<?php

declare(strict_types=1);

namespace Agent001\Http;

\defined( 'ABSPATH' ) || exit;

final class Client
{
    public const DEFAULT_TIMEOUT     = 30;
    public const DEFAULT_MAX_ATTEMPTS = 3;
    public const DEFAULT_BASE_DELAY_MS = 500;

    private int $timeout;

    private int $maxAttempts;

    private int $baseDelayMs;

    public function __construct(
        int $timeout = self::DEFAULT_TIMEOUT,
        int $maxAttempts = self::DEFAULT_MAX_ATTEMPTS,
        int $baseDelayMs = self::DEFAULT_BASE_DELAY_MS
    ) {
        $this->timeout     = max( 1, $timeout );
        $this->maxAttempts = max( 1, $maxAttempts );
        $this->baseDelayMs = max( 0, $baseDelayMs );
    }

    public function postJson( string $url, array $headers, string $body ): Result
    {
        return $this->request( 'POST', $url, $headers, $body );
    }

    public function putJson( string $url, array $headers, string $body ): Result
    {
        return $this->request( 'PUT', $url, $headers, $body );
    }

    public function getJson( string $url, array $headers ): Result
    {
        return $this->request( 'GET', $url, $headers, null );
    }

    public function delete( string $url, array $headers ): Result
    {
        return $this->request( 'DELETE', $url, $headers, null );
    }

    private function request( string $method, string $url, array $headers, ?string $body ): Result
    {
        $args = [
            'method'      => $method,
            'headers'     => $headers,
            'timeout'     => $this->timeout,
            'redirection' => 0,
            'blocking'    => true,
            'sslverify'   => true,
            'data_format' => 'body',
        ];
        if ( $body !== null ) {
            $args['body'] = $body;
        }

        $attempt      = 0;
        $lastError    = '';
        $lastStatus   = 0;
        $lastBody     = '';

        while ( $attempt < $this->maxAttempts ) {
            $attempt++;

            $response = \wp_remote_request( $url, $args );

            if ( \is_wp_error( $response ) ) {
                $lastError = (string) $response->get_error_message();

                if ( $attempt >= $this->maxAttempts ) {
                    return Result::failure(
                        0,
                        sprintf(
                            /* translators: %s: HTTP transport error message */
                            \__( 'Network error: %s', 'agent001-support-assistant-for-woocommerce' ),
                            $lastError
                        )
                    );
                }

                $this->backoff( $attempt );
                continue;
            }

            $lastStatus = (int) \wp_remote_retrieve_response_code( $response );
            $lastBody   = (string) \wp_remote_retrieve_body( $response );

            if ( $lastStatus >= 200 && $lastStatus < 300 ) {
                return Result::success( $lastStatus, $lastBody );
            }

            if ( ! $this->shouldRetry( $lastStatus ) || $attempt >= $this->maxAttempts ) {
                $message     = sprintf(
                    /* translators: %d: HTTP status code returned by the remote */
                    \__( 'Remote returned HTTP %d.', 'agent001-support-assistant-for-woocommerce' ),
                    $lastStatus
                );
                $remoteError = $this->remoteError( $lastBody );

                return Result::failure( $lastStatus, $remoteError !== '' ? $message . ' ' . $remoteError : $message );
            }

            $this->backoff( $attempt );
        }

        return Result::failure(
            $lastStatus,
            $lastError !== '' ? $lastError : \__( 'HTTP request failed.', 'agent001-support-assistant-for-woocommerce' )
        );
    }

    private function remoteError( string $body ): string
    {
        $decoded = json_decode( $body, true );
        if ( ! is_array( $decoded ) || ! isset( $decoded['error'] ) || ! is_string( $decoded['error'] ) ) {
            return '';
        }

        return substr( \sanitize_text_field( $decoded['error'] ), 0, 300 );
    }

    private function shouldRetry( int $statusCode ): bool
    {
        if ( $statusCode >= 500 && $statusCode < 600 ) {
            return true;
        }

        return $statusCode === 408 || $statusCode === 429;
    }

    private function backoff( int $attempt ): void
    {
        $delay = (int) min( 30000, $this->baseDelayMs * ( 2 ** ( $attempt - 1 ) ) );
        usleep( $delay * 1000 );
    }
}