#include <Parsers/ParserUseQuery.h>

#include <Common/typeid_cast.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/CommonParsers.h>
#include <Parsers/ASTUseQuery.h>


namespace DB
{
bool ParserUseQuery::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
    Pos begin = pos;

    ParserWhitespaceOrComments ws;
    ParserString s_use("USE", true, true);
    ParserIdentifier name_p;

    ASTPtr database;

    ws.ignore(pos, end);

    if (!s_use.ignore(pos, end, max_parsed_pos, expected))
        return false;

    ws.ignore(pos, end);

    if (!name_p.parse(pos, end, database, max_parsed_pos, expected))
        return false;

    ws.ignore(pos, end);

    auto query = std::make_shared<ASTUseQuery>(StringRange(begin, pos));
    query->database = typeid_cast<ASTIdentifier &>(*database).name;
    node = query;

    return true;
}
}