Initial project skeleton (M0)

Add SPECS.md, JSON config loader with env overrides and validation,
and an empty tview shell with tabs and status bar.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/ui/app.go

@@ -0,0 +1,115 @@
+// Package ui contains the tview user interface.
+package ui
+
+import (
+	"fmt"
+
+	"github.com/gdamore/tcell/v2"
+	"github.com/rivo/tview"
+)
+
+type view struct {
+	key  rune
+	name string
+	body tview.Primitive
+}
+
+// App is the top-level arr-tui application.
+type App struct {
+	app    *tview.Application
+	tabs   *tview.TextView
+	pages  *tview.Pages
+	status *tview.TextView
+	views  []view
+	active int
+}
+
+// New builds the application shell: a tab bar, one page per view and a status bar.
+func New() *App {
+	a := &App{
+		app:    tview.NewApplication(),
+		tabs:   tview.NewTextView().SetDynamicColors(true),
+		pages:  tview.NewPages(),
+		status: tview.NewTextView().SetDynamicColors(true),
+	}
+
+	a.views = []view{
+		{'1', "Movies", placeholder("Movie search (M2)")},
+		{'2', "Series", placeholder("Series search (M3)")},
+		{'3', "Downloads", placeholder("Downloads (M4/M5)")},
+		{'4', "Library", placeholder("Library (v0.2)")},
+	}
+	for i, v := range a.views {
+		a.pages.AddPage(v.name, v.body, true, i == 0)
+	}
+
+	layout := tview.NewFlex().SetDirection(tview.FlexRow).
+		AddItem(a.tabs, 1, 0, false).
+		AddItem(a.pages, 0, 1, true).
+		AddItem(a.status, 1, 0, false)
+
+	a.app.SetRoot(layout, true).EnableMouse(false)
+	a.app.SetInputCapture(a.handleKey)
+	a.SetStatus("[gray]q quit · Tab / 1-4 switch view")
+	a.switchTo(0)
+	return a
+}
+
+// SetStatus replaces the status bar text. Safe to call only from the UI goroutine;
+// use QueueUpdateDraw from other goroutines.
+func (a *App) SetStatus(text string) {
+	a.status.SetText(text)
+}
+
+// Run starts the event loop and blocks until the application quits.
+func (a *App) Run() error {
+	return a.app.Run()
+}
+
+func (a *App) handleKey(ev *tcell.EventKey) *tcell.EventKey {
+	switch ev.Key() {
+	case tcell.KeyCtrlC:
+		a.app.Stop()
+		return nil
+	case tcell.KeyTab:
+		a.switchTo((a.active + 1) % len(a.views))
+		return nil
+	case tcell.KeyBacktab:
+		a.switchTo((a.active + len(a.views) - 1) % len(a.views))
+		return nil
+	case tcell.KeyRune:
+		if ev.Rune() == 'q' {
+			a.app.Stop()
+			return nil
+		}
+		for i, v := range a.views {
+			if ev.Rune() == v.key {
+				a.switchTo(i)
+				return nil
+			}
+		}
+	}
+	return ev
+}
+
+func (a *App) switchTo(i int) {
+	a.active = i
+	a.pages.SwitchToPage(a.views[i].name)
+	a.renderTabs()
+}
+
+func (a *App) renderTabs() {
+	var s string
+	for i, v := range a.views {
+		if i == a.active {
+			s += fmt.Sprintf("[black:white] %c %s [-:-] ", v.key, v.name)
+		} else {
+			s += fmt.Sprintf("[gray] %c %s [-] ", v.key, v.name)
+		}
+	}
+	a.tabs.SetText(s)
+}
+
+func placeholder(text string) tview.Primitive {
+	return tview.NewTextView().SetText(text).SetTextAlign(tview.AlignCenter)
+}