const express = require('express');
const router = express.Router();
const { getDb } = require('../dbPool');
const { requireAuth, requireAdmin } = require('../middlewares/auth');

// tkuser page_name → default_access 매핑 (permissionModel.js의 DEFAULT_PAGES와 동기화)
const TKUSER_DEFAULT_ACCESS = {
  's1.dashboard': true,
  's1.work.tbm': true,
  's1.work.report_create': true,
  's1.work.analysis': false,
  's1.work.nonconformity': true,
  's1.factory.repair_management': false,
  's1.inspection.daily_patrol': false,
  's1.inspection.checkin': true,
  's1.inspection.work_status': false,
  's1.safety.visit_request': true,
  's1.safety.management': false,
  's1.safety.checklist_manage': false,
  's1.attendance.my_vacation_info': true,
  's1.attendance.monthly': true,
  's1.attendance.vacation_request': true,
  's1.attendance.vacation_management': false,
  's1.attendance.vacation_allocation': false,
  's1.attendance.annual_overview': false,
  's1.admin.workers': false,
  's1.admin.projects': false,
  's1.admin.tasks': false,
  's1.admin.workplaces': false,
  's1.admin.equipments': false,
  's1.admin.issue_categories': false,
  's1.admin.attendance_report': false,
};

// system1 page_key → tkuser page_name 매핑
const PAGEKEY_TO_TKUSER = {
  'dashboard': 's1.dashboard',
  'work.tbm': 's1.work.tbm',
  'work.report-create': 's1.work.report_create',
  'work.report-view': 's1.work.report_create',
  'work.analysis': 's1.work.analysis',
  'work.visit-request': 's1.safety.visit_request',
  'work.issue-report': 's1.work.nonconformity',
  'work.issue-list': 's1.work.nonconformity',
  'work.issue-detail': 's1.work.nonconformity',
  'safety.issue_report': 's1.work.nonconformity',
  'safety.issue_list': 's1.work.nonconformity',
  'safety.issue_detail': 's1.work.nonconformity',
  'safety.checklist_manage': 's1.safety.checklist_manage',
  'admin.workers': 's1.admin.workers',
  'admin.projects': 's1.admin.projects',
  'admin.tasks': 's1.admin.tasks',
  'admin.workplaces': 's1.admin.workplaces',
  'admin.equipments': 's1.admin.equipments',
  'admin.codes': 's1.admin.tasks',
  'admin.safety-management': 's1.safety.management',
  'admin.safety-training-conduct': 's1.safety.management',
  'admin.attendance-report-comparison': 's1.admin.attendance_report',
  'admin.departments': 's1.admin.workers',
  'common.daily-attendance': 's1.inspection.checkin',
  'common.monthly-attendance': 's1.attendance.monthly',
  'common.vacation-request': 's1.attendance.vacation_request',
  'common.vacation-management': 's1.attendance.vacation_management',
  'common.annual-vacation-overview': 's1.attendance.annual_overview',
  'common.vacation-allocation': 's1.attendance.vacation_allocation',
  'inspection.daily_patrol': 's1.inspection.daily_patrol',
  'attendance.vacation_approval': 's1.attendance.vacation_management',
  'attendance.vacation_input': 's1.attendance.vacation_allocation',
};

/**
 * 모든 페이지 목록 조회
 * GET /api/pages
 */
router.get('/pages', requireAuth, async (req, res) => {
  try {
    const db = await getDb();
    const [pages] = await db.query(`
      SELECT id, page_key, page_name, page_path, category, description, is_admin_only, display_order
      FROM pages
      ORDER BY display_order, page_name
    `);

    res.json({ success: true, data: pages });
  } catch (error) {
    console.error('페이지 목록 조회 오류:', error);
    res.status(500).json({ success: false, error: '페이지 목록을 불러오는데 실패했습니다.' });
  }
});

/**
 * 특정 사용자의 페이지 접근 권한 조회
 * GET /api/users/:userId/page-access
 */
router.get('/users/:userId/page-access', requireAuth, async (req, res) => {
  try {
    const ssoUserId = req.params.userId;
    const db = await getDb();

    // SSO 사용자 조회 (department_id 포함)
    const [ssoRows] = await db.query(
      'SELECT user_id, username, name, role, department_id FROM sso_users WHERE user_id = ?',
      [ssoUserId]
    );
    if (ssoRows.length === 0) {
      return res.status(404).json({ success: false, error: '사용자를 찾을 수 없습니다.' });
    }
    const ssoUser = ssoRows[0];

    // SSO role로 Admin 체크
    const ssoRole = (ssoUser.role || '').toLowerCase();
    if (ssoRole === 'admin' || ssoRole === 'system') {
      const [allPages] = await db.query(`
        SELECT id, page_key, page_name, page_path, category, is_admin_only
        FROM pages
        ORDER BY display_order, page_name
      `);

      const pageAccess = allPages.map(page => ({
        page_id: page.id,
        page_key: page.page_key,
        page_name: page.page_name,
        page_path: page.page_path,
        category: page.category,
        is_admin_only: page.is_admin_only,
        can_access: true,
        is_default: true
      }));

      return res.json({ success: true, data: { user: ssoUser, pageAccess } });
    }

    // 일반 사용자: tkuser 권한 테이블에서 조회
    // 1) 개인 권한 (user_page_permissions)
    const [userPerms] = await db.query(
      'SELECT page_name, can_access FROM user_page_permissions WHERE user_id = ?',
      [ssoUserId]
    );
    const userPermMap = {};
    userPerms.forEach(p => { userPermMap[p.page_name] = !!p.can_access; });

    // 2) 부서 권한 (department_page_permissions)
    const deptPermMap = {};
    if (ssoUser.department_id) {
      const [deptPerms] = await db.query(
        'SELECT page_name, can_access FROM department_page_permissions WHERE department_id = ?',
        [ssoUser.department_id]
      );
      deptPerms.forEach(p => { deptPermMap[p.page_name] = !!p.can_access; });
    }

    // 3) 페이지 목록 조회 + 권한 매핑
    const [pages] = await db.query(`
      SELECT id, page_key, page_name, page_path, category, is_admin_only
      FROM pages
      WHERE is_admin_only = 0
      ORDER BY display_order, page_name
    `);

    const pageAccess = pages.map(page => {
      const tkuserKey = PAGEKEY_TO_TKUSER[page.page_key];
      let canAccess = false;

      if (tkuserKey) {
        // 우선순위: 개인 권한 > 부서 권한 > default_access
        if (tkuserKey in userPermMap) {
          canAccess = userPermMap[tkuserKey];
        } else if (tkuserKey in deptPermMap) {
          canAccess = deptPermMap[tkuserKey];
        } else if (tkuserKey in TKUSER_DEFAULT_ACCESS) {
          canAccess = TKUSER_DEFAULT_ACCESS[tkuserKey];
        }
      }

      return {
        page_id: page.id,
        page_key: page.page_key,
        page_name: page.page_name,
        page_path: page.page_path,
        category: page.category,
        is_admin_only: page.is_admin_only,
        can_access: canAccess ? 1 : 0
      };
    });

    res.json({ success: true, data: { user: ssoUser, pageAccess } });
  } catch (error) {
    console.error('페이지 접근 권한 조회 오류:', error);
    res.status(500).json({ success: false, error: '페이지 접근 권한을 불러오는데 실패했습니다.' });
  }
});

/**
 * 사용자에게 페이지 접근 권한 부여/회수
 * POST /api/users/:userId/page-access
 * Body: { pageIds: [1, 2, 3], canAccess: true }
 */
router.post('/users/:userId/page-access', requireAuth, async (req, res) => {
  try {
    const { userId } = req.params;
    const { pageIds, canAccess } = req.body;
    const adminUserId = req.user.user_id; // 권한을 부여하는 Admin의 user_id

    // Admin 권한 확인
    const db = await getDb();
    const [adminRows] = await db.query(`
      SELECT u.role_id, r.name as role_name
      FROM users u
      LEFT JOIN roles r ON u.role_id = r.id
      WHERE u.user_id = ?
    `, [adminUserId]);

    if (adminRows.length === 0 || (adminRows[0].role_name !== 'Admin' && adminRows[0].role_name !== 'System Admin')) {
      return res.status(403).json({ success: false, error: '권한이 없습니다. Admin 계정만 사용자 권한을 관리할 수 있습니다.' });
    }

    // 사용자 존재 확인
    const [userRows] = await db.query('SELECT user_id FROM users WHERE user_id = ?', [userId]);
    if (userRows.length === 0) {
      return res.status(404).json({ success: false, error: '사용자를 찾을 수 없습니다.' });
    }

    // 페이지 접근 권한 업데이트
    for (const pageId of pageIds) {
      // 기존 권한 확인
      const [existing] = await db.query(
        'SELECT * FROM user_page_access WHERE user_id = ? AND page_id = ?',
        [userId, pageId]
      );

      if (existing.length > 0) {
        // 업데이트
        await db.query(
          'UPDATE user_page_access SET can_access = ?, granted_at = NOW(), granted_by = ? WHERE user_id = ? AND page_id = ?',
          [canAccess ? 1 : 0, adminUserId, userId, pageId]
        );
      } else {
        // 삽입
        await db.query(
          'INSERT INTO user_page_access (user_id, page_id, can_access, granted_by) VALUES (?, ?, ?, ?)',
          [userId, pageId, canAccess ? 1 : 0, adminUserId]
        );
      }
    }

    res.json({ success: true, message: '페이지 접근 권한이 업데이트되었습니다.' });
  } catch (error) {
    console.error('페이지 접근 권한 부여 오류:', error);
    res.status(500).json({ success: false, error: '페이지 접근 권한을 업데이트하는데 실패했습니다.' });
  }
});

/**
 * 특정 페이지의 접근 권한 회수
 * DELETE /api/users/:userId/page-access/:pageId
 */
router.delete('/users/:userId/page-access/:pageId', requireAuth, async (req, res) => {
  try {
    const { userId, pageId } = req.params;
    const adminUserId = req.user.user_id;

    // Admin 권한 확인
    const db = await getDb();
    const [adminRows] = await db.query(`
      SELECT u.role_id, r.name as role_name
      FROM users u
      LEFT JOIN roles r ON u.role_id = r.id
      WHERE u.user_id = ?
    `, [adminUserId]);

    if (adminRows.length === 0 || (adminRows[0].role_name !== 'Admin' && adminRows[0].role_name !== 'System Admin')) {
      return res.status(403).json({ success: false, error: '권한이 없습니다.' });
    }

    // 접근 권한 삭제
    await db.query(
      'DELETE FROM user_page_access WHERE user_id = ? AND page_id = ?',
      [userId, pageId]
    );

    res.json({ success: true, message: '페이지 접근 권한이 회수되었습니다.' });
  } catch (error) {
    console.error('페이지 접근 권한 회수 오류:', error);
    res.status(500).json({ success: false, error: '페이지 접근 권한을 회수하는데 실패했습니다.' });
  }
});

/**
 * 모든 사용자의 페이지 접근 권한 요약 조회 (Admin용)
 * GET /api/page-access/summary
 */
router.get('/page-access/summary', requireAuth, async (req, res) => {
  try {
    const adminUserId = req.user.user_id;

    // Admin 권한 확인
    const db = await getDb();
    const [adminRows] = await db.query(`
      SELECT u.role_id, r.name as role_name
      FROM users u
      LEFT JOIN roles r ON u.role_id = r.id
      WHERE u.user_id = ?
    `, [adminUserId]);

    if (adminRows.length === 0 || (adminRows[0].role_name !== 'Admin' && adminRows[0].role_name !== 'System Admin')) {
      return res.status(403).json({ success: false, error: '권한이 없습니다.' });
    }

    // 모든 사용자와 페이지 권한 조회
    const [summary] = await db.query(`
      SELECT
        u.user_id,
        u.username,
        u.name,
        r.name as role_name,
        COUNT(DISTINCT upa.page_id) as accessible_pages_count,
        (SELECT COUNT(*) FROM pages WHERE is_admin_only = 0) as total_pages_count
      FROM users u
      LEFT JOIN roles r ON u.role_id = r.id
      LEFT JOIN user_page_access upa ON u.user_id = upa.user_id AND upa.can_access = 1
      WHERE r.name NOT IN ('Admin', 'System Admin')
      GROUP BY u.user_id, u.username, u.name, r.name
      ORDER BY u.username
    `);

    res.json({ success: true, data: summary });
  } catch (error) {
    console.error('페이지 접근 권한 요약 조회 오류:', error);
    res.status(500).json({ success: false, error: '페이지 접근 권한 요약을 불러오는데 실패했습니다.' });
  }
});

module.exports = router;