// Copyright (c) 2014-2020 Dr. Colin Hirsch and Daniel Frey
// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/

#ifndef TAO_PEGTL_CONTRIB_HTTP_HPP
#define TAO_PEGTL_CONTRIB_HTTP_HPP

#include "../ascii.hpp"
#include "../config.hpp"
#include "../nothing.hpp"
#include "../rules.hpp"
#include "../utf8.hpp"

#include "abnf.hpp"
#include "remove_first_state.hpp"
#include "uri.hpp"

namespace tao
{
   namespace TAO_PEGTL_NAMESPACE
   {
      namespace http
      {
         // HTTP 1.1 grammar according to RFC 7230.

         // This grammar is a direct PEG translation of the original HTTP grammar.
         // It should be considered experimental -- in case of any issues, in particular
         // missing rules for attached actions, please contact the developers.

         using OWS = star< abnf::WSP >;  // optional whitespace
         using RWS = plus< abnf::WSP >;  // required whitespace
         using BWS = OWS;                // "bad" whitespace

         using obs_text = not_range< 0x00, 0x7F >;
         using obs_fold = seq< abnf::CRLF, plus< abnf::WSP > >;

         // clang-format off
         struct tchar : sor< abnf::ALPHA, abnf::DIGIT, one< '!', '#', '$', '%', '&', '\'', '*', '+', '-', '.', '^', '_', '`', '|', '~' > > {};
         struct token : plus< tchar > {};

         struct field_name : token {};

         struct field_vchar : sor< abnf::VCHAR, obs_text > {};
         struct field_content : list< field_vchar, plus< abnf::WSP > > {};
         struct field_value : star< sor< field_content, obs_fold > > {};

         struct header_field : seq< field_name, one< ':' >, OWS, field_value, OWS > {};

         struct method : token {};

         struct absolute_path : plus< one< '/' >, uri::segment > {};

         struct origin_form : seq< absolute_path, uri::opt_query >  {};
         struct absolute_form : uri::absolute_URI {};
         struct authority_form : uri::authority {};
         struct asterisk_form : one< '*' > {};

         struct request_target : sor< origin_form, absolute_form, authority_form, asterisk_form > {};

         struct status_code : rep< 3, abnf::DIGIT > {};
         struct reason_phrase : star< sor< abnf::VCHAR, obs_text, abnf::WSP > > {};

         struct HTTP_version : if_must< string< 'H', 'T', 'T', 'P', '/' >, abnf::DIGIT, one< '.' >, abnf::DIGIT > {};

         struct request_line : if_must< method, abnf::SP, request_target, abnf::SP, HTTP_version, abnf::CRLF > {};
         struct status_line : if_must< HTTP_version, abnf::SP, status_code, abnf::SP, reason_phrase, abnf::CRLF > {};
         struct start_line : sor< status_line, request_line > {};

         struct message_body : star< abnf::OCTET > {};
         struct HTTP_message : seq< start_line, star< header_field, abnf::CRLF >, abnf::CRLF, opt< message_body > > {};

         struct Content_Length : plus< abnf::DIGIT > {};

         struct uri_host : uri::host {};
         struct port : uri::port {};

         struct Host : seq< uri_host, opt< one< ':' >, port > > {};

         // PEG are different from CFGs! (this replaces ctext and qdtext)
         using text = sor< abnf::HTAB, range< 0x20, 0x7E >, obs_text >;

         struct quoted_pair : if_must< one< '\\' >, sor< abnf::VCHAR, obs_text, abnf::WSP > > {};
         struct quoted_string : if_must< abnf::DQUOTE, until< abnf::DQUOTE, sor< quoted_pair, text > > > {};

         struct transfer_parameter : seq< token, BWS, one< '=' >, BWS, sor< token, quoted_string > > {};
         struct transfer_extension : seq< token, star< OWS, one< ';' >, OWS, transfer_parameter > > {};
         struct transfer_coding : sor< istring< 'c', 'h', 'u', 'n', 'k', 'e', 'd' >,
                                       istring< 'c', 'o', 'm', 'p', 'r', 'e', 's', 's' >,
                                       istring< 'd', 'e', 'f', 'l', 'a', 't', 'e' >,
                                       istring< 'g', 'z', 'i', 'p' >,
                                       transfer_extension > {};

         struct rank : sor< seq< one< '0' >, opt< one< '.' >, rep_opt< 3, abnf::DIGIT > > >,
                            seq< one< '1' >, opt< one< '.' >, rep_opt< 3, one< '0' > > > > > {};

         struct t_ranking : seq< OWS, one< ';' >, OWS, one< 'q', 'Q' >, one< '=' >, rank > {};
         struct t_codings : sor< istring< 't', 'r', 'a', 'i', 'l', 'e', 'r', 's' >, seq< transfer_coding, opt< t_ranking > > > {};

         struct TE : opt< sor< one< ',' >, t_codings >, star< OWS, one< ',' >, opt< OWS, t_codings > > > {};

         template< typename T >
         using make_comma_list = seq< star< one< ',' >, OWS >, T, star< OWS, one< ',' >, opt< OWS, T > > >;

         struct connection_option : token {};
         struct Connection : make_comma_list< connection_option > {};

         struct Trailer : make_comma_list< field_name > {};

         struct Transfer_Encoding : make_comma_list< transfer_coding > {};

         struct protocol_name : token {};
         struct protocol_version : token {};
         struct protocol : seq< protocol_name, opt< one< '/' >, protocol_version > > {};
         struct Upgrade : make_comma_list< protocol > {};

         struct pseudonym : token {};

         struct received_protocol : seq< opt< protocol_name, one< '/' > >, protocol_version > {};
         struct received_by : sor< seq< uri_host, opt< one< ':' >, port > >, pseudonym > {};

         struct comment : if_must< one< '(' >, until< one< ')' >, sor< comment, quoted_pair, text > > > {};

         struct Via : make_comma_list< seq< received_protocol, RWS, received_by, opt< RWS, comment > > > {};

         struct http_URI : if_must< istring< 'h', 't', 't', 'p', ':', '/', '/' >, uri::authority, uri::path_abempty, uri::opt_query, uri::opt_fragment > {};
         struct https_URI : if_must< istring< 'h', 't', 't', 'p', 's', ':', '/', '/' >, uri::authority, uri::path_abempty, uri::opt_query, uri::opt_fragment > {};

         struct partial_URI : seq< uri::relative_part, uri::opt_query > {};

         // clang-format on
         struct chunk_size
         {
            using analyze_t = plus< abnf::HEXDIG >::analyze_t;

            template< apply_mode A,
                      rewind_mode M,
                      template< typename... >
                      class Action,
                      template< typename... >
                      class Control,
                      typename Input,
                      typename... States >
            static bool match( Input& in, std::size_t& size, States&&... /*unused*/ )
            {
               size = 0;
               std::size_t i = 0;
               while( in.size( i + 1 ) >= i + 1 ) {
                  const auto c = in.peek_char( i );
                  if( ( '0' <= c ) && ( c <= '9' ) ) {
                     size <<= 4;
                     size |= std::size_t( c - '0' );
                     ++i;
                     continue;
                  }
                  if( ( 'a' <= c ) && ( c <= 'f' ) ) {
                     size <<= 4;
                     size |= std::size_t( c - 'a' + 10 );
                     ++i;
                     continue;
                  }
                  if( ( 'A' <= c ) && ( c <= 'F' ) ) {
                     size <<= 4;
                     size |= std::size_t( c - 'A' + 10 );
                     ++i;
                     continue;
                  }
                  break;
               }
               in.bump_in_this_line( i );
               return i > 0;
            }
         };
         // clang-format off

         struct chunk_ext_name : token {};
         struct chunk_ext_val : sor< quoted_string, token > {};
         struct chunk_ext : star_must< one< ';' >, chunk_ext_name, if_must< one< '=' >, chunk_ext_val > > {};

         // clang-format on
         struct chunk_data
         {
            using analyze_t = star< abnf::OCTET >::analyze_t;

            template< apply_mode A,
                      rewind_mode M,
                      template< typename... >
                      class Action,
                      template< typename... >
                      class Control,
                      typename Input,
                      typename... States >
            static bool match( Input& in, const std::size_t size, States&&... /*unused*/ )
            {
               if( in.size( size ) >= size ) {
                  in.bump( size );
                  return true;
               }
               return false;
            }
         };

         namespace internal
         {
            namespace chunk_helper
            {
               template< typename Base >
               struct control;

               template< template< typename... > class Control, typename Rule >
               struct control< Control< Rule > >
                  : Control< Rule >
               {
                  template< apply_mode A,
                            rewind_mode M,
                            template< typename... >
                            class Action,
                            template< typename... >
                            class,
                            typename Input,
                            typename State,
                            typename... States >
                  static bool match( Input& in, State&& /*unused*/, States&&... st )
                  {
                     return Control< Rule >::template match< A, M, Action, Control >( in, st... );
                  }
               };

               template< template< typename... > class Control >
               struct control< Control< chunk_size > >
                  : remove_first_state< Control< chunk_size > >
               {};

               template< template< typename... > class Control >
               struct control< Control< chunk_data > >
                  : remove_first_state< Control< chunk_data > >
               {};

               template< template< typename... > class Control >
               struct bind
               {
                  template< typename Rule >
                  using type = control< Control< Rule > >;
               };

            }  // namespace chunk_helper

         }  // namespace internal

         struct chunk
         {
            using impl = seq< chunk_size, chunk_ext, abnf::CRLF, chunk_data, abnf::CRLF >;
            using analyze_t = impl::analyze_t;

            template< apply_mode A,
                      rewind_mode M,
                      template< typename... >
                      class Action,
                      template< typename... >
                      class Control,
                      typename Input,
                      typename... States >
            static bool match( Input& in, States&&... st )
            {
               std::size_t size{};
               return impl::template match< A, M, Action, internal::chunk_helper::bind< Control >::template type >( in, size, st... );
            }
         };

         // clang-format off
         struct last_chunk : seq< plus< one< '0' > >, not_at< digit >, chunk_ext, abnf::CRLF > {};

         struct trailer_part : star< header_field, abnf::CRLF > {};

         struct chunked_body : seq< until< last_chunk, chunk >, trailer_part, abnf::CRLF > {};
         // clang-format on

      }  // namespace http

   }  // namespace TAO_PEGTL_NAMESPACE

}  // namespace tao

#endif
