#include <Columns/ColumnString.h>
#include <DataTypes/DataTypeString.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeTuple.h>
#include <DataStreams/OneBlockInputStream.h>
#include <Interpreters/ProcessList.h>
#include <Storages/System/StorageSystemProcesses.h>
#include <Interpreters/Context.h>
#include <Storages/System/VirtualColumnsProcessor.h>


namespace DB
{


StorageSystemProcesses::StorageSystemProcesses(const std::string & name_)
    : name(name_)
{
    setColumns(ColumnsDescription({
        { "is_initial_query",     std::make_shared<DataTypeUInt8>() },

        { "user",                 std::make_shared<DataTypeString>() },
        { "query_id",             std::make_shared<DataTypeString>() },
        { "address",              std::make_shared<DataTypeString>() },
        { "port",                 std::make_shared<DataTypeUInt16>() },

        { "initial_user",         std::make_shared<DataTypeString>() },
        { "initial_query_id",     std::make_shared<DataTypeString>() },
        { "initial_address",      std::make_shared<DataTypeString>() },
        { "initial_port",         std::make_shared<DataTypeUInt16>() },

        { "interface",            std::make_shared<DataTypeUInt8>() },

        { "os_user",              std::make_shared<DataTypeString>() },
        { "client_hostname",      std::make_shared<DataTypeString>() },
        { "client_name",          std::make_shared<DataTypeString>() },
        { "client_version_major", std::make_shared<DataTypeUInt64>() },
        { "client_version_minor", std::make_shared<DataTypeUInt64>() },
        { "client_revision",      std::make_shared<DataTypeUInt64>() },

        { "http_method",          std::make_shared<DataTypeUInt8>() },
        { "http_user_agent",      std::make_shared<DataTypeString>() },

        { "quota_key",            std::make_shared<DataTypeString>() },

        { "elapsed",              std::make_shared<DataTypeFloat64>() },
        { "is_cancelled",         std::make_shared<DataTypeUInt8>() },
        { "read_rows",            std::make_shared<DataTypeUInt64>() },
        { "read_bytes",           std::make_shared<DataTypeUInt64>() },
        { "total_rows_approx",    std::make_shared<DataTypeUInt64>() },
        { "written_rows",         std::make_shared<DataTypeUInt64>() },
        { "written_bytes",        std::make_shared<DataTypeUInt64>() },
        { "memory_usage",         std::make_shared<DataTypeInt64>() },
        { "peak_memory_usage",    std::make_shared<DataTypeInt64>() },
        { "query",                std::make_shared<DataTypeString>() },
    }));

    virtual_columns = ColumnsWithTypeAndName{
        {
            std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt32>()),
            "thread_numbers"
        },
        {
            std::make_shared<DataTypeArray>(std::make_shared<DataTypeTuple>(
                DataTypes{std::make_shared<DataTypeString>(), std::make_shared<DataTypeUInt64 >()})),
            "profile_counters"
        }
    };
}


BlockInputStreams StorageSystemProcesses::read(
    const Names & column_names,
    const SelectQueryInfo &,
    const Context & context,
    QueryProcessingStage::Enum & processed_stage,
    const size_t /*max_block_size*/,
    const unsigned /*num_streams*/)
{
    processed_stage = QueryProcessingStage::FetchColumns;

    auto virtual_columns_processor = getVirtualColumnsProcessor();
    bool has_thread_numbers, has_profile_counters;
    Names real_columns = virtual_columns_processor.process(column_names, {&has_thread_numbers, &has_profile_counters});
    check(real_columns);

    Block res_block = getSampleBlock().cloneEmpty();
    virtual_columns_processor.appendVirtualColumns(res_block);
    MutableColumns res_columns = res_block.cloneEmptyColumns();

    ProcessList::Info info = context.getProcessList().getInfo(has_thread_numbers, has_profile_counters);

    for (const auto & process : info)
    {
        size_t i = 0;
        res_columns[i++]->insert(UInt64(process.client_info.query_kind == ClientInfo::QueryKind::INITIAL_QUERY));
        res_columns[i++]->insert(process.client_info.current_user);
        res_columns[i++]->insert(process.client_info.current_query_id);
        res_columns[i++]->insert(process.client_info.current_address.host().toString());
        res_columns[i++]->insert(UInt64(process.client_info.current_address.port()));
        res_columns[i++]->insert(process.client_info.initial_user);
        res_columns[i++]->insert(process.client_info.initial_query_id);
        res_columns[i++]->insert(process.client_info.initial_address.host().toString());
        res_columns[i++]->insert(UInt64(process.client_info.initial_address.port()));
        res_columns[i++]->insert(UInt64(process.client_info.interface));
        res_columns[i++]->insert(process.client_info.os_user);
        res_columns[i++]->insert(process.client_info.client_hostname);
        res_columns[i++]->insert(process.client_info.client_name);
        res_columns[i++]->insert(process.client_info.client_version_major);
        res_columns[i++]->insert(process.client_info.client_version_minor);
        res_columns[i++]->insert(UInt64(process.client_info.client_revision));
        res_columns[i++]->insert(UInt64(process.client_info.http_method));
        res_columns[i++]->insert(process.client_info.http_user_agent);
        res_columns[i++]->insert(process.client_info.quota_key);
        res_columns[i++]->insert(process.elapsed_seconds);
        res_columns[i++]->insert(UInt64(process.is_cancelled));
        res_columns[i++]->insert(UInt64(process.read_rows));
        res_columns[i++]->insert(UInt64(process.read_bytes));
        res_columns[i++]->insert(UInt64(process.total_rows));
        res_columns[i++]->insert(UInt64(process.written_rows));
        res_columns[i++]->insert(UInt64(process.written_bytes));
        res_columns[i++]->insert(process.memory_usage);
        res_columns[i++]->insert(process.peak_memory_usage);
        res_columns[i++]->insert(process.query);

        if (has_thread_numbers)
        {
            Array thread_numbers;
            thread_numbers.reserve(process.thread_numbers.size());

            for (const UInt32 thread_number : process.thread_numbers)
                thread_numbers.emplace_back(UInt64(thread_number));

            res_columns[i++]->insert(std::move(thread_numbers));
        }

        if (has_profile_counters)
        {
            Array profile_counters;
            profile_counters.reserve(ProfileEvents::Counters::num_counters);

            for (ProfileEvents::Event event = 0; event < ProfileEvents::Counters::num_counters; ++event)
            {
                Array name_and_counter{
                    String(ProfileEvents::getDescription(event)),
                    UInt64((*process.profile_counters)[event].load(std::memory_order_relaxed))
                };

                profile_counters.emplace_back(Tuple(std::move(name_and_counter)));
            }

            res_columns[i++]->insert(std::move(profile_counters));
        }
    }

    return BlockInputStreams(1, std::make_shared<OneBlockInputStream>(res_block.cloneWithColumns(std::move(res_columns))));
}

}