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

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

class KKART_API_Reports extends KKART_API_Resource {

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

	/** @var KKART_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' ),     KKART_API_Server::READABLE ),
		);

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

		# GET /reports/sales/top_sellers
		$routes[ $this->base . '/sales/top_sellers' ] = array(
			array( array( $this, 'get_top_sellers_report' ), KKART_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', 'sales/top_sellers' ) );
	}

	/**
	 * Get the sales report
	 *
	 * @since 2.1
	 * @param string $fields fields to include in response
	 * @param array $filter date filtering
	 * @return array|WP_Error
	 */
	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,
		) );

		// new customers
		$users_query = new WP_User_Query(
			array(
				'fields'  => array( 'user_registered' ),
				'role'    => 'customer',
			)
		);

		$customers = $users_query->get_results();

		foreach ( $customers as $key => $customer ) {
			if ( strtotime( $customer->user_registered ) < $this->report->start_date || strtotime( $customer->user_registered ) > $this->report->end_date ) {
				unset( $customers[ $key ] );
			}
		}

		$total_customers = count( $customers );

		// 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',
				),
				'_order_tax' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'total_tax',
				),
				'_order_shipping_tax' => array(
					'type'     => 'meta',
					'function' => 'SUM',
					'name'     => 'total_shipping_tax',
				),
				'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;
			}

			// set the customer signups for each period
			$customer_count = 0;
			foreach ( $customers as $customer ) {

				if ( date( ( 'day' == $this->report->chart_groupby ) ? 'Y-m-d' : 'Y-m', strtotime( $customer->user_registered ) ) == $time ) {
					$customer_count++;
				}
 			}

			$period_totals[ $time ] = array(
				'sales'     => kkart_format_decimal( 0.00, 2 ),
				'orders'    => 0,
				'items'     => 0,
				'tax'       => kkart_format_decimal( 0.00, 2 ),
				'shipping'  => kkart_format_decimal( 0.00, 2 ),
				'discount'  => kkart_format_decimal( 0.00, 2 ),
				'customers' => $customer_count,
			);
		}

		// 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']    = kkart_format_decimal( $order->total_sales, 2 );
			$period_totals[ $time ]['orders']   = (int) $order->total_orders;
			$period_totals[ $time ]['tax']      = kkart_format_decimal( $order->total_tax + $order->total_shipping_tax, 2 );
			$period_totals[ $time ]['shipping'] = kkart_format_decimal( $order->total_shipping, 2 );
		}

		// 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'] = (int) $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'] = kkart_format_decimal( $discount->discount_amount, 2 );
		}

		$sales_data = array(
			'total_sales'       => kkart_format_decimal( $totals->sales, 2 ),
			'average_sales'     => kkart_format_decimal( $totals->sales / ( $this->report->chart_interval + 1 ), 2 ),
			'total_orders'      => (int) $totals->order_count,
			'total_items'       => $total_items,
			'total_tax'         => kkart_format_decimal( $totals->tax + $totals->shipping_tax, 2 ),
			'total_shipping'    => kkart_format_decimal( $totals->shipping, 2 ),
			'total_discount'    => is_null( $total_discount ) ? kkart_format_decimal( 0.00, 2 ) : kkart_format_decimal( $total_discount, 2 ),
			'totals_grouped_by' => $this->report->chart_groupby,
			'totals'            => $period_totals,
			'total_customers'   => $total_customers,
		);

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

	/**
	 * Get the top sellers report
	 *
	 * @since 2.1
	 * @param string $fields fields to include in response
	 * @param array $filter date filtering
	 * @return array|WP_Error
	 */
	public function get_top_sellers_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 );

		$top_sellers = $this->report->get_order_report_data( array(
			'data' => array(
				'_product_id' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'line_item',
					'function'        => '',
					'name'            => 'product_id',
				),
				'_qty' => array(
					'type'            => 'order_item_meta',
					'order_item_type' => 'line_item',
					'function'        => 'SUM',
					'name'            => 'order_item_qty',
				),
			),
			'order_by'     => 'order_item_qty DESC',
			'group_by'     => 'product_id',
			'limit'        => isset( $filter['limit'] ) ? absint( $filter['limit'] ) : 12,
			'query_type'   => 'get_results',
			'filter_range' => true,
		) );

		$top_sellers_data = array();

		foreach ( $top_sellers as $top_seller ) {

			$product = kkart_get_product( $top_seller->product_id );

			$top_sellers_data[] = array(
				'title'      => $product->get_name(),
				'product_id' => $top_seller->product_id,
				'quantity'   => $top_seller->order_item_qty,
			);
		}

		return array( 'top_sellers' => apply_filters( 'kkart_api_report_response', $top_sellers_data, $this->report, $fields, $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( KKART()->plugin_path() . '/includes/admin/reports/class-kkart-admin-report.php' );

		$this->report = new KKART_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 KKART_Admin_Report::calculate_current_range() for custom date ranges
				$_GET['start_date'] = $this->server->parse_datetime( $filter['date_min'] );
				$_GET['end_date'] = isset( $filter['date_max'] ) ? $this->server->parse_datetime( $filter['date_max'] ) : null;

			} else {

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

			// ensure period is valid
			if ( ! in_array( $filter['period'], array( 'week', 'month', 'last_month', 'year' ) ) ) {
				$filter['period'] = 'week';
			}

			// TODO: change KKART_Admin_Report class to use "week" instead, as it's more consistent with other periods
			// allow "week" for period instead of "7day"
			if ( 'week' === $filter['period'] ) {
				$filter['period'] = '7day';
			}
		}

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

	/**
	 * Verify that the current user has permission to view reports
	 *
	 * @since 2.1
	 * @see KKART_API_Resource::validate_request()
	 * @param null $id unused
	 * @param null $type unused
	 * @param null $context unused
	 * @return true|WP_Error
	 */
	protected function validate_request( $id = null, $type = null, $context = null ) {

		if ( ! current_user_can( 'view_kkart_reports' ) ) {

			return new WP_Error( 'kkart_api_user_cannot_read_report', __( 'You do not have permission to read this report', 'kkart' ), array( 'status' => 401 ) );

		} else {

			return true;
		}
	}
}
