<?php defined('BASEPATH') or exit('No direct script access allowed');

/* ----------------------------------------------------------------------------
 * Easy!Appointments - Open Source Web Scheduler
 *
 * @package     EasyAppointments
 * @author      A.Tselegidis <alextselegidis@gmail.com>
 * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
 * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
 * @link        http://easyappointments.org
 * @since       v1.0.0
 * ---------------------------------------------------------------------------- */

/**
 * Customers model
 *
 * Handles all the database operations of the customer resource.
 *
 * @package Models
 */
class Customers_model extends EA_Model {
    /**
     * Save (insert or update) a customer.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @return int Returns the customer ID.
     *
     * @throws InvalidArgumentException
     */
    public function save(array $customer): int
    {
        $this->validate($customer);

        if ($this->exists($customer) && empty($customer['id']))
        {
            $customer['id'] = $this->find_record_id($customer);
        }

        if (empty($customer['id']))
        {
            return $this->insert($customer);
        }
        else
        {
            return $this->update($customer);
        }
    }

    /**
     * Validate the customer data.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @throws InvalidArgumentException
     */
    public function validate(array $customer)
    {
        // If a customer ID is provided then check whether the record really exists in the database.
        if ( ! empty($customer['id']))
        {
            $count = $this->db->get_where('users', ['id' => $customer['id']])->num_rows();

            if ( ! $count)
            {
                throw new InvalidArgumentException('The provided customer ID does not exist in the database: ' . $customer['id']);
            }
        }

        // Make sure all required fields are provided.
        $phone_number_required = filter_var(setting('require_phone_number'), FILTER_VALIDATE_BOOLEAN);

        if (
            empty($customer['first_name'])
            || empty($customer['last_name'])
            || empty($customer['email'])
            || (empty($customer['phone_number']) && $phone_number_required)
        )
        {
            throw new InvalidArgumentException('Not all required fields are provided: ' . print_r($customer, TRUE));
        }

        // Validate the email address.
        if ( ! filter_var($customer['email'], FILTER_VALIDATE_EMAIL))
        {
            throw new InvalidArgumentException('Invalid email address provided: ' . $customer['email']);
        }

        // Make sure the email address is unique.
        $customer_id = $customer['id'] ?? NULL;

        $count = $this
            ->db
            ->select()
            ->from('users')
            ->join('roles', 'roles.id = users.id_roles', 'inner')
            ->where('roles.slug', DB_SLUG_CUSTOMER)
            ->where('users.email', $customer['email'])
            ->where('users.id !=', $customer_id)
            ->get()
            ->num_rows();

        if ($count > 0)
        {
            throw new InvalidArgumentException('The provided email address is already in use, please use a different one.');
        }
    }

    /**
     * Insert a new customer into the database.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @return int Returns the customer ID.
     *
     * @throws RuntimeException
     */
    protected function insert(array $customer): int
    {
        $customer['id_roles'] = $this->get_customer_role_id();

        if ( ! $this->db->insert('users', $customer))
        {
            throw new RuntimeException('Could not insert customer.');
        }

        return $this->db->insert_id();
    }

    /**
     * Update an existing customer.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @return int Returns the customer ID.
     *
     * @throws RuntimeException
     */
    protected function update(array $customer): int
    {
        if ( ! $this->db->update('users', $customer, ['id' => $customer['id']]))
        {
            throw new RuntimeException('Could not update customer.');
        }

        return $customer['id'];
    }

    /**
     * Remove an existing customer from the database.
     *
     * @param int $customer_id Customer ID.
     *
     * @throws RuntimeException
     */
    public function delete(int $customer_id)
    {
        if ( ! $this->db->delete('users', ['id' => $customer_id]))
        {
            throw new RuntimeException('Could not delete customer.');
        }
    }

    /**
     * Get a specific customer from the database.
     *
     * @param int $customer_id The ID of the record to be returned.
     *
     * @return array Returns an array with the customer data.
     *
     * @throws InvalidArgumentException
     */
    public function find(int $customer_id): array
    {
        if ( ! $this->db->get_where('users', ['id' => $customer_id])->num_rows())
        {
            throw new InvalidArgumentException('The provided customer ID was not found in the database: ' . $customer_id);
        }

        return $this->db->get_where('users', ['id' => $customer_id])->row_array();
    }

    /**
     * Get a specific field value from the database.
     *
     * @param int $customer_id Customer ID.
     * @param string $field Name of the value to be returned.
     *
     * @return string Returns the selected customer value from the database.
     *
     * @throws InvalidArgumentException
     */
    public function value(int $customer_id, string $field): string
    {
        if (empty($field))
        {
            throw new InvalidArgumentException('The field argument is cannot be empty.');
        }

        if (empty($customer_id))
        {
            throw new InvalidArgumentException('The customer ID argument cannot be empty.');
        }

        // Check whether the customer exists.
        $query = $this->db->get_where('users', ['id' => $customer_id]);

        if ( ! $query->num_rows())
        {
            throw new InvalidArgumentException('The provided customer ID was not found in the database: ' . $customer_id);
        }

        // Check if the required field is part of the customer data.
        $customer = $query->row_array();

        if ( ! array_key_exists($field, $customer))
        {
            throw new InvalidArgumentException('The requested field was not found in the customer data: ' . $field);
        }

        return $customer[$field];
    }

    /**
     * Get all customers that match the provided criteria.
     *
     * @param array|string $where Where conditions.
     * @param int|null $limit Record limit.
     * @param int|null $offset Record offset.
     * @param string|null $order_by Order by.
     *
     * @return array Returns an array of customers.
     */
    public function get($where = NULL, int $limit = NULL, int $offset = NULL, string $order_by = NULL): array
    {
        $role_id = $this->get_customer_role_id();

        if ($where !== NULL)
        {
            $this->db->where($where);
        }

        if ($order_by !== NULL)
        {
            $this->db->order_by($order_by);
        }

        return $this->db->get_where('users', ['id_roles' => $role_id], $limit, $offset)->result_array();
    }

    /**
     * Get the customer role ID.
     *
     * @return int Returns the role ID.
     */
    public function get_customer_role_id(): int
    {
        $role = $this->db->get_where('roles', ['slug' => DB_SLUG_ADMIN])->row_array();

        if (empty($role))
        {
            throw new RuntimeException('The admin role was not found in the database.');
        }

        return $role['id'];
    }

    /**
     * Check if a particular customer record already exists in the database.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @return bool Returns whether there is a record matching the provided one or not.
     *
     * @throws InvalidArgumentException
     */
    public function exists(array $customer): bool
    {
        if (empty($customer['email']))
        {
            throw new InvalidArgumentException('The customer email was not provided: ' . print_r($customer, TRUE));
        }

        $count = $this
            ->db
            ->select()
            ->from('users')
            ->join('roles', 'roles.id = users.id_roles', 'inner')
            ->where('users.email', $customer['email'])
            ->where('roles.slug', DB_SLUG_CUSTOMER)
            ->get()
            ->num_rows();

        return $count > 0;
    }

    /**
     * Find the record ID of a customer.
     *
     * @param array $customer Associative array with the customer data.
     *
     * @return int Returns the ID of the record that matches the provided argument.
     *
     * @throws InvalidArgumentException
     */
    public function find_record_id(array $customer): int
    {
        if (empty($customer['email']))
        {
            throw new InvalidArgumentException('The customer email was not provided: ' . print_r($customer, TRUE));
        }

        $customer = $this
            ->db
            ->select('users.id')
            ->from('users')
            ->join('roles', 'roles.id = users.id_roles', 'inner')
            ->where('users.email', $customer['email'])
            ->where('roles.slug', DB_SLUG_CUSTOMER)
            ->get()
            ->row_array();

        if (empty($customer))
        {
            throw new InvalidArgumentException('Could not find customer record id.');
        }

        return $customer['id'];
    }

    /**
     * Get the query builder interface, configured for use with the users (customer-filtered) table.
     *
     * @return CI_DB_query_builder
     */
    public function query(): CI_DB_query_builder
    {
        $role_id = $this->get_customer_role_id();

        return $this->db->from('users')->where('id_roles', $role_id);
    }

    /**
     * Search customers by the provided keyword.
     *
     * @param string $keyword Search keyword.
     * @param int|null $limit Record limit.
     * @param int|null $offset Record offset.
     * @param string|null $order_by Order by.
     *
     * @return array Returns an array of customers.
     */
    public function search(string $keyword, int $limit = NULL, int $offset = NULL, string $order_by = NULL): array
    {
        $role_id = $this->get_customer_role_id();
        
        return $this
            ->db
            ->select()
            ->from('users')
            ->where('id_roles', $role_id)
            ->like('first_name', $keyword)
            ->or_like('last_name', $keyword)
            ->or_like('email', $keyword)
            ->or_like('phone_number', $keyword)
            ->or_like('mobile_number', $keyword)
            ->or_like('address', $keyword)
            ->or_like('city', $keyword)
            ->or_like('state', $keyword)
            ->or_like('zip_code', $keyword)
            ->or_like('notes', $keyword)
            ->limit($limit)
            ->offset($offset)
            ->order_by($order_by)
            ->get()
            ->result_array();
    }

    /**
     * Attach related resources to a customer.
     *
     * @param array $customer Associative array with the customer data.
     * @param array $resources Resource names to be attached.
     *
     * @throws InvalidArgumentException
     */
    public function attach(array &$customer, array $resources)
    {
        // Customers do not currently have any related resources. 
    }
}