/**
 * Palantir - A Lightweight, RESTful DICOM Store
 * Copyright (C) 2012 Medical Physics Department, CHU of Liege,
 * Belgium
 *
 * 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, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * 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 "HttpOutput.h"

#include <vector>
#include <stdio.h>
#include <boost/lexical_cast.hpp>
#include "../PalantirException.h"
#include "../Toolbox.h"
#include "../../PalantirCppClient/HttpException.h"

namespace Palantir
{
  void HttpOutput::SendString(const std::string& s)
  {
    if (s.size() > 0)
      Send(&s[0], s.size());
  }

  void HttpOutput::SendOkHeader(const std::string& contentType)
  {
    SendOkHeader(contentType.c_str(), false, 0);
  }

  void HttpOutput::SendOkHeader()
  {
    SendOkHeader(NULL, false, 0);
  }

  void HttpOutput::SendOkHeader(uint64_t contentLength)
  {
    SendOkHeader(NULL, true, contentLength);
  }

  void HttpOutput::SendOkHeader(const std::string& contentType,
                                uint64_t contentLength)
  {
    SendOkHeader(contentType.c_str(), true, contentLength);
  }


  void HttpOutput::SendOkHeader(const char* contentType,
                                bool hasContentLength,
                                size_t contentLength)
  {
    std::string s = "HTTP/1.1 200 OK\r\n";

    if (contentType)
    {
      s += "Content-Type: " + std::string(contentType) + "\r\n";
    }

    if (hasContentLength)
    {
      s += "Content-Length: " + boost::lexical_cast<std::string>(contentLength) + "\r\n";
    }

    s += "\r\n";

    Send(&s[0], s.size());
  }


  void HttpOutput::SendMethodNotAllowedError(const std::string& allowed)
  {
    std::string s = 
      "HTTP/1.1 405 " + std::string(HttpException::GetDescription(HttpStatus_405_MethodNotAllowed)) +
      "\r\nAllow: " + allowed + 
      "\r\n\r\n";
    Send(&s[0], s.size());
  }


  void HttpOutput::SendHeader(HttpStatus status)
  {
    if (status == HttpStatus_200_Ok ||
        status == HttpStatus_405_MethodNotAllowed)
    {
      throw PalantirException("Please use the dedicated methods to this HTTP status code in HttpOutput");
    }
    
    SendHeaderInternal(status);
  }


  void HttpOutput::SendHeaderInternal(HttpStatus status)
  {
    std::string s = "HTTP/1.1 " + 
      boost::lexical_cast<std::string>(status) +
      " " + std::string(HttpException::GetDescription(status)) +
      "\r\n\r\n";
    Send(&s[0], s.size());
  }


  void HttpOutput::AnswerBufferWithContentType(const std::string& buffer,
                                               const std::string& contentType)
  {
    SendOkHeader(contentType.c_str(), true, buffer.size());
    SendString(buffer);
  }


  void HttpOutput::AnswerBufferWithContentType(const void* buffer,
                                               size_t size,
                                               const std::string& contentType)
  {
    SendOkHeader(contentType.c_str(), true, size);
    Send(buffer, size);
  }


  void HttpOutput::AnswerFileWithContentType(const std::string& path,
                                             const std::string& contentType)
  {
    uint64_t fileSize = Toolbox::GetFileSize(path);
  
    FILE* fp = fopen(path.c_str(), "rb");
    if (!fp)
    {
      SendHeaderInternal(HttpStatus_500_InternalServerError);
      return;
    }
  
    SendOkHeader(contentType.c_str(), true, fileSize);

    std::vector<uint8_t> buffer(1024 * 1024);  // Chunks of 1MB

    for (;;)
    {
      size_t nbytes = fread(&buffer[0], 1, buffer.size(), fp);
      if (nbytes == 0)
      {
        break;
      }
      else
      {
        Send(&buffer[0], nbytes);
      }
    }

    fclose(fp);
  }


  void HttpOutput::AnswerFileAutodetectContentType(const std::string& path)
  {
    AnswerFileWithContentType(path, Toolbox::AutodetectMimeType(path));
  }


  void HttpOutput::AnswerFile(const FileStorage& storage,
                              const std::string& uuid,
                              const std::string& contentType)
  {
    boost::filesystem::path p(storage.GetPath(uuid));
    AnswerFileWithContentType(p.string(), contentType);
  }



  void HttpOutput::Redirect(const std::string& path)
  {
    std::string s = 
      "HTTP/1.1 301 " + std::string(HttpException::GetDescription(HttpStatus_301_MovedPermanently)) + 
      "\r\nLocation: " + path +
      "\r\n\r\n";
    Send(&s[0], s.size());  
  }
}