#pragma once

#include <Parsers/IAST.h>


namespace DB
{

/** Represents a user name.
  * It can be a simple string or identifier or something like `name@host`.
  * In the last case `host` specifies the hosts user is allowed to connect from.
  * The `host` can be an ip address, ip subnet, or a host name.
  * The % and _ wildcard characters are permitted in `host`.
  * These have the same meaning as for pattern-matching operations performed with the LIKE operator.
  */
class ASTUserNameWithHost : public IAST
{
public:
    String base_name;
    String host_pattern;

    String toString() const;
    void concatParts();

    ASTUserNameWithHost() = default;
    explicit ASTUserNameWithHost(const String & name_) : base_name(name_) {}
    String getID(char) const override { return "UserNameWithHost"; }
    ASTPtr clone() const override { return std::make_shared<ASTUserNameWithHost>(*this); }
    void formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const override;
    void replace(String name_);
};


class ASTUserNamesWithHost : public IAST
{
public:
    std::vector<std::shared_ptr<ASTUserNameWithHost>> names;

    size_t size() const { return names.size(); }
    auto begin() const { return names.begin(); }
    auto end() const { return names.end(); }
    auto front() const { return *begin(); }
    void push_back(const String & name_) { names.push_back(std::make_shared<ASTUserNameWithHost>(name_)); } /// NOLINT

    Strings toStrings() const;
    void concatParts();
    bool getHostPatternIfCommon(String & out_common_host_pattern) const;

    String getID(char) const override { return "UserNamesWithHost"; }
    ASTPtr clone() const override { return std::make_shared<ASTUserNamesWithHost>(*this); }
    void formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const override;
};

}