// 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_RAW_STRING_HPP
#define TAO_PEGTL_CONTRIB_RAW_STRING_HPP

#include <cstddef>
#include <type_traits>

#include "../apply_mode.hpp"
#include "../config.hpp"
#include "../rewind_mode.hpp"

#include "../internal/bytes.hpp"
#include "../internal/eof.hpp"
#include "../internal/eol.hpp"
#include "../internal/must.hpp"
#include "../internal/not_at.hpp"
#include "../internal/seq.hpp"
#include "../internal/skip_control.hpp"
#include "../internal/star.hpp"

#include "../analysis/generic.hpp"

namespace tao
{
   namespace TAO_PEGTL_NAMESPACE
   {
      namespace internal
      {
         template< char Open, char Marker >
         struct raw_string_open
         {
            using analyze_t = analysis::generic< analysis::rule_type::any >;

            template< apply_mode A,
                      rewind_mode,
                      template< typename... >
                      class Action,
                      template< typename... >
                      class Control,
                      typename Input,
                      typename... States >
            static bool match( Input& in, std::size_t& marker_size, States&&... /*unused*/ ) noexcept( noexcept( in.size( 0 ) ) )
            {
               if( in.empty() || ( in.peek_char( 0 ) != Open ) ) {
                  return false;
               }
               for( std::size_t i = 1; i < in.size( i + 1 ); ++i ) {
                  switch( const auto c = in.peek_char( i ) ) {
                     case Open:
                        marker_size = i + 1;
                        in.bump_in_this_line( marker_size );
                        eol::match( in );
                        return true;
                     case Marker:
                        break;
                     default:
                        return false;
                  }
               }
               return false;
            }
         };

         template< char Open, char Marker >
         struct skip_control< raw_string_open< Open, Marker > > : std::true_type
         {
         };

         template< char Marker, char Close >
         struct at_raw_string_close
         {
            using analyze_t = analysis::generic< analysis::rule_type::opt >;

            template< apply_mode A,
                      rewind_mode,
                      template< typename... >
                      class Action,
                      template< typename... >
                      class Control,
                      typename Input,
                      typename... States >
            static bool match( Input& in, const std::size_t& marker_size, States&&... /*unused*/ ) noexcept( noexcept( in.size( 0 ) ) )
            {
               if( in.size( marker_size ) < marker_size ) {
                  return false;
               }
               if( in.peek_char( 0 ) != Close ) {
                  return false;
               }
               if( in.peek_char( marker_size - 1 ) != Close ) {
                  return false;
               }
               for( std::size_t i = 0; i < ( marker_size - 2 ); ++i ) {
                  if( in.peek_char( i + 1 ) != Marker ) {
                     return false;
                  }
               }
               return true;
            }
         };

         template< char Marker, char Close >
         struct skip_control< at_raw_string_close< Marker, Close > > : std::true_type
         {
         };

         template< typename Cond, typename... Rules >
         struct raw_string_until;

         template< typename Cond >
         struct raw_string_until< Cond >
         {
            using analyze_t = analysis::generic< analysis::rule_type::seq, star< not_at< Cond >, not_at< eof >, bytes< 1 > >, Cond >;

            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& marker_size, States&&... st )
            {
               auto m = in.template mark< M >();

               while( !Control< Cond >::template match< A, rewind_mode::required, Action, Control >( in, marker_size, st... ) ) {
                  if( in.empty() ) {
                     return false;
                  }
                  in.bump();
               }
               return m( true );
            }
         };

         template< typename Cond, typename... Rules >
         struct raw_string_until
         {
            using analyze_t = analysis::generic< analysis::rule_type::seq, star< not_at< Cond >, not_at< eof >, Rules... >, Cond >;

            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& marker_size, States&&... st )
            {
               auto m = in.template mark< M >();
               using m_t = decltype( m );

               while( !Control< Cond >::template match< A, rewind_mode::required, Action, Control >( in, marker_size, st... ) ) {
                  if( in.empty() || ( !Control< seq< Rules... > >::template match< A, m_t::next_rewind_mode, Action, Control >( in, st... ) ) ) {
                     return false;
                  }
               }
               return m( true );
            }
         };

         template< typename Cond, typename... Rules >
         struct skip_control< raw_string_until< Cond, Rules... > > : std::true_type
         {
         };

      }  // namespace internal

      // raw_string matches Lua-style long literals.
      //
      // The following description was taken from the Lua documentation
      // (see http://www.lua.org/docs.html):
      //
      // - An "opening long bracket of level n" is defined as an opening square
      //   bracket followed by n equal signs followed by another opening square
      //   bracket. So, an opening long bracket of level 0 is written as `[[`,
      //   an opening long bracket of level 1 is written as `[=[`, and so on.
      // - A "closing long bracket" is defined similarly; for instance, a closing
      //   long bracket of level 4 is written as `]====]`.
      // - A "long literal" starts with an opening long bracket of any level and
      //   ends at the first closing long bracket of the same level. It can
      //   contain any text except a closing bracket of the same level.
      // - Literals in this bracketed form can run for several lines, do not
      //   interpret any escape sequences, and ignore long brackets of any other
      //   level.
      // - For convenience, when the opening long bracket is immediately followed
      //   by a newline, the newline is not included in the string.
      //
      // Note that unlike Lua's long literal, a raw_string is customizable to use
      // other characters than `[`, `=` and `]` for matching. Also note that Lua
      // introduced newline-specific replacements in Lua 5.2, which we do not
      // support on the grammar level.

      template< char Open, char Marker, char Close, typename... Contents >
      struct raw_string
      {
         // This is used for binding the apply()-method and for error-reporting
         // when a raw string is not closed properly or has invalid content.
         struct content
            : internal::raw_string_until< internal::at_raw_string_close< Marker, Close >, Contents... >
         {
         };

         using analyze_t = typename internal::seq< internal::bytes< 1 >, content, internal::bytes< 1 > >::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 marker_size;
            if( internal::raw_string_open< Open, Marker >::template match< A, M, Action, Control >( in, marker_size, st... ) ) {
               internal::must< content >::template match< A, M, Action, Control >( in, marker_size, st... );
               in.bump_in_this_line( marker_size );
               return true;
            }
            return false;
         }
      };

   }  // namespace TAO_PEGTL_NAMESPACE

}  // namespace tao

#endif
