/**
* 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/>.
*/
#pragma once
#include <memory>
#include <string>
#include <vector>
#include <codecvt>
#include <regex>
#include <locale>
#include <stdexcept>
#include <curl/curl.h>
#include <uuid/uuid.h>
#include <relpipe/common/type/typedefs.h>
#include <relpipe/reader/TypeId.h>
#include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
#include <relpipe/reader/handlers/AttributeMetadata.h>
#include <relpipe/writer/Factory.h>
#include <relpipe/writer/TypeId.h>
#include <relpipe/cli/RelpipeCLIException.h>
#include "Configuration.h"
#include "HTTPClient.h"
namespace relpipe {
namespace tr {
namespace http {
class HTTPHandler : public relpipe::reader::handlers::RelationalReaderStringHandler {
private:
class HeaderDefinition {
public:
std::wregex request = std::wregex(L".*");
std::wregex url = std::wregex(L".*");
relpipe::common::type::StringX name;
relpipe::common::type::StringX value;
bool matches(const relpipe::common::type::StringX& request, const relpipe::common::type::StringX& url) const {
bool result = false;
result |= std::regex_match(request, this->request);
result |= std::regex_match(url, this->url);
return result;
}
};
std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
shared_ptr<relpipe::writer::RelationalWriter> relationalWriter;
Configuration configuration;
relpipe::common::type::StringX currentRelationName;
std::vector<relpipe::reader::handlers::AttributeMetadata> currentReaderMetadata;
std::vector<relpipe::writer::AttributeMetadata> currentWriterMetadata;
HeaderDefinition requestHeader;
relpipe::common::type::StringX requestId;
HTTPClient::Request request;
std::vector<HeaderDefinition> requestHeaders;
std::vector<relpipe::common::type::StringX> responseHeaders;
size_t currentAttributeIndex = 0;
size_t currentRecordNumber = 1;
void writeHeaders() {
if (responseHeaders.size()) {
relationalWriter->startRelation(L"header",{
{L"request", relpipe::writer::TypeId::STRING},
{L"url", relpipe::writer::TypeId::STRING},
{L"name", relpipe::writer::TypeId::STRING},
{L"value", relpipe::writer::TypeId::STRING},
}, true);
for (auto s : responseHeaders) relationalWriter->writeAttribute(s);
responseHeaders.clear();
}
}
HTTPClient::Method parseMethod(const relpipe::common::type::StringX& value) {
if (value.size() == 0) return HTTPClient::Method::GET;
else if (value == L"GET") return HTTPClient::Method::GET;
else if (value == L"HEAD") return HTTPClient::Method::HEAD;
else if (value == L"POST") return HTTPClient::Method::POST;
else if (value == L"PUT") return HTTPClient::Method::PUT;
else if (value == L"DELETE") return HTTPClient::Method::DELETE;
else if (value == L"PATCH") return HTTPClient::Method::PATCH;
else throw std::invalid_argument("Unsupported HTTP method: " + convertor.to_bytes(value));
}
relpipe::common::type::StringX getHeaderAttributePrefix() {
// might be configurable - parametrized
return L"header.";
}
bool isHeaderAttribute(const relpipe::common::type::StringX& attributeName) {
return attributeName.rfind(getHeaderAttributePrefix(), 0) == 0;
}
relpipe::common::type::StringX fetchHeaderName(const relpipe::common::type::StringX& attributeName) {
return attributeName.substr(getHeaderAttributePrefix().size());
}
void appendRequestHeader(const relpipe::common::type::StringX& name, const relpipe::common::type::StringX& value) {
request.headers.push_back(convertor.to_bytes(name));
request.headers.push_back(convertor.to_bytes(value));
}
relpipe::common::type::StringX generateRequestId() {
char buffer[37];
uuid_t uuid;
uuid_generate_random(uuid);
// uuid_generate_time(uuid);
uuid_unparse_lower(uuid, buffer);
return convertor.from_bytes(buffer);
}
public:
HTTPHandler(shared_ptr<relpipe::writer::RelationalWriter> relationalWriter, Configuration configuration) : relationalWriter(relationalWriter), configuration(configuration) {
}
virtual ~HTTPHandler() {
}
void startRelation(relpipe::common::type::StringX name, std::vector<relpipe::reader::handlers::AttributeMetadata> attributes) override {
writeHeaders(); // from previous relation
currentRelationName = name;
currentReaderMetadata = attributes;
currentAttributeIndex = 0;
if (currentRelationName == L"header") {
// TODO: analyze header attributes
} else if (currentRelationName == L"request") {
relationalWriter->startRelation(L"response",{
// TODO: body in hexadecimal/binary format
{L"request", relpipe::writer::TypeId::STRING},
{L"url", relpipe::writer::TypeId::STRING},
{L"body", relpipe::writer::TypeId::STRING},
{L"code", relpipe::writer::TypeId::INTEGER},
}, true);
}
}
void attribute(const relpipe::common::type::StringX& value) override {
if (currentRelationName == L"header") headerAttribute(value);
else if (currentRelationName == L"request") requestAttribute(value);
else throw std::invalid_argument("Unsupported relation: " + convertor.to_bytes(currentRelationName));
}
private:
void headerAttribute(const relpipe::common::type::StringX& value) {
auto attributeName = currentReaderMetadata[currentAttributeIndex].getAttributeName();
if (attributeName == L"name") requestHeader.name = value;
else if (attributeName == L"value") requestHeader.value = value;
else if (attributeName == L"request") requestHeader.request = std::wregex(value.size() ? value : L".*"); // TODO: null instead of empty value (when supported)
else if (attributeName == L"url") requestHeader.url = std::wregex(value.size() ? value : L".*"); // TODO: null instead of empty value (when supported)
else throw std::invalid_argument("Unsupported attribute in the header relation: " + convertor.to_bytes(attributeName + L" = " + value));
currentAttributeIndex++;
if (currentAttributeIndex % currentReaderMetadata.size() == 0) {
currentAttributeIndex = 0;
requestHeaders.push_back(requestHeader);
requestHeader = HeaderDefinition();
}
}
void requestAttribute(const relpipe::common::type::StringX& value) {
auto attributeName = currentReaderMetadata[currentAttributeIndex].getAttributeName();
if (attributeName == L"id") requestId = value;
else if (attributeName == L"url") request.url = convertor.to_bytes(value);
else if (attributeName == L"method") request.method = parseMethod(value);
else if (isHeaderAttribute(attributeName)) appendRequestHeader(fetchHeaderName(attributeName), value);
else throw std::invalid_argument("Unsupported attribute in the header relation: " + convertor.to_bytes(attributeName + L" = " + value));
currentAttributeIndex++;
if (currentAttributeIndex % currentReaderMetadata.size() == 0) {
currentAttributeIndex = 0;
std::shared_ptr<HTTPClient> http(HTTPClient::open());
if (requestId.empty()) requestId = generateRequestId();
for (const HeaderDefinition& h : requestHeaders) if (h.matches(requestId, convertor.from_bytes(request.url))) appendRequestHeader(h.name, h.value);
std::string body;
relpipe::common::type::Integer responseCode = -1;
try {
HTTPClient::Response response = http->exchange(request);
responseCode = response.responseCode;
body = response.body;
for (size_t i = 0; i < response.headers.size(); i += 2) {
responseHeaders.push_back(requestId);
responseHeaders.push_back(convertor.from_bytes(request.url));
responseHeaders.push_back(convertor.from_bytes(response.headers[i]));
responseHeaders.push_back(convertor.from_bytes(response.headers[i + 1]));
}
} catch (const HTTPClient::Exception& e) {
body = e.getFullMessage();
// TODO: move error message into separate attribute?
}
relationalWriter->writeAttribute(requestId);
relationalWriter->writeAttribute(convertor.from_bytes(request.url));
relationalWriter->writeAttribute(convertor.from_bytes(body));
relationalWriter->writeAttribute(&responseCode, typeid (responseCode));
request = HTTPClient::Request();
requestId.clear();
}
}
public:
void endOfPipe() {
writeHeaders(); // from last relation
}
};
}
}
}