<?php
/**
 * WooCommerce API Reports Class
 *
 * Handles requests to the /reports endpoint
 *
 * @author      WooThemes
 * @category    API
 * @package     WooCommerce/API
 * @since       2.1
 */

if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly


class WC_API_Reports extends WC_API_Resource {

	/** @var string $base the route base */
	protected $base = '/reports';

	/** @var WC_Admin_Report instance */
	private $report;

	/**
	 * Register the routes for this class
	 *
	 * GET /reports
	 * GET /reports/sales
	 *
	 * @since 2.1
	 * @param array $routes
	 * @return array
	 */
	public function register_routes( $routes ) {

		# GET /reports
		$routes[ $this->base ] = array(
			array( array( $this, 'get_reports' ),     WC_API_Server::READABLE ),
		);

		# GET /reports/sales
		$routes[ $this->base . '/sales'] = array(
			array( array( $this, 'get_sales_report' ), WC_API_Server::READABLE ),
		);

		return $routes;
	}

	/**
	 * Get a simple listing of available reports
	 *
	 * @since 2.1
	 * @return array
	 */
	public function get_reports() {

		return array( 'reports' => array( 'sales' ) );
	}

	/**
	 * Get the sales report
	 *
	 * @since 2.1
	 * @param string $fields fields to include in response
	 * @param array $filter date filtering
	 * @return array
	 */
	public function get_sales_report( $fields = null, $filter = array() ) {

		// check user permissions
		$check = $this->validate_request();

		if ( is_wp_error( $check ) )
			return $check;

		// set date filtering
		$this->setup_report( $filter );

		// total sales, taxes, shipping, and order count
		$totals = $this->report->get_order_report_data( array(
			'data' => array(
				'_order_total' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'sales'
				),
				'_order_tax' => array(
					'type'            => 'meta',
					'function'        => 'SUM',
					'name'            => 'tax'
				),
				'_order_shipping_tax' => array(
					'type'            => 'meta',
					'function'        => 'SUM',
					'name'            => 'shipping_tax'
				),
				'_order_shipping' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'shipping'
				),
				'ID' => array(
					'type'     => 'post_data',
					'function' => 'COUNT',
					'name'     => 'order_count'
				)
			),
			'filter_range' => true,
		) );

		// total items ordered
		$total_items = absint( $this->report->get_order_report_data( array(
			'data' => array(
				'_qty' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'line_item',
					'function'        => 'SUM',
					'name'            => 'order_item_qty'
				)
			),
			'query_type' => 'get_var',
			'filter_range' => true,
		) ) );

		// total discount used
		$total_discount = $this->report->get_order_report_data( array(
			'data' => array(
				'discount_amount' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'coupon',
					'function'        => 'SUM',
					'name'            => 'discount_amount'
				)
			),
			'where' => array(
				array(
					'key'      => 'order_item_type',
					'value'    => 'coupon',
					'operator' => '='
				)
			),
			'query_type' => 'get_var',
			'filter_range' => true,
		) );

		// get order totals grouped by period
		$orders = $this->report->get_order_report_data( array(
			'data' => array(
				'_order_total' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'total_sales'
				),
				'_order_shipping' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'total_shipping'
				),
				'ID' => array(
					'type'     => 'post_data',
					'function' => 'COUNT',
					'name'     => 'total_orders',
					'distinct' => true,
				),
				'post_date' => array(
					'type'     => 'post_data',
					'function' => '',
					'name'     => 'post_date'
				),
			),
			'group_by'     => $this->report->group_by_query,
			'order_by'     => 'post_date ASC',
			'query_type'   => 'get_results',
			'filter_range' => true,
		) );

		// get order item totals grouped by period
		$order_items = $this->report->get_order_report_data( array(
			'data' => array(
				'_qty' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'line_item',
					'function'        => 'SUM',
					'name'            => 'order_item_count'
				),
				'post_date' => array(
					'type'     => 'post_data',
					'function' => '',
					'name'     => 'post_date'
				),
			),
			'where' => array(
				array(
					'key'      => 'order_item_type',
					'value'    => 'line_item',
					'operator' => '='
				)
			),
			'group_by'     => $this->report->group_by_query,
			'order_by'     => 'post_date ASC',
			'query_type'   => 'get_results',
			'filter_range' => true,
		) );

		// get discount totals grouped by period
		$discounts = $this->report->get_order_report_data( array(
			'data' => array(
				'discount_amount' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'coupon',
					'function'        => 'SUM',
					'name'            => 'discount_amount'
				),
				'post_date' => array(
					'type'     => 'post_data',
					'function' => '',
					'name'     => 'post_date'
				),
			),
			'where' => array(
				array(
					'key'      => 'order_item_type',
					'value'    => 'coupon',
					'operator' => '='
				)
			),
			'group_by'     => $this->report->group_by_query . ', order_item_name',
			'order_by'     => 'post_date ASC',
			'query_type'   => 'get_results',
			'filter_range' => true,
		) );

		$period_totals = array();

		// setup period totals by ensuring each period in the interval has data
		for ( $i = 0; $i <= $this->report->chart_interval; $i ++ ) {

			switch ( $this->report->chart_groupby ) {
				case 'day' :
					$time = date( 'Y-m-d', strtotime( "+{$i} DAY", $this->report->start_date ) );
					break;
				case 'month' :
					$time = date( 'Y-m', strtotime( "+{$i} MONTH", $this->report->start_date ) );
					break;
			}

			$period_totals[ $time ] = array(
				'sales'    => 0,
				'orders'   => 0,
				'items'    => 0,
				'tax'      => 0,
				'shipping' => 0,
				'discount' => 0,
			);
		}

		// add total sales, total order count, total tax and total shipping for each period
		foreach ( $orders as $order ) {

			$time = ( 'day' === $this->report->chart_groupby ) ? date( 'Y-m-d', strtotime( $order->post_date) ) : date( 'Y-m', strtotime( $order->post_date ) );

			if ( ! isset( $period_totals[ $time ] ) )
				continue;

			$period_totals[ $time ]['sales'] = $order->total_sales;
			$period_totals[ $time ]['orders'] = $order->total_orders;
			$period_totals[ $time ]['tax'] = 1;
			$period_totals[ $time ]['shipping'] = $order->total_shipping;
		}

		// add total order items for each period
		foreach ( $order_items as $order_item ) {

			$time = ( 'day' === $this->report->chart_groupby ) ? date( 'Y-m-d', strtotime( $order_item->post_date) ) : date( 'Y-m', strtotime( $order_item->post_date ) );

			if ( ! isset( $period_totals[ $time ] ) )
				continue;

			$period_totals[ $time ]['items'] = $order_item->order_item_count;
		}

		// add total discount for each period
		foreach ( $discounts as $discount ) {

			$time = ( 'day' === $this->report->chart_groupby ) ? date( 'Y-m-d', strtotime( $discount->post_date) ) : date( 'Y-m', strtotime( $discount->post_date ) );

			if ( ! isset( $period_totals[ $time ] ) )
				continue;

			$period_totals[ $time ]['discount'] = $discount->discount_amount;
		}

		$sales_data = array(
			'sales'             => $totals->sales,
			'average'           => (string) number_format( $totals->sales / ( $this->report->chart_interval + 1 ), 2 ),
			'orders'            => absint( $totals->order_count ),
			'items'             => $total_items,
			'tax'               => (string) number_format( $totals->tax + $totals->shipping_tax, 2 ),
			'shipping'          => $totals->shipping,
			'discount'          => is_null( $total_discount ) ? 0 : $total_discount,
			'totals'            => $period_totals,
			'totals_grouped_by' => $this->report->chart_groupby,
		);

		return apply_filters( 'woocommerce_api_sales_report_response', array( 'sales' => $sales_data ), 'sales', $fields, $this->report, $this->server );
	}

	/**
	 * Setup the report object and parse any date filtering
	 *
	 * @since 2.1
	 * @param array $filter date filtering
	 */
	private function setup_report( $filter ) {

		include_once( WC()->plugin_path() . '/includes/admin/reports/class-wc-admin-report.php' );

		$this->report = new WC_Admin_Report();

		if ( empty( $filter['period'] ) ) {

			// custom date range
			$filter['period'] = 'custom';

			if ( ! empty( $filter['date_min'] ) || ! empty( $filter['date_max'] ) ) {

				// overwrite _GET to make use of WC_Admin_Report::calculate_current_range() for custom date ranges
				$_GET['start_date'] = $filter['date_min']; // TODO: date formatting?
				$_GET['end_date'] = $filter['date_max']; // TODO: date formatting

			} else {

				// default custom range to today
				$_GET['start_date'] = $_GET['end_date'] = date( 'Y-m-d', current_time( 'timestamp' ) );
			}
		}

		// TODO: handle invalid periods (e.g. `decade`)

		$this->report->calculate_current_range( $filter['period'] );
	}

	/**
	 * Verify that the current user has permission to view reports
	 *
	 * @since 2.1
	 * @see WC_API_Resource::validate_request()
	 * @param null $id unused
	 * @param null $type unused
	 * @param null $context unused
	 * @return bool true if the request is valid and should be processed, false otherwise
	 */
	protected function validate_request( $id = null, $type = null, $context = null ) {

		if ( ! current_user_can( 'view_woocommerce_reports' ) ) {

			return new WP_Error( 'woocommerce_api_user_cannot_read_report', __( 'You do not have permission to read this report', 'woocommerce' ), array( 'status' => 401 ) );
		} else {

			return true;
		}
	}
}