/**
 * Management Portal API Routes
 * Completely separate authentication system for security isolation
 */

const express = require('express');
const router = express.Router();
const jwt = require('jsonwebtoken');
const bcrypt = require('bcryptjs'); // Fixed: use bcryptjs instead of bcrypt
const { Op } = require('sequelize'); // Add Sequelize operators
const { Tenant, User, ManagementUser } = require('../models');

// Management-specific authentication middleware - NO shared auth with tenants
const requireManagementAuth = (req, res, next) => {
  const token = req.headers.authorization?.replace('Bearer ', '');
  
  if (!token) {
    return res.status(401).json({
      success: false,
      message: 'Management authentication required'
    });
  }
  
  try {
    // Use separate JWT secret for management
    const MANAGEMENT_SECRET = process.env.MANAGEMENT_JWT_SECRET || 'mgmt-super-secret-change-in-production';
    const decoded = jwt.verify(token, MANAGEMENT_SECRET);
    
    // Verify this is a management token with proper role
    if (!decoded.isManagement || !['super_admin', 'platform_admin'].includes(decoded.role)) {
      return res.status(403).json({
        success: false,
        message: 'Insufficient management privileges'
      });
    }
    
    req.managementUser = {
      id: decoded.userId,
      username: decoded.username,
      role: decoded.role,
      isManagement: true
    };
    
    next();
  } catch (error) {
    return res.status(403).json({
      success: false,
      message: 'Invalid management token',
      error: error.message
    });
  }
};

// Management login endpoint - separate from tenant auth
router.post('/auth/login', async (req, res) => {
  try {
    const { username, password } = req.body;
    
    // Use ManagementUser model instead of hardcoded users
    const managementUser = await ManagementUser.findByCredentials(username, password);
    
    if (!managementUser) {
      return res.status(401).json({
        success: false,
        message: 'Invalid management credentials'
      });
    }
    
    const MANAGEMENT_SECRET = process.env.MANAGEMENT_JWT_SECRET || 'mgmt-super-secret-change-in-production';
    const token = jwt.sign({
      userId: managementUser.id,
      username: managementUser.username,
      role: managementUser.role,
      isManagement: true
    }, MANAGEMENT_SECRET, { expiresIn: '8h' });
    
    res.json({
      success: true,
      token,
      user: {
        id: managementUser.id,
        username: managementUser.username,
        email: managementUser.email,
        first_name: managementUser.first_name,
        last_name: managementUser.last_name,
        role: managementUser.role
      }
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: 'Management authentication error',
      error: error.message
    });
  }
});

// Apply management authentication to all other routes
router.use(requireManagementAuth);

// Security audit logging for all management operations
router.use((req, res, next) => {
  const auditLog = {
    timestamp: new Date().toISOString(),
    user: req.managementUser.username,
    role: req.managementUser.role,
    method: req.method,
    path: req.path,
    ip: req.ip,
    userAgent: req.headers['user-agent']
  };
  
  console.log('[MANAGEMENT AUDIT]', JSON.stringify(auditLog));
  next();
});

/**
 * GET /api/management/system-info - Platform system information
 */
router.get('/system-info', async (req, res) => {
  try {
    const tenantCount = await Tenant.count();
    const userCount = await User.count();
    
    res.json({
      success: true,
      data: {
        platform: {
          name: 'UAMILS Platform',
          version: '1.0.0',
          environment: process.env.NODE_ENV || 'development'
        },
        statistics: {
          tenants: tenantCount,
          total_users: userCount,
          uptime: process.uptime()
        },
        security: {
          management_access_level: req.managementUser.role,
          last_backup: process.env.LAST_BACKUP_DATE || 'Not configured'
        }
      }
    });
  } catch (error) {
    console.error('Management: Error fetching system info:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch system information',
      error: error.message
    });
  }
});

/**
 * GET /api/management/tenants - List all tenants with admin details
 */
router.get('/tenants', async (req, res) => {
  try {
    const { limit = 50, offset = 0, search, auth_provider } = req.query;
    
    const whereClause = {};
    if (search) {
      whereClause[Op.or] = [
        { name: { [Op.iLike]: `%${search}%` } },
        { slug: { [Op.iLike]: `%${search}%` } },
        { domain: { [Op.iLike]: `%${search}%` } }
      ];
    }
    if (auth_provider) {
      whereClause.auth_provider = auth_provider;
    }

    const tenants = await Tenant.findAndCountAll({
      where: whereClause,
      include: [{
        model: User,
        as: 'users',
        attributes: ['id', 'username', 'email', 'role', 'last_login', 'created_at'],
        limit: 10
      }],
      limit: Math.min(parseInt(limit), 100),
      offset: parseInt(offset),
      order: [['created_at', 'DESC']]
    });

    res.json({
      success: true,
      data: tenants.rows,
      pagination: {
        total: tenants.count,
        limit: parseInt(limit),
        offset: parseInt(offset),
        pages: Math.ceil(tenants.count / parseInt(limit))
      }
    });

  } catch (error) {
    console.error('Management: Error fetching tenants:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch tenants'
    });
  }
});

/**
 * POST /api/management/tenants - Create new tenant
 */
router.post('/tenants', async (req, res) => {
  try {
    const tenantData = req.body;
    
    // Enhanced validation for management portal
    if (!tenantData.name || !tenantData.slug) {
      return res.status(400).json({
        success: false,
        message: 'Name and slug are required'
      });
    }

    // Convert empty domain string to null to avoid unique constraint issues
    if (tenantData.domain === '') {
      tenantData.domain = null;
    }

    // Check for unique slug
    const existingTenant = await Tenant.findOne({ where: { slug: tenantData.slug } });
    if (existingTenant) {
      return res.status(409).json({
        success: false,
        message: 'Tenant slug already exists'
      });
    }

    // Check for unique domain if provided
    if (tenantData.domain) {
      const existingDomain = await Tenant.findOne({ where: { domain: tenantData.domain } });
      if (existingDomain) {
        return res.status(409).json({
          success: false,
          message: 'Domain already exists for another tenant'
        });
      }
    }

    // Log management action
    console.log(`Management: Admin ${req.managementUser.username} creating tenant: ${tenantData.name}`);

    const tenant = await Tenant.create(tenantData);

    res.status(201).json({
      success: true,
      data: tenant,
      message: 'Tenant created successfully'
    });

  } catch (error) {
    console.error('Management: Error creating tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to create tenant'
    });
  }
});

/**
 * GET /api/management/tenants/:id - Get tenant details
 */
router.get('/tenants/:id', async (req, res) => {
  try {
    const tenant = await Tenant.findByPk(req.params.id, {
      include: [{
        model: User,
        as: 'users',
        attributes: ['id', 'username', 'email', 'role', 'last_login', 'created_at']
      }]
    });

    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }

    res.json({
      success: true,
      data: tenant
    });

  } catch (error) {
    console.error('Management: Error fetching tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch tenant'
    });
  }
});

/**
 * PUT /api/management/tenants/:id - Update tenant
 */
router.put('/tenants/:id', async (req, res) => {
  try {
    const tenant = await Tenant.findByPk(req.params.id);
    
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }

    const updateData = req.body;

    // Convert empty domain string to null to avoid unique constraint issues
    if (updateData.domain === '') {
      updateData.domain = null;
    }

    // Check for unique domain if provided and different from current
    if (updateData.domain && updateData.domain !== tenant.domain) {
      const existingDomain = await Tenant.findOne({ 
        where: { 
          domain: updateData.domain,
          id: { [require('sequelize').Op.ne]: tenant.id }
        } 
      });
      if (existingDomain) {
        return res.status(409).json({
          success: false,
          message: 'Domain already exists for another tenant'
        });
      }
    }

    // Log management action
    console.log(`Management: Admin ${req.managementUser.username} updating tenant: ${tenant.name}`);

    await tenant.update(updateData);

    res.json({
      success: true,
      data: tenant,
      message: 'Tenant updated successfully'
    });

  } catch (error) {
    console.error('Management: Error updating tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to update tenant'
    });
  }
});

/**
 * DELETE /api/management/tenants/:id - Delete tenant
 */
router.delete('/tenants/:id', async (req, res) => {
  try {
    const tenant = await Tenant.findByPk(req.params.id);
    
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }

    // Prevent deletion of default tenant
    if (tenant.slug === 'default') {
      return res.status(403).json({
        success: false,
        message: 'Cannot delete default tenant'
      });
    }

    // Log management action
    console.log(`Management: Admin ${req.managementUser.username} deleting tenant: ${tenant.name}`);

    await tenant.destroy();

    res.json({
      success: true,
      message: 'Tenant deleted successfully'
    });

  } catch (error) {
    console.error('Management: Error deleting tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to delete tenant'
    });
  }
});

/**
 * GET /api/management/users - List all users across tenants
 */
router.get('/users', async (req, res) => {
  try {
    const { limit = 50, offset = 0, search, role, tenant_id } = req.query;
    
    const whereClause = {};
    if (search) {
      whereClause[Op.or] = [
        { username: { [Op.iLike]: `%${search}%` } },
        { email: { [Op.iLike]: `%${search}%` } }
      ];
    }
    if (role) {
      whereClause.role = role;
    }
    if (tenant_id) {
      whereClause.tenant_id = tenant_id;
    }

    const users = await User.findAndCountAll({
      where: whereClause,
      include: [{
        model: Tenant,
        as: 'tenant',
        attributes: ['id', 'name', 'slug']
      }],
      attributes: { exclude: ['password'] }, // Never expose passwords
      limit: Math.min(parseInt(limit), 100),
      offset: parseInt(offset),
      order: [['created_at', 'DESC']]
    });

    res.json({
      success: true,
      data: users.rows,
      pagination: {
        total: users.count,
        limit: parseInt(limit),
        offset: parseInt(offset),
        pages: Math.ceil(users.count / parseInt(limit))
      }
    });

  } catch (error) {
    console.error('Management: Error fetching users:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch users'
    });
  }
});

/**
 * GET /api/management/system/info - System information
 */
router.get('/system/info', async (req, res) => {
  try {
    // Gather system statistics
    const tenantCount = await Tenant.count();
    const userCount = await User.count();
    const activeTenantsCount = await Tenant.count({ where: { is_active: true } });
    
    const systemInfo = {
      version: process.env.APP_VERSION || '1.0.0',
      environment: process.env.NODE_ENV || 'production',
      uptime: process.uptime(),
      database: {
        status: 'connected',
        version: 'PostgreSQL 15',
        connections: 5, // You can get this from pg pool
        maxConnections: 100
      },
      statistics: {
        tenants: tenantCount,
        users: userCount,
        activeTenants: activeTenantsCount
      },
      memory: {
        used: Math.round(process.memoryUsage().heapUsed / 1024 / 1024) + 'MB',
        total: Math.round(process.memoryUsage().heapTotal / 1024 / 1024) + 'MB',
        percentage: Math.round((process.memoryUsage().heapUsed / process.memoryUsage().heapTotal) * 100)
      },
      lastBackup: new Date(Date.now() - 24*60*60*1000).toISOString(), // Mock
      ssl: {
        status: 'valid',
        expiresAt: new Date(Date.now() + 90*24*60*60*1000).toISOString() // Mock 90 days
      }
    };

    res.json({
      success: true,
      data: systemInfo
    });

  } catch (error) {
    console.error('Management: Error fetching system info:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch system information'
    });
  }
});

/**
 * POST /api/management/tenants/:tenantId/users - Create user in specific tenant
 */
router.post('/tenants/:tenantId/users', async (req, res) => {
  try {
    const { tenantId } = req.params;
    const userData = req.body;
    
    // Verify tenant exists
    const tenant = await Tenant.findByPk(tenantId);
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }
    
    // Check if user already exists in this tenant
    const existingUser = await User.findOne({
      where: { 
        username: userData.username,
        tenant_id: tenantId
      }
    });
    
    if (existingUser) {
      return res.status(409).json({
        success: false,
        message: 'User already exists in this tenant'
      });
    }
    
    // Hash password
    const bcrypt = require('bcryptjs');
    const hashedPassword = await bcrypt.hash(userData.password, 10);
    
    // Create user with tenant association
    const user = await User.create({
      ...userData,
      password_hash: hashedPassword, // Use correct field name
      tenant_id: tenantId,
      created_by: req.managementUser.username
    });
    
    // Remove password_hash from response
    const userResponse = user.toJSON();
    delete userResponse.password_hash;
    
    console.log(`Management: Admin ${req.managementUser.username} created user ${userData.username} in tenant ${tenant.name}`);
    
    res.status(201).json({
      success: true,
      data: userResponse,
      message: 'User created successfully'
    });
    
  } catch (error) {
    console.error('Management: Error creating user:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to create user',
      error: error.message
    });
  }
});

/**
 * PUT /api/management/tenants/:tenantId/users/:userId - Update user in tenant
 */
router.put('/tenants/:tenantId/users/:userId', async (req, res) => {
  try {
    const { tenantId, userId } = req.params;
    const updates = req.body;
    
    const user = await User.findOne({
      where: { 
        id: userId,
        tenant_id: tenantId
      },
      include: [{
        model: Tenant,
        as: 'tenant',
        attributes: ['name']
      }]
    });
    
    if (!user) {
      return res.status(404).json({
        success: false,
        message: 'User not found in this tenant'
      });
    }
    
    // Hash password if provided
    if (updates.password) {
      const bcrypt = require('bcryptjs');
      updates.password_hash = await bcrypt.hash(updates.password, 10);
      delete updates.password; // Remove plain password
    }
    
    await user.update(updates);
    
    // Remove password_hash from response
    const userResponse = user.toJSON();
    delete userResponse.password_hash;
    
    console.log(`Management: Admin ${req.managementUser.username} updated user ${user.username} in tenant ${user.tenant.name}`);
    
    res.json({
      success: true,
      data: userResponse,
      message: 'User updated successfully'
    });
    
  } catch (error) {
    console.error('Management: Error updating user:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to update user',
      error: error.message
    });
  }
});

/**
 * DELETE /api/management/tenants/:tenantId/users/:userId - Delete user from tenant
 */
router.delete('/tenants/:tenantId/users/:userId', async (req, res) => {
  try {
    const { tenantId, userId } = req.params;
    
    const user = await User.findOne({
      where: { 
        id: userId,
        tenant_id: tenantId
      },
      include: [{
        model: Tenant,
        as: 'tenant',
        attributes: ['name']
      }]
    });
    
    if (!user) {
      return res.status(404).json({
        success: false,
        message: 'User not found in this tenant'
      });
    }
    
    // Prevent deleting the last admin user
    if (user.role === 'admin') {
      const adminCount = await User.count({
        where: {
          tenant_id: tenantId,
          role: 'admin'
        }
      });
      
      if (adminCount <= 1) {
        return res.status(403).json({
          success: false,
          message: 'Cannot delete the last admin user in tenant'
        });
      }
    }
    
    console.log(`Management: Admin ${req.managementUser.username} deleting user ${user.username} from tenant ${user.tenant.name}`);
    
    await user.destroy();
    
    res.json({
      success: true,
      message: 'User deleted successfully'
    });
    
  } catch (error) {
    console.error('Management: Error deleting user:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to delete user',
      error: error.message
    });
  }
});

/**
 * GET /api/management/tenants/:tenantId/users - Get all users in a tenant
 */
router.get('/tenants/:tenantId/users', async (req, res) => {
  try {
    const { tenantId } = req.params;
    const { limit = 50, offset = 0, search, role } = req.query;
    
    // Verify tenant exists
    const tenant = await Tenant.findByPk(tenantId);
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }
    
    const whereClause = { tenant_id: tenantId };
    
    if (search) {
      whereClause[Op.or] = [
        { username: { [Op.iLike]: `%${search}%` } },
        { email: { [Op.iLike]: `%${search}%` } },
        { first_name: { [Op.iLike]: `%${search}%` } },
        { last_name: { [Op.iLike]: `%${search}%` } }
      ];
    }
    
    if (role) {
      whereClause.role = role;
    }
    
    const users = await User.findAndCountAll({
      where: whereClause,
      attributes: { exclude: ['password_hash'] }, // Exclude password_hash, not password
      limit: Math.min(parseInt(limit), 100),
      offset: parseInt(offset),
      order: [['created_at', 'DESC']]
    });
    
    res.json({
      success: true,
      data: users.rows,
      pagination: {
        total: users.count,
        limit: parseInt(limit),
        offset: parseInt(offset),
        pages: Math.ceil(users.count / parseInt(limit))
      },
      tenant: {
        id: tenant.id,
        name: tenant.name,
        slug: tenant.slug
      }
    });
    
  } catch (error) {
    console.error('Management: Error fetching tenant users:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch tenant users',
      error: error.message
    });
  }
});

/**
 * POST /api/management/tenants/:tenantId/activate - Activate tenant
 */
router.post('/tenants/:tenantId/activate', async (req, res) => {
  try {
    const { tenantId } = req.params;
    
    const tenant = await Tenant.findByPk(tenantId);
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }
    
    await tenant.update({ is_active: true });
    
    console.log(`Management: Admin ${req.managementUser.username} activated tenant ${tenant.name}`);
    
    res.json({
      success: true,
      data: tenant,
      message: 'Tenant activated successfully'
    });
    
  } catch (error) {
    console.error('Management: Error activating tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to activate tenant'
    });
  }
});

/**
 * POST /api/management/tenants/:tenantId/deactivate - Deactivate tenant
 */
router.post('/tenants/:tenantId/deactivate', async (req, res) => {
  try {
    const { tenantId } = req.params;
    
    const tenant = await Tenant.findByPk(tenantId);
    if (!tenant) {
      return res.status(404).json({
        success: false,
        message: 'Tenant not found'
      });
    }
    
    await tenant.update({ is_active: false });
    
    console.log(`Management: Admin ${req.managementUser.username} deactivated tenant ${tenant.name}`);
    
    res.json({
      success: true,
      data: tenant,
      message: 'Tenant deactivated successfully'
    });
    
  } catch (error) {
    console.error('Management: Error deactivating tenant:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to deactivate tenant'
    });
  }
});

module.exports = router;