/*
Minetest
Copyright (C) 2015 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "profiler.h"
#include "porting.h"

static Profiler main_profiler;
Profiler *g_profiler = &main_profiler;
ScopeProfiler::ScopeProfiler(
		Profiler *profiler, const std::string &name, ScopeProfilerType type) :
		m_profiler(profiler),
		m_name(name), m_type(type)
{
	m_name.append(" [ms]");
	if (m_profiler)
		m_timer = new TimeTaker(m_name, nullptr, PRECISION_MILLI);
}

ScopeProfiler::~ScopeProfiler()
{
	if (!m_timer)
		return;

	float duration_ms = m_timer->stop(true);
	float duration = duration_ms;
	if (m_profiler) {
		switch (m_type) {
		case SPT_ADD:
			m_profiler->add(m_name, duration);
			break;
		case SPT_AVG:
			m_profiler->avg(m_name, duration);
			break;
		case SPT_GRAPH_ADD:
			m_profiler->graphAdd(m_name, duration);
			break;
		case SPT_MAX:
			m_profiler->max(m_name, duration);
			break;
		}
	}
	delete m_timer;
}

Profiler::Profiler()
{
	m_start_time = porting::getTimeMs();
}

void Profiler::add(const std::string &name, float value)
{
	MutexAutoLock lock(m_mutex);
	{
		/* No average shall have been used; mark add/max used as -2 */
		std::map<std::string, int>::iterator n = m_avgcounts.find(name);
		if (n == m_avgcounts.end()) {
			m_avgcounts[name] = -2;
		} else {
			if (n->second == -1)
				n->second = -2;
			assert(n->second == -2);
		}
	}
	{
		std::map<std::string, float>::iterator n = m_data.find(name);
		if (n == m_data.end())
			m_data[name] = value;
		else
			n->second += value;
	}
}

void Profiler::max(const std::string &name, float value)
{
	MutexAutoLock lock(m_mutex);
	{
		/* No average shall have been used; mark add/max used as -2 */
		auto n = m_avgcounts.find(name);
		if (n == m_avgcounts.end()) {
			m_avgcounts[name] = -2;
		} else {
			if (n->second == -1)
				n->second = -2;
			assert(n->second == -2);
		}
	}
	{
		auto n = m_data.find(name);
		if (n == m_data.end())
			m_data[name] = value;
		else if (value > n->second)
			n->second = value;
	}
}

void Profiler::avg(const std::string &name, float value)
{
	MutexAutoLock lock(m_mutex);
	int &count = m_avgcounts[name];

	assert(count != -2);
	count = MYMAX(count, 0) + 1;
	m_data[name] += value;
}

void Profiler::clear()
{
	MutexAutoLock lock(m_mutex);
	for (auto &it : m_data) {
		it.second = 0;
	}
	m_avgcounts.clear();
	m_start_time = porting::getTimeMs();
}

float Profiler::getValue(const std::string &name) const
{
	auto numerator = m_data.find(name);
	if (numerator == m_data.end())
		return 0.f;

	auto denominator = m_avgcounts.find(name);
	if (denominator != m_avgcounts.end()) {
		if (denominator->second >= 1)
			return numerator->second / denominator->second;
	}

	return numerator->second;
}

int Profiler::getAvgCount(const std::string &name) const
{
	auto n = m_avgcounts.find(name);

	if (n != m_avgcounts.end() && n->second >= 1)
		return n->second;

	return 1;
}

u64 Profiler::getElapsedMs() const
{
	return porting::getTimeMs() - m_start_time;
}

int Profiler::print(std::ostream &o, u32 page, u32 pagecount)
{
	GraphValues values;
	getPage(values, page, pagecount);
	char buffer[50];

	for (const auto &i : values) {
		o << "  " << i.first << " ";
		if (i.second == 0) {
			o << std::endl;
			continue;
		}

		{
			// Padding
			s32 space = std::max(0, 44 - (s32)i.first.size());
			memset(buffer, '_', space);
			buffer[space] = '\0';
			o << buffer;
		}

		porting::mt_snprintf(buffer, sizeof(buffer), "% 5ix % 7g",
				getAvgCount(i.first), floor(i.second * 1000.0) / 1000.0);
		o << buffer << std::endl;
	}
	return values.size();
}

void Profiler::getPage(GraphValues &o, u32 page, u32 pagecount)
{
	MutexAutoLock lock(m_mutex);

	u32 minindex, maxindex;
	paging(m_data.size(), page, pagecount, minindex, maxindex);

	for (const auto &i : m_data) {
		if (maxindex == 0)
			break;
		maxindex--;

		if (minindex != 0) {
			minindex--;
			continue;
		}

		o[i.first] = i.second / getAvgCount(i.first);
	}
}
