<?php

namespace DeliciousBrains\WPMDB\Common\Upgrades;

use DeliciousBrains\WPMDB\Common\Properties\Properties;
use stdClass;
use WP_Error;

class PluginUpdateManager {
	/**
	 * Default WP Product Info API base
	 */
	const UPDATE_BASE = 'https://wp-product-info.wpesvc.net/v1/plugins';

	/**
	 * API Cache Time
	 */
	const CACHE_TIME = HOUR_IN_SECONDS * 12;

	/**
	 * @var Properties
	 */
	private $properties;

	/**
	 * @param Properties $properties
	 */
	public function __construct( Properties $properties ) {
		$this->properties = $properties;
	}

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function register() {
		add_filter( 'plugins_api', [ $this, 'filter_plugin_update_info' ], 20, 3 );
		add_filter( 'site_transient_update_plugins', [ $this, 'filter_plugin_update_transient' ] );
	}

	/**
	 * Filter the plugin update transient to take over update notifications.
	 *
	 * @param object $transient
	 *
	 * @handles site_transient_update_plugins
	 * @return object
	 */
	public function filter_plugin_update_transient( $transient ) {
		if ( empty( $transient->checked ) ) {
			return $transient;
		}

		$result = $this->fetch_plugin_info();

		if ( false === $result ) {
			return $transient;
		}

		if ( version_compare( $this->properties->plugin_version, $result->version, '<' ) ) {
			$res                                 = $this->parse_plugin_info( $result );
			$transient->response[ $res->plugin ] = $res;
			$transient->checked[ $res->plugin ]  = $result->version;
		}

		return $transient;
	}

	/**
	 * Filters the plugin update information.
	 *
	 * @param object $res
	 * @param string $action
	 * @param object $args
	 *
	 * @handles plugins_api
	 * @return object
	 */
	public function filter_plugin_update_info( $res, $action, $args ) {
		// do nothing if this is not about getting plugin information
		if ( 'plugin_information' !== $action ) {
			return $res;
		}

		// do nothing if it is not our plugin
		if ( $this->properties->plugin_slug !== $args->slug ) {
			return $res;
		}

		$result = $this->fetch_plugin_info();

		// do nothing if we don't get the correct response from the server
		if ( false === $result ) {
			return $res;
		}

		return $this->parse_plugin_info( $result );
	}

	/**
	 * Fetches the plugin update object from the WP Product Info API.
	 *
	 * @return object|false
	 */
	private function fetch_plugin_info() {
		//Fetch cache first
		$response = get_transient( WPMDB_PRODUCT_INFO_RESPONSE_TRANSIENT );

		if ( empty( $response ) ) {
			$response = wp_remote_get(
				sprintf( '%s/%s', self::UPDATE_BASE, $this->properties->plugin_slug ),
				array(
					'timeout' => 10,
					'headers' => array(
						'Accept' => 'application/json',
					),
				)
			);

			if (
				is_wp_error( $response ) ||
				200 !== wp_remote_retrieve_response_code( $response ) ||
				empty( wp_remote_retrieve_body( $response ) )
			) {
				return false;
			}

			$response = wp_remote_retrieve_body( $response );

			//Cache the response
			set_transient( WPMDB_PRODUCT_INFO_RESPONSE_TRANSIENT, $response, self::CACHE_TIME );
		}

		return json_decode( $response );
	}

	/**
	 * Parses the product info response into an object that WordPress would be able to understand.
	 *
	 * @param object $response
	 *
	 * @return stdClass
	 */
	private function parse_plugin_info( $response ) {
		global $wp_version;

		$res                = new stdClass();
		$res->name          = $response->name;
		$res->slug          = $response->slug;
		$res->version       = $response->version;
		$res->requires      = $response->requires_at_least;
		$res->download_link = $response->download_link;
		$res->trunk         = $response->download_link;
		$res->new_version   = $response->version;
		$res->plugin        = $this->properties->plugin_basename;
		$res->package       = $response->download_link;

		// Plugin information modal and core update table use a strict version comparison, which is weird.
		// If we're genuinely not compatible with the point release, use our WP tested up to version,
		// otherwise use exact same version as WP to avoid false positive.
		$res->tested = 1 === version_compare( substr( $wp_version, 0, 3 ), $response->tested_up_to )
			? $response->tested_up_to
			: $wp_version;

		$res->sections = array(
			'description' => $response->sections->description,
			'changelog'   => $response->sections->changelog,
		);

		return $res;
	}
}