DDTTYLogger.m

#import "DDTTYLogger.h"

#import <unistd.h>
#import <sys/uio.h>

/**
 * Welcome to Cocoa Lumberjack!
 * 
 * The project page has a wealth of documentation if you have any questions.
 * https://github.com/CocoaLumberjack/CocoaLumberjack
 * 
 * If you're new to the project you may wish to read the "Getting Started" wiki.
 * https://github.com/CocoaLumberjack/CocoaLumberjack/wiki/GettingStarted
**/

#if ! __has_feature(objc_arc)
#warning This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
#endif

// We probably shouldn't be using DDLog() statements within the DDLog implementation.
// But we still want to leave our log statements for any future debugging,
// and to allow other developers to trace the implementation (which is a great learning tool).
// 
// So we use primitive logging macros around NSLog.
// We maintain the NS prefix on the macros to be explicit about the fact that we're using NSLog.

#define LOG_LEVEL 2

#define NSLogError(frmt, ...)    do{ if(LOG_LEVEL >= 1) NSLog((frmt), ##__VA_ARGS__); } while(0)
#define NSLogWarn(frmt, ...)     do{ if(LOG_LEVEL >= 2) NSLog((frmt), ##__VA_ARGS__); } while(0)
#define NSLogInfo(frmt, ...)     do{ if(LOG_LEVEL >= 3) NSLog((frmt), ##__VA_ARGS__); } while(0)
#define NSLogDebug(frmt, ...)    do{ if(LOG_LEVEL >= 4) NSLog((frmt), ##__VA_ARGS__); } while(0)
#define NSLogVerbose(frmt, ...)  do{ if(LOG_LEVEL >= 5) NSLog((frmt), ##__VA_ARGS__); } while(0)

// Xcode does NOT natively support colors in the Xcode debugging console.
// You'll need to install the XcodeColors plugin to see colors in the Xcode console.
// https://github.com/robbiehanson/XcodeColors
// 
// The following is documentation from the XcodeColors project:
// 
// 
// How to apply color formatting to your log statements:
// 
// To set the foreground color:
// Insert the ESCAPE_SEQ into your string, followed by "fg124,12,255;" where r=124, g=12, b=255.
// 
// To set the background color:
// Insert the ESCAPE_SEQ into your string, followed by "bg12,24,36;" where r=12, g=24, b=36.
// 
// To reset the foreground color (to default value):
// Insert the ESCAPE_SEQ into your string, followed by "fg;"
// 
// To reset the background color (to default value):
// Insert the ESCAPE_SEQ into your string, followed by "bg;"
// 
// To reset the foreground and background color (to default values) in one operation:
// Insert the ESCAPE_SEQ into your string, followed by ";"

#define XCODE_COLORS_ESCAPE_SEQ "\033["

#define XCODE_COLORS_RESET_FG  XCODE_COLORS_ESCAPE_SEQ "fg;" // Clear any foreground color
#define XCODE_COLORS_RESET_BG  XCODE_COLORS_ESCAPE_SEQ "bg;" // Clear any background color
#define XCODE_COLORS_RESET     XCODE_COLORS_ESCAPE_SEQ ";"   // Clear any foreground or background color

// Some simple defines to make life easier on ourself

#if TARGET_OS_IPHONE
  #define MakeColor(r, g, b) [UIColor colorWithRed:(r/255.0f) green:(g/255.0f) blue:(b/255.0f) alpha:1.0f]
#else
  #define MakeColor(r, g, b) [NSColor colorWithCalibratedRed:(r/255.0f) green:(g/255.0f) blue:(b/255.0f) alpha:1.0f]
#endif

#if TARGET_OS_IPHONE
  #define OSColor UIColor
#else
  #define OSColor NSColor
#endif

// If running in a shell, not all RGB colors will be supported.
// In this case we automatically map to the closest available color.
// In order to provide this mapping, we have a hard-coded set of the standard RGB values available in the shell.
// However, not every shell is the same, and Apple likes to think different even when it comes to shell colors.
// 
// Map to standard Terminal.app colors (1), or
// map to standard xterm colors (0).

#define MAP_TO_TERMINAL_APP_COLORS 1


@interface DDTTYLoggerColorProfile : NSObject {
@public
    int mask;
    int context;
    
    uint8_t fg_r;
    uint8_t fg_g;
    uint8_t fg_b;
    
    uint8_t bg_r;
    uint8_t bg_g;
    uint8_t bg_b;
    
    NSUInteger fgCodeIndex;
    NSString *fgCodeRaw;
    
    NSUInteger bgCodeIndex;
    NSString *bgCodeRaw;
    
    char fgCode[24];
    size_t fgCodeLen;
    
    char bgCode[24];
    size_t bgCodeLen;
    
    char resetCode[8];
    size_t resetCodeLen;
}

- (instancetype)initWithForegroundColor:(OSColor *)fgColor backgroundColor:(OSColor *)bgColor flag:(int)mask context:(int)ctxt;

@end

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

@implementation DDTTYLogger

static BOOL isaColorTTY;
static BOOL isaColor256TTY;
static BOOL isaXcodeColorTTY;

static NSArray *codes_fg = nil;
static NSArray *codes_bg = nil;
static NSArray *colors   = nil;

static DDTTYLogger *sharedInstance;

/**
 * Initializes the colors array, as well as the codes_fg and codes_bg arrays, for 16 color mode.
 * 
 * This method is used when the application is running from within a shell that only supports 16 color mode.
 * This method is not invoked if the application is running within Xcode, or via normal UI app launch.
**/
+ (void)initialize_colors_16
{
    if (codes_fg || codes_bg || colors) return;
    
    NSMutableArray *m_codes_fg = [NSMutableArray arrayWithCapacity:16];
    NSMutableArray *m_codes_bg = [NSMutableArray arrayWithCapacity:16];
    NSMutableArray *m_colors   = [NSMutableArray arrayWithCapacity:16];
    
    // In a standard shell only 16 colors are supported.
    // 
    // More information about ansi escape codes can be found online.
    // http://en.wikipedia.org/wiki/ANSI_escape_code
    
    [m_codes_fg addObject:@"30m"];   // normal - black
    [m_codes_fg addObject:@"31m"];   // normal - red
    [m_codes_fg addObject:@"32m"];   // normal - green
    [m_codes_fg addObject:@"33m"];   // normal - yellow
    [m_codes_fg addObject:@"34m"];   // normal - blue
    [m_codes_fg addObject:@"35m"];   // normal - magenta
    [m_codes_fg addObject:@"36m"];   // normal - cyan
    [m_codes_fg addObject:@"37m"];   // normal - gray
    [m_codes_fg addObject:@"1;30m"]; // bright - darkgray
    [m_codes_fg addObject:@"1;31m"]; // bright - red
    [m_codes_fg addObject:@"1;32m"]; // bright - green
    [m_codes_fg addObject:@"1;33m"]; // bright - yellow
    [m_codes_fg addObject:@"1;34m"]; // bright - blue
    [m_codes_fg addObject:@"1;35m"]; // bright - magenta
    [m_codes_fg addObject:@"1;36m"]; // bright - cyan
    [m_codes_fg addObject:@"1;37m"]; // bright - white
    
    [m_codes_bg addObject:@"40m"];   // normal - black
    [m_codes_bg addObject:@"41m"];   // normal - red
    [m_codes_bg addObject:@"42m"];   // normal - green
    [m_codes_bg addObject:@"43m"];   // normal - yellow
    [m_codes_bg addObject:@"44m"];   // normal - blue
    [m_codes_bg addObject:@"45m"];   // normal - magenta
    [m_codes_bg addObject:@"46m"];   // normal - cyan
    [m_codes_bg addObject:@"47m"];   // normal - gray
    [m_codes_bg addObject:@"1;40m"]; // bright - darkgray
    [m_codes_bg addObject:@"1;41m"]; // bright - red
    [m_codes_bg addObject:@"1;42m"]; // bright - green
    [m_codes_bg addObject:@"1;43m"]; // bright - yellow
    [m_codes_bg addObject:@"1;44m"]; // bright - blue
    [m_codes_bg addObject:@"1;45m"]; // bright - magenta
    [m_codes_bg addObject:@"1;46m"]; // bright - cyan
    [m_codes_bg addObject:@"1;47m"]; // bright - white
    
#if MAP_TO_TERMINAL_APP_COLORS
    
    // Standard Terminal.app colors:
    // 
    // These are the default colors used by Apple's Terminal.app.
    
    [m_colors addObject:MakeColor(  0,   0,   0)]; // normal - black
    [m_colors addObject:MakeColor(194,  54,  33)]; // normal - red
    [m_colors addObject:MakeColor( 37, 188,  36)]; // normal - green
    [m_colors addObject:MakeColor(173, 173,  39)]; // normal - yellow
    [m_colors addObject:MakeColor( 73,  46, 225)]; // normal - blue
    [m_colors addObject:MakeColor(211,  56, 211)]; // normal - magenta
    [m_colors addObject:MakeColor( 51, 187, 200)]; // normal - cyan
    [m_colors addObject:MakeColor(203, 204, 205)]; // normal - gray
    [m_colors addObject:MakeColor(129, 131, 131)]; // bright - darkgray
    [m_colors addObject:MakeColor(252,  57,  31)]; // bright - red
    [m_colors addObject:MakeColor( 49, 231,  34)]; // bright - green
    [m_colors addObject:MakeColor(234, 236,  35)]; // bright - yellow
    [m_colors addObject:MakeColor( 88,  51, 255)]; // bright - blue
    [m_colors addObject:MakeColor(249,  53, 248)]; // bright - magenta
    [m_colors addObject:MakeColor( 20, 240, 240)]; // bright - cyan
    [m_colors addObject:MakeColor(233, 235, 235)]; // bright - white
    
#else
    
    // Standard xterm colors:
    // 
    // These are the default colors used by most xterm shells.
    
    [m_colors addObject:MakeColor(  0,   0,   0)]; // normal - black
    [m_colors addObject:MakeColor(205,   0,   0)]; // normal - red
    [m_colors addObject:MakeColor(  0, 205,   0)]; // normal - green
    [m_colors addObject:MakeColor(205, 205,   0)]; // normal - yellow
    [m_colors addObject:MakeColor(  0,   0, 238)]; // normal - blue
    [m_colors addObject:MakeColor(205,   0, 205)]; // normal - magenta
    [m_colors addObject:MakeColor(  0, 205, 205)]; // normal - cyan
    [m_colors addObject:MakeColor(229, 229, 229)]; // normal - gray
    [m_colors addObject:MakeColor(127, 127, 127)]; // bright - darkgray
    [m_colors addObject:MakeColor(255,   0,   0)]; // bright - red
    [m_colors addObject:MakeColor(  0, 255,   0)]; // bright - green
    [m_colors addObject:MakeColor(255, 255,   0)]; // bright - yellow
    [m_colors addObject:MakeColor( 92,  92, 255)]; // bright - blue
    [m_colors addObject:MakeColor(255,   0, 255)]; // bright - magenta
    [m_colors addObject:MakeColor(  0, 255, 255)]; // bright - cyan
    [m_colors addObject:MakeColor(255, 255, 255)]; // bright - white
    
#endif
    
    codes_fg = [m_codes_fg copy];
    codes_bg = [m_codes_bg copy];
    colors   = [m_colors   copy];
    
    NSAssert([codes_fg count] == [codes_bg count], @"Invalid colors/codes array(s)");
    NSAssert([codes_fg count] == [colors count],   @"Invalid colors/codes array(s)");
}

/**
 * Initializes the colors array, as well as the codes_fg and codes_bg arrays, for 256 color mode.
 * 
 * This method is used when the application is running from within a shell that supports 256 color mode.
 * This method is not invoked if the application is running within Xcode, or via normal UI app launch.
**/
+ (void)initialize_colors_256
{
    if (codes_fg || codes_bg || colors) return;
    
    NSMutableArray *m_codes_fg = [NSMutableArray arrayWithCapacity:(256-16)];
    NSMutableArray *m_codes_bg = [NSMutableArray arrayWithCapacity:(256-16)];
    NSMutableArray *m_colors   = [NSMutableArray arrayWithCapacity:(256-16)];
    
    #if MAP_TO_TERMINAL_APP_COLORS
    
    // Standard Terminal.app colors:
    // 
    // These are the colors the Terminal.app uses in xterm-256color mode.
    // In this mode, the terminal supports 256 different colors, specified by 256 color codes.
    // 
    // The first 16 color codes map to the original 16 color codes supported by the earlier xterm-color mode.
    // These are actually configurable, and thus we ignore them for the purposes of mapping,
    // as we can't rely on them being constant. They are largely duplicated anyway.
    // 
    // The next 216 color codes are designed to run the spectrum, with several shades of every color.
    // While the color codes are standardized, the actual RGB values for each color code is not.
    // Apple's Terminal.app uses different RGB values from that of a standard xterm.
    // Apple's choices in colors are designed to be a little nicer on the eyes.
    // 
    // The last 24 color codes represent a grayscale.
    // 
    // Unfortunately, unlike the standard xterm color chart,
    // Apple's RGB values cannot be calculated using a simple formula (at least not that I know of).
    // Also, I don't know of any ways to programmatically query the shell for the RGB values.
    // So this big giant color chart had to be made by hand.
    // 
    // More information about ansi escape codes can be found online.
    // http://en.wikipedia.org/wiki/ANSI_escape_code
    
    // Colors
    
    [m_colors addObject:MakeColor( 47,  49,  49)];
    [m_colors addObject:MakeColor( 60,  42, 144)];
    [m_colors addObject:MakeColor( 66,  44, 183)];
    [m_colors addObject:MakeColor( 73,  46, 222)];
    [m_colors addObject:MakeColor( 81,  50, 253)];
    [m_colors addObject:MakeColor( 88,  51, 255)];
    
    [m_colors addObject:MakeColor( 42, 128,  37)];
    [m_colors addObject:MakeColor( 42, 127, 128)];
    [m_colors addObject:MakeColor( 44, 126, 169)];
    [m_colors addObject:MakeColor( 56, 125, 209)];
    [m_colors addObject:MakeColor( 59, 124, 245)];
    [m_colors addObject:MakeColor( 66, 123, 255)];
    
    [m_colors addObject:MakeColor( 51, 163,  41)];
    [m_colors addObject:MakeColor( 39, 162, 121)];
    [m_colors addObject:MakeColor( 42, 161, 162)];
    [m_colors addObject:MakeColor( 53, 160, 202)];
    [m_colors addObject:MakeColor( 45, 159, 240)];
    [m_colors addObject:MakeColor( 58, 158, 255)];
    
    [m_colors addObject:MakeColor( 31, 196,  37)];
    [m_colors addObject:MakeColor( 48, 196, 115)];
    [m_colors addObject:MakeColor( 39, 195, 155)];
    [m_colors addObject:MakeColor( 49, 195, 195)];
    [m_colors addObject:MakeColor( 32, 194, 235)];
    [m_colors addObject:MakeColor( 53, 193, 255)];
    
    [m_colors addObject:MakeColor( 50, 229,  35)];
    [m_colors addObject:MakeColor( 40, 229, 109)];
    [m_colors addObject:MakeColor( 27, 229, 149)];
    [m_colors addObject:MakeColor( 49, 228, 189)];
    [m_colors addObject:MakeColor( 33, 228, 228)];
    [m_colors addObject:MakeColor( 53, 227, 255)];
    
    [m_colors addObject:MakeColor( 27, 254,  30)];
    [m_colors addObject:MakeColor( 30, 254, 103)];
    [m_colors addObject:MakeColor( 45, 254, 143)];
    [m_colors addObject:MakeColor( 38, 253, 182)];
    [m_colors addObject:MakeColor( 38, 253, 222)];
    [m_colors addObject:MakeColor( 42, 253, 252)];
    
    [m_colors addObject:MakeColor(140,  48,  40)];
    [m_colors addObject:MakeColor(136,  51, 136)];
    [m_colors addObject:MakeColor(135,  52, 177)];
    [m_colors addObject:MakeColor(134,  52, 217)];
    [m_colors addObject:MakeColor(135,  56, 248)];
    [m_colors addObject:MakeColor(134,  53, 255)];
    
    [m_colors addObject:MakeColor(125, 125,  38)];
    [m_colors addObject:MakeColor(124, 125, 125)];
    [m_colors addObject:MakeColor(122, 124, 166)];
    [m_colors addObject:MakeColor(123, 124, 207)];
    [m_colors addObject:MakeColor(123, 122, 247)];
    [m_colors addObject:MakeColor(124, 121, 255)];
    
    [m_colors addObject:MakeColor(119, 160,  35)];
    [m_colors addObject:MakeColor(117, 160, 120)];
    [m_colors addObject:MakeColor(117, 160, 160)];
    [m_colors addObject:MakeColor(115, 159, 201)];
    [m_colors addObject:MakeColor(116, 158, 240)];
    [m_colors addObject:MakeColor(117, 157, 255)];
    
    [m_colors addObject:MakeColor(113, 195,  39)];
    [m_colors addObject:MakeColor(110, 194, 114)];
    [m_colors addObject:MakeColor(111, 194, 154)];
    [m_colors addObject:MakeColor(108, 194, 194)];
    [m_colors addObject:MakeColor(109, 193, 234)];
    [m_colors addObject:MakeColor(108, 192, 255)];
    
    [m_colors addObject:MakeColor(105, 228,  30)];
    [m_colors addObject:MakeColor(103, 228, 109)];
    [m_colors addObject:MakeColor(105, 228, 148)];
    [m_colors addObject:MakeColor(100, 227, 188)];
    [m_colors addObject:MakeColor( 99, 227, 227)];
    [m_colors addObject:MakeColor( 99, 226, 253)];
    
    [m_colors addObject:MakeColor( 92, 253,  34)];
    [m_colors addObject:MakeColor( 96, 253, 103)];
    [m_colors addObject:MakeColor( 97, 253, 142)];
    [m_colors addObject:MakeColor( 88, 253, 182)];
    [m_colors addObject:MakeColor( 93, 253, 221)];
    [m_colors addObject:MakeColor( 88, 254, 251)];
    
    [m_colors addObject:MakeColor(177,  53,  34)];
    [m_colors addObject:MakeColor(174,  54, 131)];
    [m_colors addObject:MakeColor(172,  55, 172)];
    [m_colors addObject:MakeColor(171,  57, 213)];
    [m_colors addObject:MakeColor(170,  55, 249)];
    [m_colors addObject:MakeColor(170,  57, 255)];
    
    [m_colors addObject:MakeColor(165, 123,  37)];
    [m_colors addObject:MakeColor(163, 123, 123)];
    [m_colors addObject:MakeColor(162, 123, 164)];
    [m_colors addObject:MakeColor(161, 122, 205)];
    [m_colors addObject:MakeColor(161, 121, 241)];
    [m_colors addObject:MakeColor(161, 121, 255)];
    
    [m_colors addObject:MakeColor(158, 159,  33)];
    [m_colors addObject:MakeColor(157, 158, 118)];
    [m_colors addObject:MakeColor(157, 158, 159)];
    [m_colors addObject:MakeColor(155, 157, 199)];
    [m_colors addObject:MakeColor(155, 157, 239)];
    [m_colors addObject:MakeColor(154, 156, 255)];
    
    [m_colors addObject:MakeColor(152, 193,  40)];
    [m_colors addObject:MakeColor(151, 193, 113)];
    [m_colors addObject:MakeColor(150, 193, 153)];
    [m_colors addObject:MakeColor(150, 192, 193)];
    [m_colors addObject:MakeColor(148, 192, 232)];
    [m_colors addObject:MakeColor(149, 191, 253)];
    
    [m_colors addObject:MakeColor(146, 227,  28)];
    [m_colors addObject:MakeColor(144, 227, 108)];
    [m_colors addObject:MakeColor(144, 227, 147)];
    [m_colors addObject:MakeColor(144, 227, 187)];
    [m_colors addObject:MakeColor(142, 226, 227)];
    [m_colors addObject:MakeColor(142, 225, 252)];
    
    [m_colors addObject:MakeColor(138, 253,  36)];
    [m_colors addObject:MakeColor(137, 253, 102)];
    [m_colors addObject:MakeColor(136, 253, 141)];
    [m_colors addObject:MakeColor(138, 254, 181)];
    [m_colors addObject:MakeColor(135, 255, 220)];
    [m_colors addObject:MakeColor(133, 255, 250)];
    
    [m_colors addObject:MakeColor(214,  57,  30)];
    [m_colors addObject:MakeColor(211,  59, 126)];
    [m_colors addObject:MakeColor(209,  57, 168)];
    [m_colors addObject:MakeColor(208,  55, 208)];
    [m_colors addObject:MakeColor(207,  58, 247)];
    [m_colors addObject:MakeColor(206,  61, 255)];
    
    [m_colors addObject:MakeColor(204, 121,  32)];
    [m_colors addObject:MakeColor(202, 121, 121)];
    [m_colors addObject:MakeColor(201, 121, 161)];
    [m_colors addObject:MakeColor(200, 120, 202)];
    [m_colors addObject:MakeColor(200, 120, 241)];
    [m_colors addObject:MakeColor(198, 119, 255)];
    
    [m_colors addObject:MakeColor(198, 157,  37)];
    [m_colors addObject:MakeColor(196, 157, 116)];
    [m_colors addObject:MakeColor(195, 156, 157)];
    [m_colors addObject:MakeColor(195, 156, 197)];
    [m_colors addObject:MakeColor(194, 155, 236)];
    [m_colors addObject:MakeColor(193, 155, 255)];
    
    [m_colors addObject:MakeColor(191, 192,  36)];
    [m_colors addObject:MakeColor(190, 191, 112)];
    [m_colors addObject:MakeColor(189, 191, 152)];
    [m_colors addObject:MakeColor(189, 191, 191)];
    [m_colors addObject:MakeColor(188, 190, 230)];
    [m_colors addObject:MakeColor(187, 190, 253)];
    
    [m_colors addObject:MakeColor(185, 226,  28)];
    [m_colors addObject:MakeColor(184, 226, 106)];
    [m_colors addObject:MakeColor(183, 225, 146)];
    [m_colors addObject:MakeColor(183, 225, 186)];
    [m_colors addObject:MakeColor(182, 225, 225)];
    [m_colors addObject:MakeColor(181, 224, 252)];
    
    [m_colors addObject:MakeColor(178, 255,  35)];
    [m_colors addObject:MakeColor(178, 255, 101)];
    [m_colors addObject:MakeColor(177, 254, 141)];
    [m_colors addObject:MakeColor(176, 254, 180)];
    [m_colors addObject:MakeColor(176, 254, 220)];
    [m_colors addObject:MakeColor(175, 253, 249)];
    
    [m_colors addObject:MakeColor(247,  56,  30)];
    [m_colors addObject:MakeColor(245,  57, 122)];
    [m_colors addObject:MakeColor(243,  59, 163)];
    [m_colors addObject:MakeColor(244,  60, 204)];
    [m_colors addObject:MakeColor(242,  59, 241)];
    [m_colors addObject:MakeColor(240,  55, 255)];
    
    [m_colors addObject:MakeColor(241, 119,  36)];
    [m_colors addObject:MakeColor(240, 120, 118)];
    [m_colors addObject:MakeColor(238, 119, 158)];
    [m_colors addObject:MakeColor(237, 119, 199)];
    [m_colors addObject:MakeColor(237, 118, 238)];
    [m_colors addObject:MakeColor(236, 118, 255)];
    
    [m_colors addObject:MakeColor(235, 154,  36)];
    [m_colors addObject:MakeColor(235, 154, 114)];
    [m_colors addObject:MakeColor(234, 154, 154)];
    [m_colors addObject:MakeColor(232, 154, 194)];
    [m_colors addObject:MakeColor(232, 153, 234)];
    [m_colors addObject:MakeColor(232, 153, 255)];
    
    [m_colors addObject:MakeColor(230, 190,  30)];
    [m_colors addObject:MakeColor(229, 189, 110)];
    [m_colors addObject:MakeColor(228, 189, 150)];
    [m_colors addObject:MakeColor(227, 189, 190)];
    [m_colors addObject:MakeColor(227, 189, 229)];
    [m_colors addObject:MakeColor(226, 188, 255)];
    
    [m_colors addObject:MakeColor(224, 224,  35)];
    [m_colors addObject:MakeColor(223, 224, 105)];
    [m_colors addObject:MakeColor(222, 224, 144)];
    [m_colors addObject:MakeColor(222, 223, 184)];
    [m_colors addObject:MakeColor(222, 223, 224)];
    [m_colors addObject:MakeColor(220, 223, 253)];
    
    [m_colors addObject:MakeColor(217, 253,  28)];
    [m_colors addObject:MakeColor(217, 253,  99)];
    [m_colors addObject:MakeColor(216, 252, 139)];
    [m_colors addObject:MakeColor(216, 252, 179)];
    [m_colors addObject:MakeColor(215, 252, 218)];
    [m_colors addObject:MakeColor(215, 251, 250)];
    
    [m_colors addObject:MakeColor(255,  61,  30)];
    [m_colors addObject:MakeColor(255,  60, 118)];
    [m_colors addObject:MakeColor(255,  58, 159)];
    [m_colors addObject:MakeColor(255,  56, 199)];
    [m_colors addObject:MakeColor(255,  55, 238)];
    [m_colors addObject:MakeColor(255,  59, 255)];
    
    [m_colors addObject:MakeColor(255, 117,  29)];
    [m_colors addObject:MakeColor(255, 117, 115)];
    [m_colors addObject:MakeColor(255, 117, 155)];
    [m_colors addObject:MakeColor(255, 117, 195)];
    [m_colors addObject:MakeColor(255, 116, 235)];
    [m_colors addObject:MakeColor(254, 116, 255)];
    
    [m_colors addObject:MakeColor(255, 152,  27)];
    [m_colors addObject:MakeColor(255, 152, 111)];
    [m_colors addObject:MakeColor(254, 152, 152)];
    [m_colors addObject:MakeColor(255, 152, 192)];
    [m_colors addObject:MakeColor(254, 151, 231)];
    [m_colors addObject:MakeColor(253, 151, 253)];
    
    [m_colors addObject:MakeColor(255, 187,  33)];
    [m_colors addObject:MakeColor(253, 187, 107)];
    [m_colors addObject:MakeColor(252, 187, 148)];
    [m_colors addObject:MakeColor(253, 187, 187)];
    [m_colors addObject:MakeColor(254, 187, 227)];
    [m_colors addObject:MakeColor(252, 186, 252)];
    
    [m_colors addObject:MakeColor(252, 222,  34)];
    [m_colors addObject:MakeColor(251, 222, 103)];
    [m_colors addObject:MakeColor(251, 222, 143)];
    [m_colors addObject:MakeColor(250, 222, 182)];
    [m_colors addObject:MakeColor(251, 221, 222)];
    [m_colors addObject:MakeColor(252, 221, 252)];
    
    [m_colors addObject:MakeColor(251, 252,  15)];
    [m_colors addObject:MakeColor(251, 252,  97)];
    [m_colors addObject:MakeColor(249, 252, 137)];
    [m_colors addObject:MakeColor(247, 252, 177)];
    [m_colors addObject:MakeColor(247, 253, 217)];
    [m_colors addObject:MakeColor(254, 255, 255)];
    
    // Grayscale
    
    [m_colors addObject:MakeColor( 52,  53,  53)];
    [m_colors addObject:MakeColor( 57,  58,  59)];
    [m_colors addObject:MakeColor( 66,  67,  67)];
    [m_colors addObject:MakeColor( 75,  76,  76)];
    [m_colors addObject:MakeColor( 83,  85,  85)];
    [m_colors addObject:MakeColor( 92,  93,  94)];
    
    [m_colors addObject:MakeColor(101, 102, 102)];
    [m_colors addObject:MakeColor(109, 111, 111)];
    [m_colors addObject:MakeColor(118, 119, 119)];
    [m_colors addObject:MakeColor(126, 127, 128)];
    [m_colors addObject:MakeColor(134, 136, 136)];
    [m_colors addObject:MakeColor(143, 144, 145)];
    
    [m_colors addObject:MakeColor(151, 152, 153)];
    [m_colors addObject:MakeColor(159, 161, 161)];
    [m_colors addObject:MakeColor(167, 169, 169)];
    [m_colors addObject:MakeColor(176, 177, 177)];
    [m_colors addObject:MakeColor(184, 185, 186)];
    [m_colors addObject:MakeColor(192, 193, 194)];
    
    [m_colors addObject:MakeColor(200, 201, 202)];
    [m_colors addObject:MakeColor(208, 209, 210)];
    [m_colors addObject:MakeColor(216, 218, 218)];
    [m_colors addObject:MakeColor(224, 226, 226)];
    [m_colors addObject:MakeColor(232, 234, 234)];
    [m_colors addObject:MakeColor(240, 242, 242)];
    
    // Color codes
    
    int index = 16;
    
    while (index < 256)
    {
        [m_codes_fg addObject:[NSString stringWithFormat:@"38;5;%dm", index]];
        [m_codes_bg addObject:[NSString stringWithFormat:@"48;5;%dm", index]];
        
        index++;
    }
    
    #else
    
    // Standard xterm colors:
    // 
    // These are the colors xterm shells use in xterm-256color mode.
    // In this mode, the shell supports 256 different colors, specified by 256 color codes.
    // 
    // The first 16 color codes map to the original 16 color codes supported by the earlier xterm-color mode.
    // These are generally configurable, and thus we ignore them for the purposes of mapping,
    // as we can't rely on them being constant. They are largely duplicated anyway.
    // 
    // The next 216 color codes are designed to run the spectrum, with several shades of every color.
    // The last 24 color codes represent a grayscale.
    // 
    // While the color codes are standardized, the actual RGB values for each color code is not.
    // However most standard xterms follow a well known color chart,
    // which can easily be calculated using the simple formula below.
    // 
    // More information about ansi escape codes can be found online.
    // http://en.wikipedia.org/wiki/ANSI_escape_code
    
    int index = 16;
    
    int r; // red
    int g; // green
    int b; // blue
    
    int ri; // r increment
    int gi; // g increment
    int bi; // b increment
    
    // Calculate xterm colors (using standard algorithm)
    
    int r = 0;
    int g = 0;
    int b = 0;
    
    for (ri = 0; ri < 6; ri++)
    {
        r = (ri == 0) ? 0 : 95 + (40 * (ri - 1));
        
        for (gi = 0; gi < 6; gi++)
        {
            g = (gi == 0) ? 0 : 95 + (40 * (gi - 1));
            
            for (bi = 0; bi < 6; bi++)
            {
                b = (bi == 0) ? 0 : 95 + (40 * (bi - 1));
                
                [m_codes_fg addObject:[NSString stringWithFormat:@"38;5;%dm", index]];
                [m_codes_bg addObject:[NSString stringWithFormat:@"48;5;%dm", index]];
                [m_colors addObject:MakeColor(r, g, b)];
                
                index++;
            }
        }
    }
    
    // Calculate xterm grayscale (using standard algorithm)
    
    r = 8;
    g = 8;
    b = 8;
    
    while (index < 256)
    {
        [m_codes_fg addObject:[NSString stringWithFormat:@"38;5;%dm", index]];
        [m_codes_bg addObject:[NSString stringWithFormat:@"48;5;%dm", index]];
        [m_colors addObject:MakeColor(r, g, b)];
        
        r += 10;
        g += 10;
        b += 10;
        
        index++;
    }
    
    #endif
    
    codes_fg = [m_codes_fg copy];
    codes_bg = [m_codes_bg copy];
    colors   = [m_colors   copy];
             
    NSAssert([codes_fg count] == [codes_bg count], @"Invalid colors/codes array(s)");
    NSAssert([codes_fg count] == [colors count],   @"Invalid colors/codes array(s)");
}

+ (void)getRed:(CGFloat *)rPtr green:(CGFloat *)gPtr blue:(CGFloat *)bPtr fromColor:(OSColor *)color
{
    #if TARGET_OS_IPHONE
    
    // iOS
    
    BOOL done = NO;
    
    if ([color respondsToSelector:@selector(getRed:green:blue:alpha:)])
    {
        done = [color getRed:rPtr green:gPtr blue:bPtr alpha:NULL];
    }
    
    if (!done)
    {
        // The method getRed:green:blue:alpha: was only available starting iOS 5.
        // So in iOS 4 and earlier, we have to jump through hoops.
        
        CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
        
        unsigned char pixel[4];
        CGContextRef context = CGBitmapContextCreate(&pixel, 1, 1, 8, 4, rgbColorSpace, kCGBitmapAlphaInfoMask & kCGImageAlphaNoneSkipLast);
        
        CGContextSetFillColorWithColor(context, [color CGColor]);
        CGContextFillRect(context, CGRectMake(0, 0, 1, 1));
        
        if (rPtr) { *rPtr = pixel[0] / 255.0f; }
        if (gPtr) { *gPtr = pixel[1] / 255.0f; }
        if (bPtr) { *bPtr = pixel[2] / 255.0f; }
        
        CGContextRelease(context);
        CGColorSpaceRelease(rgbColorSpace);
    }
    
    #else
    
    // Mac OS X
    
    NSColor *safeColor = [color colorUsingColorSpaceName:NSCalibratedRGBColorSpace];
    
    [safeColor getRed:rPtr green:gPtr blue:bPtr alpha:NULL];
    
    #endif
}

/**
 * Maps the given color to the closest available color supported by the shell.
 * The shell may support 256 colors, or only 16.
 * 
 * This method loops through the known supported color set, and calculates the closest color.
 * The array index of that color, within the colors array, is then returned.
 * This array index may also be used as the index within the codes_fg and codes_bg arrays.
**/
+ (NSUInteger)codeIndexForColor:(OSColor *)inColor
{
    CGFloat inR, inG, inB;
    [self getRed:&inR green:&inG blue:&inB fromColor:inColor];
    
    NSUInteger bestIndex = 0;
    CGFloat lowestDistance = 100.0f;
    
    NSUInteger i = 0;
    for (OSColor *color in colors)
    {
        // Calculate Euclidean distance (lower value means closer to given color)
        
        CGFloat r, g, b;
        [self getRed:&r green:&g blue:&b fromColor:color];
        
    #if CGFLOAT_IS_DOUBLE
        CGFloat distance = sqrt(pow(r-inR, 2.0) + pow(g-inG, 2.0) + pow(b-inB, 2.0));
    #else
        CGFloat distance = sqrtf(powf(r-inR, 2.0f) + powf(g-inG, 2.0f) + powf(b-inB, 2.0f));
    #endif
        
        NSLogVerbose(@"DDTTYLogger: %3lu : %.3f,%.3f,%.3f & %.3f,%.3f,%.3f = %.6f",
                     (unsigned long)i, inR, inG, inB, r, g, b, distance);
        
        if (distance < lowestDistance)
        {
            bestIndex = i;
            lowestDistance = distance;
            
            NSLogVerbose(@"DDTTYLogger: New best index = %lu", (unsigned long)bestIndex);
        }
        
        i++;
    }
    
    return bestIndex;
}

/**
 * The runtime sends initialize to each class in a program exactly one time just before the class,
 * or any class that inherits from it, is sent its first message from within the program. (Thus the
 * method may never be invoked if the class is not used.) The runtime sends the initialize message to
 * classes in a thread-safe manner. Superclasses receive this message before their subclasses.
 *
 * This method may also be called directly (assumably by accident), hence the safety mechanism.
**/
+ (void)initialize
{
    static BOOL initialized = NO;
    if (!initialized)
    {
        initialized = YES;
        
        char *term = getenv("TERM");
        if (term)
        {
            if (strcasestr(term, "color") != NULL)
            {
                isaColorTTY = YES;
                isaColor256TTY = (strcasestr(term, "256") != NULL);
                
                if (isaColor256TTY)
                    [self initialize_colors_256];
                else
                    [self initialize_colors_16];
            }
        }
        else
        {
            // Xcode does NOT natively support colors in the Xcode debugging console.
            // You'll need to install the XcodeColors plugin to see colors in the Xcode console.
            // 
            // PS - Please read the header file before diving into the source code.
            
            char *xcode_colors = getenv("XcodeColors");
            if (xcode_colors && (strcmp(xcode_colors, "YES") == 0))
            {
                isaXcodeColorTTY = YES;
            }
        }
        
        NSLogInfo(@"DDTTYLogger: isaColorTTY = %@", (isaColorTTY ? @"YES" : @"NO"));
        NSLogInfo(@"DDTTYLogger: isaColor256TTY: %@", (isaColor256TTY ? @"YES" : @"NO"));
        NSLogInfo(@"DDTTYLogger: isaXcodeColorTTY: %@", (isaXcodeColorTTY ? @"YES" : @"NO"));
        
        sharedInstance = [[[self class] alloc] init];
    }
}

+ (instancetype)sharedInstance
{
    return sharedInstance;
}

- (id)init
{
    if (sharedInstance != nil)
    {
        return nil;
    }
    
    if ((self = [super init]))
    {
        calendar = [NSCalendar autoupdatingCurrentCalendar];
        
        calendarUnitFlags = 0;
        calendarUnitFlags |= NSYearCalendarUnit;
        calendarUnitFlags |= NSMonthCalendarUnit;
        calendarUnitFlags |= NSDayCalendarUnit;
        calendarUnitFlags |= NSHourCalendarUnit;
        calendarUnitFlags |= NSMinuteCalendarUnit;
        calendarUnitFlags |= NSSecondCalendarUnit;
        
        // Initialze 'app' variable (char *)
        
        appName = [[NSProcessInfo processInfo] processName];
        
        appLen = [appName lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
        app = (char *)malloc(appLen + 1);
        if (app == NULL) return nil;
        
        [appName getCString:app maxLength:(appLen+1) encoding:NSUTF8StringEncoding];
        
        // Initialize 'pid' variable (char *)
        
        processID = [NSString stringWithFormat:@"%i", (int)getpid()];
        
        pidLen = [processID lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
        pid = (char *)malloc(pidLen + 1);
        if (pid == NULL) return nil;
        
        BOOL processedID = [processID getCString:pid maxLength:(pidLen+1) encoding:NSUTF8StringEncoding];
        if (NO == processedID) return nil;
        
        // Initialize color stuff
        
        colorsEnabled = NO;
        colorProfilesArray = [[NSMutableArray alloc] initWithCapacity:8];
        colorProfilesDict = [[NSMutableDictionary alloc] initWithCapacity:8];
    }
    return self;
}

- (void)loadDefaultColorProfiles
{
    [self setForegroundColor:MakeColor(214,  57,  30) backgroundColor:nil forFlag:LOG_FLAG_ERROR];
    [self setForegroundColor:MakeColor(204, 121,  32) backgroundColor:nil forFlag:LOG_FLAG_WARN];
}

- (BOOL)colorsEnabled
{
    // The design of this method is taken from the DDAbstractLogger implementation.
    // For extensive documentation please refer to the DDAbstractLogger implementation.
    
    // Note: The internal implementation MUST access the colorsEnabled variable directly,
    // This method is designed explicitly for external access.
    //
    // Using "self." syntax to go through this method will cause immediate deadlock.
    // This is the intended result. Fix it by accessing the ivar directly.
    // Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
    
    NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
    NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
    
    dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
    
    __block BOOL result;
    
    dispatch_sync(globalLoggingQueue, ^{
        dispatch_sync(loggerQueue, ^{
            result = colorsEnabled;
        });
    });
    
    return result;
}

- (void)setColorsEnabled:(BOOL)newColorsEnabled
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        colorsEnabled = newColorsEnabled;
        
        if ([colorProfilesArray count] == 0) {
            [self loadDefaultColorProfiles];
        }
    }};
    
    // The design of this method is taken from the DDAbstractLogger implementation.
    // For extensive documentation please refer to the DDAbstractLogger implementation.
    
    // Note: The internal implementation MUST access the colorsEnabled variable directly,
    // This method is designed explicitly for external access.
    //
    // Using "self." syntax to go through this method will cause immediate deadlock.
    // This is the intended result. Fix it by accessing the ivar directly.
    // Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
    
    NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
    NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
    
    dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
    
    dispatch_async(globalLoggingQueue, ^{
        dispatch_async(loggerQueue, block);
    });
}

- (void)setForegroundColor:(OSColor *)txtColor backgroundColor:(OSColor *)bgColor forFlag:(int)mask
{
    [self setForegroundColor:txtColor backgroundColor:bgColor forFlag:mask context:LOG_CONTEXT_ALL];
}

- (void)setForegroundColor:(OSColor *)txtColor backgroundColor:(OSColor *)bgColor forFlag:(int)mask context:(int)ctxt
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        DDTTYLoggerColorProfile *newColorProfile =
            [[DDTTYLoggerColorProfile alloc] initWithForegroundColor:txtColor
                                                     backgroundColor:bgColor
                                                                flag:mask
                                                             context:ctxt];
        
        NSLogInfo(@"DDTTYLogger: newColorProfile: %@", newColorProfile);
        
        NSUInteger i = 0;
        for (DDTTYLoggerColorProfile *colorProfile in colorProfilesArray)
        {
            if ((colorProfile->mask == mask) && (colorProfile->context == ctxt))
            {
                break;
            }
            
            i++;
        }
        
        if (i < [colorProfilesArray count])
            [colorProfilesArray replaceObjectAtIndex:i withObject:newColorProfile];
        else
            [colorProfilesArray addObject:newColorProfile];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)setForegroundColor:(OSColor *)txtColor backgroundColor:(OSColor *)bgColor forTag:(id <NSCopying>)tag
{
    NSAssert([(id <NSObject>)tag conformsToProtocol:@protocol(NSCopying)], @"Invalid tag");
    
    dispatch_block_t block = ^{ @autoreleasepool {
        
        DDTTYLoggerColorProfile *newColorProfile =
            [[DDTTYLoggerColorProfile alloc] initWithForegroundColor:txtColor
                                                     backgroundColor:bgColor
                                                                flag:0
                                                             context:0];
        
        NSLogInfo(@"DDTTYLogger: newColorProfile: %@", newColorProfile);
        
        [colorProfilesDict setObject:newColorProfile forKey:tag];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)clearColorsForFlag:(int)mask
{
    [self clearColorsForFlag:mask context:0];
}

- (void)clearColorsForFlag:(int)mask context:(int)context
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        NSUInteger i = 0;
        for (DDTTYLoggerColorProfile *colorProfile in colorProfilesArray)
        {
            if ((colorProfile->mask == mask) && (colorProfile->context == context))
            {
                break;
            }
            
            i++;
        }
        
        if (i < [colorProfilesArray count])
        {
            [colorProfilesArray removeObjectAtIndex:i];
        }
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)clearColorsForTag:(id <NSCopying>)tag
{
    NSAssert([(id <NSObject>)tag conformsToProtocol:@protocol(NSCopying)], @"Invalid tag");
    
    dispatch_block_t block = ^{ @autoreleasepool {
        
        [colorProfilesDict removeObjectForKey:tag];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)clearColorsForAllFlags
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        [colorProfilesArray removeAllObjects];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)clearColorsForAllTags
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        [colorProfilesDict removeAllObjects];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)clearAllColors
{
    dispatch_block_t block = ^{ @autoreleasepool {
        
        [colorProfilesArray removeAllObjects];
        [colorProfilesDict removeAllObjects];
    }};
    
    // The design of the setter logic below is taken from the DDAbstractLogger implementation.
    // For documentation please refer to the DDAbstractLogger implementation.
    
    if ([self isOnInternalLoggerQueue])
    {
        block();
    }
    else
    {
        dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
        NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
        
        dispatch_async(globalLoggingQueue, ^{
            dispatch_async(loggerQueue, block);
        });
    }
}

- (void)logMessage:(DDLogMessage *)logMessage
{
    NSString *logMsg = logMessage->logMsg;
    BOOL isFormatted = NO;
    
    if (formatter)
    {
        logMsg = [formatter formatLogMessage:logMessage];
        isFormatted = logMsg != logMessage->logMsg;
    }
    
    if (logMsg)
    {
        // Search for a color profile associated with the log message
        
        DDTTYLoggerColorProfile *colorProfile = nil;
        
        if (colorsEnabled)
        {
            if (logMessage->tag)
            {
                colorProfile = [colorProfilesDict objectForKey:logMessage->tag];
            }
            if (colorProfile == nil)
            {
                for (DDTTYLoggerColorProfile *cp in colorProfilesArray)
                {
                    if (logMessage->logFlag & cp->mask)
                    {
                        // Color profile set for this context?
                        if (logMessage->logContext == cp->context)
                        {
                            colorProfile = cp;
                            
                            // Stop searching
                            break;
                        }
                        
                        // Check if LOG_CONTEXT_ALL was specified as a default color for this flag
                        if (cp->context == LOG_CONTEXT_ALL)
                        {
                            colorProfile = cp;
                            
                            // We don't break to keep searching for more specific color profiles for the context
                        }
                    }
                }
            }
        }
        
        // Convert log message to C string.
        // 
        // We use the stack instead of the heap for speed if possible.
        // But we're extra cautious to avoid a stack overflow.
        
        NSUInteger msgLen = [logMsg lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
        const BOOL useStack = msgLen < (1024 * 4);
        
        char msgStack[useStack ? (msgLen + 1) : 1]; // Analyzer doesn't like zero-size array, hence the 1
        char *msg = useStack ? msgStack : (char *)malloc(msgLen + 1);
        if (msg == NULL) return;
        
        BOOL logMsgEnc = [logMsg getCString:msg maxLength:(msgLen + 1) encoding:NSUTF8StringEncoding];
        if (!logMsgEnc)
        {
            if (!useStack && msg != NULL) free(msg);
            return;
        }
        
        // Write the log message to STDERR
        
        if (isFormatted)
        {
            // The log message has already been formatted.
            
            struct iovec v[5];
            
            if (colorProfile)
            {
                v[0].iov_base = colorProfile->fgCode;
                v[0].iov_len = colorProfile->fgCodeLen;

                v[1].iov_base = colorProfile->bgCode;
                v[1].iov_len = colorProfile->bgCodeLen;

                v[4].iov_base = colorProfile->resetCode;
                v[4].iov_len = colorProfile->resetCodeLen;
            }
            else
            {
                v[0].iov_base = "";
                v[0].iov_len = 0;
                
                v[1].iov_base = "";
                v[1].iov_len = 0;
                
                v[4].iov_base = "";
                v[4].iov_len = 0;
            }
            
            v[2].iov_base = (char *)msg;
            v[2].iov_len = msgLen;
            
            v[3].iov_base = "\n";
            v[3].iov_len = (msg[msgLen] == '\n') ? 0 : 1;
            
            writev(STDERR_FILENO, v, 5);
        }
        else
        {
            // The log message is unformatted, so apply standard NSLog style formatting.
            
            int len;
            
            // Calculate timestamp.
            // The technique below is faster than using NSDateFormatter.
            
            NSDateComponents *components = [calendar components:calendarUnitFlags fromDate:logMessage->timestamp];
            
            NSTimeInterval epoch = [logMessage->timestamp timeIntervalSinceReferenceDate];
            int milliseconds = (int)((epoch - floor(epoch)) * 1000);
            
            char ts[24];
            len = snprintf(ts, 24, "%04ld-%02ld-%02ld %02ld:%02ld:%02ld:%03d", // yyyy-MM-dd HH:mm:ss:SSS
                           (long)components.year,
                           (long)components.month,
                           (long)components.day,
                           (long)components.hour,
                           (long)components.minute,
                           (long)components.second, milliseconds);
            
            size_t tsLen = MIN(24-1, len);
            
            // Calculate thread ID
            // 
            // How many characters do we need for the thread id?
            // logMessage->machThreadID is of type mach_port_t, which is an unsigned int.
            // 
            // 1 hex char = 4 bits
            // 8 hex chars for 32 bit, plus ending '\0' = 9
            
            char tid[9];
            len = snprintf(tid, 9, "%x", logMessage->machThreadID);
            
            size_t tidLen = MIN(9-1, len);
            
            // Here is our format: "%s %s[%i:%s] %s", timestamp, appName, processID, threadID, logMsg
            
            struct iovec v[13];
            
            if (colorProfile)
            {
                v[0].iov_base = colorProfile->fgCode;
                v[0].iov_len = colorProfile->fgCodeLen;

                v[1].iov_base = colorProfile->bgCode;
                v[1].iov_len = colorProfile->bgCodeLen;

                v[12].iov_base = colorProfile->resetCode;
                v[12].iov_len = colorProfile->resetCodeLen;
            }
            else
            {
                v[0].iov_base = "";
                v[0].iov_len = 0;

                v[1].iov_base = "";
                v[1].iov_len = 0;

                v[12].iov_base = "";
                v[12].iov_len = 0;
            }
            
            v[2].iov_base = ts;
            v[2].iov_len = tsLen;
            
            v[3].iov_base = " ";
            v[3].iov_len = 1;
            
            v[4].iov_base = app;
            v[4].iov_len = appLen;
            
            v[5].iov_base = "[";
            v[5].iov_len = 1;
            
            v[6].iov_base = pid;
            v[6].iov_len = pidLen;
            
            v[7].iov_base = ":";
            v[7].iov_len = 1;
            
            v[8].iov_base = tid;
            v[8].iov_len = MIN((size_t)8, tidLen); // snprintf doesn't return what you might think
            
            v[9].iov_base = "] ";
            v[9].iov_len = 2;
            
            v[10].iov_base = (char *)msg;
            v[10].iov_len = msgLen;
            
            v[11].iov_base = "\n";
            v[11].iov_len = (msg[msgLen] == '\n') ? 0 : 1;
            
            writev(STDERR_FILENO, v, 13);
        }
        
        if (!useStack) {
            free(msg);
        }
    }
}

- (NSString *)loggerName
{
    return @"cocoa.lumberjack.ttyLogger";
}

@end

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

@implementation DDTTYLoggerColorProfile

- (instancetype)initWithForegroundColor:(OSColor *)fgColor backgroundColor:(OSColor *)bgColor flag:(int)aMask context:(int)ctxt
{
    if ((self = [super init]))
    {
        mask = aMask;
        context = ctxt;
        
        CGFloat r, g, b;
        
        if (fgColor)
        {
            [DDTTYLogger getRed:&r green:&g blue:&b fromColor:fgColor];
            
            fg_r = (uint8_t)(r * 255.0f);
            fg_g = (uint8_t)(g * 255.0f);
            fg_b = (uint8_t)(b * 255.0f);
        }
        if (bgColor)
        {
            [DDTTYLogger getRed:&r green:&g blue:&b fromColor:bgColor];
            
            bg_r = (uint8_t)(r * 255.0f);
            bg_g = (uint8_t)(g * 255.0f);
            bg_b = (uint8_t)(b * 255.0f);
        }
        
        if (fgColor && isaColorTTY)
        {
            // Map foreground color to closest available shell color
            
            fgCodeIndex = [DDTTYLogger codeIndexForColor:fgColor];
            fgCodeRaw   = [codes_fg objectAtIndex:fgCodeIndex];
            
            NSString *escapeSeq = @"\033[";
            
            NSUInteger len1 = [escapeSeq lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
            NSUInteger len2 = [fgCodeRaw lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
            
            BOOL escapeSeqEnc = [escapeSeq getCString:(fgCode)      maxLength:(len1+1) encoding:NSUTF8StringEncoding];
            BOOL fgCodeRawEsc = [fgCodeRaw getCString:(fgCode+len1) maxLength:(len2+1) encoding:NSUTF8StringEncoding];
            if (!escapeSeqEnc || !fgCodeRawEsc) return nil;
            
            fgCodeLen = len1+len2;
        }
        else if (fgColor && isaXcodeColorTTY)
        {
            // Convert foreground color to color code sequence
            
            const char *escapeSeq = XCODE_COLORS_ESCAPE_SEQ;
            
            int result = snprintf(fgCode, 24, "%sfg%u,%u,%u;", escapeSeq, fg_r, fg_g, fg_b);
            fgCodeLen = MIN(result, (24-1));
        }
        else
        {
            // No foreground color or no color support
            
            fgCode[0] = '\0';
            fgCodeLen = 0;
        }
        
        if (bgColor && isaColorTTY)
        {
            // Map background color to closest available shell color
            
            bgCodeIndex = [DDTTYLogger codeIndexForColor:bgColor];
            bgCodeRaw   = [codes_bg objectAtIndex:bgCodeIndex];
            
            NSString *escapeSeq = @"\033[";
            
            NSUInteger len1 = [escapeSeq lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
            NSUInteger len2 = [bgCodeRaw lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
            
            BOOL escapeSeqEnc = [escapeSeq getCString:(bgCode)      maxLength:(len1+1) encoding:NSUTF8StringEncoding];
            BOOL bgCodeRawEsc = [bgCodeRaw getCString:(bgCode+len1) maxLength:(len2+1) encoding:NSUTF8StringEncoding];
            if (!escapeSeqEnc || !bgCodeRawEsc) return nil;
            
            bgCodeLen = len1+len2;
        }
        else if (bgColor && isaXcodeColorTTY)
        {
            // Convert background color to color code sequence
            
            const char *escapeSeq = XCODE_COLORS_ESCAPE_SEQ;
            
            int result = snprintf(bgCode, 24, "%sbg%u,%u,%u;", escapeSeq, bg_r, bg_g, bg_b);
            bgCodeLen = MIN(result, (24-1));
        }
        else
        {
            // No background color or no color support
            
            bgCode[0] = '\0';
            bgCodeLen = 0;
        }
        
        if (isaColorTTY)
        {
            resetCodeLen = snprintf(resetCode, 8, "\033[0m");
        }
        else if (isaXcodeColorTTY)
        {
            resetCodeLen = snprintf(resetCode, 8, XCODE_COLORS_RESET);
        }
        else
        {
            resetCode[0] = '\0';
            resetCodeLen = 0;
        }
    }
    return self;
}

- (NSString *)description
{
    return [NSString stringWithFormat:
            @"<DDTTYLoggerColorProfile: %p mask:%i ctxt:%i fg:%u,%u,%u bg:%u,%u,%u fgCode:%@ bgCode:%@>",
            self, mask, context, fg_r, fg_g, fg_b, bg_r, bg_g, bg_b, fgCodeRaw, bgCodeRaw];
}

@end