// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_TOOLS_BALSA_BALSA_VISITOR_INTERFACE_H_
#define NET_TOOLS_BALSA_BALSA_VISITOR_INTERFACE_H_

#include <cstddef>

namespace net {

class BalsaFrame;
class BalsaHeaders;

// By default the BalsaFrame instantiates a class derived from this interface
// which does absolutely nothing. If you'd prefer to have interesting
// functionality execute when any of the below functions are called by the
// BalsaFrame, then you should subclass it, and set an instantiation of your
// subclass as the current visitor for the BalsaFrame class using
// BalsaFrame::set_visitor().
class BalsaVisitorInterface {
 public:
  virtual ~BalsaVisitorInterface() {}

  // Summary:
  //   This is how the BalsaFrame passes you the raw input which it knows to
  //   be a part of the body. To be clear, every byte of the Balsa which isn't
  //   part of the header (or its framing), or trailers will be passed through
  //   this function.  This includes data as well as chunking framing.
  // Arguments:
  //   input - contains the bytes available for read.
  //   size - contains the number of bytes it is safe to read from input.
  virtual void ProcessBodyInput(const char *input, size_t size) = 0;

  // Summary:
  //   This is like ProcessBodyInput, but it will only include those parts of
  //   the body which would be stored by a program such as wget, i.e. the bytes
  //   indicating chunking (it will have been omitted). Trailers will not be
  //   passed in through this function-- they'll be passed in through
  //   ProcessTrailers.
  // Arguments:
  //  input - contains the bytes available for read.
  //  size - contains the number of bytes it is safe to read from input.
  virtual void ProcessBodyData(const char *input, size_t size) = 0;

  // Summary:
  //   BalsaFrame passes the raw header data through this function. This is
  //   not cleaned up in any way.
  // Arguments:
  //  input - contains the bytes available for read.
  //  size - contains the number of bytes it is safe to read from input.
  virtual void ProcessHeaderInput(const char *input, size_t size) = 0;

  // Summary:
  //   BalsaFrame passes the raw trailer data through this function. This is
  //   not cleaned up in any way.  Note that trailers only occur in a message
  //   if there was a chunked encoding, and not always then.
  //
  // Arguments:
  //  input - contains the bytes available for read.
  //  size - contains the number of bytes it is safe to read from input.
  virtual void ProcessTrailerInput(const char *input, size_t size) = 0;

  // Summary:
  //   Since the BalsaFrame already has to parse the headers in order to
  //   determine proper framing, it might as well pass the parsed and
  //   cleaned-up results to whatever might need it.  This function exists for
  //   that purpose-- parsed headers are passed into this function.
  // Arguments:
  //   headers - contains the parsed headers in the order in which
  //             they occured in the header.
  virtual void ProcessHeaders(const BalsaHeaders& headers) = 0;

  // Summary:
  //   Called when the first line of the message is parsed, in this case, for a
  //   request.
  // Arguments:
  //   line_input - pointer to the beginning of the first line string.
  //   line_length - length of the first line string. (i.e. the numer of
  //                 bytes it is safe to read from line_ptr)
  //   method_input - pointer to the beginning of the method string
  //   method_length - length of the method string (i.e. the number
  //                   of bytes it is safe to read from method_input)
  //   request_uri_input - pointer to the beginning of the request uri
  //                       string.
  //   request_uri_length - length of the method string (i.e. the number
  //                        of bytes it is safe to read from method_input)
  //   version_input - pointer to the beginning of the version string.
  //   version_length - length of the version string (i.e. the number
  //                    of bytes it i ssafe to read from version_input)
  virtual void ProcessRequestFirstLine(const char* line_input,
                                       size_t line_length,
                                       const char* method_input,
                                       size_t method_length,
                                       const char* request_uri_input,
                                       size_t request_uri_length,
                                       const char* version_input,
                                       size_t version_length) = 0;

  // Summary:
  //   Called when the first line of the message is parsed, in this case, for a
  //   response.
  // Arguments:
  //   line_input - pointer to the beginning of the first line string.
  //   line_length - length of the first line string. (i.e. the numer of
  //                 bytes it is safe to read from line_ptr)
  //   version_input - pointer to the beginning of the version string.
  //   version_length - length of the version string (i.e. the number
  //                    of bytes it i ssafe to read from version_input)
  //   status_input - pointer to the beginning of the status string
  //   status_length - length of the status string (i.e. the number
  //                   of bytes it is safe to read from status_input)
  //   reason_input - pointer to the beginning of the reason string
  //   reason_length - length of the reason string (i.e. the number
  //                   of bytes it is safe to read from reason_input)
  virtual void ProcessResponseFirstLine(const char *line_input,
                                        size_t line_length,
                                        const char *version_input,
                                        size_t version_length,
                                        const char *status_input,
                                        size_t status_length,
                                        const char *reason_input,
                                        size_t reason_length) = 0;

  // Called when a chunk length is parsed.
  // Arguments:
  //   chunk length - the length of the next incoming chunk.
  virtual void ProcessChunkLength(size_t chunk_length) = 0;

  // Summary:
  //   BalsaFrame passes the raw chunk extension data through this function.
  //   The data is not cleaned up at all, use
  //   BalsaFrame::ProcessChunkExtentions to get the parsed and cleaned up
  //   chunk extensions.
  //
  // Arguments:
  //  input - contains the bytes available for read.
  //  size - contains the number of bytes it is safe to read from input.
  virtual void ProcessChunkExtensions(const char* input, size_t size) = 0;

  // Summary:
  //   Called when the header is framed and processed.
  virtual void HeaderDone() = 0;

  // Summary:
  //   Called when the message is framed and processed.
  virtual void MessageDone() = 0;

  // Summary:
  //   Called when an error is detected while parsing the header.
  // Arguments:
  //   framer - the framer in which an error occured.
  virtual void HandleHeaderError(BalsaFrame* framer) = 0;

  // Summary:
  //   Called when something meriting a warning is detected while
  //   parsing the header.
  // Arguments:
  //   framer - the framer in which an error occured.
  virtual void HandleHeaderWarning(BalsaFrame* framer) = 0;

  // Summary:
  //   Called when an error is detected while parsing a chunk.
  // Arguments:
  //   framer - the framer in which an error occured.
  virtual void HandleChunkingError(BalsaFrame* framer) = 0;

  // Summary:
  //   Called when an error is detected while handling the entity-body.
  //   Currently, this can only be called when there is an error
  //   with the BytesSpliced() function, but in the future other interesting
  //   errors could occur.
  // Arguments:
  //   framer - the framer in which an error occured.
  virtual void HandleBodyError(BalsaFrame* framer) = 0;
};

}  // namespace net

#endif  // NET_TOOLS_BALSA_BALSA_VISITOR_INTERFACE_H_