<?php

namespace App\Models;

use CodeIgniter\Database\ResultInterface;
use CodeIgniter\Session\Session;

/**
 * Employee class
 *
 * @property session session
 *
 */
class Employee extends Person
{
	public Session $session;
	protected $table = 'Employees';
	protected $primaryKey = 'person_id';
	protected $useAutoIncrement = false;
	protected $useSoftDeletes = false;
	protected $allowedFields = [
		'username',
		'password',
		'deleted',
		'hashversion',
		'language',
		'language_code'
	];

	public function __construct()
	{
		parent::__construct();
		$this->session = session();
	}

	/**
	 * Determines if a given person_id is an employee
	 */
	public function exists(int $person_id): bool
	{
		$builder = $this->db->table('employees');
		$builder->join('people', 'people.person_id = employees.person_id');
		$builder->where('employees.person_id', $person_id);

		return ($builder->get()->getNumRows() == 1);	//TODO: ===
	}

	/**
	 * @param int $employee_id
	 * @param string $username
	 * @return bool
	 */
	public function username_exists(int $employee_id, string $username): bool
	{
		$builder = $this->db->table('employees');
		$builder->where('employees.username', $username);
		$builder->where('employees.person_id <>', $employee_id);

		return ($builder->get()->getNumRows() == 1);	//TODO: ===
	}

	/**
	 * Gets total of rows
	 */
	public function get_total_rows(): int
	{
		$builder = $this->db->table('employees');
		$builder->where('deleted', 0);

		return $builder->countAllResults();
	}

	/**
	 * Returns all the employees
	 */
	public function get_all(int $limit = 10000, int $offset = 0): ResultInterface
	{
		$builder = $this->db->table('employees');
		$builder->where('deleted', 0);
		$builder->join('people', 'employees.person_id = people.person_id');
		$builder->orderBy('last_name', 'asc');
		$builder->limit($limit);
		$builder->offset($offset);

		return $builder->get();
	}

	/**
	 * Gets information about a particular employee
	 */
	public function get_info(int $person_id): object
	{
		$builder = $this->db->table('employees');
		$builder->join('people', 'people.person_id = employees.person_id');
		$builder->where('employees.person_id', $person_id);
		$query = $builder->get();

		if($query->getNumRows() == 1)	//TODO: ===
		{
			return $query->getRow();
		}

		//Get empty base parent object, as $employee_id is NOT an employee
		$person_obj = parent::get_info(NEW_ITEM);

		//Get all the fields from employee table
		//append those fields to base parent object, we have a complete empty object
		foreach($this->db->getFieldNames('employees') as $field)
		{
			$person_obj->$field = null;
		}

		return $person_obj;
	}

	/**
	 * Gets information about multiple employees
	 */
	public function get_multiple_info(array $person_ids): ResultInterface
	{
		$builder = $this->db->table('employees');
		$builder->join('people', 'people.person_id = employees.person_id');
		$builder->whereIn('employees.person_id', $person_ids);
		$builder->orderBy('last_name', 'asc');

		return $builder->get();
	}

	/**
	 * Inserts or updates an employee
	 */
	public function save_employee(array &$person_data, array &$employee_data, array &$grants_data, int $employee_id = NEW_ENTRY): bool
	{
		$success = false;

		//Run these queries as a transaction, we want to make sure we do all or nothing
		$this->db->transStart();

		if(ENVIRONMENT != 'testing' && parent::save_value($person_data, $employee_id))
		{
			$builder = $this->db->table('employees');
			if($employee_id == NEW_ENTRY || !$this->exists($employee_id))
			{
				$employee_data['person_id'] = $employee_id = $person_data['person_id'];
				$success = $builder->insert($employee_data);
			}
			else
			{
				$builder->where('person_id', $employee_id);
				$success = $builder->update($employee_data);
			}

			//We have either inserted or updated a new employee, now lets set permissions.
			if($success)
			{
				//First lets clear out any grants the employee currently has.
				$builder = $this->db->table('grants');
				$success = $builder->delete(['person_id' => $employee_id]);

				//Now insert the new grants
				if($success)
				{
					foreach($grants_data as $grant)
					{
						$data = [
							'permission_id' => $grant['permission_id'],
							'person_id' => $employee_id,
							'menu_group' => $grant['menu_group']
						];

						$builder = $this->db->table('grants');
						$success = $builder->insert($data);
					}
				}
			}
		}

		$this->db->transComplete();

		$success &= $this->db->transStatus();

		return $success;
	}

	/**
	 * Deletes one employee
	 */
	public function delete($employee_id = null, bool $purge = false): bool
	{
		$success = false;

		//Don't let employees delete themselves
		if($employee_id == $this->get_logged_in_employee_info()->person_id)
		{
			return false;
		}

		//Run these queries as a transaction, we want to make sure we do all or nothing
		$this->db->transStart();

		//Delete permissions
		$builder = $this->db->table('grants');

		if($builder->delete(['person_id' => $employee_id]))
		{
			$builder = $this->db->table('employees');
			$builder->where('person_id', $employee_id);
			$success = $builder->update(['deleted' => 1]);
		}

		$this->db->transComplete();

		return $success;
	}

	/**
	 * Deletes a list of employees
	 */
	public function delete_list(array $person_ids): bool
	{
		$success = false;

		//Don't let employees delete themselves
		if(in_array($this->get_logged_in_employee_info()->person_id, $person_ids))
		{
			return false;
		}

		//Run these queries as a transaction, we want to make sure we do all or nothing
		$this->db->transStart();

		$builder = $this->db->table('grants');
		$builder->whereIn('person_id', $person_ids);
		//Delete permissions
		if($builder->delete())
		{
			//delete from employee table
			$builder = $this->db->table('employees');
			$builder->whereIn('person_id', $person_ids);
			$success = $builder->update(['deleted' => 1]);
		}

		$this->db->transComplete();
		$success &= $this->db->transStatus();

		return $success;
 	}

	/**
	 * Get search suggestions to find employees
	 */
	public function get_search_suggestions(string $search, int $limit = 25, bool $unique = false): array
	{
		$suggestions = [];

		$builder = $this->db->table('employees');
		$builder->join('people', 'employees.person_id = people.person_id');
		$builder->groupStart();
			$builder->like('first_name', $search);
			$builder->orLike('last_name', $search);
			$builder->orLike('CONCAT(first_name, " ", last_name)', $search);
		$builder->groupEnd();

		if(!$unique)
		{
			$builder->where('deleted', 0);
		}

		$builder->orderBy('last_name', 'asc');

		foreach($builder->get()->getResult() as $row)
		{
			$suggestions[] = ['value' => $row->person_id, 'label' => $row->first_name.' '.$row->last_name];
		}

		$builder = $this->db->table('employees');
		$builder->join('people', 'employees.person_id = people.person_id');

		if(!$unique)
		{
			$builder->where('deleted', 0);
		}

		$builder->like('email', $search);
		$builder->orderBy('email', 'asc');

		foreach($builder->get()->getResult() as $row)
		{
			$suggestions[] = ['value' => $row->person_id, 'label' => $row->email];
		}

		$builder = $this->db->table('employees');
		$builder->join('people', 'employees.person_id = people.person_id');

		if(!$unique)
		{
			$builder->where('deleted', 0);
		}

		$builder->like('username', $search);
		$builder->orderBy('username', 'asc');

		foreach($builder->get()->getResult() as $row)
		{
			$suggestions[] = ['value' => $row->person_id, 'label' => $row->username];
		}

		$builder = $this->db->table('employees');
		$builder->join('people', 'employees.person_id = people.person_id');

		if(!$unique)
		{
			$builder->where('deleted', 0);
		}

		$builder->like('phone_number', $search);
		$builder->orderBy('phone_number', 'asc');

		foreach($builder->get()->getResult() as $row)
		{
			$suggestions[] = ['value' => $row->person_id, 'label' => $row->phone_number];
		}

		//only return $limit suggestions
		if(count($suggestions) > $limit)
		{
			$suggestions = array_slice($suggestions, 0, $limit);
		}

		return $suggestions;
	}

 	/**
	 * Gets rows
	 */
	public function get_found_rows(string $search): int
	{
		return $this->search($search, 0, 0, 'last_name', 'asc', true);
	}

	/**
	 * Performs a search on employees
	 */
	public function search(string $search, ?int $rows = 0, ?int $limit_from = 0, ?string $sort = 'last_name', ?string $order = 'asc', ?bool $count_only = false)
	{
		// Set default values
		if($rows == null) $rows = 0;
		if($limit_from == null) $limit_from = 0;
		if($sort == null) $sort = 'last_name';
		if($order == null) $order = 'asc';
		if($count_only == null) $count_only = false;

		$builder = $this->db->table('employees AS employees');

		// get_found_rows case
		if($count_only)
		{
			$builder->select('COUNT(employees.person_id) as count');
		}

		$builder->join('people', 'employees.person_id = people.person_id');
		$builder->groupStart();
			$builder->like('first_name', $search);
			$builder->orLike('last_name', $search);
			$builder->orLike('email', $search);
			$builder->orLike('phone_number', $search);
			$builder->orLike('username', $search);
			$builder->orLike('CONCAT(first_name, " ", last_name)', $search);
		$builder->groupEnd();
		$builder->where('deleted', 0);

		// get_found_rows case
		if($count_only)
		{
			return $builder->get()->getRow()->count;
		}

		$builder->orderBy($sort, $order);

		if($rows > 0)
		{
			$builder->limit($rows, $limit_from);
		}

		return $builder->get();
	}

	/**
	 * Attempts to log in employee and set session. Returns boolean based on outcome.
	 */
	public function login(string $username, string $password): bool
	{
		$builder = $this->db->table('employees');
		$query = $builder->getWhere(['username' => $username, 'deleted' => 0], 1);

		if($query->getNumRows() === 1)
		{
			$row = $query->getRow();

			// compare passwords depending on the hash version
			if($row->hash_version === '1' && $row->password === md5($password))
			{
				$builder->where('person_id', $row->person_id);
				$this->session->set('person_id', $row->person_id);
				$password_hash = password_hash($password, PASSWORD_DEFAULT);

				return $builder->update(['hash_version' => 2, 'password' => $password_hash]);
			}
			elseif($row->hash_version === '2' && password_verify($password, $row->password))
			{
				$this->session->set('person_id', $row->person_id);

				return true;
			}
		}

		return false;
	}

	/**
	 * Logs out a user by destroying all session data and redirect to log in
	 */
	public function logout(): void
	{
		session()->destroy();
	}

	/**
	 * Determines if an employee is logged in
	 */
	public function is_logged_in(): bool
	{
		return ($this->session->get('person_id') != false);
	}

	/**
	 * Gets information about the currently logged in employee.
	 */
	public function get_logged_in_employee_info()
	{
		if($this->is_logged_in())
		{
			return $this->get_info($this->session->get('person_id'));
		}

		return false;
	}

	/**
	 * Determines whether the employee has access to at least one submodule
	 */
	public function has_module_grant(string $permission_id, int $person_id): bool
	{
		$builder = $this->db->table('grants');
		$builder->like('permission_id', $permission_id, 'after');
		$builder->where('person_id', $person_id);
		$result_count = $builder->get()->getNumRows();

		if($result_count != 1)
		{
			return ($result_count != 0);
		}

		return $this->has_subpermissions($permission_id);
	}

 	/**
	 * Checks permissions
	 */
	public function has_subpermissions(string $permission_id): bool
	{
		$builder = $this->db->table('permissions');
		$builder->like('permission_id', $permission_id.'_', 'after');

		return ($builder->get()->getNumRows() == 0);	//TODO: ===
	}

	/**
	 * Determines whether the employee specified employee has access the specific module.
	 */
	public function has_grant(?string $permission_id, ?int $person_id): bool
	{
		//if no module_id is null, allow access
		if($permission_id == null)
		{
			return true;
		}
		if($person_id == null)
		{
			return false;
		}

		$builder = $this->db->table('grants');
		$query = $builder->getWhere(['person_id' => $person_id, 'permission_id' => $permission_id], 1);

		return ($query->getNumRows() == 1);	//TODO: ===
	}

	/**
	 * Returns the menu group designation that this module is to appear in
	 */
	public function get_menu_group(string $permission_id, ?int $person_id): string
	{
		$builder = $this->db->table('grants');
		$builder->select('menu_group');
		$builder->where('permission_id', $permission_id);
		$builder->where('person_id', $person_id);

		$row = $builder->get()->getRow();

		// If no grants are assigned yet then set the default to 'home'
		if($row == null)
		{
			return 'home';
		}
		else
		{
			return $row->menu_group;
		}
	}

	/**
	 * Gets employee permission grants
	 */
	public function get_employee_grants(int $person_id): array
	{
		$builder = $this->db->table('grants');
		$builder->where('person_id', $person_id);

		return $builder->get()->getResultArray();
	}

	/**
	 * Attempts to log in employee and set session. Returns boolean based on outcome.
	 */
	public function check_password(string $username, string $password): bool
	{
		$builder = $this->db->table('employees');
		$query = $builder->getWhere(['username' => $username, 'deleted' => 0], 1);

		if($query->getNumRows() == 1)	//TODO: ===
		{
			$row = $query->getRow();

			if(password_verify($password, $row->password))
			{
				return true;
			}
		}

		return false;
	}

	/**
	 * Change password for the employee
	 */
	public function change_password(array $employee_data, $employee_id = false): bool
	{
		$success = false;

		if(ENVIRONMENT != 'testing')
		{
			$this->db->transStart();

			$builder = $this->db->table('employees');
			$builder->where('person_id', $employee_id);
			$success = $builder->update($employee_data);

			$this->db->transComplete();

			$success &= $this->db->transStatus();
		}

		return $success;
	}
}
