From c01cf5902b6981963a05c3c9c1da9f810639a26c Mon Sep 17 00:00:00 2001
From: Andrey Teplyashin <platinumthinker@gmail.com>
Date: Sun, 9 Nov 2014 14:04:05 +0600
Subject: [PATCH] Add colored logs

---
 THANKS                         |  1 +
 ebin/rebar.app                 |  3 +++
 inttest/logging/logging_rt.erl | 31 ++++++++++++++++++++++++-------
 src/rebar_log.erl              | 29 ++++++++++++++++++++++++++++-
 4 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/THANKS b/THANKS
index 3db3b4c..1fcc531 100644
--- a/THANKS
+++ b/THANKS
@@ -127,3 +127,4 @@ alisdair sullivan
 Alexander Verbitsky
 Andras Horvath
 Drew Varner
+Andrey Teplyashin
diff --git a/ebin/rebar.app b/ebin/rebar.app
index 55454e9..12208e2 100644
--- a/ebin/rebar.app
+++ b/ebin/rebar.app
@@ -54,6 +54,9 @@
          %% Default log level
          {log_level, warn},
 
+         %% Log colored
+         {log_colored, true},
+
          %% any_dir processing modules
          {any_dir_modules, [
                             rebar_require_vsn,
diff --git a/inttest/logging/logging_rt.erl b/inttest/logging/logging_rt.erl
index 2b8e54b..d086892 100644
--- a/inttest/logging/logging_rt.erl
+++ b/inttest/logging/logging_rt.erl
@@ -14,23 +14,40 @@ run(_Dir) ->
     SharedExpected = "==> logging_rt \\(compile\\)",
     %% provoke ERROR due to an invalid app file
     retest:log(info, "Check 'compile' failure output~n"),
+    {ERROR, WARN, INFO, DEBUG} =
+        case application:get_env(rebar, log_colored) of
+            {ok, true} ->
+                {
+                 "\\e\\[1m\\e\\[31mERROR: \\e\\[0m",
+                 "\\e\\[33mWARN: \\e\\[0m",
+                 "\\e\\[32mINFO: \\e\\[0m",
+                 "\\e\\[34mDEBUG: \\e\\[0m"
+                };
+            _ ->
+                {
+                 "ERROR: ",
+                 "WARN: ",
+                 "INFO: ",
+                 "DEBUG: "
+                }
+        end,
     ok = check_output("./rebar compile -q", should_fail,
-                      [SharedExpected, "ERROR: "],
-                      ["WARN: ", "INFO: ", "DEBUG: "]),
+                      [SharedExpected, ERROR],
+                      [WARN, INFO, DEBUG]),
     %% fix bad app file
     ok = file:write_file(?APP_FILE, app(logging, [])),
     retest:log(info, "Check 'compile' success output~n"),
     ok = check_output("./rebar compile", should_succeed,
                       [SharedExpected],
-                      ["ERROR: ", "WARN: ", "INFO: ", "DEBUG: "]),
+                      [ERROR, WARN, INFO, DEBUG]),
     retest:log(info, "Check 'compile -v' success output~n"),
     ok = check_output("./rebar compile -v", should_succeed,
                       [SharedExpected],
-                      ["ERROR: ", "INFO: ", "DEBUG: "]),
+                      [ERROR, INFO, DEBUG]),
     retest:log(info, "Check 'compile -vv' success output~n"),
     ok = check_output("./rebar compile -vv", should_succeed,
-                      [SharedExpected, "DEBUG: "],
-                      ["ERROR: ", "INFO: "]),
+                      [SharedExpected, DEBUG],
+                      [ERROR, INFO]),
     ok.
 
 check_output(Cmd, FailureMode, Expected, Unexpected) ->
@@ -47,7 +64,7 @@ check_output(Cmd, FailureMode, Expected, Unexpected) ->
     end.
 
 check_output1(Cmd, Captured, Expected, Unexpected) ->
-    ReOpts = [{capture, all, list}],
+    ReOpts = [{capture, all, list}, unicode],
     ExMatches =
         lists:zf(
           fun(Pattern) ->
diff --git a/src/rebar_log.erl b/src/rebar_log.erl
index ba25332..689e628 100644
--- a/src/rebar_log.erl
+++ b/src/rebar_log.erl
@@ -60,9 +60,10 @@ log(Level, Str, Args) ->
 
 log(Device, Level, Str, Args) ->
     {ok, LogLevel} = application:get_env(rebar, log_level),
+    {ok, LogColored} = application:get_env(rebar, log_colored),
     case should_log(LogLevel, Level) of
         true ->
-            io:format(Device, log_prefix(Level) ++ Str, Args);
+            io:format(Device, log_prefix(Level, LogColored) ++ Str, Args);
         false ->
             ok
     end.
@@ -90,7 +91,33 @@ should_log(error, error) -> true;
 should_log(error, _)     -> false;
 should_log(_, _)         -> false.
 
+log_prefix(Level, _Colored = false) ->
+    log_prefix(Level);
+log_prefix(Level, _Colored = true) ->
+    color_from_level(Level) ++ log_prefix(Level) ++ reset_color().
+
 log_prefix(debug) -> "DEBUG: ";
 log_prefix(info)  -> "INFO:  ";
 log_prefix(warn)  -> "WARN:  ";
 log_prefix(error) -> "ERROR: ".
+
+color_from_level(debug) ->
+    color_foreground(blue);
+color_from_level(info) ->
+    color_foreground(green);
+color_from_level(warn) ->
+    color_foreground(yellow);
+color_from_level(error) ->
+    color_bold() ++ color_foreground(red).
+
+color_foreground(black)   -> "\e[30m";
+color_foreground(red)     -> "\e[31m";
+color_foreground(green)   -> "\e[32m";
+color_foreground(yellow)  -> "\e[33m";
+color_foreground(blue)    -> "\e[34m";
+color_foreground(magenta) -> "\e[35m";
+color_foreground(cyan)    -> "\e[36m";
+color_foreground(white)   -> "\e[37m".
+
+color_bold()  -> "\e[1m".
+reset_color() -> "\e[0m".