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

#ifndef TAO_JSON_PEGTL_INTERNAL_ISTRING_HPP
#define TAO_JSON_PEGTL_INTERNAL_ISTRING_HPP

#include <type_traits>

#include "../config.hpp"

#include "bump_help.hpp"
#include "result_on_found.hpp"
#include "skip_control.hpp"
#include "trivial.hpp"

#include "../analysis/counted.hpp"

namespace TAO_JSON_PEGTL_NAMESPACE::internal
{
   template< char C >
   inline constexpr bool is_alpha = ( ( 'a' <= C ) && ( C <= 'z' ) ) || ( ( 'A' <= C ) && ( C <= 'Z' ) );

   template< char C >
   [[nodiscard]] bool ichar_equal( const char c ) noexcept
   {
      if constexpr( is_alpha< C > ) {
         return ( C | 0x20 ) == ( c | 0x20 );
      }
      else {
         return c == C;
      }
   }

   template< char... Cs >
   [[nodiscard]] bool istring_equal( const char* r ) noexcept
   {
      return ( ichar_equal< Cs >( *r++ ) && ... );
   }

   template< char... Cs >
   struct istring;

   template<>
   struct istring<>
      : trivial< true >
   {
   };

   template< char... Cs >
   struct istring
   {
      using analyze_t = analysis::counted< analysis::rule_type::any, sizeof...( Cs ) >;

      template< typename Input >
      [[nodiscard]] static bool match( Input& in ) noexcept( noexcept( in.size( 0 ) ) )
      {
         if( in.size( sizeof...( Cs ) ) >= sizeof...( Cs ) ) {
            if( istring_equal< Cs... >( in.current() ) ) {
               bump_help< result_on_found::success, Input, char, Cs... >( in, sizeof...( Cs ) );
               return true;
            }
         }
         return false;
      }
   };

   template< char... Cs >
   inline constexpr bool skip_control< istring< Cs... > > = true;

}  // namespace TAO_JSON_PEGTL_NAMESPACE::internal

#endif