import { fail, redirect } from '@sveltejs/kit';
import { getSessionUser } from '$lib/server/auth/session';
import { getDatabase } from '$lib/server/database';
import { getPagination, getRegistrySearch } from '$lib/server/pagination';
import { NOTIFICATION_CATEGORIES } from '$lib/server/notifications';
import { getPermissions } from '$lib/server/auth/authorization';
import {
  OVERSIGHT_NOTIFICATION_CATEGORIES,
  OVERSIGHT_NOTIFICATION_FREQUENCIES,
} from '$lib/server/oversight-notifications';
import {
  notificationOrderBy,
  parseNotificationSort,
  parseNotificationState,
} from '$lib/server/notification-sort';
import type { Actions, PageServerLoad } from './$types';

export const load: PageServerLoad = async ({ cookies, url }) => {
  const user = await getSessionUser(cookies);
  if (!user) redirect(303, '/sign-in');
  const database = await getDatabase();
  const state = parseNotificationState(url.searchParams.get('state'));
  const sort = parseNotificationSort(url.searchParams.get('sort'));
  const { search, pattern } = getRegistrySearch(url);
  const conditions = [
    'n.user_id=?',
    '(n.mandatory=1 OR COALESCE(p.in_app_enabled,1)=1)',
  ];
  const args: unknown[] = [user.id];
  if (state === 'unread') conditions.push('n.read_at IS NULL');
  if (state === 'read') conditions.push('n.read_at IS NOT NULL');
  if (search) {
    conditions.push(`(n.title LIKE ? ESCAPE '\\' COLLATE NOCASE
			OR n.body LIKE ? ESCAPE '\\' COLLATE NOCASE
			OR n.source LIKE ? ESCAPE '\\' COLLATE NOCASE)`);
    args.push(pattern, pattern, pattern);
  }
  const where = `WHERE ${conditions.join(' AND ')}`;
  const orderBy = notificationOrderBy(sort);
  const total = Number(
    (
      await (
        await database.prepare(
          `SELECT COUNT(*) AS total FROM notifications n LEFT JOIN notification_preferences p ON p.user_id=n.user_id AND p.category=n.category ${where}`,
        )
      ).get(...args)
    )?.total ?? 0,
  );
  const pagination = getPagination(url, total);
  const notifications = await (
    await database.prepare(`SELECT n.* FROM notifications n
		LEFT JOIN notification_preferences p ON p.user_id=n.user_id AND p.category=n.category
		${where} ORDER BY ${orderBy} LIMIT ? OFFSET ?`)
  ).all(...args, pagination.perPage, pagination.offset);
  const preferenceRows = await (
    await database.prepare(
      'SELECT * FROM notification_preferences WHERE user_id=?',
    )
  ).all(user.id);
  const permissions = await getPermissions(user);
  const oversightCategories = OVERSIGHT_NOTIFICATION_CATEGORIES.filter(
    (category) =>
      permissions.includes('*') || permissions.includes(category.permission),
  );
  const oversightRows = oversightCategories.length
    ? await (
        await database.prepare(
          'SELECT * FROM oversight_notification_preferences WHERE user_id=?',
        )
      ).all(user.id)
    : [];
  const oversightPreferences = oversightCategories.map((category) => ({
    ...category,
    frequency: String(
      oversightRows.find((row) => row.oversight_category === category.id)
        ?.frequency ?? 'immediate',
    ),
  }));
  const preferences = NOTIFICATION_CATEGORIES.map((name) => {
    const stored = preferenceRows.find((row) => row.category === name);
    return {
      category: name,
      inApp:
        name === 'isac'
          ? true
          : stored?.in_app_enabled === undefined
            ? true
            : Boolean(stored.in_app_enabled),
      browser: Boolean(stored?.browser_enabled),
      emailFrequency: String(stored?.email_frequency ?? 'none'),
    };
  });
  const unread = Number(
    (
      await (
        await database.prepare(`SELECT COUNT(*) AS count FROM notifications n
		LEFT JOIN notification_preferences p ON p.user_id=n.user_id AND p.category=n.category
		WHERE n.user_id=? AND n.read_at IS NULL AND (n.mandatory=1 OR COALESCE(p.in_app_enabled,1)=1)`)
      ).get(user.id)
    )?.count ?? 0,
  );
  return {
    notifications,
    preferences,
    oversightPreferences,
    pagination,
    filters: { state, sort, search },
    unread,
    hasVerifiedEmail: Boolean(
      await (
        await database.prepare('SELECT 1 FROM user_emails WHERE user_id=?')
      ).get(user.id),
    ),
  };
};

export const actions: Actions = {
  markRead: async ({ cookies, request }) => {
    const user = await getSessionUser(cookies);
    if (!user) redirect(303, '/sign-in');
    const id = String((await request.formData()).get('id') ?? '');
    await (
      await (
        await getDatabase()
      ).prepare(
        'UPDATE notifications SET read_at=COALESCE(read_at,?) WHERE id=? AND user_id=?',
      )
    ).run(new Date().toISOString(), id, user.id);
    return { notificationUpdated: true };
  },
  markAllRead: async ({ cookies }) => {
    const user = await getSessionUser(cookies);
    if (!user) redirect(303, '/sign-in');
    await (
      await (
        await getDatabase()
      ).prepare(
        'UPDATE notifications SET read_at=? WHERE user_id=? AND read_at IS NULL',
      )
    ).run(new Date().toISOString(), user.id);
    return { notificationsCleared: true };
  },
  savePreferences: async ({ cookies, request }) => {
    const user = await getSessionUser(cookies);
    if (!user) redirect(303, '/sign-in');
    const form = await request.formData();
    const database = await getDatabase();
    const now = new Date().toISOString();
    const hasEmail = Boolean(
      await (
        await database.prepare('SELECT 1 FROM user_emails WHERE user_id=?')
      ).get(user.id),
    );
    for (const category of NOTIFICATION_CATEGORIES) {
      const inApp =
        category === 'isac' || form.get(`inApp:${category}`) === 'on';
      const browser = form.get(`browser:${category}`) === 'on';
      const emailFrequency = String(form.get(`email:${category}`) ?? 'none');
      if (!['none', 'immediate', 'daily'].includes(emailFrequency))
        return fail(400, {
          notificationPreferenceError: 'Choose a valid email frequency.',
        });
      if (emailFrequency !== 'none' && !hasEmail)
        return fail(400, {
          notificationPreferenceError:
            'Add and verify a magic-link email before enabling email notifications.',
        });
      await (
        await database.prepare(`INSERT INTO notification_preferences(user_id,category,in_app_enabled,browser_enabled,email_frequency,updated_at)
				VALUES(?,?,?,?,?,?) ON CONFLICT(user_id,category) DO UPDATE SET
				in_app_enabled=excluded.in_app_enabled,browser_enabled=excluded.browser_enabled,email_frequency=excluded.email_frequency,updated_at=excluded.updated_at`)
      ).run(
        user.id,
        category,
        inApp ? 1 : 0,
        browser ? 1 : 0,
        emailFrequency,
        now,
      );
    }
    return {
      notificationPreferencesSaved: true,
      notificationPreferenceSaveToken: crypto.randomUUID(),
    };
  },
  saveOversightPreferences: async ({ cookies, request }) => {
    const user = await getSessionUser(cookies);
    if (!user) redirect(303, '/sign-in');
    const permissions = await getPermissions(user);
    const available = OVERSIGHT_NOTIFICATION_CATEGORIES.filter(
      (category) =>
        permissions.includes('*') || permissions.includes(category.permission),
    );
    if (!available.length)
      return fail(403, {
        oversightPreferenceError: 'Oversight permission is required.',
      });
    const form = await request.formData();
    const database = await getDatabase();
    const now = new Date().toISOString();
    for (const category of available) {
      const frequency = String(
        form.get(`oversight:${category.id}`) ?? 'immediate',
      );
      if (!OVERSIGHT_NOTIFICATION_FREQUENCIES.includes(frequency as any)) {
        return fail(400, {
          oversightPreferenceError:
            'Choose a valid Oversight notification frequency.',
        });
      }
      await (
        await database.prepare(`INSERT INTO oversight_notification_preferences(user_id,oversight_category,frequency,updated_at)
				VALUES(?,?,?,?) ON CONFLICT(user_id,oversight_category) DO UPDATE SET
				frequency=excluded.frequency,updated_at=excluded.updated_at`)
      ).run(user.id, category.id, frequency, now);
    }
    return {
      oversightPreferencesSaved: true,
      notificationPreferenceSaveToken: crypto.randomUUID(),
    };
  },
};