Log output is now colored

color/color.go

@@ -0,0 +1,31 @@
+// Package color provides a list of escape sequences to output colored text to terminal
+package color
+
+import "io"
+
+const (
+	None   = ""
+	Reset  = "\033[0m"
+	Bold   = "\033[1m"
+	Red    = "\033[31m"
+	Green  = "\033[32m"
+	Yellow = "\033[33m"
+	Blue   = "\033[34m"
+	Purple = "\033[35m"
+	Cyan   = "\033[36m"
+	Gray   = "\033[37m"
+	White  = "\033[97m"
+)
+
+func Apply(writer io.StringWriter, color string, do func()) {
+	if color == None {
+		do()
+		return
+	}
+
+	writer.WriteString(color)
+
+	do()
+
+	writer.WriteString(Reset)
+}

ctrls/log/log.go

@@ -0,0 +1,7 @@
+package log
+
+import "github.com/thehungry-dev/cog"
+
+func LogTextExample() cog.Writer {
+	return cog.TagsWriter
+}

ctrls/message/message.go

@@ -1,4 +1,4 @@
-package handler
+package message
 
 import (
 	tagfilterctrls "github.com/thehungry-dev/cog/ctrls/tag/filter"

device/device.go

@@ -0,0 +1,14 @@
+// Package device provides different kind of devices valid for log output
+package device
+
+import "io"
+
+var Null io.StringWriter
+
+type nullStringWriter struct{}
+
+func (nullStringWriter) WriteString(_ string) (int, error) { return 0, nil }
+
+func init() {
+	Null = nullStringWriter{}
+}

go.mod

@@ -2,4 +2,7 @@ module github.com/thehungry-dev/cog
 
 go 1.16
 
-require github.com/thehungry-dev/asserting v0.2.0
+require (
+	github.com/mattn/go-isatty v0.0.13
+	github.com/thehungry-dev/asserting v0.2.0
+)

go.sum

@@ -1,2 +1,6 @@
+github.com/mattn/go-isatty v0.0.13 h1:qdl+GuBjcsKKDco5BsxPJlId98mSWNKqYA+Co0SC1yA=
+github.com/mattn/go-isatty v0.0.13/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/thehungry-dev/asserting v0.2.0 h1:hgQgVuRR7zUOSF547H0MQ2JvZdAwxLIC2f9cukQMCl4=
 github.com/thehungry-dev/asserting v0.2.0/go.mod h1:rwslLo/jyrmtsHYm8f9YIuI2qKwUQAQUR/oCz1jeN6A=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42 h1:vEOn+mP2zCOVzKckCZy6YsCtDblrpj/w7B9nxGNELpg=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

message/transform/to_text.go

@@ -17,38 +17,53 @@ func ToTextConfigured(msg message.Message, config Config) string {
 	text := msg.Body
 
 	var buf strings.Builder
+	painter := config.BuildPainter(&buf)
+
+	painter.BeginMessage(msg)
 
 	if config.Timestamp {
-		timestamp(&buf, msg)
+		painter.BeginTimestamp(msg)
+		putTimestamp(&buf, msg)
+		painter.EndTimestamp(msg)
 	}
 
 	if config.Tags {
-		tags(&buf, msg)
+		painter.BeginTags(msg)
+		putTags(&buf, msg)
+		painter.EndTags(msg)
 	}
 
 	if config.Level {
-		level(&buf, msg)
+		painter.BeginLevel(msg)
+		putLevel(&buf, msg)
+		painter.EndLevel(msg)
 	}
 
+	painter.BeginBody(msg)
 	buf.WriteString(text)
+	painter.EndBody(msg)
 
 	if config.Fields {
-		fields(&buf, msg)
+		painter.BeginFields(msg)
+		putFields(&buf, msg)
+		painter.EndFields(msg)
 	}
 
+	painter.EndMessage(msg)
+
 	buf.WriteString("\n")
 
 	return buf.String()
 }
 
-func timestamp(buf io.StringWriter, msg message.Message) {
+func putTimestamp(buf io.StringWriter, msg message.Message) {
 	buf.WriteString("[")
 	data := msg.Timestamp.Format(time.RFC3339)
 	buf.WriteString(data)
 	buf.WriteString("] ")
 }
 
-func tags(buf io.StringWriter, msg message.Message) {
+func putTags(buf io.StringWriter, msg message.Message) {
 	if len(msg.Tags) == 0 {
 		return
 	}
@@ -65,14 +80,14 @@ func tags(buf io.StringWriter, msg message.Message) {
 	buf.WriteString("| ")
 }
 
-func level(buf io.StringWriter, msg message.Message) {
+func putLevel(buf io.StringWriter, msg message.Message) {
 	lvlText := msg.Level.String()
 	lvlText = strings.ToUpper(lvlText)
 	lvlText = fmt.Sprintf("%-5s ", lvlText)
 	buf.WriteString(lvlText)
 }
 
-func fields(buf io.StringWriter, msg message.Message) {
+func putFields(buf io.StringWriter, msg message.Message) {
 	switch msg.Content {
 	case message.DataContent:
 		data := FieldsToTextJSON(msg)

message/transform/transform.go

@@ -1,28 +1,37 @@
 // Package transform converts a build message into different formats
 package transform
 
+import (
+	"io"
+
+	"github.com/thehungry-dev/cog/paint"
+)
+
 type Config struct {
-	Timestamp bool
-	Tags      bool
-	Level     bool
-	Fields    bool
+	Timestamp    bool
+	Tags         bool
+	Level        bool
+	Fields       bool
+	BuildPainter func(io.StringWriter) paint.Painter
 }
 
 var DefaultConfig Config
 var EverythingConfig Config
 
 func init() {
 	DefaultConfig = Config{
-		Timestamp: true,
-		Tags:      false,
-		Level:     true,
-		Fields:    true,
+		Timestamp:    true,
+		Tags:         false,
+		Level:        true,
+		Fields:       true,
+		BuildPainter: paint.NewFullPainter,
 	}
 
 	EverythingConfig = Config{
-		Timestamp: true,
-		Tags:      true,
-		Level:     true,
-		Fields:    true,
+		Timestamp:    true,
+		Tags:         true,
+		Level:        true,
+		Fields:       true,
+		BuildPainter: paint.NewFullPainter,
 	}
 }

paint/full_painter.go

@@ -0,0 +1,46 @@
+package paint
+
+import (
+	"io"
+
+	"github.com/thehungry-dev/cog/color"
+	"github.com/thehungry-dev/cog/message"
+)
+
+type fullPainter struct {
+	buf    io.StringWriter
+	styled bool
+}
+
+func NewFullPainter(buf io.StringWriter) Painter {
+	return &fullPainter{buf: buf, styled: false}
+}
+
+func (painter *fullPainter) BeginMessage(msg message.Message) {
+	clr := Color(msg.Level)
+
+	painter.styled = clr != color.None
+
+	painter.buf.WriteString(clr)
+}
+
+func (painter *fullPainter) EndMessage(msg message.Message) {
+	if !painter.styled {
+		return
+	}
+
+	painter.styled = false
+
+	painter.buf.WriteString(color.Reset)
+}
+
+func (*fullPainter) BeginTimestamp(_ message.Message) {}
+func (*fullPainter) EndTimestamp(_ message.Message)   {}
+func (*fullPainter) BeginTags(_ message.Message)      {}
+func (*fullPainter) EndTags(_ message.Message)        {}
+func (*fullPainter) BeginLevel(_ message.Message)     {}
+func (*fullPainter) EndLevel(_ message.Message)       {}
+func (*fullPainter) BeginBody(_ message.Message)      {}
+func (*fullPainter) EndBody(_ message.Message)        {}
+func (*fullPainter) BeginFields(_ message.Message)    {}
+func (*fullPainter) EndFields(_ message.Message)      {}

paint/null_painter.go

@@ -0,0 +1,24 @@
+package paint
+
+import (
+	"io"
+
+	"github.com/thehungry-dev/cog/message"
+)
+
+type nullPainter struct{}
+
+func (nullPainter) BeginMessage(_ message.Message)   {}
+func (nullPainter) EndMessage(_ message.Message)     {}
+func (nullPainter) BeginTimestamp(_ message.Message) {}
+func (nullPainter) EndTimestamp(_ message.Message)   {}
+func (nullPainter) BeginTags(_ message.Message)      {}
+func (nullPainter) EndTags(_ message.Message)        {}
+func (nullPainter) BeginLevel(_ message.Message)     {}
+func (nullPainter) EndLevel(_ message.Message)       {}
+func (nullPainter) BeginBody(_ message.Message)      {}
+func (nullPainter) EndBody(_ message.Message)        {}
+func (nullPainter) BeginFields(_ message.Message)    {}
+func (nullPainter) EndFields(_ message.Message)      {}
+
+func NewNullPainter(_ io.StringWriter) Painter { return NullPainter }

paint/paint.go

@@ -0,0 +1,39 @@
+// Package paint provides an interface to set terminal output colors for parts or the entirety of a log message
+package paint
+
+import (
+	"github.com/thehungry-dev/cog/color"
+	"github.com/thehungry-dev/cog/level"
+	"github.com/thehungry-dev/cog/message"
+)
+
+type Painter interface {
+	BeginMessage(msg message.Message)
+	EndMessage(msg message.Message)
+	BeginTimestamp(msg message.Message)
+	EndTimestamp(msg message.Message)
+	BeginTags(msg message.Message)
+	EndTags(msg message.Message)
+	BeginLevel(msg message.Message)
+	EndLevel(msg message.Message)
+	BeginBody(msg message.Message)
+	EndBody(msg message.Message)
+	BeginFields(msg message.Message)
+	EndFields(msg message.Message)
+}
+
+var NullPainter Painter
+
+func Color(lvl level.Level) string {
+	clr, ok := palette[lvl]
+
+	if !ok {
+		return color.None
+	}
+
+	return clr
+}
+
+func init() {
+	NullPainter = nullPainter{}
+}

paint/palette.go

@@ -0,0 +1,18 @@
+package paint
+
+import (
+	"github.com/thehungry-dev/cog/color"
+	"github.com/thehungry-dev/cog/level"
+)
+
+var palette map[level.Level]string
+
+func init() {
+	palette = make(map[level.Level]string, 6)
+	palette[level.Trace] = color.None
+	palette[level.Debug] = color.Green
+	palette[level.Info] = color.White
+	palette[level.Warn] = color.Yellow
+	palette[level.Error] = color.Red
+	palette[level.Fatal] = color.Red + color.Bold
+}