primeiro commit

internal/ui/graph.go

@@ -0,0 +1,113 @@
+package ui
+
+import (
+	"math"
+	"sync"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/rivo/tview"
+)
+
+type rateSample struct {
+	inBitsPerSecond  float64
+	outBitsPerSecond float64
+}
+
+// RateGraph draws inbound and outbound bit-rate history.
+type RateGraph struct {
+	*tview.Box
+	mu         sync.Mutex
+	samples    []rateSample
+	maxSamples int
+}
+
+// NewRateGraph creates a graph primitive with bounded history.
+func NewRateGraph(maxSamples int) *RateGraph {
+	graph := &RateGraph{
+		Box:        tview.NewBox().SetBorder(true).SetTitle(" Interface traffic "),
+		maxSamples: maxSamples,
+	}
+	return graph
+}
+
+// AddSample appends one inbound/outbound sample to the graph.
+func (g *RateGraph) AddSample(inBitsPerSecond float64, outBitsPerSecond float64) {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	g.samples = append(g.samples, rateSample{
+		inBitsPerSecond:  inBitsPerSecond,
+		outBitsPerSecond: outBitsPerSecond,
+	})
+	if len(g.samples) > g.maxSamples {
+		g.samples = g.samples[len(g.samples)-g.maxSamples:]
+	}
+}
+
+// Draw renders the graph primitive.
+func (g *RateGraph) Draw(screen tcell.Screen) {
+	g.Box.DrawForSubclass(screen, g)
+	x, y, width, height := g.GetInnerRect()
+	if width <= 0 || height <= 0 {
+		return
+	}
+
+	samples := g.copySamples()
+	if len(samples) == 0 {
+		return
+	}
+
+	maxRate := maxSampleRate(samples)
+	if maxRate <= 0 {
+		maxRate = 1
+	}
+
+	label := "in: green  out: blue"
+	for i, r := range label {
+		if i >= width {
+			break
+		}
+		screen.SetContent(x+i, y, r, nil, tcell.StyleDefault.Foreground(tcell.ColorGray))
+	}
+
+	start := 0
+	if len(samples) > width {
+		start = len(samples) - width
+	}
+	plotHeight := height - 1
+	for col, sample := range samples[start:] {
+		drawPoint(screen, x+col, y+1, plotHeight, sample.inBitsPerSecond, maxRate, tcell.ColorGreen)
+		drawPoint(screen, x+col, y+1, plotHeight, sample.outBitsPerSecond, maxRate, tcell.ColorDodgerBlue)
+	}
+}
+
+func (g *RateGraph) copySamples() []rateSample {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	samples := make([]rateSample, len(g.samples))
+	copy(samples, g.samples)
+	return samples
+}
+
+func maxSampleRate(samples []rateSample) float64 {
+	var maxRate float64
+	for _, sample := range samples {
+		maxRate = math.Max(maxRate, sample.inBitsPerSecond)
+		maxRate = math.Max(maxRate, sample.outBitsPerSecond)
+	}
+	return maxRate
+}
+
+func drawPoint(screen tcell.Screen, x int, y int, height int, value float64, maxRate float64, color tcell.Color) {
+	if height <= 0 {
+		return
+	}
+	ratio := value / maxRate
+	if ratio < 0 {
+		ratio = 0
+	}
+	if ratio > 1 {
+		ratio = 1
+	}
+	row := height - 1 - int(math.Round(ratio*float64(height-1)))
+	screen.SetContent(x, y+row, '●', nil, tcell.StyleDefault.Foreground(color))
+}