<?php

abstract class Yoast_GA_Dashboards_Driver_Generate {

	/**
	 * @var string - Which type of data should be loaded
	 */
	protected $graph_type;

	/**
	 * @var string - For which period should the data be shown
	 */
	protected $period;

	/**
	 * @var string - The end date
	 */
	protected $end_date;

	/**
	 * @var string - The start date
	 */
	protected $start_date;

	/**
	 * Construct will set all values and generate the date for response
	 */
	public function __construct() {
		$this->set_graph_type();
		$this->set_period();
		$this->set_end_date();
		$this->set_start_date();
	}

	/**
	 * Getting graph_id from post and strip HTML-prefix graph- to get the type
	 */
	protected function set_graph_type() {
		$graph_id         = filter_input( INPUT_GET, 'graph_id' );
		$graph_type       = str_replace( array( 'graph-', 'table-' ), '', $graph_id );
		$this->graph_type = $graph_type;
	}

	/**
	 * Getting the period from post
	 */
	protected function set_period() {
		$this->period = filter_input( INPUT_GET, 'period' );
	}

	/**
	 * Setting the end date
	 */
	protected function set_end_date() {
		$this->end_date = time();
	}

	/**
	 * This method will set a start_date based on $this->period
	 *
	 * The values in dropdown, that will be mapped in strtotime
	 * See: http://php.net/manual/en/datetime.formats.relative.php
	 */
	protected function set_start_date() {

		switch ( $this->period ) {
			case 'lastweek' :
				$time = '-6 days';
				break;
			default:
			case 'lastmonth' :
				$time = '-1 month';
				break;
		}

		$start_date = strtotime( $time, $this->end_date );

		$this->start_date = $start_date;
	}

	/**
	 * Getting the saved Google data
	 *
	 * @return array
	 */
	protected function get_google_data() {

		$response = Yoast_GA_Dashboards_Data::get( $this->graph_type );

		if ( $response != array() && array_key_exists( 'body', $response['value'] ) ) {
			$return = $response['value']['body'];
		} else {
			$return = $response;
		}

		return $this->filter_google_data( $return );
	}

	/**
	 * Check if given timestamp is in given period
	 *
	 * @param integer $timestamp
	 *
	 * @return bool
	 */
	protected function is_date_in_period( $timestamp ) {
		return ( $timestamp >= $this->start_date && $timestamp <= $this->end_date );
	}

	/**
	 * Should always be available
	 *
	 * @return mixed
	 */
	abstract public function get_json();

}
