<?php
/**
 * Canonical coordinate storage.
 *
 * Whatever the configured location source is, coordinates always end
 * up in the `_mapsemble_lat` / `_mapsemble_lng` post meta keys — the
 * single, uniformly queryable representation the features feed reads.
 *
 * @package Mapsemble
 */

namespace Mapsemble\Geo;

use Mapsemble\MapConfig;
use Mapsemble\MapConfigRepository;

/**
 * Reads and writes the canonical coordinate meta.
 */
class Coordinates {

	public const META_LAT    = '_mapsemble_lat';
	public const META_LNG    = '_mapsemble_lng';
	public const META_HIDDEN = '_mapsemble_hidden';

	/**
	 * Config repository.
	 *
	 * @var MapConfigRepository
	 */
	private MapConfigRepository $repository;

	/**
	 * Constructor.
	 *
	 * @param MapConfigRepository $repository Config repository.
	 */
	public function __construct( MapConfigRepository $repository ) {
		$this->repository = $repository;
	}

	/**
	 * Returns a post's coordinates, or null when it has none.
	 *
	 * @param int $post_id Post ID.
	 * @return array{lat: float, lng: float}|null
	 */
	public function get( int $post_id ): ?array {
		$lat = get_post_meta( $post_id, self::META_LAT, true );
		$lng = get_post_meta( $post_id, self::META_LNG, true );
		if ( '' === $lat || '' === $lng || ! is_numeric( $lat ) || ! is_numeric( $lng ) ) {
			return null;
		}
		return array(
			'lat' => (float) $lat,
			'lng' => (float) $lng,
		);
	}

	/**
	 * Reads coordinates from two arbitrary meta keys.
	 *
	 * The meta-keys source's twin of AcfIntegration::read_field_coords():
	 * both values must be present and numeric, or there is no location.
	 *
	 * @param int    $post_id Post ID.
	 * @param string $lat_key Latitude meta key.
	 * @param string $lng_key Longitude meta key.
	 * @return array{lat: float, lng: float}|null
	 */
	public function read_from_meta_keys( int $post_id, string $lat_key, string $lng_key ): ?array {
		$lat = get_post_meta( $post_id, $lat_key, true );
		$lng = get_post_meta( $post_id, $lng_key, true );
		if ( ! is_numeric( $lat ) || ! is_numeric( $lng ) ) {
			return null;
		}
		return array(
			'lat' => (float) $lat,
			'lng' => (float) $lng,
		);
	}

	/**
	 * Writes (or clears) a post's canonical coordinates.
	 *
	 * Runs the mapsemble_post_coordinates filter first, so custom code
	 * can supply, override, or suppress (return null) the coordinates.
	 *
	 * @param int                                $post_id Post ID.
	 * @param array{lat: float, lng: float}|null $coords  Coordinates from the configured source.
	 */
	public function write( int $post_id, ?array $coords ): void {
		$config = $this->find_config_for_post( $post_id );

		/**
		 * Filters a post's coordinates before they are stored.
		 *
		 * @param array{lat: float, lng: float}|null $coords  Coordinates, or null for none.
		 * @param int                                $post_id Post ID.
		 * @param MapConfig|null                     $config  The map config covering this post type, if any.
		 */
		$coords = apply_filters( 'mapsemble_post_coordinates', $coords, $post_id, $config );

		if ( null === $coords || ! $this->is_valid( $coords ) ) {
			delete_post_meta( $post_id, self::META_LAT );
			delete_post_meta( $post_id, self::META_LNG );
			return;
		}
		update_post_meta( $post_id, self::META_LAT, sprintf( '%.6F', (float) $coords['lat'] ) );
		update_post_meta( $post_id, self::META_LNG, sprintf( '%.6F', (float) $coords['lng'] ) );
	}

	/**
	 * Marks a post hidden from (or visible on) maps.
	 *
	 * @param int  $post_id Post ID.
	 * @param bool $hidden  Whether the post is excluded from maps.
	 */
	public function set_hidden( int $post_id, bool $hidden ): void {
		if ( $hidden ) {
			update_post_meta( $post_id, self::META_HIDDEN, '1' );
		} else {
			delete_post_meta( $post_id, self::META_HIDDEN );
		}
	}

	/**
	 * Whether a coordinate pair is within valid WGS84 bounds.
	 *
	 * @param array $coords Candidate coordinates.
	 */
	public function is_valid( array $coords ): bool {
		if ( ! isset( $coords['lat'], $coords['lng'] )
			|| ! is_numeric( $coords['lat'] ) || ! is_numeric( $coords['lng'] ) ) {
			return false;
		}
		$lat = (float) $coords['lat'];
		$lng = (float) $coords['lng'];
		return $lat >= -90.0 && $lat <= 90.0 && $lng >= -180.0 && $lng <= 180.0;
	}

	/**
	 * Returns the first WordPress-mode map config covering a post's type.
	 *
	 * Hosted maps are skipped even though they may still carry a post type:
	 * switching a map to hosted deliberately keeps its source settings so
	 * switching back is lossless, and treating that retained value as live
	 * would have a hosted map dictate how content on this site is indexed.
	 *
	 * @param int $post_id Post ID.
	 */
	public function find_config_for_post( int $post_id ): ?MapConfig {
		$post_type = get_post_type( $post_id );
		if ( false === $post_type ) {
			return null;
		}
		foreach ( $this->repository->all() as $config ) {
			if ( ! $config->is_hosted() && $config->post_type === $post_type ) {
				return $config;
			}
		}
		return null;
	}
}