/*
 * (C) Copyright 1996-2017 ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

#include <unistd.h>
#include <errno.h>

#include "eckit/log/Colour.h"
#include "eckit/config/Resource.h"


namespace eckit {

//----------------------------------------------------------------------------------------------------------------------

static int xindex = std::ios::xalloc();

enum { RESET = 0, BOLD  =  1,  UNDERLINE  =  4, BLINK =  5, REVERSE = 7, HIDDEN =8 } ;
enum { BLACK = 0, RED     =  1, GREEN = 2,  YELLOW    = 3, BLUE = 4, MAGENTA = 5, CYAN  = 6, WHITE = 7};

//#define X(a) putchar(a)
//#define X(a) out << (a)
#define X(a) out << char(a)

static bool connected_to_console() {
    int save_errno = errno;
    bool result = ::isatty(1); // This may change errno
    errno = save_errno;
    return result;
}

static std::ostream& put(std::ostream& out, int fg, int bg, int attr)
{
    static bool colourOutput = Resource<bool>("$ECKIT_COLOUR_OUTPUT;-colour;colourOutput", connected_to_console());

	if (colourOutput && out.iword(xindex) == 0)
    {
        int n = 0;
        X( char(0x1B) );
        X( '[');

        if (attr>=0)
        {
            n++;
            X( attr + '0');
        }

        if (fg >= 0) {
            if (n) {
                X( ';');
            }
            X( '3');
            X( fg + '0');
            n++;
        }
        if (bg >= 0) {
            if (n) {
                X( ';');
            }
            X( '4');
            X( bg + '0');
            n++;
        }

        X( 'm');

    }

    return out;
}



std::ostream& Colour::on(std::ostream& s) {
    s.iword(xindex) = 0;
    return s;
}

std::ostream& Colour::off(std::ostream& s) {
    s.iword(xindex) = 1;
    return s;
}

std::ostream& Colour::reset(std::ostream& s) {
    return put(s,-1,-1,RESET);
}

std::ostream& Colour::bold(std::ostream& s) {
    return put(s,-1,-1,BOLD);
}

std::ostream& Colour::underline(std::ostream& s) {
    return put(s,-1,-1,UNDERLINE);
}

std::ostream& Colour::blink(std::ostream& s) {
    return put(s,-1,-1,BLINK);
}

std::ostream& Colour::reverse(std::ostream& s) {
    return put(s,-1,-1,REVERSE);
}

std::ostream& Colour::hidden(std::ostream& s) {
    return put(s,-1,-1,HIDDEN);
}

std::ostream& Colour::black(std::ostream& s) {
    return put(s,BLACK,-1,-1);
}

std::ostream& Colour::red(std::ostream& s) {
    return put(s,RED,-1,-1);
}

std::ostream& Colour::green(std::ostream& s) {
    return put(s,GREEN,-1,-1);
}

std::ostream& Colour::yellow(std::ostream& s) {
    return put(s,YELLOW,-1,-1);
}

std::ostream& Colour::magenta(std::ostream& s) {
    return put(s,MAGENTA,-1,-1);
}

std::ostream& Colour::blue(std::ostream& s) {
    return put(s,BLUE,-1,-1);
}

std::ostream& Colour::cyan(std::ostream& s) {
    return put(s,CYAN,-1,-1);
}

std::ostream& Colour::white(std::ostream& s) {
    return put(s,WHITE,-1,-1);
}

std::ostream& Colour::blackBackground(std::ostream& s) {
    return put(s,-1,BLACK,-1);
}
std::ostream& Colour::redBackground(std::ostream& s) {
    return put(s,-1,RED,-1);
}
std::ostream& Colour::greenBackground(std::ostream& s) {
    return put(s,-1,GREEN,-1);
}

std::ostream& Colour::yellowBackground(std::ostream& s) {
    return put(s,-1,YELLOW,-1);
}


std::ostream& Colour::magentaBackground(std::ostream& s) {
    return put(s,-1,MAGENTA,-1);
}


std::ostream& Colour::blueBackground(std::ostream& s) {
    return put(s,-1,BLUE,-1);
}

std::ostream& Colour::cyanBackground(std::ostream& s) {
    return put(s,-1,CYAN,-1);
}

std::ostream& Colour::whiteBackground(std::ostream& s) {
    return put(s,-1,WHITE,-1);
}

//-----------------------------------------------------------------------------

} // namespace eckit

