/*
 * Copyright (c) 2001-2007 Peter Simons <simons@cryp.to>
 *
 * This software is provided 'as-is', without any express or
 * implied warranty. In no event will the authors be held liable
 * for any damages arising from the use of this software.
 *
 * Copying and distribution of this file, with or without
 * modification, are permitted in any medium without royalty
 * provided the copyright notice and this notice are preserved.
 */

#ifndef FASTCGI_HPP_INCLUDED
#define FASTCGI_HPP_INCLUDED

#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <stdexcept>
#include <new>
#ifndef _WIN32
#include <unistd.h>
#endif

#include "../OutputStream.h"

typedef unsigned short u_int16_t;
typedef unsigned int u_int32_t;
typedef unsigned char u_int8_t;

#if defined(__GNUG__) && __GNUG__ == 3
#  include "unsigned-char-traits.hpp"
#endif

// Forward declarations.

class FCGIProtocolDriver;
class FCGIRequest;

// All exceptions we throw derive from fcgi_error.

struct fcgi_error : public std::runtime_error
{
  fcgi_error(const std::string& w) : runtime_error(w) { }
};

struct unsupported_fcgi_version : public fcgi_error
{
  unsupported_fcgi_version(const std::string& w) : fcgi_error(w) { }
};

struct duplicate_begin_request : public fcgi_error
{
  duplicate_begin_request(const std::string& w) : fcgi_error(w) { }
};

struct unknown_fcgi_request : public fcgi_error
{
  unknown_fcgi_request(const std::string& w) : fcgi_error(w) { }
};

struct fcgi_io_callback_error : public fcgi_error
{
  fcgi_io_callback_error(const std::string& w) : fcgi_error(w) { }
};

// The class representing a request.

class FCGIRequest : public IOutputStream
{
public:
  enum role_t
    { RESPONDER  = 1
    , AUTHORIZER = 2
    , FILTER     = 3
    };

  const u_int16_t id;
  const role_t role;
  const bool keep_connection;
  bool aborted;
  std::map<std::string,std::string> params;
  std::string stdin_stream, data_stream;
  bool stdin_eof, data_eof;

  FCGIRequest(FCGIProtocolDriver& driver_, u_int16_t id_, role_t role_, bool kc);
  ~FCGIRequest();

  void write(const std::string& buf, ostream_type_t stream);
  void write(const char* buf, size_t count, ostream_type_t stream = STDOUT);
  void write(const std::string  &tw);

  enum protocol_status_t
    { REQUEST_COMPLETE = 0
    , CANT_MPX_CONN    = 1
    , OVERLOADED       = 2
    , UNKNOWN_ROLE     = 3
    };
  void end_request(u_int32_t appStatus, protocol_status_t protStatus);

  struct handler
  {
    virtual ~handler() { }
    virtual void operator()(FCGIRequest*) = 0;
  };
  handler* handler_cb;

private:
  FCGIProtocolDriver& driver;
  u_int8_t tmp_buf[64];
};

//
// The FCGI protocol driver class.
//

class FCGIProtocolDriver
{
public:
  struct OutputCallback
  {
    virtual ~OutputCallback() = 0;
    virtual void operator() (const void*, size_t) = 0;
  };

public:
  FCGIProtocolDriver(OutputCallback& cb);
  ~FCGIProtocolDriver();

  void process_input(const void* buf, size_t count);
  FCGIRequest* get_request();
  bool have_active_requests();

private:                        // don't copy me
  FCGIProtocolDriver(const FCGIProtocolDriver&);
  FCGIProtocolDriver& operator= (const FCGIProtocolDriver&);

protected:
  friend class FCGIRequest;
  void terminate_request(u_int16_t id);
  OutputCallback& output_cb;

private:
  typedef void (FCGIProtocolDriver::* proc_func_t)(u_int16_t, const u_int8_t*, u_int16_t);
  static const proc_func_t proc_funcs[];

  void process_begin_request(u_int16_t id, const u_int8_t* buf, u_int16_t len);
  void process_abort_request(u_int16_t id, const u_int8_t* buf, u_int16_t len);
  void process_params(u_int16_t id, const u_int8_t* buf, u_int16_t len);
  void process_stdin(u_int16_t id, const u_int8_t* buf, u_int16_t len);
  void process_unknown(u_int8_t type);

  typedef std::map<u_int16_t,FCGIRequest*> reqmap_t;
  reqmap_t reqmap;
  std::queue<u_int16_t> new_request_queue;

  std::basic_string<u_int8_t> InputBuffer;
  u_int8_t tmp_buf[64];
};

#endif // FASTCGI_HPP_INCLUDED