import { Request, Response } from 'express';
import Role from '../models/roles';
import { FindOptions, Op } from 'sequelize';
import { logger } from '../utils/logger';
import Permission from '../models/permissions';
import RolePermission from '../models/rolePermissions';

const buildRoleWhereClause = (filter: Record<string, any>) => {

    const whereClause: any = {};

    if (filter) {
        if (filter.name) {
            whereClause.name = { [Op.like]: `%${filter.name}%` };
        }

        if (filter.date) {
            const date = new Date(filter.date); 
            if (!isNaN(date.getTime())) {
                const startOfDay = new Date(date);
                startOfDay.setHours(0, 0, 0, 0);

                const endOfDay = new Date(date);
                endOfDay.setHours(23, 59, 59, 999);

                whereClause.created_at = { 
                    [Op.gte]: startOfDay, 
                    [Op.lte]: endOfDay 
                };
            }
        }
        if (filter.created_before) {
            const beforeDate = new Date(filter.created_before);
            if (!isNaN(beforeDate.getTime())) {
                whereClause.created_at = { ...whereClause.created_at, [Op.lte]: beforeDate };
            }
        }

        if (filter.created_after) {
            const afterDate = new Date(filter.created_after);
            if (!isNaN(afterDate.getTime())) {
                whereClause.created_at = { ...whereClause.created_at, [Op.gte]: afterDate };
            }
        }

    }
    return whereClause;

}

const getAllRoles = async (req: Request, res: Response) => {
    try {
        const { sort_by, sort_order, page, limit } = req.query;
        const filter = req.query.filter as Record<string, any>;

        const allowedSortColumns = ['id', 'name', 'created_at'];

        const whereClause = buildRoleWhereClause(filter);

        const currentPage = parseInt(page as string) || 1;
        const pageSize = parseInt(limit as string) || 10;

        const options: FindOptions = {
            where: whereClause,
            limit: pageSize,
            offset: (currentPage - 1) * pageSize,
            order: []
        };
        if (sort_by && allowedSortColumns.includes(sort_by as string)) {
            options.order = [[sort_by as string, sort_order === 'desc' ? 'DESC' : 'ASC']];
        } else {
            options.order = [['id', 'ASC']];
        }

        const [roles, totalRoles] = await Promise.all([
            Role.findAll(options),
            Role.count({ where: whereClause }),
        ]);
        const data = {
            page: currentPage,
            limit: pageSize,
            total: totalRoles,
            data: roles
        }

        res.status(200).json(data);

    } catch (error) {
        logger.error('Error fetching roles:');
        logger.error(error);
        res.status(500).json({ error: 'Error fetching roles' });
    }
}

const assignPermissionsToRole = async (req: Request, res: Response) => {
  try {
    const { roleId } = req.params;
    const { permission_ids } = req.body;

    // Validate if the role exists
    const role = await Role.findByPk(roleId);
    if (!role) {
      return res.status(404).json({ error: 'Role not found' });
    }

    // Fetch all permissions that match the given IDs
    const existingPermissions = await Permission.findAll({ where: { id: permission_ids } });

    // Extract IDs of existing permissions
    const existingPermissionIds = existingPermissions.map(permission => permission.id);

    // Identify non-existent permissions
    const nonExistentPermissionIds = permission_ids.filter((id: number) => !existingPermissionIds.includes(id));

    // Assign only the existing permissions to the role
    const rolePermissions = await Promise.all(
      existingPermissionIds.map(async (permission_id: number) => {
        return await RolePermission.create({ role_id: parseInt(roleId, 10), permission_id });
      })
    );

    return res.status(201).json({
      message: 'Permissions processed successfully',
      assignedPermissions: rolePermissions,
      nonExistentPermissions: nonExistentPermissionIds,
    });

  } catch (error) {
    logger.error('Error assigning permissions to role:');
    logger.error(error);
    return res.status(500).json({
      error: 'Error while assigning permissions to the role.',
    });
  }
};

export { getAllRoles,assignPermissionsToRole }