#include <Interpreters/InterpreterInsertQuery.h>

#include <Access/AccessFlags.h>
#include <DataStreams/AddingDefaultBlockOutputStream.h>
#include <DataStreams/AddingDefaultsBlockInputStream.h>
#include <DataStreams/CheckConstraintsBlockOutputStream.h>
#include <DataStreams/CountingBlockOutputStream.h>
#include <DataStreams/InputStreamFromASTInsertQuery.h>
#include <DataStreams/NullAndDoCopyBlockInputStream.h>
#include <DataStreams/NullBlockOutputStream.h>
#include <DataStreams/PushingToViewsBlockOutputStream.h>
#include <DataStreams/RemoteBlockInputStream.h>
#include <DataStreams/SquashingBlockOutputStream.h>
#include <DataStreams/copyData.h>
#include <IO/ConcatReadBuffer.h>
#include <Interpreters/InterpreterSelectWithUnionQuery.h>
#include <Interpreters/InterpreterWatchQuery.h>
#include <Interpreters/JoinedTables.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTInsertQuery.h>
#include <Parsers/ASTSelectQuery.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Parsers/ASTTablesInSelectQuery.h>
#include <Parsers/queryToString.h>
#include <Processors/NullSink.h>
#include <Processors/Sources/SinkToOutputStream.h>
#include <Processors/Sources/SourceFromInputStream.h>
#include <Processors/Transforms/ConvertingTransform.h>
#include <Storages/StorageDistributed.h>
#include <TableFunctions/TableFunctionFactory.h>
#include <Common/checkStackSize.h>
#include <Interpreters/TranslateQualifiedNamesVisitor.h>
#include <Interpreters/getTableExpressions.h>

namespace
{
const UInt64 PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL = 2;
}


namespace DB
{

namespace ErrorCodes
{
    extern const int NO_SUCH_COLUMN_IN_TABLE;
    extern const int ILLEGAL_COLUMN;
    extern const int DUPLICATE_COLUMN;
    extern const int LOGICAL_ERROR;
}


InterpreterInsertQuery::InterpreterInsertQuery(
    const ASTPtr & query_ptr_, const Context & context_, bool allow_materialized_, bool no_squash_, bool no_destination_)
    : query_ptr(query_ptr_)
    , context(context_)
    , allow_materialized(allow_materialized_)
    , no_squash(no_squash_)
    , no_destination(no_destination_)
{
    checkStackSize();
}


StoragePtr InterpreterInsertQuery::getTable(ASTInsertQuery & query)
{
    if (query.table_function)
    {
        const auto & factory = TableFunctionFactory::instance();
        TableFunctionPtr table_function_ptr = factory.get(query.table_function, context);
        return table_function_ptr->execute(query.table_function, context, table_function_ptr->getName());
    }

    query.table_id = context.resolveStorageID(query.table_id);
    return DatabaseCatalog::instance().getTable(query.table_id, context);
}

Block InterpreterInsertQuery::getSampleBlock(
    const ASTInsertQuery & query,
    const StoragePtr & table,
    const StorageMetadataPtr & metadata_snapshot) const
{
    Block table_sample_non_materialized = metadata_snapshot->getSampleBlockNonMaterialized();
    /// If the query does not include information about columns
    if (!query.columns)
    {
        if (no_destination)
            return metadata_snapshot->getSampleBlockWithVirtuals(table->getVirtuals());
        else
            return table_sample_non_materialized;
    }

    Block table_sample = metadata_snapshot->getSampleBlock();

    /// Process column transformers (e.g. * EXCEPT(a)), asterisks and qualified columns.
    const auto & columns = metadata_snapshot->getColumns();
    auto names_and_types = columns.getOrdinary();
    removeDuplicateColumns(names_and_types);
    auto table_expr = std::make_shared<ASTTableExpression>();
    table_expr->database_and_table_name = createTableIdentifier(table->getStorageID());
    table_expr->children.push_back(table_expr->database_and_table_name);
    TablesWithColumns tables_with_columns;
    tables_with_columns.emplace_back(DatabaseAndTableWithAlias(*table_expr, context.getCurrentDatabase()), names_and_types);

    tables_with_columns[0].addHiddenColumns(columns.getMaterialized());
    tables_with_columns[0].addHiddenColumns(columns.getAliases());
    tables_with_columns[0].addHiddenColumns(table->getVirtuals());

    NameSet source_columns_set;
    for (const auto & identifier : query.columns->children)
        source_columns_set.insert(identifier->getColumnName());
    TranslateQualifiedNamesVisitor::Data visitor_data(source_columns_set, tables_with_columns);
    TranslateQualifiedNamesVisitor visitor(visitor_data);
    auto columns_ast = query.columns->clone();
    visitor.visit(columns_ast);

    /// Form the block based on the column names from the query
    Block res;
    for (const auto & identifier : columns_ast->children)
    {
        std::string current_name = identifier->getColumnName();

        /// The table does not have a column with that name
        if (!table_sample.has(current_name))
            throw Exception("No such column " + current_name + " in table " + query.table_id.getNameForLogs(),
                ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);

        if (!allow_materialized && !table_sample_non_materialized.has(current_name))
            throw Exception("Cannot insert column " + current_name + ", because it is MATERIALIZED column.", ErrorCodes::ILLEGAL_COLUMN);
        if (res.has(current_name))
            throw Exception("Column " + current_name + " specified more than once", ErrorCodes::DUPLICATE_COLUMN);

        res.insert(ColumnWithTypeAndName(table_sample.getByName(current_name).type, current_name));
    }
    return res;
}


/** A query that just reads all data without any complex computations or filetering.
  * If we just pipe the result to INSERT, we don't have to use too many threads for read.
  */
static bool isTrivialSelect(const ASTSelectQuery & select_query)
{
    const auto & tables = select_query.tables();

    if (!tables)
        return false;

    const auto & tables_in_select_query = tables->as<ASTTablesInSelectQuery &>();

    if (tables_in_select_query.children.size() != 1)
        return false;

    const auto & child = tables_in_select_query.children.front();
    const auto & table_element = child->as<ASTTablesInSelectQueryElement &>();
    const auto & table_expr = table_element.table_expression->as<ASTTableExpression &>();

    if (table_expr.subquery)
        return false;

    /// Note: how to write it in more generic way?
    return (!select_query.distinct
        && !select_query.limit_with_ties
        && !select_query.prewhere()
        && !select_query.where()
        && !select_query.groupBy()
        && !select_query.having()
        && !select_query.orderBy()
        && !select_query.limitBy());
};


BlockIO InterpreterInsertQuery::execute()
{
    const Settings & settings = context.getSettingsRef();
    auto & query = query_ptr->as<ASTInsertQuery &>();

    BlockIO res;

    StoragePtr table = getTable(query);
    auto table_lock = table->lockForShare(context.getInitialQueryId(), context.getSettingsRef().lock_acquire_timeout);
    auto metadata_snapshot = table->getInMemoryMetadataPtr();

    auto query_sample_block = getSampleBlock(query, table, metadata_snapshot);
    if (!query.table_function)
        context.checkAccess(AccessType::INSERT, query.table_id, query_sample_block.getNames());

    bool is_distributed_insert_select = false;

    if (query.select && table->isRemote() && settings.parallel_distributed_insert_select)
    {
        // Distributed INSERT SELECT
        std::shared_ptr<StorageDistributed> storage_src;
        auto & select = query.select->as<ASTSelectWithUnionQuery &>();
        auto new_query = std::dynamic_pointer_cast<ASTInsertQuery>(query.clone());
        if (select.list_of_selects->children.size() == 1)
        {
            auto & select_query = select.list_of_selects->children.at(0)->as<ASTSelectQuery &>();
            JoinedTables joined_tables(Context(context), select_query);

            if (joined_tables.tablesCount() == 1)
            {
                storage_src = std::dynamic_pointer_cast<StorageDistributed>(joined_tables.getLeftTableStorage());
                if (storage_src)
                {
                    const auto select_with_union_query = std::make_shared<ASTSelectWithUnionQuery>();
                    select_with_union_query->list_of_selects = std::make_shared<ASTExpressionList>();

                    auto new_select_query = std::dynamic_pointer_cast<ASTSelectQuery>(select_query.clone());
                    select_with_union_query->list_of_selects->children.push_back(new_select_query);

                    new_select_query->replaceDatabaseAndTable(storage_src->getRemoteDatabaseName(), storage_src->getRemoteTableName());

                    new_query->select = select_with_union_query;
                }
            }
        }

        auto storage_dst = std::dynamic_pointer_cast<StorageDistributed>(table);

        if (storage_src && storage_dst && storage_src->cluster_name == storage_dst->cluster_name)
        {
            is_distributed_insert_select = true;

            if (settings.parallel_distributed_insert_select == PARALLEL_DISTRIBUTED_INSERT_SELECT_ALL)
            {
                new_query->table_id = StorageID(storage_dst->getRemoteDatabaseName(), storage_dst->getRemoteTableName());
            }

            const auto & cluster = storage_src->getCluster();
            const auto & shards_info = cluster->getShardsInfo();

            std::vector<std::unique_ptr<QueryPipeline>> pipelines;

            String new_query_str = queryToString(new_query);
            for (size_t shard_index : ext::range(0, shards_info.size()))
            {
                const auto & shard_info = shards_info[shard_index];
                if (shard_info.isLocal())
                {
                    InterpreterInsertQuery interpreter(new_query, context);
                    pipelines.emplace_back(std::make_unique<QueryPipeline>(interpreter.execute().pipeline));
                }
                else
                {
                    auto timeouts = ConnectionTimeouts::getTCPTimeoutsWithFailover(settings);
                    auto connections = shard_info.pool->getMany(timeouts, &settings, PoolMode::GET_ONE);
                    if (connections.empty() || connections.front().isNull())
                        throw Exception(
                            "Expected exactly one connection for shard " + toString(shard_info.shard_num), ErrorCodes::LOGICAL_ERROR);

                    ///  INSERT SELECT query returns empty block
                    auto in_stream = std::make_shared<RemoteBlockInputStream>(std::move(connections), new_query_str, Block{}, context);
                    pipelines.emplace_back(std::make_unique<QueryPipeline>());
                    pipelines.back()->init(Pipe(std::make_shared<SourceFromInputStream>(std::move(in_stream))));
                    pipelines.back()->setSinks([](const Block & header, QueryPipeline::StreamType) -> ProcessorPtr
                    {
                        return std::make_shared<EmptySink>(header);
                    });
                }
            }

            res.pipeline = QueryPipeline::unitePipelines(std::move(pipelines), {});
        }
    }

    BlockOutputStreams out_streams;
    if (!is_distributed_insert_select || query.watch)
    {
        size_t out_streams_size = 1;
        if (query.select)
        {
            bool is_trivial_insert_select = false;

            if (settings.optimize_trivial_insert_select)
            {
                const auto & selects = query.select->as<ASTSelectWithUnionQuery &>().list_of_selects->children;

                is_trivial_insert_select = std::all_of(selects.begin(), selects.end(), [](const ASTPtr & select)
                {
                    return isTrivialSelect(select->as<ASTSelectQuery &>());
                });
            }

            if (is_trivial_insert_select)
            {
                /** When doing trivial INSERT INTO ... SELECT ... FROM table,
                  * don't need to process SELECT with more than max_insert_threads
                  * and it's reasonable to set block size for SELECT to the desired block size for INSERT
                  * to avoid unnecessary squashing.
                  */

                Settings new_settings = context.getSettings();

                new_settings.max_threads = std::max<UInt64>(1, settings.max_insert_threads);

                if (settings.min_insert_block_size_rows)
                    new_settings.max_block_size = settings.min_insert_block_size_rows;

                Context new_context = context;
                new_context.setSettings(new_settings);

                InterpreterSelectWithUnionQuery interpreter_select{
                    query.select, new_context, SelectQueryOptions(QueryProcessingStage::Complete, 1)};
                res = interpreter_select.execute();
            }
            else
            {
                /// Passing 1 as subquery_depth will disable limiting size of intermediate result.
                InterpreterSelectWithUnionQuery interpreter_select{
                    query.select, context, SelectQueryOptions(QueryProcessingStage::Complete, 1)};
                res = interpreter_select.execute();
            }

            if (table->supportsParallelInsert() && settings.max_insert_threads > 1)
                out_streams_size = std::min(size_t(settings.max_insert_threads), res.pipeline.getNumStreams());

            res.pipeline.resize(out_streams_size);
        }
        else if (query.watch)
        {
            InterpreterWatchQuery interpreter_watch{ query.watch, context };
            res = interpreter_watch.execute();
            res.pipeline.init(Pipe(std::make_shared<SourceFromInputStream>(std::move(res.in))));
        }

        for (size_t i = 0; i < out_streams_size; i++)
        {
            /// We create a pipeline of several streams, into which we will write data.
            BlockOutputStreamPtr out;

            /// NOTE: we explicitly ignore bound materialized views when inserting into Kafka Storage.
            ///       Otherwise we'll get duplicates when MV reads same rows again from Kafka.
            if (table->noPushingToViews() && !no_destination)
                out = table->write(query_ptr, metadata_snapshot, context);
            else
                out = std::make_shared<PushingToViewsBlockOutputStream>(table, metadata_snapshot, context, query_ptr, no_destination);

            /// Note that we wrap transforms one on top of another, so we write them in reverse of data processing order.

            /// Checking constraints. It must be done after calculation of all defaults, so we can check them on calculated columns.
            if (const auto & constraints = metadata_snapshot->getConstraints(); !constraints.empty())
                out = std::make_shared<CheckConstraintsBlockOutputStream>(
                    query.table_id, out, out->getHeader(), metadata_snapshot->getConstraints(), context);

            /// Actually we don't know structure of input blocks from query/table,
            /// because some clients break insertion protocol (columns != header)
            out = std::make_shared<AddingDefaultBlockOutputStream>(
                out, query_sample_block, out->getHeader(), metadata_snapshot->getColumns(), context);

            /// It's important to squash blocks as early as possible (before other transforms),
            ///  because other transforms may work inefficient if block size is small.

            /// Do not squash blocks if it is a sync INSERT into Distributed, since it lead to double bufferization on client and server side.
            /// Client-side bufferization might cause excessive timeouts (especially in case of big blocks).
            if (!(context.getSettingsRef().insert_distributed_sync && table->isRemote()) && !no_squash && !query.watch)
            {
                out = std::make_shared<SquashingBlockOutputStream>(
                    out,
                    out->getHeader(),
                    context.getSettingsRef().min_insert_block_size_rows,
                    context.getSettingsRef().min_insert_block_size_bytes);
            }

            auto out_wrapper = std::make_shared<CountingBlockOutputStream>(out);
            out_wrapper->setProcessListElement(context.getProcessListElement());
            out = std::move(out_wrapper);
            out_streams.emplace_back(std::move(out));
        }
    }

    /// What type of query: INSERT or INSERT SELECT or INSERT WATCH?
    if (is_distributed_insert_select)
    {
        /// Pipeline was already built.
    }
    else if (query.select || query.watch)
    {
        const auto & header = out_streams.at(0)->getHeader();

        res.pipeline.addSimpleTransform([&](const Block & in_header) -> ProcessorPtr
        {
            return std::make_shared<ConvertingTransform>(in_header, header,
                    ConvertingTransform::MatchColumnsMode::Position);
        });

        res.pipeline.setSinks([&](const Block &, QueryPipeline::StreamType type) -> ProcessorPtr
        {
            if (type != QueryPipeline::StreamType::Main)
                return nullptr;

            auto stream = std::move(out_streams.back());
            out_streams.pop_back();

            return std::make_shared<SinkToOutputStream>(std::move(stream));
        });

        if (!allow_materialized)
        {
            for (const auto & column : metadata_snapshot->getColumns())
                if (column.default_desc.kind == ColumnDefaultKind::Materialized && header.has(column.name))
                    throw Exception("Cannot insert column " + column.name + ", because it is MATERIALIZED column.", ErrorCodes::ILLEGAL_COLUMN);
        }
    }
    else if (query.data && !query.has_tail) /// can execute without additional data
    {
        // res.out = std::move(out_streams.at(0));
        res.in = std::make_shared<InputStreamFromASTInsertQuery>(query_ptr, nullptr, query_sample_block, context, nullptr);
        res.in = std::make_shared<NullAndDoCopyBlockInputStream>(res.in, out_streams.at(0));
    }
    else
        res.out = std::move(out_streams.at(0));

    res.pipeline.addStorageHolder(table);
    if (const auto * mv = dynamic_cast<const StorageMaterializedView *>(table.get()))
    {
        if (auto inner_table = mv->tryGetTargetTable())
            res.pipeline.addStorageHolder(inner_table);
    }

    return res;
}


StorageID InterpreterInsertQuery::getDatabaseTable() const
{
    return query_ptr->as<ASTInsertQuery &>().table_id;
}

}