#include "sql_values.h"
#include "sql_group_by.h"
#include "sql_query.h"
#include "sql_select.h"
#include "sql_expression.h"
#include "source.h"

namespace NSQLTranslationV1 {

using namespace NSQLv1Generated;

TSourcePtr TSqlValues::Build(const TRule_values_stmt& node, TPosition& valuesPos, const TVector<TString>& derivedColumns, TPosition derivedColumnsPos) {
    Token(node.GetToken1());
    valuesPos = Ctx.Pos();

    TVector<TVector<TNodePtr>> rows;
    const auto& rowList = node.GetRule_values_source_row_list2();
    if (!BuildRows(rowList, rows)) {
        return nullptr;
    }

    YQL_ENSURE(!rows.empty());
    const size_t columnsCount = rows.back().size();
    if (derivedColumns.size() > columnsCount) {
        Ctx.Error(derivedColumnsPos) << "Derived column list size exceeds column count in VALUES";
        return nullptr;
    }

    auto columns = derivedColumns;
    if (Ctx.WarnUnnamedColumns && columns.size() < columnsCount) {
        Ctx.Warning(valuesPos, TIssuesIds::YQL_UNNAMED_COLUMN)
            << "Autogenerated column names column" << columns.size() << "...column" << columnsCount - 1 << " will be used here";
    }

    while (columns.size() < columnsCount) {
        columns.push_back(TStringBuilder() << "column" << columns.size());
    }

    TVector<TNodePtr> labels;
    for (size_t i = 0; i < columnsCount; ++i) {
        labels.push_back(BuildQuotedAtom(derivedColumnsPos, columns[i]));
    }

    TVector<TNodePtr> items;
    for (auto& row : rows) {
        YQL_ENSURE(!row.empty());
        YQL_ENSURE(row.size() == columnsCount);
        items.push_back(BuildOrderedStructure(row.front()->GetPos(), row, labels));
    }
    auto list = new TCallNodeImpl(valuesPos, "AsListMayWarn", items);
    list = new TCallNodeImpl(valuesPos, "PersistableRepr", { list });
    list = new TCallNodeImpl(valuesPos, "AssumeColumnOrder", { list, BuildTuple(valuesPos, labels) });
    auto result = BuildNodeSource(valuesPos, list, false);
    result->AllColumns();
    return result;
}

bool TSqlValues::BuildRows(const TRule_values_source_row_list& node, TVector<TVector<TNodePtr>>& rows) {
    rows = TVector<TVector<TNodePtr>> {{}};


    if (!BuildRow(node.GetRule_values_source_row1(), rows.back())) {
        return false;
    }

    const size_t rowSize = rows.back().size();

    for (const auto& valuesSourceRow: node.GetBlock2()) {
        rows.push_back({});
        if (!BuildRow(valuesSourceRow.GetRule_values_source_row2(), rows.back())) {
            return false;
        }
        if (rows.back().size() != rowSize) {
            Token(valuesSourceRow.GetRule_values_source_row2().GetToken1());
            Error() << "All VALUES items should have same size: expecting " << rowSize << ", got " << rows.back().size();
            return false;
        }
    }
    return true;
}

bool TSqlValues::BuildRow(const TRule_values_source_row& inRow, TVector<TNodePtr>& outRow) {
    TSqlExpression sqlExpr(Ctx, Mode);
    return ExprList(sqlExpr, outRow, inRow.GetRule_expr_list2());
}

TSourcePtr TSqlValues::ValuesSource(const TRule_values_source& node, const TVector<TString>& columnsHint,
    const TString& operationName)
{
    Ctx.IncrementMonCounter("sql_features", "ValuesSource");
    TPosition pos(Ctx.Pos());
    switch (node.Alt_case()) {
        case TRule_values_source::kAltValuesSource1: {
            TVector<TVector<TNodePtr>> rows {{}};
            const auto& rowList = node.GetAlt_values_source1().GetRule_values_stmt1().GetRule_values_source_row_list2();
            if (!BuildRows(rowList, rows)) {
                return nullptr;
            }
            return BuildWriteValues(pos, operationName, columnsHint, rows);
        }
        case TRule_values_source::kAltValuesSource2: {
            TSqlSelect select(Ctx, Mode);
            TPosition selectPos;
            auto source = select.Build(node.GetAlt_values_source2().GetRule_select_stmt1(), selectPos);
            if (!source) {
                return nullptr;
            }
            return BuildWriteValues(pos, "UPDATE", columnsHint, std::move(source));
        }
        default:
            Ctx.IncrementMonCounter("sql_errors", "UnknownValuesSource");
            AltNotImplemented("values_source", node);
            return nullptr;
    }
}

TSourcePtr TSqlIntoValues::Build(const TRule_into_values_source& node, const TString& operationName) {
    switch (node.Alt_case()) {
        case TRule_into_values_source::kAltIntoValuesSource1: {
            auto alt = node.GetAlt_into_values_source1();
            TVector<TString> columnsHint;
            if (alt.HasBlock1()) {
                PureColumnListStr(alt.GetBlock1().GetRule_pure_column_list1(), *this, columnsHint);
            }
            return ValuesSource(alt.GetRule_values_source2(), columnsHint, operationName);
        }
        default:
            Ctx.IncrementMonCounter("sql_errors", "DefaultValuesOrOther");
            AltNotImplemented("into_values_source", node);
            return nullptr;
    }
}

TSourcePtr TSqlAsValues::Build(const TRule_values_source& node, const TString& operationName) {
    switch (node.Alt_case()) {
        case TRule_values_source::kAltValuesSource1: {
            Ctx.IncrementMonCounter("sql_errors", "UnknownValuesSource");
            Error() << "AS VALUES statement is not supported for " << operationName << ".";
            return nullptr;
        }
        case TRule_values_source::kAltValuesSource2: {
            return ValuesSource(node, {}, operationName);
        }
        default:
            Ctx.IncrementMonCounter("sql_errors", "UnknownValuesSource");
            AltNotImplemented("values_source", node);
            return nullptr;
    }
}

} // namespace NSQLTranslationV1