERENCES) => ({
  app: preferences?.app ?? fallbackPreferences.app ?? false,
  email: preferences?.email ?? fallbackPreferences.email ?? false,
  fcm: preferences?.fcm ?? fallbackPreferences.fcm ?? false
});

/**
 * Builds notification payloads for app, email, and FCM channels based on the provided parameters and recipient
 * preferences.
 * @param param0
 * @param param0.jobId
 * @param param0.jobRoNumber
 * @param param0.bodyShopId
 * @param param0.bodyShopName
 * @param param0.bodyShopTimezone
 * @param param0.scenarioKey
 * @param param0.scenarioTable
 * @param param0.key
 * @param param0.body
 * @param param0.variables
 * @param param0.recipients
 * @returns {{app: {jobId: *, jobRoNumber: *, bodyShopId: *, scenarioKey: *, scenarioTable: *, key: *, body: *, variables: *, recipients: *}, email: {jobId: *, jobRoNumber: *, bodyShopName: *, bodyShopTimezone: *, body: *, recipients: *}, fcm: {jobId: *, jobRoNumber: *, bodyShopId: *, bodyShopName: *, bodyShopTimezone: *, scenarioKey: *, scenarioTable: *, key: *, body: *, variables: *, recipients: *}}}
 */
const buildNotificationPayloads = ({
  jobId,
  jobRoNumber,
  bodyShopId,
  bodyShopName,
  bodyShopTimezone,
  scenarioKey,
  scenarioTable,
  key,
  body,
  variables,
  recipients
}) => ({
  app: {
    jobId,
    jobRoNumber,
    bodyShopId,
    scenarioKey,
    scenarioTable,
    key,
    body,
    variables,
    recipients: recipients
      .filter((recipient) => recipient.app)
      .map(({ user, employeeId, associationId }) => ({
        user,
        bodyShopId,
        employeeId,
        associationId
      }))
  },
  email: {
    jobId,
    jobRoNumber,
    bodyShopName,
    bodyShopTimezone,
    body,
    recipients: recipients
      .filter((recipient) => recipient.email)
      .map(({ user, firstName, lastName }) => ({ user, firstName, lastName }))
  },
  fcm: {
    jobId,
    jobRoNumber,
    bodyShopId,
    bodyShopName,
    bodyShopTimezone,
    scenarioKey,
    scenarioTable,
    key,
    body,
    variables,
    recipients: recipients
      .filter((recipient) => recipient.fcm)
      .map(({ user, employeeId, associationId }) => ({
        user,
        bodyShopId,
        employeeId,
        associationId
      }))
  }
});

/**
 * Dispatches notifications to job watchers based on their preferences for a given scenario. It retrieves the watchers
 * of a job, determines their notification preferences, builds the appropriate payloads for each channel, and dispatches
 * the notifications to the respective queues.
 * @param param0
 * @param param0.jobId
 * @param param0.scenarioKey
 * @param param0.key
 * @param param0.body
 * @param param0.variables
 * @param param0.scenarioTable
 * @param param0.extraRecipientEmails
 * @param param0.defaultChannelPreferences
 * @param param0.logger
 * @returns {Promise<boolean>}
 */
async function dispatchJobWatcherNotification({
  jobId,
  scenarioKey,
  key,
  body,
  variables = {},
  scenarioTable = "esignature_documents",
  extraRecipientEmails = [],
  defaultChannelPreferences = DEFAULT_CHANNEL_PREFERENCES,
  logger
}) {
  if (!jobId || !scenarioKey || !key || !body) {
    return false;
  }

  const watcherData = await gqlClient.request(GET_JOB_WATCHERS, { jobid: jobId });
  const bodyShopId = watcherData?.job?.bodyshop?.id;
  const bodyShopName = watcherData?.job?.bodyshop?.shopname;
  const bodyShopTimezone = watcherData?.job?.bodyshop?.timezone;
  const jobRoNumber = watcherData?.job?.ro_number;

  if (!bodyShopId || !bodyShopName) {
    logger?.log?.("dispatch-job-watcher-notification-missing-job-meta", "WARN", "notifications", "api", {
      jobId,
      scenarioKey
    });
    return false;
  }

  const recipientsByEmail = new Map();

  for (const watcher of watcherData?.job_watchers || []) {
    if (!watcher?.user_email) continue;

    recipientsByEmail.set(watcher.user_email, {
      email: watcher.user_email,
      firstName: watcher?.user?.employee?.first_name || null,
      lastName: watcher?.user?.employee?.last_name || null,
      employeeId: watcher?.user?.employee?.id || null
    });
  }

  for (const recipientEmail of extraRecipientEmails) {
    if (!recipientEmail || recipientsByEmail.has(recipientEmail)) continue;
    recipientsByEmail.set(recipientEmail, {
      email: recipientEmail,
      firstName: null,
      lastName: null,
      employeeId: null
    });
  }

  const recipientEmails = [...recipientsByEmail.keys()];

  if (!recipientEmails.length) {
    logger?.log?.("dispatch-job-watcher-notification-no-recipients", "INFO", "notifications", "api", {
      jobId,
      scenarioKey
    });
    return false;
  }

  const associationsData = await gqlClient.request(GET_NOTIFICATION_ASSOCIATIONS, {
    emails: recipientEmails,
    shopid: bodyShopId
  });

  const eligibleRecipients = (associationsData?.associations || [])
    .map((association) => {
      const preferences = normalizeChannelPreferences(
        association?.notification_settings?.[scenarioKey],
        defaultChannelPreferences
      );

      if (!preferences.app && !preferences.email && !preferences.fcm) {
        return null;
      }

      const watcher = recipientsByEmail.get(association.useremail);

      return {
        user: association.useremail,
        app: preferences.app,
        email: preferences.email,
        fcm: preferences.fcm,
        firstName: watcher?.firstName || null,
        lastName: watcher?.lastName || null,
        employeeId: watcher?.employeeId || null,
        associationId: association.id
      };
    })
    .filter(Boolean);

  if (!eligibleRecipients.length) {
    logger?.log?.("dispatch-job-watcher-notification-no-eligible-recipients", "INFO", "notifications", "api", {
      jobId,
      scenarioKey,
      bodyShopId
    });
    return false;
  }

  const payloads = buildNotificationPayloads({
    jobId,
    jobRoNumber,
    bodyShopId,
    bodyShopName,
    bodyShopTimezone,
    scenarioKey,
    scenarioTable,
    key,
    body,
    variables,
    recipients: eligibleRecipients
  });

  const dispatches = [];

  if (payloads.email.recipients.length) {
    dispatches.push(dispatchEmailsToQueue({ emailsToDispatch: [payloads.email], logger }));
  }

  if (payloads.app.recipients.length) {
    dispatches.push(dispatchAppsToQueue({ appsToDispatch: [payloads.app], logger }));
  }

  if (payloads.fcm.recipients.length) {
    dispatches.push(dispatchFcmsToQueue({ fcmsToDispatch: [payloads.fcm], logger }));
  }

  if (!dispatches.length) {
    return false;
  }

  await Promise.all(dispatches);

  return true;
}

module.exports = {
  DEFAULT_CHANNEL_PREFERENCES,
  dispatchJobWatcherNotification
};