<?php
/**
 * Report selection shared by the overview, the list and exports.
 *
 * @package Dealroot
 */

namespace Dealroot\Admin;

use Dealroot\Reports;

defined( 'ABSPATH' ) || exit;

/**
 * Reads period, dimension, model and drill-down from the request and remembers them per user.
 *
 * Links and forms on the screens carry a nonce, and only a request with a valid one changes what
 * is remembered. Any other link, e.g. a bookmark, shows the selection without saving it.
 */
class Report_State {

	const META_KEY = 'dealroot_report';

	/**
	 * Request argument with the nonce.
	 */
	const KEEP = 'dealroot_keep';

	/**
	 * Whether the request may change the remembered selection.
	 *
	 * @return bool
	 */
	public static function remembers() {
		if ( ! isset( $_GET[ self::KEEP ] ) || ! current_user_can( Admin::capability() ) ) {
			return false;
		}

		if ( ! wp_verify_nonce( sanitize_key( wp_unslash( $_GET[ self::KEEP ] ) ), 'dealroot_keep_view' ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Current selection.
	 *
	 * @return array period, dimension, model, group_value (null when no drill-down).
	 */
	public static function current() {
		static $state = null;

		if ( null !== $state ) {
			return $state;
		}

		$saved = get_user_meta( get_current_user_id(), self::META_KEY, true );
		$saved = is_array( $saved ) ? $saved : array();

		// phpcs:disable WordPress.Security.NonceVerification.Recommended -- Only shown; it is saved below with a verified nonce.
		$period    = isset( $_GET['period'] ) ? sanitize_key( wp_unslash( $_GET['period'] ) ) : ( $saved['period'] ?? 'all' );
		$dimension = isset( $_GET['dim'] ) ? sanitize_key( wp_unslash( $_GET['dim'] ) ) : ( $saved['dimension'] ?? 'channel' );
		$model     = isset( $_GET['model'] ) ? sanitize_key( wp_unslash( $_GET['model'] ) ) : ( $saved['model'] ?? 'first' );
		$value     = isset( $_GET['group_value'] ) ? sanitize_text_field( wp_unslash( $_GET['group_value'] ) ) : null;
		// phpcs:enable

		$state = array(
			'period'      => array_key_exists( $period, Reports::periods() ) || preg_match( '/^\d{4}-\d{2}-\d{2}_\d{4}-\d{2}-\d{2}$/', $period ) ? $period : 'all',
			'dimension'   => array_key_exists( $dimension, Reports::dimensions() ) ? $dimension : 'channel',
			'model'       => 'last' === $model ? 'last' : 'first',
			'group_value' => $value,
		);

		$remember = array(
			// Days asked for once, e.g. by the assistant, are not kept as the usual period.
			'period'    => array_key_exists( $state['period'], Reports::periods() ) ? $state['period'] : ( $saved['period'] ?? 'all' ),
			'dimension' => $state['dimension'],
			'model'     => $state['model'],
		);

		if ( $remember !== $saved && self::remembers() ) {
			update_user_meta( get_current_user_id(), self::META_KEY, $remember );
		}

		return $state;
	}

	/**
	 * The periods to choose from, with days asked for once, e.g. by the assistant, as one more.
	 *
	 * @return array<string, string>
	 */
	public static function periods() {
		$periods = Reports::periods();
		$current = self::current()['period'];

		if ( ! isset( $periods[ $current ] ) ) {
			list( $from, $to ) = explode( '_', $current );
			$format            = get_option( 'date_format' );

			$periods[ $current ] = wp_date( $format, (int) strtotime( $from . ' 12:00:00' ) ) . ' – ' . wp_date( $format, (int) strtotime( $to . ' 12:00:00' ) );
		}

		return $periods;
	}

	/**
	 * Query arguments for Leads::query() matching the selection.
	 *
	 * @return array
	 */
	public static function query_args() {
		$state = self::current();

		list( $from, $to ) = Reports::range( $state['period'] );

		$args = array(
			'from' => $from,
			'to'   => $to,
		);

		if ( null !== $state['group_value'] ) {
			$args['column'] = Reports::column( $state['dimension'], $state['model'] );
			$args['value']  = $state['group_value'];
		}

		return $args;
	}

	/**
	 * URL arguments that keep the selection when linking within the screen.
	 *
	 * @param bool $with_drilldown Include the drill-down value.
	 * @return array
	 */
	public static function url_args( $with_drilldown = true ) {
		$state = self::current();
		$page  = isset( $_GET['page'] ) ? sanitize_key( wp_unslash( $_GET['page'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$args  = array(
			'page'     => Admin::LEADS_PAGE === $page ? Admin::LEADS_PAGE : Admin::PAGE,
			'period'   => $state['period'],
			'dim'      => $state['dimension'],
			'model'    => $state['model'],
			self::KEEP => wp_create_nonce( 'dealroot_keep_view' ),
		);

		if ( $with_drilldown && null !== $state['group_value'] ) {
			$args['group_value'] = $state['group_value'];
		}

		return $args;
	}
}