From 8ee5950308ef08a4f2805486660c677a3dac1bd1 Mon Sep 17 00:00:00 2001
From: "Sean E. Russell" <ser@ser1.net>
Date: Tue, 18 Feb 2020 11:27:29 -0600
Subject: [PATCH] Adds a battery gauge.

---
 CHANGELOG.md            |  6 +++-
 README.md               |  2 +-
 layout/layout.go        |  4 +++
 termui/gauge.go         | 22 ++++++++++++
 widgets/batterygauge.go | 77 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 109 insertions(+), 2 deletions(-)
 create mode 100644 termui/gauge.go
 create mode 100644 widgets/batterygauge.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32bd5e4..91f6405 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,7 +13,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 > - **Fixed**: for any bug fixes.
 > - **Security**: in case of vulnerabilities.
 
-## [3.3.0] - 
+## [3.x.x] - 
+
+- Adds a battery gauge as `power`
+
+## [3.3.0] - 2020-02-17
 
 - Added: Logs are now rotated. Settings are currently hard-coded at 4 files of 5MB
   each, so logs shouldn't take up more than 20MB.  I'm going to see how many
diff --git a/README.md b/README.md
index a3ff80c..b2dcebc 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ and these are separated by spaces.
 1. Each line is a row
 2. Empty lines are skipped
 3. Spaces are compressed (so you can do limited visual formatting)
-4. Legal widget names are: cpu, disk, mem, temp, batt, net, procs
+4. Legal widget names are: cpu, disk, mem, temp, batt, net, procs, power
 5. Widget names are not case sensitive
 4. The simplest row is a single widget, by name, e.g.
    ```
diff --git a/layout/layout.go b/layout/layout.go
index c78bb67..5872cf2 100644
--- a/layout/layout.go
+++ b/layout/layout.go
@@ -170,6 +170,10 @@ func makeWidget(c gotop.Config, widRule widgetRule) interface{} {
 			i++
 		}
 		w = b
+	case "power":
+		b := widgets.NewBatteryGauge()
+		b.BarColor = ui.Color(c.Colorscheme.ProcCursor)
+		w = b
 	default:
 		log.Printf("Invalid widget name %s.  Must be one of %v", widRule.Widget, widgetNames)
 		return ui.NewBlock()
diff --git a/termui/gauge.go b/termui/gauge.go
new file mode 100644
index 0000000..db9a9c0
--- /dev/null
+++ b/termui/gauge.go
@@ -0,0 +1,22 @@
+package termui
+
+import (
+	. "github.com/gizak/termui/v3"
+	gizak "github.com/gizak/termui/v3/widgets"
+)
+
+// LineGraph implements a line graph of data points.
+type Gauge struct {
+	*gizak.Gauge
+}
+
+func NewGauge() *Gauge {
+	return &Gauge{
+		Gauge: gizak.NewGauge(),
+	}
+}
+
+func (self *Gauge) Draw(buf *Buffer) {
+	self.Gauge.Draw(buf)
+	self.Gauge.SetRect(self.Min.X, self.Min.Y, self.Inner.Dx(), self.Inner.Dy())
+}
diff --git a/widgets/batterygauge.go b/widgets/batterygauge.go
new file mode 100644
index 0000000..04b1434
--- /dev/null
+++ b/widgets/batterygauge.go
@@ -0,0 +1,77 @@
+package widgets
+
+import (
+	"fmt"
+	"log"
+	//"math"
+	//"strconv"
+	"time"
+
+	"github.com/distatus/battery"
+	"github.com/prometheus/client_golang/prometheus"
+
+	. "github.com/xxxserxxx/gotop/termui"
+)
+
+type BatteryGauge struct {
+	*Gauge
+	metric prometheus.Gauge
+}
+
+func NewBatteryGauge() *BatteryGauge {
+	self := &BatteryGauge{Gauge: NewGauge()}
+	self.Title = " Power Level "
+
+	self.update()
+
+	go func() {
+		for range time.NewTicker(time.Second).C {
+			self.Lock()
+			self.update()
+			self.Unlock()
+		}
+	}()
+
+	return self
+}
+
+func (b *BatteryGauge) EnableMetric() {
+	bats, err := battery.GetAll()
+	if err != nil {
+		log.Printf("error setting up metrics: %v", err)
+		return
+	}
+	mx := 0.0
+	cu := 0.0
+	for _, bat := range bats {
+		mx += bat.Full
+		cu += bat.Current
+		gauge := prometheus.NewGauge(prometheus.GaugeOpts{
+			Namespace: "gotop",
+			Subsystem: "battery",
+			Name:      "total",
+		})
+		gauge.Set(cu / mx)
+		b.metric = gauge
+		prometheus.MustRegister(gauge)
+	}
+}
+
+func (self *BatteryGauge) update() {
+	bats, err := battery.GetAll()
+	if err != nil {
+		log.Printf("error setting up metrics: %v", err)
+		return
+	}
+	mx := 0.0
+	cu := 0.0
+	for _, bat := range bats {
+		mx += bat.Full
+		cu += bat.Current
+	}
+	self.Percent = int((cu / mx) * 100.0)
+	self.Label = fmt.Sprintf("%d%%", self.Percent)
+	if self.metric != nil {
+		self.metric.Set(cu / mx)
+	}
+}