1 files changed, 146 insertions, 0 deletions
diff --git a/liust-50/cmd/liustatus/status.go b/liust-50/cmd/liustatus/status.go
new file mode 100644
index 0000000..06784ba
--- /dev/null
+++ b/liust-50/cmd/liustatus/status.go
@@ -0,0 +1,146 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"strings"
+	"time"
+
+	"janouch.name/desktop-tools/liust-50/charset"
+)
+
+const (
+	displayWidth  = 20
+	displayHeight = 2
+	targetCharset = 0x63
+)
+
+type DisplayState struct {
+	Display [displayHeight][displayWidth]uint8
+}
+
+type Display struct {
+	Current, Last DisplayState
+}
+
+func NewDisplay() *Display {
+	t := &Display{}
+	for y := 0; y < displayHeight; y++ {
+		for x := 0; x < displayWidth; x++ {
+			t.Current.Display[y][x] = ' '
+			t.Last.Display[y][x] = ' '
+		}
+	}
+	return t
+}
+
+func (t *Display) SetLine(row int, content string) {
+	if row < 0 || row >= displayHeight {
+		return
+	}
+
+	runes := []rune(content)
+	for x := 0; x < displayWidth; x++ {
+		if x < len(runes) {
+			b, ok := charset.ResolveRune(runes[x], targetCharset)
+			if ok {
+				t.Current.Display[row][x] = b
+			} else {
+				t.Current.Display[row][x] = '?'
+			}
+		} else {
+			t.Current.Display[row][x] = ' '
+		}
+	}
+}
+
+func (t *Display) HasChanges() bool {
+	for y := 0; y < displayHeight; y++ {
+		for x := 0; x < displayWidth; x++ {
+			if t.Current.Display[y][x] != t.Last.Display[y][x] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (t *Display) Update() {
+	for y := 0; y < displayHeight; y++ {
+		start := -1
+		for x := 0; x < displayWidth; x++ {
+			if t.Current.Display[y][x] != t.Last.Display[y][x] {
+				start = x
+				break
+			}
+		}
+		if start >= 0 {
+			fmt.Printf("\x1b[%d;%dH%s",
+				y+1, start+1, []byte(t.Current.Display[y][start:]))
+			copy(t.Last.Display[y][start:], t.Current.Display[y][start:])
+		}
+	}
+}
+
+func statusProducer(lines chan<- string) {
+	ticker := time.NewTicker(1 * time.Second)
+	defer ticker.Stop()
+
+	temperature, fetcher := "", NewWeatherFetcher()
+	temperatureChan := make(chan string)
+	go fetcher.Run(5*time.Minute, temperatureChan)
+
+	for {
+		select {
+		case newTemperature := <-temperatureChan:
+			temperature = newTemperature
+		default:
+		}
+
+		now := time.Now()
+		status := fmt.Sprintf("%s %3s %s",
+			now.Format("Mon _2 Jan"), temperature, now.Format("15:04"))
+
+		// Ensure exactly 20 characters.
+		runes := []rune(status)
+		if len(runes) > displayWidth {
+			status = string(runes[:displayWidth])
+		} else if len(runes) < displayWidth {
+			status = status + strings.Repeat(" ", displayWidth-len(runes))
+		}
+
+		lines <- status
+		<-ticker.C
+	}
+}
+
+func main() {
+	rand.Seed(time.Now().UTC().UnixNano())
+	terminal := NewDisplay()
+
+	kaomojiChan := make(chan string, 1)
+	statusChan := make(chan string, 1)
+	go func() {
+		kaomojiChan <- strings.Repeat(" ", displayWidth)
+		statusChan <- strings.Repeat(" ", displayWidth)
+	}()
+
+	go kaomojiProducer(kaomojiChan)
+	go statusProducer(statusChan)
+
+	// TODO(p): And we might want to disable cursor visibility as well.
+	fmt.Printf("\x1bR%c", targetCharset)
+	fmt.Print("\x1b[2J") // Clear display
+
+	for {
+		select {
+		case line := <-kaomojiChan:
+			terminal.SetLine(0, line)
+		case line := <-statusChan:
+			terminal.SetLine(1, line)
+		}
+		if terminal.HasChanges() {
+			terminal.Update()
+		}
+	}
+}