<?php
// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
    die;
}

/**
 * GitHub adapter for the Repository_Provider interface.
 *
 * Preserves the GitHub URL/header/asset behavior from the original
 * helper-functions.php verbatim.
 *
 * @since 1.1.0
 */
class GitHub_Provider implements Repository_Provider {

    private string $repo_url;
    private string $api_token;

    public function __construct( string $repo_url, string $api_token = '' ) {
        $this->repo_url  = rtrim( $repo_url, '/' );
        $this->api_token = $api_token;
    }

    public function get_id(): string {
        return 'github';
    }

    public function get_label(): string {
        return 'GitHub';
    }

    public function get_repo_data(): ?array {
        if ( empty( $this->repo_url ) ) {
            error_log( 'Projects Portfolio: GitHub URL is empty.' );
            return null;
        }

        $api_url = str_replace( 'https://github.com/', 'https://api.github.com/repos/', $this->repo_url );

        $cache_key   = 'projects_portfolio_provider_data_' . md5( $api_url );
        $cached_data = get_transient( $cache_key );
        if ( $cached_data ) {
            return $cached_data;
        }

        $headers = [ 'Accept' => 'application/vnd.github.v3+json' ];
        if ( ! empty( $this->api_token ) ) {
            $headers['Authorization'] = 'token ' . $this->api_token;
        } else {
            error_log( 'Projects Portfolio: GitHub API token is missing. Using unauthenticated requests.' );
        }

        $response = wp_remote_get( $api_url, [ 'headers' => $headers ] );

        if ( is_wp_error( $response ) ) {
            error_log( 'Projects Portfolio: GitHub API error: ' . $response->get_error_message() );
            return null;
        }

        $code = wp_remote_retrieve_response_code( $response );
        if ( 403 === $code ) {
            $remaining = wp_remote_retrieve_header( $response, 'x-ratelimit-remaining' );
            $reset     = wp_remote_retrieve_header( $response, 'x-ratelimit-reset' );
            error_log( 'Projects Portfolio: GitHub API 403: Rate limit exceeded. Remaining: ' . $remaining . ' Reset at: ' . date( 'Y-m-d H:i:s', (int) $reset ) );
            return null;
        }
        if ( 200 !== $code ) {
            error_log( 'Projects Portfolio: GitHub API error: Received status ' . $code );
            return null;
        }

        $data = json_decode( wp_remote_retrieve_body( $response ), true );
        if ( empty( $data ) || ! is_array( $data ) ) {
            error_log( 'Projects Portfolio: GitHub API error: Invalid data received.' );
            return null;
        }

        set_transient( $cache_key, $data, HOUR_IN_SECONDS );
        return $data;
    }

    public function get_release_url(): ?string {
        $api_url = $this->release_api_url();
        if ( null === $api_url ) {
            return null;
        }

        $cache_key = 'projects_portfolio_provider_release_' . md5( $api_url );
        $cached    = get_transient( $cache_key );
        if ( $cached ) {
            return $cached;
        }

        $headers = [ 'Accept' => 'application/vnd.github.v3+json' ];
        if ( ! empty( $this->api_token ) ) {
            $headers['Authorization'] = 'token ' . $this->api_token;
        }

        $response = wp_remote_get( $api_url, [ 'headers' => $headers ] );
        if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
            return null;
        }

        $data = json_decode( wp_remote_retrieve_body( $response ), true );
        if ( ! is_array( $data ) ) {
            return null;
        }

        if ( ! empty( $data['assets'] ) && is_array( $data['assets'] ) ) {
            foreach ( $data['assets'] as $asset ) {
                if ( isset( $asset['name'] ) && 'zip' === pathinfo( $asset['name'], PATHINFO_EXTENSION ) ) {
                    $url = $asset['browser_download_url'] ?? null;
                    if ( $url ) {
                        set_transient( $cache_key, $url, HOUR_IN_SECONDS );
                        return $url;
                    }
                }
            }
        }

        $zipball = $data['zipball_url'] ?? null;
        if ( $zipball ) {
            set_transient( $cache_key, $zipball, HOUR_IN_SECONDS );
        }
        return $zipball;
    }

    public function get_latest_version(): string {
        $api_url = $this->release_api_url();
        if ( null === $api_url ) {
            return 'Unknown';
        }

        $cache_key = 'projects_portfolio_provider_release_version_' . md5( $api_url );
        $cached    = get_transient( $cache_key );
        if ( $cached ) {
            return $cached;
        }

        $response = wp_remote_get( $api_url, [] );
        if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
            return 'Unknown';
        }

        $data = json_decode( wp_remote_retrieve_body( $response ), true );
        $tag  = is_array( $data ) && isset( $data['tag_name'] ) ? (string) $data['tag_name'] : 'Unknown';

        set_transient( $cache_key, $tag, HOUR_IN_SECONDS );
        return $tag;
    }

    public function get_repo_browse_url(): string {
        return $this->repo_url;
    }

    public function get_owner_data( string $owner_login ): ?array {
        if ( empty( $owner_login ) ) {
            return null;
        }

        $api_url = 'https://api.github.com/users/' . $owner_login;
        $ctx = stream_context_create( [
            'http' => [
                'method' => 'GET',
                'header' => "User-Agent: WORDPRESS\r\n",
            ],
        ] );
        $body = @file_get_contents( $api_url, false, $ctx );

        if ( false === $body ) {
            error_log( 'Projects Portfolio: Error fetching data from GitHub API.' );
            return null;
        }

        $data = json_decode( $body, true );
        if ( JSON_ERROR_NONE !== json_last_error() || ! is_array( $data ) ) {
            error_log( 'Projects Portfolio: Error decoding JSON data: ' . json_last_error_msg() );
            return null;
        }

        return [
            'avatar_url' => $data['avatar_url'] ?? '',
            'login'      => $data['login']      ?? $owner_login,
            'html_url'   => $data['html_url']   ?? ( 'https://github.com/' . $owner_login ),
        ];
    }

    private function release_api_url(): ?string {
        if ( empty( $this->repo_url ) ) {
            return null;
        }
        return str_replace( 'https://github.com/', 'https://api.github.com/repos/', $this->repo_url ) . '/releases/latest';
    }
}