/*
 * Copyright (C) 2013 Emeric Poupon
 *
 * This file is part of LMS.
 *
 * LMS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LMS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "SqlQuery.hpp"

#include <algorithm>
#include <cassert>
#include <sstream>

namespace lms::db
{
    WhereClause& WhereClause::And(const WhereClause& otherClause)
    {
        if (!otherClause._clause.empty()) {
            if (!_clause.empty())
                _clause += " AND ";
            _clause += "(" + otherClause._clause + ")";

            // Add associated bind args
            for (const std::string& otherBindArg : otherClause._bindArgs)
            {
                _bindArgs.push_back(otherBindArg);
            }
        }
        return *this;
    }

    WhereClause& WhereClause::Or(const WhereClause& otherClause)
    {
        if (!otherClause._clause.empty()) {
            if (!_clause.empty())
                _clause += " OR ";
            _clause += "(" + otherClause._clause + ")";

            // Add associated bind args
            for (const std::string& otherBindArg : otherClause._bindArgs)
            {
                _bindArgs.push_back(otherBindArg);
            }
        }
        return *this;
    }

    std::string WhereClause::get() const
    {
        if (!_clause.empty())
            return "WHERE " + _clause;
        else
            return "";
    }

    WhereClause& WhereClause::bind(std::string_view bindArg)
    {
        assert(_bindArgs.size() < static_cast<std::size_t>(std::count(_clause.begin(), _clause.end(), '?')));

        _bindArgs.push_back(std::string{ bindArg });

        return *this;
    }

    InnerJoinClause::InnerJoinClause(const std::string& clause)
        :_clause(clause)
    {
    }

    InnerJoinClause& InnerJoinClause::And(const InnerJoinClause& clause)
    {
        if (!_clause.empty())
            _clause += " ";

        _clause += "INNER JOIN " + clause._clause;

        return *this;
    }

    SelectStatement::SelectStatement(const std::string& statement)
    {
        And(statement);
    }

    SelectStatement& SelectStatement::And(const std::string& statement)
    {
        _statement.push_back(statement);

        std::sort(_statement.begin(), _statement.end());
        _statement.erase(std::unique(_statement.begin(), _statement.end()), _statement.end());

        return *this;
    }

    std::string SelectStatement::get() const
    {
        std::string res = "SELECT ";

        for (auto it = _statement.begin(); it != _statement.end(); ++it)
        {
            if (it != _statement.begin())
                res += ",";
            res += *it;
        }

        return res;
    }

    GroupByStatement& GroupByStatement::And(const GroupByStatement& statement)
    {
        if (_statement.empty() && !statement._statement.empty())
            _statement = "GROUP BY ";
        else if (!_statement.empty() && !statement._statement.empty())
            _statement += ",";

        _statement += statement._statement;
        return *this;
    }

    FromClause::FromClause(const std::string& clause)
    {
        _clause.push_back(clause);
    }

    FromClause& FromClause::And(const FromClause& clause)
    {
        for (const std::string& fromClause : clause._clause)
        {
            _clause.push_back(fromClause);
        }

        std::sort(_clause.begin(), _clause.end());
        _clause.erase(std::unique(_clause.begin(), _clause.end()), _clause.end());

        return *this;
    }

    std::string FromClause::get() const
    {
        std::ostringstream oss;

        if (!_clause.empty())
        {
            oss << "FROM ";
            for (auto it = _clause.begin(); it != _clause.end(); ++it) {
                if (it != _clause.begin())
                    oss << ",";

                oss << *it;
            }
        }

        return oss.str();
    }

    std::string SqlQuery::get() const
    {
        std::ostringstream oss;

        oss << _selectStatement.get();

        if (!_fromClause.get().empty())
            oss << " " << _fromClause.get();

        if (!_innerJoinClause.get().empty())
            oss << " " << _innerJoinClause.get();

        if (!_whereClause.get().empty())
            oss << " " << _whereClause.get();

        if (!_groupByStatement.get().empty())
            oss << " " << _groupByStatement.get();

        return oss.str();
    }
}