/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008. All Rights Reserved.							  */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in $(WIND_BASE)/WPILib.  */
/*----------------------------------------------------------------------------*/

#include "Utility.h"

//#include "NetworkCommunication/FRCComm.h"
#include "HAL/HAL.hpp"
#include "Task.h"
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <execinfo.h>
#include <cxxabi.h>
#include "nivision.h"

static bool suspendOnAssertEnabled = false;

/**
 * Enable suspend on asssert.
 * If enabled, the user task will be suspended whenever an assert fails. This
 * will allow the user to attach to the task with the debugger and examine variables
 * around the failure.
 */
void wpi_suspendOnAssertEnabled(bool enabled)
{
	suspendOnAssertEnabled = enabled;
}

/**
 * Assert implementation.
 * This allows breakpoints to be set on an assert.
 * The users don't call this, but instead use the wpi_assert macros in Utility.h.
 */
bool wpi_assert_impl(bool conditionValue,
                     const char *conditionText,
                     const char *message,
                     const char *fileName,
                     uint32_t lineNumber,
                     const char *funcName)
{
	if(!conditionValue)
	{
		std::stringstream errorStream;

		errorStream << "Assertion \"" << conditionText << "\" ";
		errorStream << "on line " << lineNumber << " ";
		errorStream << "of "<< basename(fileName) << " ";

		if(message)
		{
			errorStream << "failed: " << message << std::endl;
		}
		else
		{
			errorStream << "failed." << std::endl;
		}

		errorStream << GetStackTrace(2);

		std::string error = errorStream.str();

		// Print the error and send it to the DriverStation
		std::cout << error << std::endl;
		HALSetErrorData(error.c_str(), error.size(), 100);

		if (suspendOnAssertEnabled) suspendTask(0);
	}

	return conditionValue;
}

/**
 * Common error routines for wpi_assertEqual_impl and wpi_assertNotEqual_impl
 * This should not be called directly; it should only be used by wpi_assertEqual_impl
 * and wpi_assertNotEqual_impl.
 */
void wpi_assertEqual_common_impl(const char *valueA,
                                 const char *valueB,
                                 const char *equalityType,
                                 const char *message,
                                 const char *fileName,
                                 uint32_t lineNumber,
                                 const char *funcName)
{
	std::stringstream errorStream;

	errorStream << "Assertion \"" << valueA << " " << equalityType << " " << valueB << "\" ";
	errorStream << "on line " << lineNumber << " ";
	errorStream << "of "<< basename(fileName) << " ";

	if(message)
	{
		errorStream << "failed: " << message << std::endl;
	}
	else
	{
		errorStream << "failed." << std::endl;
	}

	errorStream << GetStackTrace(3);

	std::string error = errorStream.str();

	// Print the error and send it to the DriverStation
	std::cout << error << std::endl;
	HALSetErrorData(error.c_str(), error.size(), 100);

	if (suspendOnAssertEnabled) suspendTask(0);
}

/**
 * Assert equal implementation.
 * This determines whether the two given integers are equal. If not,
 * the value of each is printed along with an optional message string.
 * The users don't call this, but instead use the wpi_assertEqual macros in Utility.h.
 */
bool wpi_assertEqual_impl(int valueA,
                          int valueB,
                          const char *valueAString,
                          const char *valueBString,
                          const char *message,
                          const char *fileName,
                          uint32_t lineNumber,
                          const char *funcName)
{
	if(!(valueA == valueB))
	{
		wpi_assertEqual_common_impl(valueAString, valueBString,
			"==", message, fileName, lineNumber, funcName);
	}
	return valueA == valueB;
}

/**
 * Assert not equal implementation.
 * This determines whether the two given integers are equal. If so,
 * the value of each is printed along with an optional message string.
 * The users don't call this, but instead use the wpi_assertNotEqual macros in Utility.h.
 */
bool wpi_assertNotEqual_impl(int valueA,
                             int valueB,
                             const char *valueAString,
                             const char *valueBString,
                             const char *message,
                             const char *fileName,
                             uint32_t lineNumber,
                             const char *funcName)
{
	if(!(valueA != valueB))
	{
		wpi_assertEqual_common_impl(valueAString, valueBString,
			"!=", message, fileName, lineNumber, funcName);
	}
	return valueA != valueB;
}


/**
 * Return the FPGA Version number.
 * For now, expect this to be competition year.
 * @return FPGA Version number.
 */
uint16_t GetFPGAVersion()
{
	int32_t status = 0;
	uint16_t version = getFPGAVersion(&status);
	wpi_setGlobalErrorWithContext(status, getHALErrorMessage(status));
	return version;
}

/**
 * Return the FPGA Revision number.
 * The format of the revision is 3 numbers.
 * The 12 most significant bits are the Major Revision.
 * the next 8 bits are the Minor Revision.
 * The 12 least significant bits are the Build Number.
 * @return FPGA Revision number.
 */
uint32_t GetFPGARevision()
{
	int32_t status = 0;
	uint32_t revision = getFPGARevision(&status);
	wpi_setGlobalErrorWithContext(status, getHALErrorMessage(status));
	return revision;
}

/**
 * Read the microsecond-resolution timer on the FPGA.
 *
 * @return The current time in microseconds according to the FPGA (since FPGA reset).
 */
uint32_t GetFPGATime()
{
	int32_t status = 0;
	uint32_t time = getFPGATime(&status);
	wpi_setGlobalErrorWithContext(status, getHALErrorMessage(status));
	return time;
}

/**
 * Get the state of the "USER" button on the RoboRIO
 * @return true if the button is currently pressed down
 */
bool GetUserButton()
{
	int32_t status = 0;

	bool value = getFPGAButton(&status);
	wpi_setGlobalError(status);

	return value;
}

/**
 * Demangle a C++ symbol, used for printing stack traces.
 */
static std::string demangle(char const *mangledSymbol)
{
	char buffer[256];
	size_t length;
	int status;


	if(sscanf(mangledSymbol, "%*[^(]%*[(]%255[^)+]", buffer))
	{
		char *symbol = abi::__cxa_demangle(buffer, NULL, &length, &status);
		if(status == 0)
		{
			return symbol;
		}
		else
		{
			// If the symbol couldn't be demangled, it's probably a C function,
			// so just return it as-is.
			return buffer;
		}
	}

	// If everything else failed, just return the mangled symbol
	return mangledSymbol;
}

/**
 * Get a stack trace, ignoring the first "offset" symbols.
 */
std::string GetStackTrace(uint32_t offset)
{
	void *stackTrace[128];
	int stackSize = backtrace(stackTrace, 128);
	char **mangledSymbols = backtrace_symbols(stackTrace, stackSize);
	std::stringstream trace;

	for(int i = offset; i < stackSize; i++)
	{
		// Only print recursive functions once in a row.
		if(i == 0 ||stackTrace[i] != stackTrace[i - 1])
		{
			trace << "\tat " << demangle(mangledSymbols[i]) << std::endl;
		}
	}

	free(mangledSymbols);

	return trace.str();
}
