<?php

namespace RomhackPlaza\API;
defined( 'ABSPATH' ) || exit;

class File_Server {

    const int FAV_SERVER_NEED_CHANGE = 3600; // In seconds.

    const array ENDPOINTS = [
        'random-server' => "Getrandomserver",
        'server-by-id' => "Getserver&server_id=%d",
        'server-by-url' => "Getserver&server_url=%s"
    ];

    private(set) public string $server_url;
    private(set) public int $server_id;

    public function __construct( int $post_id = 0, bool $get_a_server = true ) {

        if( $get_a_server ){
            $resp = self::get_favorite_server( $post_id );
            if( !isset( $resp['_wp_error'] ) ) {
                $this->server_url = $resp['server_url'];
                $this->server_id = $resp['server_id'];
            } else {
                $this->server_url = "";
                $this->server_id = -1;
            }
        }

    }

    public function print_js(){

        echo sprintf( '<script>const chosenDownloadServer="%s";const chosenDownloadServerId="%d";</script>', $this->server_url, $this->server_id );

    }

    public function print(){

        echo $this->server_url . "|" . $this->server_id;

    }

    public static function build_url( string $endpoint, ...$args ){

        return sprintf( $_ENV['ROMHACKPLAZA_API_URL'] . "index.php?action=" . $endpoint, ...$args );

    }

    public static function generate_token(
        int $user_id,
        string $to,
        string $action
    ): string {

        $info = [
            'user_id' => $user_id,
            'to' => $to,
            'action' => $action,
            'generated_at' => time(),
            'expires_at' => time() + ( 15 * 60 ),
            'romhackplaza' => \bin2hex( random_bytes( 16 ) )
        ];

        $json = json_encode( $info );
        $sig = hash_hmac( 'sha256', $json, $_ENV['ROMHACKPLAZAFS_SECRET_KEY'] );

        $end = base64_encode( $json ) . "|" . $sig;
        return $end;

    }

    public static function get_favorite_server( int $post_id ): array {

        if( $post_id == 0 )
            return self::get_a_random_server();

        $favorite_server = get_post_meta( $post_id, 'favorite_server', true ) ?? false;
        $favorite_server_timestamp = get_post_meta( $post_id, 'favorite_server_timestamp', true ) ?? false;

        if( $favorite_server === false || $favorite_server_timestamp === false )
            return self::get_a_random_server();

        $time = time() - intval( $favorite_server_timestamp );
        if( $time > self::FAV_SERVER_NEED_CHANGE )
            return self::get_a_random_server();

        $request = wp_remote_get( self::build_url( self::ENDPOINTS['server-by-id'], $favorite_server ) );
        if( is_wp_error( $request ) ) {
            return [ '_wp_error' => 1 ];
        }

        $body = json_decode( wp_remote_retrieve_body( $request ), ARRAY_A );
        if( $body['success'] !== true ){
            return [ '_wp_error' => 2 ];
        }

        return $body['server'];

    }

    public static function get_a_random_server(): array {

        $request = wp_remote_get( self::build_url( self::ENDPOINTS['random-server'] ) );
        if( is_wp_error( $request ) ) {
            return [ '_wp_error' => 1 ];
        }

        $body = json_decode( wp_remote_retrieve_body( $request ), ARRAY_A );
        if( $body['success'] !== true ){
            return [ '_wp_error' => 2 ];
        }

        return $body['server'];

    }

}