<?php
/**
 * WC_Admin_Reports_Taxes_Data_Store class file.
 *
 * @package WooCommerce Admin/Classes
 */

defined( 'ABSPATH' ) || exit;

/**
 * WC_Admin_Reports_Taxes_Data_Store.
 */
class WC_Admin_Reports_Taxes_Data_Store extends WC_Admin_Reports_Data_Store implements WC_Admin_Reports_Data_Store_Interface {

	/**
	 * Table used to get the data.
	 *
	 * @var string
	 */
	const TABLE_NAME = 'wc_order_tax_lookup';

	/**
	 * Mapping columns to data type to return correct response types.
	 *
	 * @var array
	 */
	protected $column_types = array(
		'tax_rate_id'  => 'intval',
		'name'         => 'strval',
		'tax_rate'     => 'floatval',
		'country'      => 'strval',
		'state'        => 'strval',
		'priority'     => 'intval',
		'total_tax'    => 'floatval',
		'order_tax'    => 'floatval',
		'shipping_tax' => 'floatval',
		'orders_count' => 'intval',
	);

	/**
	 * SQL columns to select in the db query and their mapping to SQL code.
	 *
	 * @var array
	 */
	protected $report_columns = array(
		'tax_rate_id'  => 'tax_rate_id',
		'name'         => 'tax_rate_name as name',
		'tax_rate'     => 'tax_rate',
		'country'      => 'tax_rate_country as country',
		'state'        => 'tax_rate_state as state',
		'priority'     => 'tax_rate_priority as priority',
		'total_tax'    => 'SUM(total_tax) as total_tax',
		'order_tax'    => 'SUM(order_tax) as order_tax',
		'shipping_tax' => 'SUM(shipping_tax) as shipping_tax',
		'orders_count' => 'COUNT(DISTINCT order_id) as orders_count',
	);

	/**
	 * Constructor
	 */
	public function __construct() {
		global $wpdb;
		$table_name                          = $wpdb->prefix . self::TABLE_NAME;
		// Avoid ambigious column tax_rate_id in SQL query.
		$this->report_columns['tax_rate_id'] = $table_name . '.' . $this->report_columns['tax_rate_id'];
	}

	/**
	 * Updates the database query with parameters used for Taxes report: categories and order status.
	 *
	 * @param array $query_args Query arguments supplied by the user.
	 * @return array            Array of parameters used for SQL query.
	 */
	protected function get_sql_query_params( $query_args ) {
		global $wpdb;

		$order_tax_lookup_table = $wpdb->prefix . self::TABLE_NAME;

		$sql_query_params = $this->get_time_period_sql_params( $query_args, $order_tax_lookup_table );
		$sql_query_params = array_merge( $sql_query_params, $this->get_limit_sql_params( $query_args ) );
		$sql_query_params = array_merge( $sql_query_params, $this->get_order_by_sql_params( $query_args ) );

		if ( isset( $query_args['taxes'] ) && ! empty( $query_args['taxes'] ) ) {
			$allowed_taxes                     = implode( ',', $query_args['taxes'] );
			$sql_query_params['where_clause'] .= " AND {$order_tax_lookup_table}.tax_rate_id IN ({$allowed_taxes})";
		}

		$sql_query_params['from_clause'] .= " JOIN {$wpdb->prefix}woocommerce_tax_rates ON {$order_tax_lookup_table}.tax_rate_id = {$wpdb->prefix}woocommerce_tax_rates.tax_rate_id";

		return $sql_query_params;
	}

	/**
	 * Fills ORDER BY clause of SQL request based on user supplied parameters.
	 *
	 * @param array $query_args Parameters supplied by the user.
	 * @return array
	 */
	protected function get_order_by_sql_params( $query_args ) {
		$sql_query['order_by_clause'] = '';
		if ( isset( $query_args['orderby'] ) ) {
			$sql_query['order_by_clause'] = $this->normalize_order_by( $query_args['orderby'] );
		}

		if ( isset( $query_args['order'] ) ) {
			$sql_query['order_by_clause'] .= ' ' . $query_args['order'];
		} else {
			$sql_query['order_by_clause'] .= ' DESC';
		}

		return $sql_query;
	}

	/**
	 * Returns the report data based on parameters supplied by the user.
	 *
	 * @param array $query_args  Query parameters.
	 * @return stdClass|WP_Error Data.
	 */
	public function get_data( $query_args ) {
		global $wpdb;

		$table_name = $wpdb->prefix . self::TABLE_NAME;
		$now        = time();
		$week_back  = $now - WEEK_IN_SECONDS;

		// These defaults are only partially applied when used via REST API, as that has its own defaults.
		$defaults   = array(
			'per_page' => get_option( 'posts_per_page' ),
			'page'     => 1,
			'order'    => 'DESC',
			'orderby'  => 'tax_rate_id',
			'before'   => date( WC_Admin_Reports_Interval::$iso_datetime_format, $now ),
			'after'    => date( WC_Admin_Reports_Interval::$iso_datetime_format, $week_back ),
			'fields'   => '*',
			'taxes'    => array(),
		);
		$query_args = wp_parse_args( $query_args, $defaults );

		$cache_key = $this->get_cache_key( $query_args );
		$data      = wp_cache_get( $cache_key, $this->cache_group );

		if ( false === $data ) {
			$data = (object) array(
				'data'    => array(),
				'total'   => 0,
				'pages'   => 0,
				'page_no' => 0,
			);

			$selections       = $this->selected_columns( $query_args );
			$sql_query_params = $this->get_sql_query_params( $query_args );

			$db_records_count = (int) $wpdb->get_var(
				"SELECT COUNT(*) FROM (
							SELECT
								{$table_name}.tax_rate_id
							FROM
								{$table_name}
								{$sql_query_params['from_clause']}
							WHERE
								1=1
								{$sql_query_params['where_time_clause']}
								{$sql_query_params['where_clause']}
							GROUP BY
								{$table_name}.tax_rate_id
					  		) AS tt"
			); // WPCS: cache ok, DB call ok, unprepared SQL ok.

			$total_pages = (int) ceil( $db_records_count / $sql_query_params['per_page'] );
			if ( $query_args['page'] < 1 || $query_args['page'] > $total_pages ) {
				return $data;
			}

			$tax_data = $wpdb->get_results(
				"SELECT
						{$selections}
					FROM
						{$table_name}
						{$sql_query_params['from_clause']}
					WHERE
						1=1
						{$sql_query_params['where_time_clause']}
						{$sql_query_params['where_clause']}
					GROUP BY
						{$table_name}.tax_rate_id
					ORDER BY
						{$sql_query_params['order_by_clause']}
					{$sql_query_params['limit']}
					",
				ARRAY_A
			); // WPCS: cache ok, DB call ok, unprepared SQL ok.

			if ( null === $tax_data ) {
				return $data;
			}

			$tax_data = array_map( array( $this, 'cast_numbers' ), $tax_data );
			$data     = (object) array(
				'data'    => $tax_data,
				'total'   => $db_records_count,
				'pages'   => $total_pages,
				'page_no' => (int) $query_args['page'],
			);

			wp_cache_set( $cache_key, $data, $this->cache_group );
		}

		return $data;
	}

	/**
	 * Returns string to be used as cache key for the data.
	 *
	 * @param array $params Query parameters.
	 * @return string
	 */
	protected function get_cache_key( $params ) {
		return 'woocommerce_' . self::TABLE_NAME . '_' . md5( wp_json_encode( $params ) );
	}

	/**
	 * Maps ordering specified by the user to columns in the database/fields in the data.
	 *
	 * @param string $order_by Sorting criterion.
	 * @return string
	 */
	protected function normalize_order_by( $order_by ) {
		global $wpdb;

		if ( 'rate' === $order_by ) {
			return $wpdb->prefix . 'woocommerce_tax_rates.tax_rate';
		}

		return $order_by;
	}

}