Closes #52. Add Power module

This module displaysw which source is providing power (AC or battery)
and for the battery displays the current charge capacity, how long it
will last, and the battery state.

cmdrunner/widget.go

@@ -21,7 +21,6 @@ type Widget struct {
 }
 
 func NewWidget() *Widget {
-
 	widget := Widget{
 		TextWidget: wtf.NewTextWidget(" 🏃 Runner ", "cmdrunner", false),
 

power/battery.go

@@ -0,0 +1,116 @@
+package power
+
+import (
+	"fmt"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/senorprogrammer/wtf/wtf"
+)
+
+const TimeRegExp = "^(?:\\d|[01]\\d|2[0-3]):[0-5]\\d"
+
+type Battery struct {
+	args   []string
+	cmd    string
+	result string
+
+	Charge    string
+	Remaining string
+}
+
+func NewBattery() *Battery {
+	battery := Battery{
+		args: []string{"-g", "batt"},
+		cmd:  "pmset",
+	}
+
+	return &battery
+}
+
+/* -------------------- Exported Functions -------------------- */
+
+func (battery *Battery) Refresh() {
+	data := battery.execute()
+	battery.result = battery.parse(data)
+}
+
+func (battery *Battery) String() string {
+	return battery.result
+}
+
+/* -------------------- Unexported Functions -------------------- */
+
+func (battery *Battery) execute() string {
+	cmd := exec.Command(battery.cmd, battery.args...)
+	return wtf.ExecuteCommand(cmd)
+}
+
+func (battery *Battery) parse(data string) string {
+	lines := strings.Split(data, "\n")
+	if len(lines) < 2 {
+		return "unknown (1)"
+	}
+
+	stats := strings.Split(lines[1], "\t")
+	if len(stats) < 2 {
+		return "unknown (2)"
+	}
+
+	details := strings.Split(stats[1], "; ")
+	if len(details) < 3 {
+		return "unknown (3)"
+	}
+
+	str := ""
+	str = str + fmt.Sprintf(" %10s: %s\n", "Charge", battery.formatCharge(details[0]))
+	str = str + fmt.Sprintf(" %10s: %s\n", "Remaining", battery.formatRemaining(details[2]))
+	str = str + fmt.Sprintf(" %10s: %s\n", "State", battery.formatState(details[1]))
+
+	return str
+}
+
+func (battery *Battery) formatCharge(data string) string {
+	percent, _ := strconv.ParseFloat(strings.Replace(data, "%", "", -1), 32)
+
+	color := ""
+
+	switch {
+	case percent >= 70:
+		color = "[green]"
+	case percent >= 35:
+		color = "[yellow]"
+	default:
+		color = "[red]"
+	}
+
+	return color + data + "[white]"
+}
+
+func (battery *Battery) formatRemaining(data string) string {
+	r, _ := regexp.Compile(TimeRegExp)
+
+	result := r.FindString(data)
+	if result == "" {
+		result = "∞"
+	}
+
+	return result
+}
+
+func (battery *Battery) formatState(data string) string {
+	color := ""
+
+	switch data {
+	case "charging":
+		color = "[green]"
+	case "discharging":
+		color = "[yellow]"
+	default:
+		color = "[white]"
+	}
+
+	return color + data + "[white]"
+}

power/source.go

@@ -0,0 +1,25 @@
+package power
+
+import (
+	"os/exec"
+	"regexp"
+	"strings"
+
+	"github.com/senorprogrammer/wtf/wtf"
+)
+
+const SingleQuotesRegExp = "'(.*)'"
+
+// powerSource returns the name of the current power source, probably one of
+// "AC Power" or "Battery Power"
+func powerSource() string {
+	cmd := exec.Command("pmset", []string{"-g", "ps"}...)
+	result := wtf.ExecuteCommand(cmd)
+
+	r, _ := regexp.Compile(SingleQuotesRegExp)
+
+	source := r.FindString(result)
+	source = strings.Replace(source, "'", "", -1)
+
+	return source
+}

power/widget.go

@@ -0,0 +1,45 @@
+package power
+
+import (
+	"fmt"
+
+	"github.com/olebedev/config"
+	"github.com/senorprogrammer/wtf/wtf"
+)
+
+// Config is a pointer to the global config object
+var Config *config.Config
+
+type Widget struct {
+	wtf.TextWidget
+
+	Battery *Battery
+}
+
+func NewWidget() *Widget {
+	widget := Widget{
+		TextWidget: wtf.NewTextWidget(" ⚡️ Power ", "power", false),
+		Battery:    NewBattery(),
+	}
+
+	widget.View.SetWrap(true)
+
+	return &widget
+}
+
+func (widget *Widget) Refresh() {
+	if widget.Disabled() {
+		return
+	}
+
+	widget.UpdateRefreshedAt()
+	widget.Battery.Refresh()
+	widget.View.Clear()
+
+	str := ""
+	str = str + fmt.Sprintf(" %10s: %s\n", "Source", powerSource())
+	str = str + "\n"
+	str = str + widget.Battery.String()
+
+	fmt.Fprintf(widget.View, "%s", str)
+}

wtf.go

@@ -18,6 +18,7 @@ import (
 	"github.com/senorprogrammer/wtf/jira"
 	"github.com/senorprogrammer/wtf/newrelic"
 	"github.com/senorprogrammer/wtf/opsgenie"
+	"github.com/senorprogrammer/wtf/power"
 	"github.com/senorprogrammer/wtf/security"
 	"github.com/senorprogrammer/wtf/status"
 	"github.com/senorprogrammer/wtf/system"
@@ -157,6 +158,7 @@ func main() {
 	jira.Config = Config
 	newrelic.Config = Config
 	opsgenie.Config = Config
+	power.Config = Config
 	security.Config = Config
 	status.Config = Config
 	system.Config = Config
@@ -175,6 +177,7 @@ func main() {
 		jira.NewWidget(),
 		newrelic.NewWidget(),
 		opsgenie.NewWidget(),
+		power.NewWidget(),
 		security.NewWidget(),
 		status.NewWidget(),
 		system.NewWidget(date, version),