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/* Author: Ioan Sucan */

#include "ompl/util/Console.h"
#include <boost/thread/mutex.hpp>
#include <iostream>
#include <cstdio>
#include <cstdarg>
#ifdef _WIN32
#include <stdio.h>
#include <io.h>
#define isatty(x) _isatty(x)
#define fileno(x) _fileno(x)
#else
#include <unistd.h>
#endif

#define ANSI_COLOR_RED     "\x1b[31m"
#define ANSI_COLOR_GREEN   "\x1b[32m"
#define ANSI_COLOR_YELLOW  "\x1b[33m"
#define ANSI_COLOR_BLUE    "\x1b[34m"
#define ANSI_COLOR_MAGENTA "\x1b[35m"
#define ANSI_COLOR_CYAN    "\x1b[36m"
#define ANSI_COLOR_RESET   "\x1b[0m"

/// @cond IGNORE

struct DefaultOutputHandler
{
    DefaultOutputHandler()
    {
        output_handler_ = static_cast<ompl::msg::OutputHandler*>(&std_output_handler_);
        previous_output_handler_ = output_handler_;
        logLevel_ = ompl::msg::LOG_DEBUG;
    }

    ompl::msg::OutputHandlerSTD std_output_handler_;
    ompl::msg::OutputHandler   *output_handler_;
    ompl::msg::OutputHandler   *previous_output_handler_;
    ompl::msg::LogLevel         logLevel_;
    boost::mutex                lock_; // it is likely the outputhandler does some I/O, so we serialize it
};

// we use this function because we want to handle static initialization correctly
// however, the first run of this function is not thread safe, due to the use of a static
// variable inside the function. For this reason, we ensure the first call happens during
// static initialization using a proxy class
static DefaultOutputHandler* getDOH()
{
    static DefaultOutputHandler DOH;
    return &DOH;
}

#define USE_DOH                                                                \
    DefaultOutputHandler *doh = getDOH();                                      \
    boost::mutex::scoped_lock slock(doh->lock_)

#define MAX_BUFFER_SIZE 1024

/// @endcond

void ompl::msg::noOutputHandler()
{
    USE_DOH;
    doh->previous_output_handler_ = doh->output_handler_;
    doh->output_handler_ = NULL;
}

void ompl::msg::restorePreviousOutputHandler()
{
    USE_DOH;
    std::swap(doh->previous_output_handler_, doh->output_handler_);
}

void ompl::msg::useOutputHandler(OutputHandler *oh)
{
    USE_DOH;
    doh->previous_output_handler_ = doh->output_handler_;
    doh->output_handler_ = oh;
}

ompl::msg::OutputHandler* ompl::msg::getOutputHandler()
{
    return getDOH()->output_handler_;
}

void ompl::msg::log(const char *file, int line, LogLevel level, const char *m, ...)
{
    USE_DOH;
    if (doh->output_handler_ && level >= doh->logLevel_)
    {
        va_list __ap;
        va_start(__ap, m);
        char buf[MAX_BUFFER_SIZE];
        vsnprintf(buf, sizeof(buf), m, __ap);
        va_end(__ap);
        buf[MAX_BUFFER_SIZE - 1] = '\0';

        doh->output_handler_->log(buf, level, file, line);
    }
}

void ompl::msg::setLogLevel(LogLevel level)
{
    USE_DOH;
    doh->logLevel_ = level;
}

ompl::msg::LogLevel ompl::msg::getLogLevel()
{
    USE_DOH;
    return doh->logLevel_;
}

static const char *LogLevelString[6] = {"Dev2:    ", "Dev1:    ", "Debug:   ", "Info:    ", "Warning: ", "Error:   "};
static const char *LogColorString[6] = {ANSI_COLOR_MAGENTA, ANSI_COLOR_GREEN, ANSI_COLOR_BLUE, ANSI_COLOR_CYAN, ANSI_COLOR_YELLOW, ANSI_COLOR_RED};

void ompl::msg::OutputHandlerSTD::log(const std::string &text, LogLevel level, const char *filename, int line)
{
    if (level >= LOG_WARN)
    {
        bool isTTY(isatty(fileno(stderr)));
        if (isTTY)
            std::cerr << LogColorString[level + 2];
        std::cerr << LogLevelString[level + 2] << text << std::endl;
        std::cerr << "         at line " << line << " in " << filename << std::endl;
        if (isTTY)
            std::cerr << ANSI_COLOR_RESET;
        std::cerr.flush();
    }
    else
    {
        bool isTTY(isatty(fileno(stdout)));
        if (isTTY)
            std::cout << LogColorString[level + 2];
        std::cout << LogLevelString[level + 2] << text << std::endl;
        std::cout.flush();
        if (isTTY)
            std::cout << ANSI_COLOR_RESET;
    }
}

ompl::msg::OutputHandlerFile::OutputHandlerFile(const char *filename) : OutputHandler()
{
    file_ = fopen(filename, "a");
    if (!file_)
        std::cerr << "Unable to open log file: '" << filename << "'" << std::endl;
}

ompl::msg::OutputHandlerFile::~OutputHandlerFile()
{
    if (file_)
        if (fclose(file_) != 0)
            std::cerr << "Error closing logfile" << std::endl;
}

void ompl::msg::OutputHandlerFile::log(const std::string &text, LogLevel level, const char *filename, int line)
{
    if (file_)
    {
        fprintf(file_, "%s%s\n", LogLevelString[level], text.c_str());
        if(level >= LOG_WARN)
            fprintf(file_, "         at line %d in %s\n", line, filename);
        fflush(file_);
    }
}
