#include "name.h"

#include <yql/essentials/utils/yql_panic.h>
#include <yql/essentials/core/sql_types/normalize_name.h>

#include <util/string/split.h>
#include <util/charset/utf8.h>

namespace NYql::NDocs {

const RE2 NormalizedNameRegex(R"re([a-z_]{1,2}[a-z0-9]*)re");

bool IsNormalizedName(TStringBuf name) {
    return RE2::FullMatch(name, NormalizedNameRegex);
}

TMaybe<TString> NormalizedName(TString name) {
    if (TMaybe<TIssue> issue = NormalizeName(TPosition(), name)) {
        return Nothing();
    }

    if (!IsNormalizedName(name)) {
        return Nothing();
    }

    return name;
}

bool IsUDF(TStringBuf name) {
    return name.Contains("::");
}

TMaybe<std::pair<TString, TString>> SplitUDF(TString name) {
    if (!IsUDF(name)) {
        return Nothing();
    }

    TVector<TString> words;
    words.reserve(2);
    StringSplitter(name).SplitByString("::").Collect(&words);
    YQL_ENSURE(words.size() == 2, "Invalid UDF pattern: " << name);

    TMaybe<TString> module = ToLowerUTF8(std::move(words[0]));
    TMaybe<TString> function = ToLowerUTF8(std::move(words[1]));
    YQL_ENSURE(module && function, "Unable to normalize " << name);

    return std::make_pair(*module, *function);
}

} // namespace NYql::NDocs