<?php

namespace Ulmus\Api\Transport;

use Ulmus\Api\Common\{ ContentTypeEnum, MethodEnum, HttpHeaderEnum };
use Ulmus\Api\Stream\JsonStream;
use Ulmus\Api\Stream\Stream;
use Psr\Http\Message\{RequestInterface, ResponseInterface, StreamInterface};
use Ulmus\Api\Response\{ Response, JsonResponse };

abstract class CurlTransport {

    # Seconds
    public int $timeout = 30;

    # Seconds
    public int $connectTimeout = 300;

    public int $maximumRedirections = 10;

    protected StreamInterface $stderr;

    public function __construct(
        public array $headers = [],
        public array $curlOptions = [],
        public null|CurlAuthorization $authorization = null,
        public ContentTypeEnum $contentType = ContentTypeEnum::Json,
        # Matching Guzzle's great user-agent syntax
        public string $userAgent = "ulmus-api/1.0 curl/{curl} php/{php}",
        public bool $debug = false,
    ) {
        $this->userAgent = str_replace([ '{curl}', '{php}', ], [ curl_version()['version'] ?? "???", phpversion() ], $this->userAgent);
    }

    public function post(string $url, mixed $data, array $headers = [], array $curlOptions = []) : mixed
    {
        return $this->request(MethodEnum::Post, $url, $data, $headers, $curlOptions);
    }

    public function get(string $url, mixed $data, array $headers = [], array $curlOptions = []) : mixed
    {
        return $this->request(MethodEnum::Get, $url, $data, $headers, $curlOptions);
    }

    public function delete(string $url, mixed $data, array $headers = [], array $curlOptions = []) : mixed
    {
        return $this->request(MethodEnum::Delete, $url, $data, $headers, $curlOptions);
    }

    public function patch(string $url, mixed $data, array $headers = [], array $curlOptions = []) : mixed
    {
        return $this->request(MethodEnum::Patch, $url, $data, $headers, $curlOptions);
    }

    public function put(string $url, mixed $data, array $headers = [], array $curlOptions = []) : mixed
    {
        return $this->request(MethodEnum::Put, $url, $data, $headers, $curlOptions);
    }

    public function fromRequest(RequestInterface $request) : ResponseInterface
    {
        return $this->request(MethodEnum::from($request->getMethod()), $request->getUri(), $request->getBody(), $request->getHeaders());
    }

    public function request(MethodEnum $method, string $url, mixed $data = null, array $headers = [], array $options = []) : ResponseInterface
    {
        $response = new Response();

        if ($this->debug) {
            $this->stderr = Stream::fromMemory();
            $stderrResource = $this->stderr->detach();
        }

        $headers = array_merge_recursive(HttpHeaderEnum::normalizeHeaderArray($headers), HttpHeaderEnum::normalizeHeaderArray($this->headers));

        $options += $this->curlOptions;

        $this->applyMethod($method, $data, $headers, $options);

        $headers += $this->authorization->headers;

        $options += $this->authorization->options;

        $options += [
            CURLOPT_URL => $url,
            CURLOPT_HTTPHEADER => HttpHeaderEnum::compileHeaders($headers),
            CURLOPT_MAXREDIRS => $this->maximumRedirections,
            CURLOPT_TIMEOUT => $this->timeout * 1000,
            CURLOPT_CONNECTTIMEOUT => $this->connectTimeout,
            CURLOPT_SSL_VERIFYPEER => false,
            CURLOPT_SSL_VERIFYHOST => false,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_HEADERFUNCTION => function($curl, $headerLine) use (& $response) {
                if ( strpos($headerLine, ':') ) {
                    list($key, $value) = array_map('trim', explode(':', $headerLine));

                    $response = $response->withHeader($key, $value);
                }
                elseif ( strtoupper(substr($headerLine, 0, 4)) === 'HTTP' ) {
                    list(,$code, $status) = explode(' ', trim($headerLine), 3) + [ null, null, null ];

                    $response = $response->withStatus($code, $status);
                }

                return strlen($headerLine);
            }
        ] + ( $this->debug ? [
            CURLOPT_VERBOSE => true,
            CURLOPT_STDERR => $stderrResource,
        ] : [] );

        $ch = curl_init();

        foreach($options as $opt => $value) {
            curl_setopt($ch, $opt, $value);
        }

        if ( false === ( $result = curl_exec($ch) ) ) {
            $errno = curl_errno($ch);
            $errors = array_filter([ curl_error($ch) , CurlErrors::CURL_CODES[$errno] ?? null ]);

            throw new \Exception(implode(PHP_EOL, $errors), $errno);
        }

        if ($this->debug) {
            $this->stderr->attach($stderrResource);
        }

        $response = $response->withBody( Stream::fromMemory($result) );

        if ( $response->hasHeader('Content-Type') && false !== strpos($response->getHeader('Content-Type')[0], 'json') ) {
            $response = JsonResponse::fromResponse($response);
        }

        return $response;
    }

    protected function applyMethod(MethodEnum $method, mixed &$data, array &$headers, array &$options) : void
    {
        switch ($method) {
            case MethodEnum::Patch:
            case MethodEnum::Put:
            case MethodEnum::Delete:
            case MethodEnum::Post:
                if ($method === MethodEnum::Post) {
                    $options[CURLOPT_POST] = true;
                }
                else {
                    $options[CURLOPT_CUSTOMREQUEST] = $method->value;
                }

                $this->arrayToPostFields($data, $headers, $options);
            break;

            case MethodEnum::Get:
            default:
        }
    }

    protected function arrayToPostFields(mixed &$data, array &$headers, array &$options) : void
    {
        $headers["Content-Type"] = $this->contentType->value;

        switch($this->contentType) {
            case ContentTypeEnum::Json:
                if ($data instanceof JsonStream) {
                    $json = $data->getContents();
                }
                elseif (is_string($data) && empty($data)) {
                    $json = $this->contentType->defaultBody();
                }
                else {
                    $json = json_encode($data, JsonStream::DEFAULT_JSON_ENCODING_FLAGS);
                }

                $options[CURLOPT_POSTFIELDS] = $json;
                $headers['Accept'] ??= $this->contentType->value;
            break;

            case ContentTypeEnum::UrlEncoded:
                $options[CURLOPT_POSTFIELDS] = http_build_query($data, '', '&');
            break;

            case ContentTypeEnum::Multipart:
                $options[CURLOPT_POSTFIELDS] = $data;
            break;
        }
    }

    protected function unindexQueryStringArrays(string $query) : string
    {
        return preg_replace("/\[[0-9]+\]/simU", "[]", $query);
    }
}