<?php
class Services_Model extends CI_Model {
    /**
     * Class Constructor
     */
    function __construct() {
        parent::__construct();
    }
    
    /**
     * Add (insert or update) a service record on the database
     * 
     * @param array $service Contains the service data. If an 'id' value is provided then
     * the record will be updated.
     * @return numeric Returns the record id.
     */
    public function add($service) {
        if (!$this->validate($service)) {
            throw new Exception('Service data are invalid.');
        }
        
        if (!isset($service['id'])) {
            $service['id'] = $this->insert($service);
        } else {
            $this->update($service);
        }
        
        return intval($service['id']);
    }
    
    /**
     * Insert service record into database.
     * 
     * @param array $service Contains the service record data.
     * @return int Returns the new service record id.
     */
    public function insert($service) {
        if (!$this->db->insert('ea_services', $service)) {
            throw new Exception('Could not insert service record.');
        }
        return intval($this->db->insert_id());
    }
    
    /**
     * Update service record.
     * 
     * @param array $service Contains the service data. The record id needs to be included in 
     * the array.
     */
    public function update($service) {
       $this->db->where('id', $service['id']);
       if (!$this->db->update('ea_services', $service)) {
           throw new Exception('Could not update service record');
       }
    }
    
    /**
     * Checks whether an service record already exists in the database.
     * 
     * @param array $service Contains the service data. Name, duration and price values 
     * are mandatory in order to perform the checks.
     */
    public function exists($service) {
        if (!isset($service['name']) 
                || !isset($service['duration']) 
                || !isset($service['price'])) {
            throw new Exception('Not all service fields are provided in order to check whether '
                    . 'a service record already exists: ' . print_r($service, TRUE));
        }
        
        $num_rows = $this->db->get_where('ea_services', array(
            'name' => $service['name'],
            'duration' => $service['duration'],
            'price' => $service['price']
        ))->num_rows();
        
        return ($num_rows > 0) ? TRUE : FALSE;
    }
    
    /**
     * Validate a service record data.
     * 
     * @param array $service Contains the service data.
     * @return bool Returns the validation result.
     */
    public function validate($service) {
        $this->load->helper('data_validation');
        
        try {
            // If record id is provided we need to check whether the record exists
            // in the database.
            if (isset($service['id'])) {
                $num_rows = $this->db->get_where('ea_services', array('id' => $service['id']))
                        ->num_rows();
                if ($num_rows == 0) {
                    throw new Exception('Provided service id does not exist in the database.');
                }
            }
            
            // Check if service category id is valid (only when present)
            if ($service['id_service_categories'] != NULL) {
                $num_rows = $this->db->get_where('ea_service_categories', 
                        array('id' => $service['id_service_categories']))->num_rows();
                if ($num_rows == 0) {
                    throw new Exception('Provided service category id does not exist in database.');
                }
            }
            
            // Check for required fields
            if ($service['name'] == '') {
                throw new Exception('Not all required service fields where provided: ' 
                        . print_r($service, TRUE));
            }
            
            // Duration must be numeric
            if ($service['duration'] !== NULL) {
                if (!is_numeric($service['duration'])) {
                    throw new Exception('Service duration is not numeric.');
                }
            }
            
            if ($service['price'] !== NULL) {
                if (!is_numeric($service['price'])) {
                    throw new Exception('Service price is not numeric.');
                }
            }
            
            return TRUE;
        } catch(Exception $exc) {
            return FALSE;
        }
    }
    
    /**
     * Get the record id of an existing record. 
     * 
     * NOTICE! The record must exist, otherwise an exeption will be raised.
     * 
     * @param array $service Contains the service record data. Name, duration and price values
     * are mandatory for this method to complete.
     */
    public function find_record_id($service) {
        if (!isset($service['name'])
                || !isset($service['duration'])
                || !isset($service['price'])) {
            throw new Exception('Not all required fields where provided in order to find the '
                    . 'service record id.');
        }
        
        $result = $this->db->get_where('ea_services', array(
            'name' => $service['name'],
            'duration' => $service['duration'],
            'price' => $service['price']
        ));
        
        if ($result->num_rows() == 0) {
            throw new Exception('Cound not find service record id');
        }
        
        return $result->row()->id;
    }
    
    /**
     * Delete a service record from database.
     * 
     * @param numeric $service_id Record id to be deleted.
     * @return bool Returns the delete operation result.
     */
    public function delete($service_id) {
        if (!is_numeric($service_id)) {
            throw new Exception('Invalid argument type $service_id (value:"' . $service_id . '"');
        }
        
        $num_rows = $this->db->get_where('ea_services', array('id' => $service_id))->num_rows();
        if ($num_rows == 0) {
            return FALSE; // Record does not exist
        }
        
        return $this->db->delete('ea_services', array('id' => $service_id));
    }
    
    /**
     * Get a specific row from the services db table.
     * 
     * @param numeric $service_id The record's id to be returned.
     * @return array Returns an associative array with the selected
     * record's data. Each key has the same name as the database 
     * field names.
     */
    public function get_row($service_id) {
        if (!is_numeric($service_id)) {
            throw new Exception('$service_id argument is not an numeric (value: "' . $service_id . '")');
        }
        return $this->db->get_where('ea_services', array('id' => $service_id))->row_array();
    }
    
    /**
     * Get a specific field value from the database.
     * 
     * @param string $field_name The field name of the value to be
     * returned.
     * @param int $service_id The selected record's id.
     * @return string Returns the records value from the database.
     */
    public function get_value($field_name, $service_id) {
        if (!is_numeric($service_id)) {
            throw new Exception('Invalid argument provided as $service_id : ' . $service_id);
        }
        
        if (!is_string($field_name)) {
            throw new Exception('$field_name argument is not a string : ' . $field_name);
        }
        
        if ($this->db->get_where('ea_services', array('id' => $service_id))->num_rows() == 0) {
            throw new Exception('The record with the $service_id argument does not exist in the database : ' . $service_id);
        }
        
        $row_data = $this->db->get_where('ea_services', array('id' => $service_id))->row_array();
        if (!isset($row_data[$field_name])) {
            throw new Exception('The given $field_name argument does not exist in the database : ' . $field_name);
        }
        
        return $this->db->get_where('ea_services', array('id' => $service_id))->row_array()[$field_name];
    }
    
    /**
     * Get all, or specific records from service's table.
     * 
     * @example $this->Model->getBatch('id = ' . $recordId);
     * 
     * @param string $whereClause (OPTIONAL) The WHERE clause of  
     * the query to be executed. DO NOT INCLUDE 'WHERE' KEYWORD.
     * @return array Returns the rows from the database.
     */
    public function get_batch($where_clause = NULL) {
        if ($where_clause != NULL) {
            $this->db->where($where_clause);
        }
        
        return $this->db->get('ea_services')->result_array();
    }
    
    /**
     * This method returns all the services from the database.
     * 
     * @return array Returns an object array with all the 
     * database services.
     */
    public function get_available_services() {
    	$this->db->distinct();
        return $this->db
        		->select('ea_services.*')
        		->from('ea_services')
        		->join('ea_services_providers', 
        				'ea_services_providers.id_services = ea_services.id', 'inner')
        		->get()->result_array();
    }
    
    /**
     * Add (insert or update) a service category record into database.
     * 
     * @param array $category Containst the service category data.
     * @return int Returns the record id.s
     */
    public function add_category($category) {
        if (!$this->validate_category($category)) {
            throw new Exception('Service category data are invalid.');
        }
        
        if (!isset($category['id'])) {
            $this->db->insert('ea_service_categories', $category);
            $category['id'] = $this->db->insert_id();
        } else {
            $this->db->where('id', $category['id']);
            $this->db->update('ea_service_categories', $category);
        }
        
        return intval($category['id']);
    }
    
    /**
     * Delete a service category record from the database.
     * 
     * @param numeric $category_id Record id to be deleted.
     * @return bool Returns the delete operation result.
     */
    public function delete_category($category_id) {
        if (!is_numeric($category_id)) {
            throw new Exception('Invalid argument given for $category_id: ' . $category_id);
        }
        
        $num_rows = $this->db->get_where('ea_service_categories', array('id' => $category_id))
                ->num_rows();
        if ($num_rows == 0) {
            throw new Exception('Service category record not found in database.');
        }
        
        $this->db->where('id', $category_id);
        return $this->db->delete('ea_service_categories');
    }
    
    /**
     * Get a service category record data.
     * 
     * @param numeric $category_id Record id to be retrieved.
     * @return array Returns the record data from the database.
     */
    public function get_category($category_id) {
        if (!is_numeric($category_id)) {
            throw new Exception('Invalid argument type given $category_id: ' . $category_id);
        }
        
        $result = $this->db->get_where('ea_service_categories', array('id' => $category_id));
        
        if ($result->num_rows() == 0) {
            throw new Exception('Service category record does not exist.');
        }
        
        return $result->row_array();
    }
    
    /**
     * Get all service category records from database.
     * 
     * @return array Returns an array that contains all the service category records.
     */
    public function get_all_categories() {
        return $this->db->get('ea_service_categories')->result_array();
    }
    
    /**
     * Validate a service category record data. This method must be used before adding 
     * a service category record into database in order to secure the record integrity.
     * 
     * @param array $category Contains the service category data.
     * @return bool Returns the validation result.
     */
    public function validate_category($category) {
        try {
            // Required Fields
            if (!isset($category['name'])) {
                throw new Exception('Not all required fields where provided ');
            }
            
            if ($category['name'] == '' || $category['name'] == NULL) {
                throw new Exception('Required fields cannot be empty or null ($category: ' 
                        . print_r($category, TRUE) . ')');
            }
            
            return TRUE;
        } catch(Exception $exc) {
            return FALSE;
        }
            
    }
}

/* End of file services_model.php */
/* Location: ./application/models/services_model.php */