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

define('GROUP', 'GROUP');
define('DROPDOWN', 'DROPDOWN');
define('DECIMAL', 'DECIMAL');
define('DATE', 'DATE');
define('TEXT', 'TEXT');

const DEFINITION_TYPES = [GROUP, DROPDOWN, DECIMAL, TEXT, DATE];

/**
 * Attribute class
 */

class Attribute extends CI_Model
{
	const SHOW_IN_ITEMS = 1;
	const SHOW_IN_SALES = 2;
	const SHOW_IN_RECEIVINGS = 4;

	public static function get_definition_flags()
	{
		$class = new ReflectionClass(__CLASS__);

		return array_flip($class->getConstants());
	}

	/*
	 Determines if a given definition_id is an attribute
	 */
	public function exists($definition_id, $deleted = FALSE)
	{
		$this->db->from('attribute_definitions');
		$this->db->where('definition_id', $definition_id);
		$this->db->where('deleted', $deleted);

		return ($this->db->get()->num_rows() == 1);
	}

	public function link_exists($item_id, $definition_id = FALSE)
	{
		$this->db->where('sale_id');
		$this->db->where('receiving_id');
		$this->db->from('attribute_links');
		if(empty($definition_id))
		{
			$this->db->where('definition_id <>');
			$this->db->where('attribute_id');
		}
		else
		{
			$this->db->where('definition_id', $definition_id);

		}
		$this->db->where('item_id', $item_id);

		return ($this->db->get()->num_rows() > 0);
	}

	/*
	 Determines if a given attribute_value exists in the attribute_values table and returns the attribute_id if it does
	 */
	public function value_exists($attribute_value)
	{
		$this->db->distinct('attribute_id');
		$this->db->from('attribute_values');
		$this->db->where('attribute_value', $attribute_value);

		return $this->db->get()->row()->attribute_id;
	}

	/*
	 Gets information about a particular attribute definition
	 */
	public function get_info($definition_id)
	{
		$this->db->select('parent_definition.definition_name AS definition_group, definition.*');
		$this->db->from('attribute_definitions AS definition');
		$this->db->join('attribute_definitions AS parent_definition', 'parent_definition.definition_id = definition.definition_fk', 'left');
		$this->db->where('definition.definition_id', $definition_id);

		$query = $this->db->get();

		if($query->num_rows() == 1)
		{
			return $query->row();
		}
		else
		{
			//Get empty base parent object, as $item_id is NOT an item
			$item_obj = new stdClass();

			//Get all the fields from items table
			foreach($this->db->list_fields('attribute_definitions') as $field)
			{
				$item_obj->$field = '';
			}

			return $item_obj;
		}
	}

	/*
	 Performs a search on attribute definitions
	 */
	public function search($search, $rows = 0, $limit_from = 0, $sort = 'definition.definition_name', $order = 'asc')
	{
		$this->db->select('parent_definition.definition_name AS definition_group, definition.*');
		$this->db->from('attribute_definitions AS definition');
		$this->db->join('attribute_definitions AS parent_definition', 'parent_definition.definition_id = definition.definition_fk', 'left');

		$this->db->group_start();
		$this->db->like('definition.definition_name', $search);
		$this->db->or_like('definition.definition_type', $search);
		$this->db->group_end();
		$this->db->where('definition.deleted', 0);
		$this->db->order_by($sort, $order);

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

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

	public function get_attributes_by_item($item_id)
	{
		$this->db->from('attribute_definitions');
		$this->db->join('attribute_links', 'attribute_links.definition_id = attribute_definitions.definition_id');
		$this->db->where('item_id', $item_id);
		$this->db->where('receiving_id');
		$this->db->where('sale_id');
		$this->db->where('deleted', 0);

		$results = $this->db->get()->result_array();

		return $this->_to_array($results, 'definition_id');
	}

	public function get_values_by_definitions($definition_ids)
	{
		if(count($definition_ids ? : []))
		{
			$this->db->from('attribute_definitions');

			$this->db->group_start();
			$this->db->where_in('definition_fk', array_keys($definition_ids));
			$this->db->or_where_in('definition_id', array_keys($definition_ids));
			$this->db->where('definition_type !=', GROUP);
			$this->db->group_end();

			$this->db->where('deleted', 0);

			$results = $this->db->get()->result_array();

			return $this->_to_array($results, 'definition_id');
		}

		return array();
	}

	public function get_definitions_by_type($attribute_type, $definition_id = -1)
	{
		$this->db->from('attribute_definitions');
		$this->db->where('definition_type', $attribute_type);
		$this->db->where('deleted', 0);

		if($definition_id != -1)
		{
			$this->db->where('definition_id != ', $definition_id);
		}

		$this->db->where('definition_fk');
		$results = $this->db->get()->result_array();

		return $this->_to_array($results, 'definition_id', 'definition_name');
	}

	public function get_definitions_by_flags($definition_flags)
	{
		$this->db->from('attribute_definitions');
		$this->db->where('definition_flags &', $definition_flags);
		$this->db->where('deleted', 0);
		$this->db->where('definition_type <>', GROUP);
		$this->db->order_by('definition_id');
		$results = $this->db->get()->result_array();

		return $this->_to_array($results, 'definition_id', 'definition_name');
	}


	/**
	 * Returns an array of attribute definition names and IDs
	 *
	 * @param 	boolean		$groups		If FALSE does not return GROUP type attributes in the array
	 * @return	array					Array containing definition IDs, attribute names and -1 index with the local language '[SELECT]' line.
	 */
	public function get_definition_names($groups = TRUE)
	{
		$this->db->from('attribute_definitions');
		$this->db->where('deleted', 0);

		if($groups === FALSE)
		{
			$this->db->where_not_in('definition_type',GROUP);
		}

		$results = $this->db->get()->result_array();

		$definition_name = array(-1 => $this->lang->line('common_none_selected_text'));

		return $definition_name + $this->_to_array($results, 'definition_id', 'definition_name');
	}

	public function get_definition_values($definition_id)
	{
		$attribute_values = [];

		if($definition_id > -1)
		{
			$this->db->from('attribute_links');
			$this->db->join('attribute_values', 'attribute_values.attribute_id = attribute_links.attribute_id');
			$this->db->where('definition_id', $definition_id);
			$this->db->where('item_id');

			$results = $this->db->get()->result_array();

			return $this->_to_array($results, 'attribute_id', 'attribute_value');
		}

		return $attribute_values;
	}

	private function _to_array($results, $key, $value = '')
	{
		return array_column(array_map(function($result) use ($key, $value) {
			return [$result[$key], empty($value) ? $result : $result[$value]];
		}, $results), 1, 0);
	}

	/*
	 Gets total of rows
	 */
	public function get_total_rows()
	{
		$this->db->from('attribute_definitions');
		$this->db->where('deleted', 0);

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

	/*
	 Get number of rows
	 */
	public function get_found_rows($search)
	{
		return $this->search($search)->num_rows();
	}

	private function check_data_validity($definition, $from, $to)
	{
		$success = FALSE;

		if($from === TEXT)
		{
			$this->db->select('item_id,attribute_value');
			$this->db->from('attribute_values');
			$this->db->join('attribute_links', 'attribute_values.attribute_id = attribute_links.attribute_id');
			$this->db->where('definition_id',$definition);
			$success = TRUE;

			if($to === DATE)
			{
				foreach($this->db->get()->result_array() as $row)
				{
					if(valid_date($row['attribute_value']) === FALSE)
					{
						log_message('ERROR', 'item_id: ' . $row['item_id'] . ' with attribute_value: ' . $row['attribute_value'] . ' cannot be converted to datetime');
						$success = FALSE;
					}
				}
			}
			else if($to === DECIMAL)
			{
				foreach($this->db->get()->result_array() as $row)
				{
					if(valid_decimal($row['attribute_value']) === FALSE)
					{
						log_message('ERROR', 'item_id: ' . $row['item_id'] . ' with attribute_value: ' . $row['attribute_value'] . ' cannot be converted to decimal');
						$success = FALSE;
					}
				}
			}
		}
		return $success;
	}

	private function convert_definition_type($definition_id, $from_type, $to_type)
	{
		$success = FALSE;

		//From TEXT to DATETIME
		if($from_type === TEXT)
		{
			if($to_type === DATE || $to_type === DECIMAL)
			{
				$field = ($to_type === DATETIME ? 'attribute_date' : 'attribute_decimal');

				if($this->check_data_validity($definition_id, $from_type, $to_type))
				{
					$this->db->trans_start();

					$query = 'UPDATE ospos_attribute_values ';
					$query .= 'INNER JOIN ospos_attribute_links ';
					$query .= 'ON ospos_attribute_values.attribute_id = ospos_attribute_links.attribute_id ';
					$query .= 'SET '. $field .'= attribute_value, ';
					$query .= 'attribute_value = NULL ';
					$query .= 'WHERE definition_id = ' . $this->db->escape($definition_id);
					$success = $this->db->query($query);

					$this->db->trans_complete();
				}
			}
			else if($to_type === DROPDOWN)
			{
				$success = TRUE;
			}
		}

		//From DROPDOWN to TEXT
		else if($from_type === DROPDOWN)
		{
			//From DROPDOWN to TEXT
			$this->db->trans_start();

			$this->db->from('ospos_attribute_links');
			$this->db->where('definition_id',$definition_id);
			$this->db->where('item_id', NULL);
			$success = $this->db->delete();

			$this->db->trans_complete();
		}

		//Any other allowed conversion does not get checked here
		else
		{
			$success = TRUE;
		}

		return $success;
	}

	/*
	 Inserts or updates a definition
	 */
	public function save_definition(&$definition_data, $definition_id = -1)
	{
		//Run these queries as a transaction, we want to make sure we do all or nothing
		$this->db->trans_start();

		//Definition doesn't exist
		if($definition_id === -1 || !$this->exists($definition_id))
		{
			$success = $this->db->insert('attribute_definitions', $definition_data);
			$definition_data['definition_id'] = $this->db->insert_id();
		}

		//Definition already exists
		else
		{
			$this->db->select('definition_type, definition_name');
			$this->db->from('attribute_definitions');
			$this->db->where('definition_id', $definition_id);

			$row = $this->db->get()->row();
			$from_definition_type = $row->definition_type;
			$from_definition_name = $row->definition_name;
			$to_definition_type = $definition_data['definition_type'];

			if($from_definition_type !== $to_definition_type)
			{
				if(!$this->convert_definition_type($definition_id,$from_definition_type,$to_definition_type))
				{
					return FALSE;
				}
			}

			$this->db->where('definition_id', $definition_id);
			$success = $this->db->update('attribute_definitions', $definition_data);
			$definition_data['definition_id'] = $definition_id;
		}

		$this->db->trans_complete();

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

		return $success;
	}

	public function get_definition_by_name($definition_name, $definition_type = FALSE)
	{
		$this->db->from('attribute_definitions');
		$this->db->where('definition_name', $definition_name);
		if($definition_type != FALSE)
		{
			$this->db->where('definition_type', $definition_type);
		}

		return $this->db->get()->result_array();
	}

	public function save_link($item_id, $definition_id, $attribute_id)
	{
		$this->db->trans_start();

		if($this->link_exists($item_id, $definition_id))
		{
			$this->db->where('definition_id', $definition_id);
			$this->db->where('item_id', $item_id);
			$this->db->where('sale_id');
			$this->db->where('receiving_id');
			$this->db->update('attribute_links', array('attribute_id' => $attribute_id));
		}
		else
		{
			$this->db->insert('attribute_links', array('attribute_id' => $attribute_id, 'item_id' => $item_id, 'definition_id' => $definition_id));
		}

		$this->db->trans_complete();

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

	public function delete_link($item_id)
	{
		$this->db->where('sale_id');
		$this->db->where('receiving_id');

		return $this->db->delete('attribute_links', array('item_id' => $item_id));
	}

	public function get_link_value($item_id, $definition_id)
	{
		$this->db->where('item_id', $item_id);
		$this->db->where('definition_id', $definition_id);
		$this->db->where('sale_id');
		$this->db->where('receiving_id');

		return $this->db->get('attribute_links')->row_object();
	}

	public function get_link_values($item_id, $sale_receiving_fk, $id, $definition_flags)
	{
		$format = $this->db->escape(dateformat_mysql());
		$this->db->select("GROUP_CONCAT(attribute_value SEPARATOR ', ') AS attribute_values");
		$this->db->select("GROUP_CONCAT(DATE_FORMAT(attribute_date, $format) SEPARATOR ', ') AS attribute_dtvalues");
		$this->db->from('attribute_links');
		$this->db->join('attribute_values', 'attribute_values.attribute_id = attribute_links.attribute_id');
		$this->db->join('attribute_definitions', 'attribute_definitions.definition_id = attribute_links.definition_id');
		$this->db->where('definition_type <>', GROUP);
		$this->db->where('deleted', 0);

		if(!empty($id))
		{
			$this->db->where($sale_receiving_fk, $id);
		}
		else
		{
			$this->db->where('sale_id');
			$this->db->where('receiving_id');
		}
		$this->db->where('item_id', (int) $item_id);
		$this->db->where('definition_flags & ', $definition_flags);

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

	public function get_attribute_value($item_id, $definition_id)
	{
		$this->db->from('attribute_values');
		$this->db->join('attribute_links', 'attribute_links.attribute_id = attribute_values.attribute_id');
		$this->db->where('definition_id', $definition_id);
		$this->db->where('sale_id');
		$this->db->where('receiving_id');
		$this->db->where('item_id', (int) $item_id);

		return $this->db->get()->row_object();
	}

	public function copy_attribute_links($item_id, $sale_receiving_fk, $id)
	{
		$this->db->query(
			'INSERT INTO ospos_attribute_links (item_id, definition_id, attribute_id, ' . $sale_receiving_fk . ')
			  SELECT ' . $this->db->escape($item_id) . ', definition_id, attribute_id, ' . $this->db->escape($id) . '
			  FROM ' . $this->db->dbprefix('attribute_links') . '
			  WHERE item_id = ' . $this->db->escape($item_id) . ' AND sale_id IS NULL AND receiving_id IS NULL'
			);
	}

	public function get_suggestions($definition_id, $term)
	{
		$suggestions = array();
		$this->db->distinct();
		$this->db->select('attribute_value, attribute_values.attribute_id');
		$this->db->from('attribute_definitions AS definition');
		$this->db->join('attribute_links', 'attribute_links.definition_id = definition.definition_id');
		$this->db->join('attribute_values', 'attribute_values.attribute_id = attribute_links.attribute_id');
		$this->db->like('attribute_value', $term);
		$this->db->where('deleted', 0);
		$this->db->where('definition.definition_id', $definition_id);
		$this->db->order_by('attribute_value');
		foreach($this->db->get()->result() as $row)
		{
			$row_array = (array) $row;
			$suggestions[] = array('value' => $row_array['attribute_id'], 'label' => $row_array['attribute_value']);
		}

		return $suggestions;
	}

	public function save_value($attribute_value, $definition_id, $item_id = FALSE, $attribute_id = FALSE, $definition_type = DROPDOWN)
	{
		$this->db->trans_start();

		if(empty($attribute_id) || empty($item_id))
		{
			if($definition_type == TEXT || $definition_type == DROPDOWN)
			{
				$attribute_id = $this->value_exists($attribute_value);

				if(empty($attribute_id))
				{
					$this->db->insert('attribute_values', array('attribute_value' => $attribute_value));
				}
			}
			else if($definition_type == DECIMAL)
			{
				$this->db->insert('attribute_values', array('attribute_decimal' => $attribute_value));
			}
			else
			{
				$this->db->insert('attribute_values', array('attribute_date' => date('Y-m-d', strtotime($attribute_value))));
			}

			$attribute_id = $attribute_id ? $attribute_id : $this->db->insert_id();
			
			$this->db->insert('attribute_links', array(
				'attribute_id' => empty($attribute_id) ? NULL : $attribute_id,
				'item_id' => empty($item_id) ? NULL : $item_id,
				'definition_id' => $definition_id));
		}

		$this->db->trans_complete();

		return $attribute_id;
	}

	public function delete_value($attribute_value, $definition_id)
	{
		return $this->db->query("DELETE atrv, atrl FROM " . $this->db->dbprefix('attribute_values') . " atrv, " . $this->db->dbprefix('attribute_links') .  " atrl " .
			"WHERE atrl.attribute_id = atrv.attribute_id AND atrv.attribute_value = " . $this->db->escape($attribute_value) . " AND atrl.definition_id = " . $this->db->escape($definition_id));
	}

	/**
	 * Deletes an Attribute definition from the database and associated column in the items_import.csv
	 *
	 * @param	unknown	$definition_id	Attribute definition ID to remove.
	 * @return 	boolean					TRUE if successful and FALSE if there is a failure
	 */
	public function delete_definition($definition_id)
	{
		$this->db->where('definition_id', $definition_id);

		return $this->db->update('attribute_definitions', array('deleted' => 1));
	}

	public function delete_definition_list($definition_ids)
	{
		$this->db->where_in('definition_id', $definition_ids);

		return $this->db->update('attribute_definitions', array('deleted' => 1));
	}
}