/*
  Copyright (C) 2002 Kimmo Pekkola

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include <windows.h>
#include <Powrprof.h>
#include <time.h>
#include <errno.h>
#include <crtdbg.h>
#include "../../Library/RawString.h"
#include "../../Library/Export.h"	// Rainmeter's exported functions
#include "../../Library/DisableThreadLibraryCalls.h"	// contains DllMain entry point

typedef struct _PROCESSOR_POWER_INFORMATION
{
	ULONG Number;
	ULONG MaxMhz;
	ULONG CurrentMhz;
	ULONG MhzLimit;
	ULONG MaxIdleState;
	ULONG CurrentIdleState;
} PROCESSOR_POWER_INFORMATION, *PPROCESSOR_POWER_INFORMATION;

enum MeasureType
{
	POWER_UNKNOWN,
	POWER_ACLINE,
	POWER_STATUS,
	POWER_STATUS2,
	POWER_LIFETIME,
	POWER_PERCENT,
	POWER_MHZ,
	POWER_HZ
};

struct MeasureData
{
	MeasureType type;
	CRawString format;
	
	MeasureData() : type(POWER_UNKNOWN) {}
};

UINT g_NumOfProcessors = 0;

void NullCRTInvalidParameterHandler(const wchar_t* expression, const wchar_t* function,  const wchar_t* file, unsigned int line, uintptr_t pReserved)
{
	// Do nothing.
}

PLUGIN_EXPORT void Initialize(void** data)
{
	MeasureData* measure = new MeasureData;
	*data = measure;

	if (!g_NumOfProcessors)
	{
		SYSTEM_INFO si;
		GetSystemInfo(&si);
		g_NumOfProcessors = (UINT)si.dwNumberOfProcessors;
	}
}

PLUGIN_EXPORT void Reload(void* data, void* rm, double* maxValue)
{
	MeasureData* measure = (MeasureData*)data;

	LPCWSTR value = RmReadString(rm, L"PowerState", L"");
	if (_wcsicmp(L"ACLINE", value) == 0)
	{
		measure->type = POWER_ACLINE;
		*maxValue = 1.0;
	}
	else if (_wcsicmp(L"STATUS", value) == 0)
	{
		measure->type = POWER_STATUS;
		*maxValue = 4.0;
	}
	else if (_wcsicmp(L"STATUS2", value) == 0)
	{
		measure->type = POWER_STATUS2;
		*maxValue = 255.0;
	}
	else if (_wcsicmp(L"LIFETIME", value) == 0)
	{
		measure->type= POWER_LIFETIME;

		value = RmReadString(rm, L"Format", L"%H:%M");
		measure->format = value;

		SYSTEM_POWER_STATUS sps;
		if (GetSystemPowerStatus(&sps))
		{
			*maxValue = sps.BatteryFullLifeTime;
		}
	}
	else if (_wcsicmp(L"MHZ", value) == 0)
	{
		measure->type = POWER_MHZ;
	}
	else if (_wcsicmp(L"HZ", value) == 0)
	{
		measure->type = POWER_HZ;
	}
	else if (_wcsicmp(L"PERCENT", value) == 0)
	{
		measure->type = POWER_PERCENT;
		*maxValue = 100.0;
	}
}

PLUGIN_EXPORT double Update(void* data)
{
	MeasureData* measure = (MeasureData*)data;

	SYSTEM_POWER_STATUS sps;
	if (GetSystemPowerStatus(&sps))
	{
		switch (measure->type)
		{
		case POWER_ACLINE:
			return sps.ACLineStatus == 1 ? 1.0 : 0.0;

		case POWER_STATUS:
			if (sps.BatteryFlag & 128)
			{
				return 0.0;	// No battery
			}
			else if (sps.BatteryFlag & 8)
			{
				return 1.0;	// Charging
			}
			else if (sps.BatteryFlag & 4)
			{
				return 2.0;	// Critical
			}
			else if (sps.BatteryFlag & 2)
			{
				return 3.0;	// Low
			}
			else if (sps.BatteryFlag & 1)
			{
				return 4.0;	// High
			}
			break;

		case POWER_STATUS2:
			return sps.BatteryFlag;

		case POWER_LIFETIME:
			return sps.BatteryLifeTime;

		case POWER_PERCENT:
			return sps.BatteryLifePercent == 255 ? 100.0 : sps.BatteryLifePercent;

		case POWER_MHZ:
		case POWER_HZ:
			if (g_NumOfProcessors > 0)
			{
				PROCESSOR_POWER_INFORMATION* ppi = new PROCESSOR_POWER_INFORMATION[g_NumOfProcessors];
				memset(ppi, 0, sizeof(PROCESSOR_POWER_INFORMATION) * g_NumOfProcessors);
				CallNtPowerInformation(ProcessorInformation, NULL, 0, ppi, sizeof(PROCESSOR_POWER_INFORMATION) * g_NumOfProcessors);
				double value = (measure->type == POWER_MHZ) ? ppi[0].CurrentMhz : ppi[0].CurrentMhz * 1000000.0;
				delete [] ppi;
				return value;
			}
		}
	}

	return 0.0;
}

PLUGIN_EXPORT LPCWSTR GetString(void* data)
{
	static WCHAR buffer[128];
	MeasureData* measure = (MeasureData*)data;

	if (measure->type == POWER_LIFETIME)
	{
		SYSTEM_POWER_STATUS sps;
		if (GetSystemPowerStatus(&sps))
		{
			// Change it to time string
			if (sps.BatteryLifeTime == -1)
			{
				return L"Unknown";
			}
			else
			{
				tm time = {0};
				time.tm_sec = sps.BatteryLifeTime % 60;
				time.tm_min = (sps.BatteryLifeTime / 60) % 60;
				time.tm_hour = sps.BatteryLifeTime / 60 / 60;

				_invalid_parameter_handler oldHandler = _set_invalid_parameter_handler(NullCRTInvalidParameterHandler);
				_CrtSetReportMode(_CRT_ASSERT, 0);

				errno = 0;
				wcsftime(buffer, 128, measure->format.c_str(), &time);
				if (errno == EINVAL)
				{
					buffer[0] = L'\0';
				}

				_set_invalid_parameter_handler(oldHandler);

				return buffer;
			}
		}
	}

	return NULL;
}

PLUGIN_EXPORT void Finalize(void* data)
{
	MeasureData* measure = (MeasureData*)data;
	delete measure;
}