big stuff

* send empty screen after tui confirmation
* add scroll view / viewport
* auto enable scroll view on short terminals
* add motd tips
* add subdirs as categories
* add inline toggle hotkey (i)

3 files changed, 167 insertions, 0 deletions

diff --git a/viewport/scroll.go b/viewport/scroll.go
new file mode 100644
index 0000000..809fe17
--- /dev/null
+++ b/viewport/scroll.go
@@ -0,0 +1,46 @@
+package viewport
+
+import (
+	"github.com/charmbracelet/lipgloss"
+	"pik/menu/style"
+	"strings"
+)
+
+var (
+	ScrollTop          = StyleBarBackground.Render("╷")
+	ScrollSpace        = StyleBarBackground.Render("│")
+	ScrollBarTopEnd    = StyleBar.Render("╓")
+	ScrollBar          = StyleBar.Render("║")
+	ScrollBarBottomEnd = StyleBar.Render("╙")
+	ScrollBottom       = StyleBarBackground.Render("╵")
+)
+
+var (
+	StyleBar = style.New(func() lipgloss.Style {
+		return lipgloss.NewStyle()
+	})
+	StyleBarBackground = style.New(func() lipgloss.Style {
+		return StyleBar.Get().Faint(true)
+	})
+)
+
+func WithScroll(input string, barBegin int, barEnd int) string {
+	lines := strings.Split(input, "\n")
+	for i, line := range lines {
+		selection := ScrollSpace
+		switch {
+		case i == barBegin:
+			selection = StyleBar.Render(ScrollBarTopEnd)
+		case i == 0:
+			selection = StyleBarBackground.Render(ScrollTop)
+		case i == barEnd:
+			selection = StyleBar.Render(ScrollBarBottomEnd)
+		case i > barBegin && i < barEnd:
+			selection = StyleBar.Render(ScrollBar)
+		case i == len(lines)-1:
+			selection = StyleBar.Render(ScrollBottom)
+		}
+		lines[i] = selection + " " + line
+	}
+	return strings.Join(lines, "\n")
+}
diff --git a/viewport/viewport.go b/viewport/viewport.go
new file mode 100644
index 0000000..ff1ca05
--- /dev/null
+++ b/viewport/viewport.go
@@ -0,0 +1,67 @@
+package viewport
+
+import (
+	"strings"
+)
+
+const Caret = "⏵"
+
+func NeedsViewport(input string, height int) bool {
+	lines := strings.Split(input, "\n")
+	return len(lines)-1 > height
+}
+
+func Process(input string, height int) string {
+	lines := strings.Split(input, "\n")
+	if len(lines) > height {
+		cropped, top, bottom := Crop(input, lines, height)
+		return WithScroll(cropped, int(top*float32(height)), int(bottom*float32(height)))
+	}
+	return input
+}
+
+func Focus(lines []string, needle string) int {
+	for i, l := range lines {
+		if strings.Contains(l, needle) {
+			return i
+		}
+	}
+	return -1
+}
+
+func Crop(input string, lines []string, height int) (output string, scrollStart float32, scrollEnd float32) {
+	output = input
+	selectionIndex := Focus(lines, Caret)
+	size := len(lines)
+	if size <= height {
+		return output, 0, 1
+	}
+
+	linesAbove := height / 2
+	linesBelow := height - linesAbove
+	if linesAbove*2 < selectionIndex {
+		linesBelow++
+	}
+
+	start := selectionIndex - linesAbove
+	end := selectionIndex + linesBelow
+
+	if start < 0 {
+		end += -start
+		start = 0
+	}
+
+	if end >= size {
+		diff := size - 1 - end
+		start += diff
+		end += diff
+	}
+
+	scrollStart = float32(start) / float32(size)
+	scrollEnd = float32(end)/float32(size) + float32(1)/float32(size)
+	if scrollEnd > 1 {
+		scrollEnd = 1
+	}
+
+	return strings.Join(lines[start:end], "\n"), scrollStart, scrollEnd
+}
diff --git a/viewport/viewport_test.go b/viewport/viewport_test.go
new file mode 100644
index 0000000..9da4c3c
--- /dev/null
+++ b/viewport/viewport_test.go
@@ -0,0 +1,54 @@
+//go:build test
+
+package viewport
+
+import (
+	"github.com/stretchr/testify/assert"
+	"strings"
+	"testing"
+)
+
+func TestCrop(t *testing.T) {
+	input := `0000
+AAAA
+` + Caret + `BBB
+CCC`
+	expected := `AAAA
+` + Caret + `BBB`
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 2)
+	assert.Equal(t, expected, result)
+}
+
+func TestCrop_Under(t *testing.T) {
+	input := `0000
+AAAA
+` + Caret + `BBB`
+	expected := `AAAA
+` + Caret + `BBB`
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 2)
+	assert.Equal(t, expected, result)
+}
+
+func TestCrop_Unnecessary(t *testing.T) {
+	input := `AAAA
+` + Caret + `BBB
+CCC
+DDDD`
+	expected := input
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 8)
+	assert.Equal(t, expected, result)
+}
+
+func TestNeedsViewport(t *testing.T) {
+	amount := 3
+	input := strings.Repeat("\n", amount)
+	output := NeedsViewport(input, 4)
+	assert.Equal(t, false, output)
+}
+
+func TestNeedsViewport_Negative(t *testing.T) {
+	amount := 8
+	input := strings.Repeat("\n", amount)
+	output := NeedsViewport(input, 4)
+	assert.Equal(t, true, output)
+}