#ifndef RASTER_RENDERER_LEXER_H
#define RASTER_RENDERER_LEXER_H

#include "../core/basic.h"
#include "diagnostics.h"

namespace Slang
{
    struct TokenList
    {
        Token* begin() const;
        Token* end() const;

        List<Token> mTokens;
    };

    struct TokenSpan
    {
        TokenSpan();
        TokenSpan(
            TokenList const& tokenList)
            : mBegin(tokenList.begin())
            , mEnd  (tokenList.end  ())
        {}

        Token* begin() const { return mBegin; }
        Token* end  () const { return mEnd  ; }

        int GetCount() { return (int)(mEnd - mBegin); }

        Token* mBegin;
        Token* mEnd;
    };

    struct TokenReader
    {
        TokenReader();
        explicit TokenReader(TokenSpan const& tokens)
            : mCursor(tokens.begin())
            , mEnd   (tokens.end  ())
        {}
        explicit TokenReader(TokenList const& tokens)
            : mCursor(tokens.begin())
            , mEnd   (tokens.end  ())
        {}

        bool IsAtEnd() const { return mCursor == mEnd; }
        Token PeekToken() const;
        TokenType PeekTokenType() const;
        CodePosition PeekLoc() const;

        Token AdvanceToken();

        int GetCount() { return (int)(mEnd - mCursor); }

        Token* mCursor;
        Token* mEnd;
    };

    typedef unsigned int LexerFlags;
    enum
    {
        kLexerFlag_InDirective = 1 << 0,
        kLexerFlag_ExpectFileName = 2 << 0,
    };

    struct Lexer
    {
        Lexer(
            String const&   path,
            String const&   content,
            DiagnosticSink* sink);

        ~Lexer();

        Token lexToken();

        TokenList lexAllTokens();

        String          path;
        String          content;
        DiagnosticSink* sink;

        char const*     cursor;
        char const*     end;
        CodePosition    loc;
        TokenFlags      tokenFlags;
        LexerFlags      lexerFlags;
    };

    // Helper routines for extracting values from tokens
    String getStringLiteralTokenValue(Token const& token);
    String getFileNameTokenValue(Token const& token);

    typedef long long IntegerLiteralValue;
    typedef double FloatingPointLiteralValue;

    IntegerLiteralValue getIntegerLiteralValue(Token const& token, String* outSuffix = 0);
    FloatingPointLiteralValue getFloatingPointLiteralValue(Token const& token, String* outSuffix = 0);
}

#endif