/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <thrift/lib/cpp/transport/THttpServer.h>

#include <cstdlib>
#include <iostream>
#include <sstream>

#include <thrift/lib/cpp/transport/TSocket.h>

namespace apache {
namespace thrift {
namespace transport {

using namespace std;

THttpServer::THttpServer(std::shared_ptr<TTransport> transport)
    : THttpTransport(transport) {}

THttpServer::~THttpServer() {}

void THttpServer::parseHeader(char* header) {
  char* colon = strchr(header, ':');
  if (colon == nullptr) {
    return;
  }
  uint32_t sz = colon - header;
  char* value = colon + 1;

  if (strncmp(header, "Transfer-Encoding", sz) == 0) {
    if (strstr(value, "chunked") != nullptr) {
      chunked_ = true;
    }
  } else if (strncmp(header, "Content-Length", sz) == 0) {
    chunked_ = false;
    contentLength_ = atoi(value);
  }
}

bool THttpServer::parseStatusLine(char* status) {
  char* method = status;

  char* path = strchr(method, ' ');
  if (path == nullptr) {
    throw TTransportException(string("Bad Status: ") + status);
  }

  *path = '\0';
  while (*(++path) == ' ') {
  };

  char* http = strchr(path, ' ');
  if (http == nullptr) {
    throw TTransportException(string("Bad Status: ") + status);
  }
  *http = '\0';

  if (strcmp(method, "POST") == 0) {
    // POST method ok, looking for content.
    return true;
  }
  throw TTransportException(
      string("Bad Status (unsupported method): ") + status);
}

void THttpServer::flush() {
  // Fetch the contents of the write buffer
  uint8_t* buf;
  uint32_t len;
  writeBuffer_.getBuffer(&buf, &len);

  // Construct the HTTP header
  std::ostringstream h;
  h << "HTTP/1.1 200 OK" << CRLF //
    << "Date: " << getTimeRFC1123() << CRLF //
    << "Server: Thrift" << CRLF //
    << "Content-Type: application/x-thrift" << CRLF //
    << "Content-Length: " << len << CRLF //
    << "Connection: Keep-Alive" << CRLF //
    << CRLF;
  string header = h.str();

  // Write the header, then the data, then flush
  transport_->write((const uint8_t*)header.c_str(), header.size());
  transport_->write(buf, len);
  transport_->flush();

  // Reset the buffer
  writeBuffer_.resetBuffer();
}

std::string THttpServer::getTimeRFC1123() {
  static const char* Days[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
  static const char* Months[] = {
      "Jan",
      "Feb",
      "Mar",
      "Apr",
      "May",
      "Jun",
      "Jul",
      "Aug",
      "Sep",
      "Oct",
      "Nov",
      "Dec",
  };
  char buff[128];
  time_t t = time(nullptr);
  tm* broken_t = gmtime(&t);

  snprintf(
      buff,
      sizeof(buff),
      "%s, %d %s %d %d:%d:%d GMT",
      Days[broken_t->tm_wday],
      broken_t->tm_mday,
      Months[broken_t->tm_mon],
      broken_t->tm_year + 1900,
      broken_t->tm_hour,
      broken_t->tm_min,
      broken_t->tm_sec);
  return std::string(buff);
}

} // namespace transport
} // namespace thrift
} // namespace apache