#include <library/cpp/unicode/set/unicode_set_lexer.h>

#include <util/generic/yexception.h>

namespace NUnicode {
namespace NPrivate {

%%{
    machine unicode_set_lexer;

    alphtype unsigned short;

    action IncorrectCategoryError {
        throw yexception() << "incorrect category";
    }

    action IncorrectEscapedCodepointError {
        throw yexception() << "incorrect escaped codepoint";
    }

    action IncorrectQuotedPairError {
        throw yexception() << "incorrect quoted pair";
    }

    id = alpha (alnum | '_')*;
    escape = [%\\];

    category = (':' id ':') <>^IncorrectCategoryError;
    xdigit8 = xdigit{8} @^IncorrectEscapedCodepointError;
    xdigit4 = xdigit{4} @^IncorrectEscapedCodepointError;
    xdigit2 = xdigit{2} @^IncorrectEscapedCodepointError;
    symbol = any @^IncorrectQuotedPairError;

    main := |*
        '^' => {
            return YieldToken(USTT_NEGATION);
        };
        '-' => {
            return YieldToken(USTT_RANGE);
        };
        '[' => {
            return YieldToken(USTT_LBRACKET);
        };
        ']' => {
            return YieldToken(USTT_RBRACKET);
        };
        category => {
            return YieldToken(USTT_CATEGORY, ts + 1, te - ts -2);
        };
        escape 'U' xdigit8 => {
            return YieldToken(USTT_CODEPOINT32, ts + 2, 8);
        };
        escape 'u' xdigit4 => {
            return YieldToken(USTT_CODEPOINT16, ts + 2, 4);
        };
        escape 'x' xdigit2 => {
            return YieldToken(USTT_CODEPOINT8, ts + 2, 2);
        };
        escape symbol => {
            return YieldToken(USTT_QUOTED_PAIR, *(ts + 1));
        };
        any => {
            return YieldToken(USTT_SYMBOL, *ts);
        };
    *|;

}%%

namespace {

%% write data;

}

TUnicodeSetLexer::TUnicodeSetLexer(const TWtringBuf& data)
    : Data(data)
    , cs(0)
    , act(0)
    , ts(NULL)
    , te(NULL)
    , p(Data.data())
    , pe(Data.data() + Data.size())
    , eof(pe)
    , UseLast(false)
{
    %% write init;
}

EUnicodeSetTokenType TUnicodeSetLexer::GetToken() {
    if (UseLast) {
        UseLast = false;
        return LastToken.Type;
    }

    %% write exec;

    return YieldToken(USTT_EOS);
}

EUnicodeSetTokenType TUnicodeSetLexer::YieldToken(EUnicodeSetTokenType type) {
    Reset();
    LastToken = TUnicodeSetToken(type);
    return type;
}

EUnicodeSetTokenType TUnicodeSetLexer::YieldToken(EUnicodeSetTokenType type, wchar16 symbol) {
    Reset();
    LastToken = TUnicodeSetToken(type, symbol);
    return type;
}

EUnicodeSetTokenType TUnicodeSetLexer::YieldToken(EUnicodeSetTokenType type, const wchar16* dataBegin, size_t dataSize) {
    Reset();
    LastToken = TUnicodeSetToken(type, dataBegin, dataSize);
    return type;
}

void TUnicodeSetLexer::Reset() {
    p = te;
    ts = NULL;
    te = NULL;
}

} // NPrivate
} // NUnicode