/**

 * Relational pipes

 * Copyright © 2022 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 3 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

#include <sstream>

#include <iostream>

#include <curl/curl.h>

#include "HTTPClient.h"

namespace relpipe {

namespace tr {

namespace http {

class HTTPClient::HTTPClientImpl {

public:

	CURL* curl;

	std::stringstream responseBody;

	std::stringstream responseHeaders;

	HTTPClientImpl(CURL* curl) : curl(curl) {

	}

	std::vector<std::string> getResponseHeaders() {

		std::vector<std::string> heathers;

		std::stringstream name;

		std::stringstream value;

		std::stringstream* current = &name;

		for (char ch = responseHeaders.get(); responseHeaders.good(); ch = responseHeaders.get()) {

			if (ch == ':') {

				current = &value;

				for (char space = responseHeaders.get(); responseHeaders.good() && responseHeaders.peek() == ' '; space = responseHeaders.get()); // skip spaces

			} else if (ch == '\n') {

				if (name.tellp() > 0 && current == &value) {

					heathers.push_back(name.str());

					heathers.push_back(value.str());

				} else if (name.tellp() > 0 && current == &value) {

					// TODO: usually "HTTP/1.1 200 OK" → extract HTTP version and message?

				}

				name = std::stringstream();

				value = std::stringstream();

				current = &name;

			} else if (ch == '\r') {

				// ignore

			} else {

				current->put(ch);

			}

		}

		return heathers;

	}

};

class CurlList {

private:

	curl_slist* list = nullptr;

public:

	CurlList() = default;

	CurlList(const HTTPClient&) = delete;

	CurlList& operator=(const CurlList&) = delete;

	virtual ~CurlList() {

		curl_slist_free_all(list);

	}

	void append(std::string item) {

		list = curl_slist_append(list, item.c_str());

	}

	curl_slist* getList() {

		return list;

	}

};

HTTPClient* HTTPClient::open() {

}

HTTPClient::~HTTPClient() {

	curl_easy_cleanup(impl->curl);

	delete impl;

}

const HTTPClient::Response HTTPClient::exchange(const Request& request) {

	HTTPClient::Response response;

	// TODO: set request method

	// set URL

	curl_easy_setopt(impl->curl, CURLOPT_URL, request.url.c_str());

	// set request headers

	CurlList requestHeders;

	for (size_t i = 0; i < request.headers.size(); i += 2) requestHeders.append(request.headers[i] + ": " + request.headers[i + 1]); // TODO: validate, no CR/LF...

	curl_easy_setopt(impl->curl, CURLOPT_HTTPHEADER, requestHeders.getList());

	// do HTTP call

	CURLcode result = curl_easy_perform(impl->curl);

	if (result == CURLE_OK) {

		// response code and fill the result object

		curl_easy_getinfo(impl->curl, CURLINFO_RESPONSE_CODE, &response.responseCode);

		response.headers = impl->getResponseHeaders();

		response.body = impl->responseBody.str();

		impl->responseBody = std::stringstream();

		return response;

	} else {

		throw Exception(curl_easy_strerror(result));

	}

}

}

}

}