#include <iostream>
#include <limits>
#include <unistd.h>

#include <sys/stat.h>
#include <boost/program_options.hpp>

#include <DB/AggregateFunctions/ReservoirSampler.h>
#include <DB/Client/ConnectionPool.h>
#include <DB/Common/ConcurrentBoundedQueue.h>
#include <DB/Common/Stopwatch.h>
#include <DB/Common/ThreadPool.h>
#include <DB/Core/Types.h>
#include <DB/DataStreams/RemoteBlockInputStream.h>
#include <DB/Interpreters/Settings.h>
#include <DB/IO/ReadHelpers.h>
#include <DB/IO/ReadBufferFromFileDescriptor.h>


#include <Poco/AutoPtr.h>
#include <Poco/XML/XMLStream.h>
#include <Poco/SAX/InputSource.h>
#include <Poco/Util/XMLConfiguration.h>
#include <Poco/Exception.h>

#include "InterruptListener.h"

/** Tests launcher for ClickHouse.
  * The tool walks through given or default folder in order to find files with
  * tests' description and launches it.
  */
namespace DB
{

namespace ErrorCodes
{
	extern const int POCO_EXCEPTION;
	extern const int STD_EXCEPTION;
	extern const int UNKNOWN_EXCEPTION;
}

bool isNumber(const std::string & str) {
    if (str.empty()) { return false; }

    size_t dotsCounter = 0;

    if (str[0] == '.' || str[str.size() - 1] == '.') {
        return false;
    }

    for (char chr : str) {
        if (chr == '.') {
            if (dotsCounter)
                return false;
            else
                ++dotsCounter;
            continue;
        }

        if (chr < '0' || chr > '9') {
            return false;
        }
    }

    return true;
}

class JSONString {
 private:
    std::map<std::string, std::string> content;
    std::string current_key;
    size_t _padding = 1;
 public:
    JSONString() {};
    JSONString(size_t padding): _padding(padding) {};

    JSONString & operator[](const std::string & key)
    {
        current_key = key;
        return *this;
    }

    template <typename T>
	typename std::enable_if<std::is_arithmetic<T>::value, JSONString & >::type
	operator[](const T key)
    {
        current_key = std::to_string(key);
        return *this;
    }

    void set(std::string value)
    {
        if (current_key.empty()) {
            throw "cannot use set without key";
        }

        if (value.empty()) {
            value = "null";
        }

        bool reserved = (value[0] == '[' || value[0] == '{' || value == "null");

        if (!reserved && !isNumber(value)) {
            value = '\"' + value + '\"';
        }

        content[current_key] = value;
        current_key = "";
    }

	void set(const JSONString & innerJSON)
    {
    	set(innerJSON.constructOutput());
    }

	void set(const std::vector<JSONString> & runInfos)
    {
        if (current_key.empty()) {
            throw "cannot use set without key";
        }

        content[current_key] = "[\n";

        for (size_t i = 0; i < runInfos.size(); ++i) {
        	for (size_t i = 0; i < _padding + 1; ++i) {
        		content[current_key] += "\t";
        	}
        	content[current_key] += runInfos[i].constructOutput(_padding + 2);

        	if (i != runInfos.size() - 1) {
        		content[current_key] += ',';
        	}

        	content[current_key] += "\n";
        }

        for (size_t i = 0; i < _padding; ++i) {
        	content[current_key] += "\t";
        }
        content[current_key] += ']';
        current_key = "";
    }

    template <typename T>
    typename std::enable_if<std::is_arithmetic<T>::value, void>::type set(T value)
    {
        set(std::to_string(value));
    }
    std::string constructOutput() const
    {
    	return constructOutput(_padding);
    }

    std::string constructOutput(size_t padding) const
    {
        std::string output = "{";

        bool first = true;

        for (auto it = content.begin(); it != content.end(); ++it) {
            if (! first) {
                output += ',';
            } else {
                first = false;
            }

            output += "\n";
            for (size_t i = 0; i < padding; ++i) {
	            output += "\t";
            }

            std::string key   = '\"' + it->first + '\"';
            std::string value = it->second;

            output += key + ": " + value;
        }

        output += "\n";
        for (size_t i = 0; i < padding - 1; ++i) {
            output += "\t";
        }
        output += "}";
        return output;
    }
};

std::ostream & operator<<(std::ostream & stream, const JSONString & jsonObj)
{
    stream << jsonObj.constructOutput();

    return stream;
}

enum PriorityType { min, max };

struct CriterionWithPriority {
	PriorityType priority;
	size_t value;
	bool   fulfilled;

	CriterionWithPriority()
		: value(0), fulfilled(false) {}
	CriterionWithPriority(const CriterionWithPriority &) = default;
};

/// Termination criterions. The running test will be terminated in either of two conditions:
/// 1. All criterions marked 'min' are fulfilled
/// or
/// 2. Any criterion  marked 'max' is  fulfilled
class StopCriterions {
private:
	using AbstractConfiguration = Poco::AutoPtr<Poco::Util::AbstractConfiguration>;
	using Keys = std::vector<std::string>;

	void initializeStruct(const std::string & priority,
						  const AbstractConfiguration & stopCriterionsView)
	{
		Keys keys;
		stopCriterionsView->keys(priority, keys);

		for (const std::string & key : keys) {
			if (key == "timeout_ms") {
				timeout_ms.value    = stopCriterionsView->getUInt64(priority + ".timeout_ms");
				timeout_ms.priority = (priority == "min" ? min : max);
			} else if (key == "rows_read") {
				rows_read.value    = stopCriterionsView->getUInt64(priority + ".rows_read");
				rows_read.priority = (priority == "min" ? min : max);
			} else if (key == "bytes_read_uncompressed") {
				bytes_read_uncompressed.value    = stopCriterionsView->getUInt64(priority + ".bytes_read_uncompressed");
				bytes_read_uncompressed.priority = (priority == "min" ? min : max);
			} else if (key == "iterations") {
				iterations.value    = stopCriterionsView->getUInt64(priority + ".iterations");
				iterations.priority = (priority == "min" ? min : max);
			} else if (key == "min_time_not_changing_for_ms") {
				min_time_not_changing_for_ms.value    = stopCriterionsView->getUInt64(priority + ".min_time_not_changing_for_ms");
				min_time_not_changing_for_ms.priority = (priority == "min" ? min : max);
			} else if (key == "max_speed_not_changing_for_ms") {
				max_speed_not_changing_for_ms.value    = stopCriterionsView->getUInt64(priority + ".max_speed_not_changing_for_ms");
				max_speed_not_changing_for_ms.priority = (priority == "min" ? min : max);
			} else if (key == "average_speed_not_changing_for_ms") {
				average_speed_not_changing_for_ms.value    = stopCriterionsView->getUInt64(priority + ".average_speed_not_changing_for_ms");
				average_speed_not_changing_for_ms.priority = (priority == "min" ? min : max);
			} else {
				throw Poco::Exception("Met unkown stop criterion: " + key, 1);
			}

			if (priority == "min") { ++number_of_initialized_min; };
			if (priority == "max") { ++number_of_initialized_max; };
		}
	}

public:
	StopCriterions()
		: number_of_initialized_min(0), number_of_initialized_max(0),
		  fulfilled_criterions_min(0), fulfilled_criterions_max(0) {}

	StopCriterions(const StopCriterions &anotherCriterions)
		:
		timeout_ms(anotherCriterions.timeout_ms),
		rows_read(anotherCriterions.rows_read),
		bytes_read_uncompressed(anotherCriterions.bytes_read_uncompressed),
		iterations(anotherCriterions.iterations),
		min_time_not_changing_for_ms(anotherCriterions.min_time_not_changing_for_ms),
		max_speed_not_changing_for_ms(anotherCriterions.max_speed_not_changing_for_ms),
		average_speed_not_changing_for_ms(anotherCriterions.average_speed_not_changing_for_ms),

		number_of_initialized_min(anotherCriterions.number_of_initialized_min.load()),
		number_of_initialized_max(anotherCriterions.number_of_initialized_max.load()),
		fulfilled_criterions_min(anotherCriterions.fulfilled_criterions_min.load()),
		fulfilled_criterions_max(anotherCriterions.fulfilled_criterions_max.load()) {}

	void loadFromConfig(const AbstractConfiguration & stopCriterionsView)
	{
		if (stopCriterionsView->has("min")) {
			initializeStruct("min", stopCriterionsView);
		}

		if (stopCriterionsView->has("max")) {
			initializeStruct("max", stopCriterionsView);
		}
	}

	void reset()
	{
		timeout_ms.fulfilled                        = false;
		rows_read.fulfilled                         = false;
		bytes_read_uncompressed.fulfilled           = false;
		iterations.fulfilled                        = false;
		min_time_not_changing_for_ms.fulfilled      = false;
		max_speed_not_changing_for_ms.fulfilled     = false;
		average_speed_not_changing_for_ms.fulfilled = false;

		fulfilled_criterions_min = 0;
		fulfilled_criterions_max = 0;
	}

	CriterionWithPriority timeout_ms;
	CriterionWithPriority rows_read;
	CriterionWithPriority bytes_read_uncompressed;
	CriterionWithPriority iterations;
	CriterionWithPriority min_time_not_changing_for_ms;
	CriterionWithPriority max_speed_not_changing_for_ms;
	CriterionWithPriority average_speed_not_changing_for_ms;

    /// Hereafter 'min' and 'max', in context of critetions, mean a level of importance
	/// Number of initialized properties met in configuration
	std::atomic<size_t> number_of_initialized_min;
	std::atomic<size_t> number_of_initialized_max;

	std::atomic<size_t> fulfilled_criterions_min;
	std::atomic<size_t> fulfilled_criterions_max;
};

struct Stats
{
	Stopwatch watch;
	Stopwatch watch_per_query;
	Stopwatch min_time_watch;
	Stopwatch max_rows_speed_watch;
	Stopwatch max_bytes_speed_watch;
	Stopwatch avg_rows_speed_watch;
	Stopwatch avg_bytes_speed_watch;
	size_t queries;
	size_t rows_read;
	size_t bytes_read;

	using Sampler = ReservoirSampler<double>;
	Sampler sampler {1 << 16};

	/// min_time in ms
	UInt64 min_time   = std::numeric_limits<UInt64>::max();
	double total_time = 0;

	double max_rows_speed  = 0;
	double max_bytes_speed  = 0;

	double avg_rows_speed_value = 0;
	double avg_rows_speed_first = 0;
	static double avg_rows_speed_precision;

	double avg_bytes_speed_value = 0;
	double avg_bytes_speed_first = 0;
	static double avg_bytes_speed_precision;

	size_t number_of_rows_speed_info_batches  = 0;
	size_t number_of_bytes_speed_info_batches = 0;

	std::string getStatisticByName(const std::string & statisticName) {
	    if (statisticName == "min_time") {
	    	return std::to_string(min_time) + "ms";
	    }
	    if (statisticName == "quantiles") {
	    	std::string result = "\n";

	    	for (double percent = 10; percent <= 90; percent += 10) {
	    		result += "\t" + std::to_string((percent / 100));
	    		result += ": " + std::to_string(sampler.quantileInterpolated(percent / 100.0));
	    		result += "\n";
	    	}
			result += "\t0.95: "   + std::to_string(sampler.quantileInterpolated(95 / 100.0))   + "\n";
			result += "\t0.99: "   + std::to_string(sampler.quantileInterpolated(99 / 100.0))   + "\n";
			result += "\t0.999: "  + std::to_string(sampler.quantileInterpolated(99.9 / 100.))  + "\n";
			result += "\t0.9999: " + std::to_string(sampler.quantileInterpolated(99.99 / 100.));

			return result;
	    }
	    if (statisticName == "total_time") {
	    	return std::to_string(total_time) + "s";
	    }
	    if (statisticName == "queries_per_second") {
	    	return std::to_string(queries / total_time);
	    }
	    if (statisticName == "rows_per_second") {
	    	return std::to_string(rows_read / total_time);
	    }
	    if (statisticName == "bytes_per_second") {
	    	return std::to_string(bytes_read / total_time);
	    }

	    if (statisticName == "max_rows_per_second") {
	    	return std::to_string(max_rows_speed);
	    }
	    if (statisticName == "max_bytes_per_second") {
	    	return std::to_string(max_bytes_speed);
	    }
	    if (statisticName == "avg_rows_per_second") {
	    	return std::to_string(avg_rows_speed_value);
	    }
	    if (statisticName == "avg_bytes_per_second") {
	    	return std::to_string(avg_bytes_speed_value);
	    }

	    return "";
	}

	void update_min_time(const UInt64 min_time_candidate)
	{
		if (min_time_candidate < min_time) {
			min_time = min_time_candidate;
			min_time_watch.restart();
		}
	}

	void update_average_speed(const double new_speed_info, Stopwatch & avg_speed_watch,
							  size_t & number_of_info_batches, double precision,
							  double & avg_speed_first, double & avg_speed_value)
	{
		avg_speed_value = ((avg_speed_value * number_of_info_batches)
						   + new_speed_info);
		avg_speed_value /= (++number_of_info_batches);

		if (avg_speed_first == 0) {
			avg_speed_first = avg_speed_value;
		}

		if (abs(avg_speed_value - avg_speed_first) >= precision) {
			avg_speed_first = avg_speed_value;
			avg_speed_watch.restart();
		}
	}

	void update_max_speed(const size_t max_speed_candidate, Stopwatch & max_speed_watch,
						  double & max_speed)
	{
		if (max_speed_candidate > max_speed) {
			max_speed = max_speed_candidate;
			max_speed_watch.restart();
		}
	}

	void add(size_t rows_read_inc, size_t bytes_read_inc)
	{
		rows_read  += rows_read_inc;
		bytes_read += bytes_read_inc;

		double new_rows_speed  = rows_read_inc  / watch_per_query.elapsedSeconds();
		double new_bytes_speed = bytes_read_inc / watch_per_query.elapsedSeconds();

		/// Update rows speed
		update_max_speed(new_rows_speed, max_rows_speed_watch, max_rows_speed);
		update_average_speed(new_rows_speed, avg_rows_speed_watch,
							 number_of_rows_speed_info_batches, avg_rows_speed_precision,
							 avg_rows_speed_first, avg_rows_speed_value);
		/// Update bytes speed
		update_max_speed(new_bytes_speed, max_bytes_speed_watch, max_bytes_speed);
		update_average_speed(new_bytes_speed, avg_bytes_speed_watch,
							 number_of_bytes_speed_info_batches, avg_bytes_speed_precision,
							 avg_bytes_speed_first, avg_bytes_speed_value);
	}

	void updateQueryInfo()
	{
		++queries;
		sampler.insert(watch_per_query.elapsedSeconds());
		update_min_time(watch_per_query.elapsed() / (1000 * 1000)); /// ns to ms
	}

	void setTotalTime()
	{
		total_time = watch.elapsedSeconds();
	}

	void clear()
	{
		watch.restart();
		watch_per_query.restart();
		min_time_watch.restart();
		max_rows_speed_watch.restart();
		max_bytes_speed_watch.restart();
		avg_rows_speed_watch.restart();
		avg_bytes_speed_watch.restart();

		sampler.clear();

		queries    = 0;
		rows_read  = 0;
		bytes_read = 0;

		min_time   = std::numeric_limits<UInt64>::max();
		total_time = 0;
		max_rows_speed  = 0;
		max_bytes_speed = 0;
		avg_rows_speed_value  = 0;
		avg_bytes_speed_value = 0;
		avg_rows_speed_first  = 0;
		avg_bytes_speed_first = 0;
		avg_rows_speed_precision  = 0.001;
		avg_bytes_speed_precision = 0.001;
		number_of_rows_speed_info_batches  = 0;
		number_of_bytes_speed_info_batches = 0;
	}
};

double Stats::avg_rows_speed_precision = 0.001;
double Stats::avg_bytes_speed_precision = 0.001;

class PerformanceTest
{
public:
	PerformanceTest(
		const unsigned   concurrency_,
		const String   & host_,
		const UInt16     port_,
		const String   & default_database_,
		const String   & user_,
		const String   & password_,
		const std::vector<std::string> & input_files,
        const std::vector<std::string> & tags,
        const std::vector<std::string> & without_tags,
        const std::vector<std::string> & names,
        const std::vector<std::string> & without_names,
        const std::vector<std::string> & names_regexp,
        const std::vector<std::string> & without_names_regexp
	):
	   concurrency(concurrency_), queue(concurrency_),
	   connections(concurrency, host_, port_, default_database_, user_, password_),
	   pool(concurrency),
	   testsConfigurations(input_files.size())
	{
		if (input_files.size() < 1) {
			throw Poco::Exception("No tests were specified", 0);
		}

		std::cerr << std::fixed << std::setprecision(3);
		std::cout << std::fixed << std::setprecision(3);
		readTestsConfiguration(input_files);
	}

private:
	unsigned concurrency;
	std::string testName;

	using Query   = std::string;
	using Queries = std::vector<Query>;
	using QueriesWithIndexes = std::vector<std::pair<Query, size_t>>;
	Queries queries;

	using Queue = ConcurrentBoundedQueue<std::pair<Query, size_t>>;
	Queue queue;

	using Keys = std::vector<std::string>;

	ConnectionPool connections;
	ThreadPool     pool;
	Settings       settings;

	InterruptListener interrupt_listener;
	bool gotSIGINT = false;
	std::vector<std::shared_ptr<RemoteBlockInputStream>> streams;

	double average_speed_precision = 0.001;

	using XMLConfiguration  = Poco::Util::XMLConfiguration;
	using AbstractConfig    = Poco::AutoPtr<Poco::Util::AbstractConfiguration>;
	using Config            = Poco::AutoPtr<XMLConfiguration>;
	using Paths             = std::vector<std::string>;
	using StringToVector    = std::map< std::string, std::vector<std::string> >;
	StringToVector substitutions;
	std::vector<Config> testsConfigurations;

	using StringKeyValue = std::map<std::string, std::string>;
	std::vector<StringKeyValue> substitutionsMaps;

	std::vector<StopCriterions> stopCriterions;

	// TODO: create enum class instead of string
	#define incFulfilledCriterions(index, CRITERION) \
		if (! stopCriterions[index].CRITERION.fulfilled) {\
			stopCriterions[index].CRITERION.priority == min \
					? ++stopCriterions[index].fulfilled_criterions_min \
					: ++stopCriterions[index].fulfilled_criterions_max; \
			stopCriterions[index].CRITERION.fulfilled = true; \
		}

	enum ExecutionType { loop, once };
	ExecutionType execType;

	size_t timesToRun = 1;
	std::vector<Stats> statistics;
	std::mutex mutex;

	void readTestsConfiguration(const Paths & input_files)
	{
		testsConfigurations.resize(input_files.size());

		for (size_t i = 0; i != input_files.size(); ++i) {
			const std::string path = input_files[i];
			testsConfigurations[i] = Config(new XMLConfiguration(path));
		}

		// TODO: here will be tests filter on tags, names, regexp matching, etc.
		// { ... }

		// for now let's launch one test only
		if (testsConfigurations.size()) {
			for (auto & testConfig : testsConfigurations) {
				runTest(testConfig);
			}
		}
	}

	void runTest(Config & testConfig)
	{
		testName = testConfig->getString("name");
		std::cout << "Running: " << testName << "\n";

		/// Preprocess configuration file
		if (testConfig->has("settings")) {
			Keys configSettings;
			testConfig->keys("settings", configSettings);

			/// This macro goes through all settings in the Settings.h
			/// and, if found any settings in test's xml configuration
			/// with the same name, sets its value to settings
			std::vector<std::string>::iterator it;
			#define EXTRACT_SETTING(TYPE, NAME, DEFAULT) \
				it = std::find(configSettings.begin(), configSettings.end(), #NAME); \
				if (it != configSettings.end()) \
					settings.set( \
						#NAME, testConfig->getString("settings."#NAME) \
					);
				APPLY_FOR_SETTINGS(EXTRACT_SETTING)
				APPLY_FOR_LIMITS(EXTRACT_SETTING)
			#undef EXTRACT_SETTING

			if (std::find(configSettings.begin(), configSettings.end(), "profile") !=
				configSettings.end()) {
				// TODO: proceed profile settings in a proper way
			}

			if (std::find(configSettings.begin(), configSettings.end(),
						  "average_rows_speed_precision") != configSettings.end()) {
				Stats::avg_rows_speed_precision = testConfig->getDouble("settings.average_rows_speed_precision");
			}

			if (std::find(configSettings.begin(), configSettings.end(),
						  "average_bytes_speed_precision") != configSettings.end()) {
				Stats::avg_bytes_speed_precision = testConfig->getDouble("settings.average_bytes_speed_precision");
			}
		}

		Query query;

		if (! testConfig->has("query")) {
			throw Poco::Exception("Missing query field in test's config: " +
								  testName, 1);
		}

		query = testConfig->getString("query");

		if (query.empty()) {
			throw Poco::Exception("The query is empty in test's config: " +
								  testName, 1);
		}

		if (testConfig->has("substitutions")) {
			/// Make "subconfig" of inner xml block
			AbstractConfig substitutionsView(testConfig
											 ->createView("substitutions"));
			constructSubstitutions(substitutionsView, substitutions);

			queries = formatQueries(query, substitutions);
		} else {
			// TODO: probably it will be a good practice to check if
			// query string has {substitution pattern}, but no substitution field
			// was found in xml configuration

			queries.push_back(query);
		}

		if (! testConfig->has("type")) {
			throw Poco::Exception("Missing type property in config: " +
								  testName, 1);
		}

		std::string configExecType = testConfig->getString("type");
		if (configExecType == "loop")
			execType = loop;
		else if (configExecType == "once")
			execType = once;
		else
			throw Poco::Exception("Unknown type " + configExecType + " in :" +
								  testName, 1);

		if (testConfig->has("timesToRun")) {
			timesToRun = testConfig->getUInt("timesToRun");
		}

		stopCriterions.resize(timesToRun * queries.size());

		if (testConfig->has("stop")) {
			AbstractConfig stopCriterionsView(testConfig
										      ->createView("stop"));
			for (StopCriterions & stopCriterion : stopCriterions) {
				stopCriterion.loadFromConfig(stopCriterionsView);
			}
		} else {
			throw Poco::Exception("No termination conditions were found in config", 1);
		}

		AbstractConfig metricsView(testConfig->createView("metric"));
		Keys metrics;
		metricsView->keys(metrics);
		if (metrics.size() > 1) {
			throw Poco::Exception("More than 1 main metric is not allowed", 1);
		}

		if (metrics.size() == 1) {
			checkMetricInput(metrics[0]);
		}

		statistics.resize(timesToRun * queries.size());
		for (size_t numberOfLaunch = 0; numberOfLaunch < timesToRun; ++numberOfLaunch) {
			QueriesWithIndexes queriesWithIndexes;

			for (size_t queryIndex = 0; queryIndex < queries.size(); ++queryIndex) {
				size_t statisticIndex = numberOfLaunch * queries.size() + queryIndex;
				stopCriterions[statisticIndex].reset();

				queriesWithIndexes.push_back({queries[queryIndex], statisticIndex});
			}

			runQueries(queriesWithIndexes);
		}

		if (metrics.size() == 1) {
			minOutput(metrics[0]);
		}
		else {
			constructTotalInfo();
		}
	}

	void checkMetricInput(const std::string & main_metric) const {
	    std::vector<std::string> loopMetrics = {
	    	"min_time", "quantiles", "total_time", "queries_per_second",
	    	"rows_per_second", "bytes_per_second"
	    };

	    std::vector<std::string> infiniteMetrics = {
	    	"max_rows_per_second", "max_bytes_per_second", "avg_rows_per_second",
	    	"avg_bytes_per_second"
	    };

	    if (execType == loop) {
	    	if (std::find(infiniteMetrics.begin(), infiniteMetrics.end(), main_metric) != infiniteMetrics.end()) {
	    		throw Poco::Exception("Wrong type of main metric for loop "
						    		  "execution type", 1);
	    	}
	    } else {
	    	if (std::find(loopMetrics.begin(), loopMetrics.end(), main_metric) != loopMetrics.end()) {
	    		throw Poco::Exception("Wrong type of main metric for "
	    							  "inifinite execution type", 1);
	    	}
	    }
	}

	void runQueries(const QueriesWithIndexes & queriesWithIndexes)
	{
		for (size_t i = 0; i < concurrency; ++i) {
			pool.schedule(std::bind(
				&PerformanceTest::thread,
				this,
				connections.IConnectionPool::get()
			));
		}

		for (const std::pair<Query, const size_t> & queryAndIndex : queriesWithIndexes) {
			Query query = queryAndIndex.first;
			const size_t statisticIndex = queryAndIndex.second;

			queue.push({query, statisticIndex});
		}

		for (size_t i = 0; i < concurrency; ++i) {
			/// Genlty asking threads to stop
			queue.push({"", std::numeric_limits<size_t>::max()});
		}

		pool.wait();
	}

	void thread(ConnectionPool::Entry & connection)
	{
		Query query;
		size_t statisticIndex;

		std::pair<Query, size_t> queryAndIndex;

		while (true) {
			queue.pop(queryAndIndex);
			query = queryAndIndex.first;
			statisticIndex = queryAndIndex.second;

			/// Empty query means end of execution
			if (query.empty())
				break;

			size_t max_iterations = stopCriterions[statisticIndex].iterations.value;
			size_t iteration = 0;

			statistics[statisticIndex].clear();
			execute(connection, query, statisticIndex);

			if (execType == loop) {
				while (! gotSIGINT) {
					++iteration;

					/// check stop criterions
					if (max_iterations && iteration >= max_iterations) {
						incFulfilledCriterions(statisticIndex, iterations);
					}

					if (stopCriterions[statisticIndex].number_of_initialized_min &&
						(stopCriterions[statisticIndex].fulfilled_criterions_min >=
						 stopCriterions[statisticIndex].number_of_initialized_min)) {
						/// All 'min' criterions are fulfilled
						break;
					}

					if (stopCriterions[statisticIndex].number_of_initialized_max &&
						stopCriterions[statisticIndex].fulfilled_criterions_max) {
						/// Some 'max' criterions are fulfilled
						break;
					}

					execute(connection, query, statisticIndex);
				}
			}
		}
	}

	void execute(ConnectionPool::Entry & connection, const Query & query,
				 const size_t statisticIndex)
	{
		InterruptListener thread_interrupt_listener;
		statistics[statisticIndex].watch_per_query.restart();

		std::shared_ptr<RemoteBlockInputStream> stream = std::make_shared<RemoteBlockInputStream>(
			connection, query, &settings, nullptr, Tables()/*, query_processing_stage*/
		);

		size_t stream_index;
		{
			std::lock_guard<std::mutex> lock(mutex);
			streams.push_back(stream);
			stream_index = streams.size() - 1;
			// TODO: remove them later?
		}

		Progress progress;
		stream->setProgressCallback(
			[&progress, &stream, &thread_interrupt_listener, statisticIndex, this]
			(const Progress & value) {
				progress.incrementPiecewiseAtomically(value);

				this->checkFulfilledCriterionsAndUpdate(
					progress, stream, thread_interrupt_listener, statisticIndex
				);
		});

		stream->readPrefix();
		while (Block block = stream->read())
			;
		stream->readSuffix();

		std::lock_guard<std::mutex> lock(mutex);
		streams[stream_index].reset();

		statistics[statisticIndex].updateQueryInfo();
		statistics[statisticIndex].setTotalTime();
	}

	void checkFulfilledCriterionsAndUpdate(const Progress & progress,
										   const std::shared_ptr<RemoteBlockInputStream> & stream,
										   InterruptListener & thread_interrupt_listener,
										   const size_t statisticIndex)
	{
		std::lock_guard<std::mutex> lock(mutex);

		statistics[statisticIndex].add(progress.rows, progress.bytes);

		size_t max_rows_to_read = stopCriterions[statisticIndex].rows_read.value;
		if (max_rows_to_read && statistics[statisticIndex].rows_read >= max_rows_to_read) {
			incFulfilledCriterions(statisticIndex, rows_read);
		}

		size_t max_bytes_to_read = stopCriterions[statisticIndex].bytes_read_uncompressed.value;
		if (max_bytes_to_read && statistics[statisticIndex].bytes_read >= max_bytes_to_read) {
			incFulfilledCriterions(statisticIndex, bytes_read_uncompressed);
		}

		if (UInt64 max_timeout_ms = stopCriterions[statisticIndex].timeout_ms.value) {
			/// cast nanoseconds to ms
			if ((statistics[statisticIndex].watch.elapsed() / (1000 * 1000)) > max_timeout_ms) {
				incFulfilledCriterions(statisticIndex, timeout_ms);
			}
		}

		size_t min_time_not_changing_for_ms = stopCriterions[statisticIndex]
												.min_time_not_changing_for_ms.value;
		if (min_time_not_changing_for_ms) {
			size_t min_time_did_not_change_for = statistics[statisticIndex]
													.min_time_watch
													.elapsed() / (1000 * 1000);

			if (min_time_did_not_change_for >= min_time_not_changing_for_ms) {
				incFulfilledCriterions(statisticIndex, min_time_not_changing_for_ms);
			}
		}

		size_t max_speed_not_changing_for_ms = stopCriterions[statisticIndex]
												.max_speed_not_changing_for_ms
												.value;
		if (max_speed_not_changing_for_ms) {
			UInt64 speed_not_changing_time = statistics[statisticIndex]
												.max_rows_speed_watch
												.elapsed() / (1000 * 1000);
			if (speed_not_changing_time >= max_speed_not_changing_for_ms) {
				incFulfilledCriterions(statisticIndex, max_speed_not_changing_for_ms);
			}
		}

		size_t average_speed_not_changing_for_ms = stopCriterions[statisticIndex]
													.average_speed_not_changing_for_ms
													.value;
		if (average_speed_not_changing_for_ms) {
			UInt64 speed_not_changing_time = statistics[statisticIndex]
												.avg_rows_speed_watch
												.elapsed() / (1000 * 1000);
			if (speed_not_changing_time >= average_speed_not_changing_for_ms) {
				incFulfilledCriterions(statisticIndex, average_speed_not_changing_for_ms);
			}
		}

		if (stopCriterions[statisticIndex].number_of_initialized_min &&
			(stopCriterions[statisticIndex].fulfilled_criterions_min >=
			stopCriterions[statisticIndex].number_of_initialized_min)) {
			/// All 'min' criterions are fulfilled
			stream->cancel();
		}

		if (stopCriterions[statisticIndex].number_of_initialized_max &&
			stopCriterions[statisticIndex].fulfilled_criterions_max) {
			/// Some 'max' criterions are fulfilled
			stream->cancel();
		}

		if (thread_interrupt_listener.check()) { /// SIGINT
			gotSIGINT = true;

			for (const std::shared_ptr<RemoteBlockInputStream> & stream : streams) {
				if (stream) {
					stream->cancel();
				}
			}

			std::cout << "got SIGNINT; stopping streams" << std::endl;
		}
	}

	void constructSubstitutions(AbstractConfig & substitutionsView,
						        StringToVector & substitutions)
	{
		Keys xml_substitutions;
		substitutionsView->keys(xml_substitutions);

		for (size_t i = 0; i != xml_substitutions.size(); ++i) {
			const AbstractConfig xml_substitution(
				substitutionsView->createView("substitution[" +
			   								  std::to_string(i) + "]")
			);

			/// Property values for substitution will be stored in a vector
			/// accessible by property name
			std::vector<std::string> xml_values;
			xml_substitution->keys("values", xml_values);

			std::string name = xml_substitution->getString("name");

			for (size_t j = 0; j != xml_values.size(); ++j) {
				substitutions[name].push_back(
					xml_substitution->getString("values.value[" +
											    std::to_string(j) + "]")
				);
			}
		}
	}

	std::vector<std::string> formatQueries(const std::string & query,
					   					   StringToVector substitutions)
	{
		std::vector<std::string> queries;

		StringToVector::iterator substitutions_first = substitutions.begin();
		StringToVector::iterator substitutions_last  = substitutions.end();
		--substitutions_last;

		std::map<std::string, std::string> substitutionsMap;

		runThroughAllOptionsAndPush(
			substitutions_first, substitutions_last, query, queries, substitutionsMap
		);

		return queries;
	}

	/// Recursive method which goes through all substitution blocks in xml
	/// and replaces property {names} by their values
	void runThroughAllOptionsAndPush(
		StringToVector::iterator substitutions_left,
		StringToVector::iterator substitutions_right,
		const std::string & template_query,
		std::vector<std::string> & queries,
		const StringKeyValue & templateSubstitutionsMap = StringKeyValue()
	)
	{
		std::string name = substitutions_left->first;
		std::vector<std::string> values = substitutions_left->second;

		for (const std::string & value : values) {
			/// Copy query string for each unique permutation
			Query query = template_query;
			StringKeyValue substitutionsMap = templateSubstitutionsMap;
			size_t substrPos  = 0;

			while (substrPos != std::string::npos) {
				substrPos = query.find("{" + name + "}");

				if (substrPos != std::string::npos) {
					query.replace(
						substrPos, 1 + name.length() + 1,
						value
					);
				}
			}

			substitutionsMap[name] = value;

			/// If we've reached the end of substitution chain
			if (substitutions_left == substitutions_right) {
				queries.push_back(query);
				substitutionsMaps.push_back(substitutionsMap);
			} else {
				StringToVector::iterator next_it = substitutions_left;
				++next_it;

				runThroughAllOptionsAndPush(
					next_it, substitutions_right, query, queries, substitutionsMap
				);
			}
		}
	}

public:
	void constructTotalInfo()
	{
		JSONString jsonOutput;
		std::string hostname;

		char hostname_buffer[256];
		if (gethostname(hostname_buffer, 256) == 0) {
			hostname = std::string(hostname_buffer);
		}

		jsonOutput["hostname"].set(hostname);
		jsonOutput["Number of CPUs"].set(sysconf(_SC_NPROCESSORS_ONLN));
		jsonOutput["test_name"].set(testName);

		if (substitutions.size()) {
			JSONString jsonParameters(2); /// here, 2 is the size of \t padding

			for (auto it = substitutions.begin(); it != substitutions.end(); ++it) {
				std::string parameter = it->first;
				std::vector<std::string> values = it->second;

				std::string arrayString = "[";
				for (size_t i = 0; i != values.size(); ++i) {
					arrayString += '\"' + values[i] + '\"';
					if (i != values.size() - 1) {
						arrayString += ", ";
					}
				}
				arrayString += ']';

				jsonParameters[parameter].set(arrayString);
			}

			jsonOutput["parameters"].set(jsonParameters);
		}

		std::vector<JSONString> runInfos(statistics.size());
		for (size_t numberOfLaunch = 0; numberOfLaunch < statistics.size(); ++numberOfLaunch) {
			JSONString runJSON;

			size_t queryIndex = numberOfLaunch % queries.size();
			if (substitutionsMaps.size()) {
				JSONString parameters(4);

				for (auto it = substitutionsMaps[queryIndex].begin();
						  it != substitutionsMaps[queryIndex].end(); ++it) {
					parameters[it->first].set(it->second);
				}

				runJSON["parameters"].set(parameters);
			}

	        if (execType == loop) {
		    	runJSON["min_time"].set(std::to_string(statistics[numberOfLaunch].min_time / 1000)
		    			  				   + "." + std::to_string(statistics[numberOfLaunch].min_time % 1000) + "s");

	    		JSONString quantiles(4); /// here, 4 is the size of \t padding
		    	for (double percent = 10; percent <= 90; percent += 10) {
		    		quantiles[percent / 100].set(statistics[numberOfLaunch].sampler.quantileInterpolated(percent / 100.0));
		    	}
				quantiles[0.95].set(statistics[numberOfLaunch].sampler.quantileInterpolated(95 / 100.0));
				quantiles[0.99].set(statistics[numberOfLaunch].sampler.quantileInterpolated(99 / 100.0));
				quantiles[0.999].set(statistics[numberOfLaunch].sampler.quantileInterpolated(99.9 / 100.0));
				quantiles[0.9999].set(statistics[numberOfLaunch].sampler.quantileInterpolated(99.99 / 100.0));

				runJSON["quantiles"].set(quantiles);

			    runJSON["total_time"].set(std::to_string(statistics[numberOfLaunch].total_time) + "s");
			    runJSON["queries_per_second"].set(double(statistics[numberOfLaunch].queries)  / statistics[numberOfLaunch].total_time);
			    runJSON["rows_per_second"].set(double(statistics[numberOfLaunch].rows_read)   / statistics[numberOfLaunch].total_time);
			    runJSON["bytes_per_second"].set(double(statistics[numberOfLaunch].bytes_read) / statistics[numberOfLaunch].total_time);
	        } else {
			    runJSON["max_rows_per_second"].set(statistics[numberOfLaunch].max_rows_speed);
			    runJSON["max_bytes_per_second"].set(statistics[numberOfLaunch].max_bytes_speed);
			    runJSON["avg_rows_per_second"].set(statistics[numberOfLaunch].avg_rows_speed_value);
			    runJSON["avg_bytes_per_second"].set(statistics[numberOfLaunch].avg_bytes_speed_value);
	        }

	        runInfos[numberOfLaunch] = runJSON;
		}

		jsonOutput["runs"].set(runInfos);

		std::cout << jsonOutput << std::endl;
	}

	void minOutput(const std::string & main_metric)
	{
		for (size_t numberOfLaunch = 0; numberOfLaunch < timesToRun; ++numberOfLaunch) {
			for (size_t queryIndex = 0; queryIndex < queries.size(); ++queryIndex) {
				std::cout << testName << ", ";

				if (substitutionsMaps.size()) {
					for (auto it = substitutionsMaps[queryIndex].begin();
							  it != substitutionsMaps[queryIndex].end(); ++it) {
						std::cout << it->first << " = " << it->second << ", ";
					}
				}

				std::cout << "run " << numberOfLaunch + 1 << ": ";
				std::cout << main_metric << " = ";
				std::cout << statistics[numberOfLaunch * queries.size() + queryIndex]
							     .getStatisticByName(main_metric);
				std::cout << std::endl;
			}
		}
	}
};

}


int mainEntryClickhousePerformanceTest(int argc, char ** argv) {
	using namespace DB;

	try
	{
		using boost::program_options::value;
		using Strings = std::vector<std::string>;

		boost::program_options::options_description desc("Allowed options");
		desc.add_options()
			("help", 																	"produce help message")
			("concurrency,c",		value<unsigned>()->default_value(1),				"number of parallel queries")
			("host,h",				value<std::string>()->default_value("localhost"),	"")
			("port", 				value<UInt16>()->default_value(9000),				"")
			("user", 				value<std::string>()->default_value("default"),		"")
			("password",			value<std::string>()->default_value(""),			"")
			("database",			value<std::string>()->default_value("default"),		"")
			("tag",					value<Strings>(),									"Run only tests with tag")
			("without-tag",			value<Strings>(),									"Do not run tests with tag")
			("name",				value<Strings>(),									"Run tests with specific name")
			("without-name",		value<Strings>(),									"Do not run tests with name")
			("name-regexp",			value<Strings>(),									"Run tests with names matching regexp")
			("without-name-regexp",	value<Strings>(),									"Do not run tests with names matching regexp")
			;

		/// These options will not be displayed in --help
		boost::program_options::options_description hidden("Hidden options");
		hidden.add_options()
			("input-files", value< std::vector<std::string> >(), "")
			;

		/// But they will be legit, though. And they must be given without name
		boost::program_options::positional_options_description positional;
		positional.add("input-files", -1);

		boost::program_options::options_description cmdline_options;
		cmdline_options.add(desc).add(hidden);

		boost::program_options::variables_map options;
		boost::program_options::store(
			boost::program_options::command_line_parser(argc, argv)
									.options(cmdline_options)
									.positional(positional)
									.run(),
			options
		);
		boost::program_options::notify(options);

		if (options.count("help"))
		{
			std::cout << "Usage: " << argv[0] << " [options] [test_file ...] [tests_folder]\n";
			std::cout << desc << "\n";
			return 1;
		}

		if (! options.count("input-files")) {
			std::cerr << "No tests files were specified. See --help" << "\n";
			return 1;
		}

		Strings tests_tags;
		Strings skip_tags;
		Strings tests_names;
		Strings skip_names;
		Strings name_regexp;
		Strings skip_matching_regexp;

		if (options.count("tag")) {
			tests_tags = options["tag"].as<Strings>();
		}

		if (options.count("without-tag")) {
			skip_tags = options["without-tag"].as<Strings>();
		}

		if (options.count("name")) {
			tests_names = options["name"].as<Strings>();
		}

		if (options.count("without-name")) {
			skip_names = options["without-name"].as<Strings>();
		}

		if (options.count("name-regexp")) {
			name_regexp = options["name-regexp"].as<Strings>();
		}

		if (options.count("without-name-regexp")) {
			skip_matching_regexp = options["without-name-regexp"].as<Strings>();
		}

		PerformanceTest performanceTest(
			options["concurrency"].as<unsigned>(),
			options["host"       ].as<std::string>(),
			options["port"       ].as<UInt16>(),
			options["database"   ].as<std::string>(),
			options["user"       ].as<std::string>(),
			options["password"   ].as<std::string>(),
			options["input-files"].as<Strings>(),
			tests_tags,
			skip_tags,
			tests_names,
			skip_names,
			name_regexp,
			skip_matching_regexp
		);
	}
	catch (const Exception & e)
	{
		std::string text = e.displayText();

		std::cerr << "Code: " << e.code() << ". " << text << "\n\n";

		/// Если есть стек-трейс на сервере, то не будем писать стек-трейс на клиенте.
		if (std::string::npos == text.find("Stack trace"))
			std::cerr << "Stack trace:\n"
				<< e.getStackTrace().toString();

		return e.code();
	}
	catch (const Poco::Exception & e)
	{
		std::cerr << "Poco::Exception: " << e.displayText() << "\n";
		return ErrorCodes::POCO_EXCEPTION;
	}
	catch (const std::exception & e)
	{
		std::cerr << "std::exception: " << e.what() << "\n";
		return ErrorCodes::STD_EXCEPTION;
	}
	catch (...)
	{
		std::cerr << "Unknown exception\n";
		return ErrorCodes::UNKNOWN_EXCEPTION;
	}

	return 0;
}