package main

import (
	"bufio"
	"context"
	"encoding/hex"
	"encoding/json"
	"flag"
	"fmt"
	"image"
	"image/color"
	"image/draw"
	"image/gif"
	_ "image/jpeg"
	_ "image/png"
	"log"
	"math"
	"net"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"time"

	"git.i0t.app/lwoodard/streamdeck-go/internal/config"
	"git.i0t.app/lwoodard/streamdeck-go/internal/device"
	"git.i0t.app/lwoodard/streamdeck-go/internal/modules"
	"github.com/fsnotify/fsnotify"
	"github.com/srwiley/oksvg"
	"github.com/srwiley/rasterx"
	xdraw "golang.org/x/image/draw"
	"golang.org/x/image/font"
	"golang.org/x/image/font/gofont/gobold"
	"golang.org/x/image/font/opentype"
	"golang.org/x/image/math/fixed"
	"gopkg.in/yaml.v3"
)

// helperSocketPath returns the Unix socket path for the privileged helper.
// /run is the standard location on Linux; /var/run is used on macOS.
func helperSocketPath() string {
	if runtime.GOOS == "darwin" {
		return "/var/run/streamdeck-go/helper.sock"
	}
	return "/run/streamdeck-go/helper.sock"
}

func main() {
	cfgPath := flag.String("config", defaultConfigPath(), "path to config file")
	flag.Parse()

	if err := ensureConfigDir(*cfgPath); err != nil {
		log.Fatalf("setup: %v", err)
	}

	// Load .env file from the config directory so secrets (tokens, passwords)
	// are available via {{env "VAR"}} in module templates without requiring
	// shell exports or service-level environment configuration.
	envPath := filepath.Join(filepath.Dir(*cfgPath), ".env")
	if err := loadEnvFile(envPath); err != nil {
		log.Printf("warn: %v", err)
	}

	cfg, err := config.Load(*cfgPath)
	if err != nil {
		log.Fatalf("config: %v", err)
	}

	reg, err := modules.LoadRegistry(config.ModulesPath(*cfgPath))
	if err != nil {
		log.Fatalf("modules: %v", err)
	}

	// Open device — if not present at startup, wait for it.
	sd := mustConnect(cfg.Device.VendorID, cfg.Device.ProductID)

	// runDone receives true if run() exited because the device died,
	// false if it exited cleanly due to context cancellation.
	runDone := make(chan bool, 1)
	ctx, cancel := context.WithCancel(context.Background())

	startRun := func() {
		go func() {
			deviceDied := run(ctx, sd, cfg, reg)
			runDone <- deviceDied
		}()
	}
	startRun()

	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Fatalf("watcher: %v", err)
	}
	defer watcher.Close()
	_ = watcher.Add(*cfgPath)
	_ = watcher.Add(filepath.Dir(*cfgPath))

	for {
		select {

		// Device died (disconnect, USB suspend, etc.) — reconnect and restart.
		case deviceDied := <-runDone:
			if !deviceDied {
				// Clean cancellation from a config reload below; already restarted.
				continue
			}
			log.Println("device disconnected — waiting for reconnect...")
			sd.Close()
			sd = mustConnect(cfg.Device.VendorID, cfg.Device.ProductID)
			log.Println("device reconnected")
			ctx, cancel = context.WithCancel(context.Background())
			startRun()

		// Config file or modules file changed — reload and restart run().
		case event, ok := <-watcher.Events:
			if !ok {
				cancel()
				return
			}
			cfgChanged := filepath.Clean(event.Name) == filepath.Clean(*cfgPath)
			modChanged := filepath.Clean(event.Name) == filepath.Clean(config.ModulesPath(*cfgPath))
			if !cfgChanged && !modChanged {
				continue
			}
			if !event.Has(fsnotify.Write) && !event.Has(fsnotify.Create) {
				continue
			}

			log.Println("config changed, reloading...")
			cancel()
			<-runDone // wait for run() to fully exit before restarting

			newCfg, err := config.Load(*cfgPath)
			if err != nil {
				log.Printf("reload: bad config: %v — keeping current config", err)
			} else {
				cfg = newCfg
			}
			newReg, err := modules.LoadRegistry(config.ModulesPath(*cfgPath))
			if err != nil {
				log.Printf("reload: bad modules: %v — keeping current modules", err)
			} else {
				reg = newReg
			}
			ctx, cancel = context.WithCancel(context.Background())
			startRun()

		case err, ok := <-watcher.Errors:
			if !ok {
				cancel()
				return
			}
			log.Printf("watcher error: %v", err)
		}
	}
}

// run initialises the deck and handles button presses until ctx is cancelled
// or the device dies. Returns true if the device died, false if ctx was cancelled.
//
// The deck shows one page at a time: the root page (cfg.Keys) or a folder
// (cfg.Folders[name]). Pressing a key with a `folder:` field pushes that folder;
// pressing a folder's back key pops it. Each page owns its own goroutines
// (animations, polls, live text) and is torn down completely before the next
// page is drawn, so a folder's keys never fight the root page's for a slot.
func run(ctx context.Context, sd *device.StreamDeck, cfg *config.Config, reg *modules.Registry) (deviceDied bool) {
	// Recover from any panic inside this goroutine tree.
	defer func() {
		if r := recover(); r != nil {
			log.Printf("panic in run: %v — treating as device error", r)
			deviceDied = true
		}
	}()

	if err := sd.Reset(); err != nil {
		log.Printf("warn: reset: %v", err)
	}
	if err := sd.SetBrightness(cfg.Brightness); err != nil {
		log.Printf("warn: brightness: %v", err)
	}

	// Navigation stack of folder names; empty means the root page is showing.
	var stack []string
	current := openPage(ctx, sd, cfg, reg, "")
	defer func() { current.stop() }()

	showPage := func(name string) {
		current.stop()
		current = openPage(ctx, sd, cfg, reg, name)
	}

	log.Printf("stream deck ready (%d keys)", sd.KeyCount())

	prev := make([]bool, sd.KeyCount())
	consecutiveErrors := 0

	for {
		select {
		case <-ctx.Done():
			return false
		default:
		}

		buttons, err := sd.ReadButtons()
		if err != nil {
			consecutiveErrors++
			if consecutiveErrors >= 3 {
				log.Printf("device error (gave up after %d attempts): %v", consecutiveErrors, err)
				return true
			}
			log.Printf("read error (%d/3): %v", consecutiveErrors, err)
			time.Sleep(200 * time.Millisecond)
			continue
		}
		consecutiveErrors = 0

		if buttons == nil {
			continue // 250 ms timeout, no data
		}

		for i, pressed := range buttons {
			if !pressed || prev[i] {
				continue
			}

			if i == current.backKey {
				stack = stack[:len(stack)-1]
				parent := ""
				if len(stack) > 0 {
					parent = stack[len(stack)-1]
				}
				log.Printf("key %d pressed → back to %s", i, pageName(parent))
				showPage(parent)
				break // this report belongs to the old page
			}

			keyCfg, ok := current.keys[i]
			if !ok {
				continue
			}
			if keyCfg.Command != "" {
				log.Printf("key %d pressed → %s", i, keyCfg.Command)
				go func(cmd string) {
					defer func() {
						if r := recover(); r != nil {
							log.Printf("panic running command %q: %v", cmd, r)
						}
					}()
					runCommand(cmd)
				}(keyCfg.Command)
			}

			// For toggle keys, signal the poll goroutine to re-check state
			// shortly after the command runs (gives the system time to update).
			if ch, ok := current.triggers[i]; ok {
				select {
				case ch <- struct{}{}:
				default:
				}
			}

			if keyCfg.Folder != "" {
				if _, defined := cfg.Folders[keyCfg.Folder]; !defined {
					log.Printf("key %d: folder %q is not defined under folders:", i, keyCfg.Folder)
					continue
				}
				log.Printf("key %d pressed → open folder %q", i, keyCfg.Folder)
				stack = append(stack, keyCfg.Folder)
				showPage(keyCfg.Folder)
				break // this report belongs to the old page
			}
		}
		// Keys still held across a page swap stay "pressed" here, so the new
		// page sees no edge for them until they are physically released.
		prev = buttons
	}
}

// pageName names a page for log lines.
func pageName(folder string) string {
	if folder == "" {
		return "root page"
	}
	return fmt.Sprintf("folder %q", folder)
}

// page is one screenful of keys and the goroutines keeping them drawn.
type page struct {
	keys     map[int]config.KeyConfig // module templates already resolved
	triggers map[int]chan struct{}    // per-key re-poll channels
	backKey  int                      // slot that navigates up, -1 on the root page
	cancel   context.CancelFunc
	wg       sync.WaitGroup
}

// stop tears the page down: cancels its goroutines, waits for them, and blanks
// every key so the next page starts from an empty deck.
func (p *page) stop() {
	p.cancel()
	p.wg.Wait()
}

// openPage clears the deck and draws the root page (folder == "") or the named
// folder, starting whatever goroutines its keys need. Keys that fail to set up
// are logged and skipped — one bad icon must not blank the whole page.
func openPage(parent context.Context, sd *device.StreamDeck, cfg *config.Config, reg *modules.Registry, folder string) *page {
	ctx, cancel := context.WithCancel(parent)
	p := &page{
		keys:     map[int]config.KeyConfig{},
		triggers: map[int]chan struct{}{},
		backKey:  -1,
		cancel:   cancel,
	}

	for i := 0; i < sd.KeyCount(); i++ {
		if err := sd.ClearKey(i); err != nil {
			log.Printf("warn: clear key %d: %v", i, err)
		}
	}

	source := cfg.Keys
	if folder != "" {
		f := cfg.Folders[folder]
		source = f.Keys
		p.backKey = f.BackKey()
		if _, shadowed := source[p.backKey]; shadowed {
			log.Printf("folder %q: key %d is the back key — its own definition is ignored", folder, p.backKey)
		}
		drawBackKey(sd, p.backKey, f.Back, cfg.IconsDir)
	}

	for keyIdx, keyCfg := range source {
		if keyIdx == p.backKey {
			continue
		}
		if keyCfg.Folder != "" {
			if _, defined := cfg.Folders[keyCfg.Folder]; !defined {
				log.Printf("key %d: folder %q is not defined under folders:", keyIdx, keyCfg.Folder)
			}
		}
		resolved, ok := setupKey(ctx, sd, p, keyIdx, keyCfg, cfg.IconsDir, reg)
		if ok {
			p.keys[keyIdx] = resolved
		}
	}
	return p
}

// setupKey resolves module templates, draws the key's initial image, and starts
// any goroutine the key needs (animation, poll, live text). It returns the key
// config with commands resolved — the button loop dispatches from that copy.
// ok is false when the key could not be set up at all.
func setupKey(ctx context.Context, sd *device.StreamDeck, p *page, keyIdx int, keyCfg config.KeyConfig, iconsDir string, reg *modules.Registry) (resolved config.KeyConfig, ok bool) {
	// Resolve module-based commands to shell strings before any other logic.
	if keyCfg.Module != "" {
		cmd, err := reg.Resolve(keyCfg.Module, keyCfg.Function, keyCfg.Params)
		if err != nil {
			log.Printf("key %d: module: %v", keyIdx, err)
			return keyCfg, false
		}
		keyCfg.Command = cmd
	}
	if keyCfg.Poll != nil && keyCfg.Poll.Module != "" {
		cmd, err := reg.Resolve(keyCfg.Poll.Module, keyCfg.Poll.Function, keyCfg.Poll.Params)
		if err != nil {
			log.Printf("key %d: poll module: %v", keyIdx, err)
			return keyCfg, false
		}
		poll := *keyCfg.Poll // don't mutate the shared config
		poll.Command = cmd
		keyCfg.Poll = &poll
	}

	// Optional $(...) sugar → text_command.
	if keyCfg.TextCommand == "" {
		if inner, ok := unwrapCmdSubst(keyCfg.Text); ok {
			keyCfg.TextCommand = inner
			keyCfg.Text = ""
		}
	}

	spawn := func(name string, fn func()) {
		p.wg.Add(1)
		go func() {
			defer p.wg.Done()
			defer func() {
				if r := recover(); r != nil {
					log.Printf("panic in %s %d: %v", name, keyIdx, r)
				}
			}()
			fn()
		}()
	}

	// Dynamic text key: a refresh goroutine owns this key's image. It also
	// handles an optional poll block (choosing icon_true/icon_false per tick),
	// so it must take precedence over the plain toggle path below.
	if keyCfg.TextCommand != "" {
		baseIcon := keyCfg.Icon
		if keyCfg.Poll != nil {
			baseIcon = keyCfg.IconTrue
		}
		if strings.ToLower(filepath.Ext(baseIcon)) == ".gif" ||
			strings.ToLower(filepath.Ext(keyCfg.IconFalse)) == ".gif" {
			log.Printf("key %d: text_command not supported with GIF icon — skipping refresh", keyIdx)
			return keyCfg, true
		}
		trigger := make(chan struct{}, 1)
		p.triggers[keyIdx] = trigger
		kCfg := keyCfg
		spawn("refreshTextKey", func() { refreshTextKey(ctx, sd, keyIdx, kCfg, iconsDir, trigger) })
		return keyCfg, true
	}

	// Toggle/status key: managed by a polling goroutine.
	if keyCfg.Poll != nil {
		if keyCfg.IconTrue == "" || keyCfg.IconFalse == "" {
			log.Printf("key %d: toggle key requires icon_true and icon_false", keyIdx)
			return keyCfg, true
		}
		trigger := make(chan struct{}, 1)
		p.triggers[keyIdx] = trigger
		kCfg := keyCfg
		spawn("pollKey", func() { pollKey(ctx, sd, keyIdx, kCfg, iconsDir, trigger) })
		return keyCfg, true
	}

	// Regular key: load icon once.
	if keyCfg.Icon == "" {
		// No icon — render text-only key on a black background.
		if keyCfg.Text != "" {
			bg := image.NewRGBA(image.Rect(0, 0, sd.ImageWidth(), sd.ImageHeight()))
			img := overlayText(bg, keyCfg.Text, keyCfg.TextColor, sd.ImageWidth())
			if err := sd.SetKeyImage(keyIdx, img); err != nil {
				log.Printf("key %d: set image: %v", keyIdx, err)
			}
		}
		return keyCfg, true
	}
	iconPath := filepath.Join(iconsDir, keyCfg.Icon)

	if strings.ToLower(filepath.Ext(keyCfg.Icon)) == ".gif" {
		frames, delays, err := loadGIF(sd, iconPath)
		if err != nil {
			log.Printf("key %d: load gif %q: %v", keyIdx, keyCfg.Icon, err)
			return keyCfg, true
		}
		spawn("animateKey", func() { animateKey(ctx, sd, keyIdx, frames, delays) })
		return keyCfg, true
	}

	img, err := loadImage(iconPath)
	if err != nil {
		log.Printf("key %d: load icon %q: %v", keyIdx, keyCfg.Icon, err)
		return keyCfg, true
	}
	if keyCfg.Text != "" {
		img = overlayText(img, keyCfg.Text, keyCfg.TextColor, sd.ImageWidth())
	}
	if err := sd.SetKeyImage(keyIdx, img); err != nil {
		log.Printf("key %d: set image: %v", keyIdx, err)
	}
	return keyCfg, true
}

// drawBackKey renders a folder's back key: the configured icon if there is
// one, otherwise a built-in chevron on black, with a "Back" label by default.
func drawBackKey(sd *device.StreamDeck, keyIdx int, back config.BackConfig, iconsDir string) {
	if keyIdx < 0 || keyIdx >= sd.KeyCount() {
		log.Printf("back key %d is outside the deck (%d keys)", keyIdx, sd.KeyCount())
		return
	}
	var img image.Image
	if back.Icon != "" {
		loaded, err := loadImage(filepath.Join(iconsDir, back.Icon))
		if err != nil {
			log.Printf("back key %d: load icon %q: %v — using built-in arrow", keyIdx, back.Icon, err)
		} else {
			img = loaded
		}
	}
	if img == nil {
		img = backArrow(sd.ImageWidth(), sd.ImageHeight(), parseTextColor(back.TextColor))
	}
	text := back.Text
	if text == "" && back.Icon == "" {
		text = "Back"
	}
	if text != "" {
		img = overlayText(img, text, back.TextColor, sd.ImageWidth())
	}
	if err := sd.SetKeyImage(keyIdx, img); err != nil {
		log.Printf("back key %d: set image: %v", keyIdx, err)
	}
}

// backArrow draws a left-pointing chevron in the upper part of a black key,
// leaving the bottom clear for the label.
func backArrow(w, h int, c color.Color) image.Image {
	img := image.NewRGBA(image.Rect(0, 0, w, h))
	draw.Draw(img, img.Bounds(), image.Black, image.Point{}, draw.Src)

	fw, fh := float64(w), float64(h)
	tip := [2]float64{fw * 0.36, fh * 0.40}
	top := [2]float64{fw * 0.62, fh * 0.16}
	bottom := [2]float64{fw * 0.62, fh * 0.64}
	thickness := fw * 0.075

	for y := 0; y < h; y++ {
		for x := 0; x < w; x++ {
			px, py := float64(x)+0.5, float64(y)+0.5
			d := math.Min(distToSegment(px, py, top, tip), distToSegment(px, py, tip, bottom))
			if d <= thickness {
				img.Set(x, y, c)
			}
		}
	}
	return img
}

// distToSegment is the distance from point p to the segment a→b.
func distToSegment(px, py float64, a, b [2]float64) float64 {
	dx, dy := b[0]-a[0], b[1]-a[1]
	lenSq := dx*dx + dy*dy
	t := 0.0
	if lenSq > 0 {
		t = ((px-a[0])*dx + (py-a[1])*dy) / lenSq
		t = math.Max(0, math.Min(1, t))
	}
	cx, cy := a[0]+t*dx, a[1]+t*dy
	return math.Hypot(px-cx, py-cy)
}

// pollKey watches the state of a toggle key and keeps its icon up to date.
// It polls on an interval and also re-polls when triggered (e.g. after a button press).
func pollKey(ctx context.Context, sd *device.StreamDeck, keyIdx int, keyCfg config.KeyConfig, iconsDir string, trigger <-chan struct{}) {
	interval := 2 * time.Second
	if keyCfg.Poll.Interval != "" {
		if d, err := time.ParseDuration(keyCfg.Poll.Interval); err == nil {
			interval = d
		} else {
			log.Printf("key %d: invalid poll interval %q, using 2s", keyIdx, keyCfg.Poll.Interval)
		}
	}

	// Check if icon_true is an animated GIF.
	trueIsGIF := strings.ToLower(filepath.Ext(keyCfg.IconTrue)) == ".gif"
	falseIsGIF := strings.ToLower(filepath.Ext(keyCfg.IconFalse)) == ".gif"

	// Pre-load GIF frames for whichever icons are GIFs.
	var trueFrames [][]byte
	var trueDelays []time.Duration
	var falseFrames [][]byte
	var falseDelays []time.Duration
	var imgTrue, imgFalse image.Image

	if trueIsGIF {
		var err error
		trueFrames, trueDelays, err = loadGIF(sd, filepath.Join(iconsDir, keyCfg.IconTrue))
		if err != nil {
			log.Printf("key %d: load icon_true gif %q: %v", keyIdx, keyCfg.IconTrue, err)
			return
		}
	} else {
		var err error
		imgTrue, err = loadImage(filepath.Join(iconsDir, keyCfg.IconTrue))
		if err != nil {
			log.Printf("key %d: load icon_true %q: %v", keyIdx, keyCfg.IconTrue, err)
			return
		}
	}

	if falseIsGIF {
		var err error
		falseFrames, falseDelays, err = loadGIF(sd, filepath.Join(iconsDir, keyCfg.IconFalse))
		if err != nil {
			log.Printf("key %d: load icon_false gif %q: %v", keyIdx, keyCfg.IconFalse, err)
			return
		}
	} else {
		var err error
		imgFalse, err = loadImage(filepath.Join(iconsDir, keyCfg.IconFalse))
		if err != nil {
			log.Printf("key %d: load icon_false %q: %v", keyIdx, keyCfg.IconFalse, err)
			return
		}
	}
	if keyCfg.Text != "" {
		imgTrue = overlayText(imgTrue, keyCfg.Text, keyCfg.TextColor, sd.ImageWidth())
		imgFalse = overlayText(imgFalse, keyCfg.Text, keyCfg.TextColor, sd.ImageWidth())
	}

	lastState := -1 // unknown, forces initial icon set
	var animCancel context.CancelFunc
	var animWg sync.WaitGroup

	stopAnim := func() {
		if animCancel != nil {
			animCancel()
			animWg.Wait()
			animCancel = nil
		}
	}

	applyState := func() {
		state := queryPollState(keyCfg.Poll)
		if state == lastState {
			return
		}
		stopAnim()
		lastState = state

		if state == 1 {
			if trueIsGIF {
				animCtx, cancel := context.WithCancel(ctx)
				animCancel = cancel
				animWg.Add(1)
				go func() {
					defer animWg.Done()
					animateKey(animCtx, sd, keyIdx, trueFrames, trueDelays)
				}()
			} else {
				if err := sd.SetKeyImage(keyIdx, imgTrue); err != nil {
					log.Printf("key %d: set poll icon: %v", keyIdx, err)
				}
			}
		} else {
			if falseIsGIF {
				animCtx, cancel := context.WithCancel(ctx)
				animCancel = cancel
				animWg.Add(1)
				go func() {
					defer animWg.Done()
					animateKey(animCtx, sd, keyIdx, falseFrames, falseDelays)
				}()
			} else {
				if err := sd.SetKeyImage(keyIdx, imgFalse); err != nil {
					log.Printf("key %d: set poll icon: %v", keyIdx, err)
				}
			}
		}
	}

	applyState() // set icon immediately on startup

	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			stopAnim()
			return
		case <-ticker.C:
			applyState()
		case <-trigger:
			// Wait briefly for the toggle command to take effect, then re-poll.
			select {
			case <-ctx.Done():
				stopAnim()
				return
			case <-time.After(400 * time.Millisecond):
			}
			applyState()
		}
	}
}

// queryPollState runs the poll command and returns 1 (on) or 0 (off).
// If Match is set, checks for that substring in stdout.
// If Match is empty, uses exit code: 0 → on, non-zero → off.
func queryPollState(poll *config.PollConfig) int {
	cmd := exec.Command("sh", "-c", poll.Command)
	output, err := cmd.CombinedOutput()
	if poll.Match == "" {
		if err == nil {
			return 1
		}
		return 0
	}
	if strings.Contains(string(output), poll.Match) {
		return 1
	}
	return 0
}

// refreshTextKey periodically runs keyCfg.TextCommand and renders its stdout as
// the key's text overlay, compositing over the key's base icon each tick (never
// accumulating — overlayText always renders onto a fresh image from the base).
// If the key also has a Poll block, the base icon is chosen from the polled
// state (icon_true/icon_false) so a single goroutine owns the key's image.
func refreshTextKey(ctx context.Context, sd *device.StreamDeck, keyIdx int, keyCfg config.KeyConfig, iconsDir string, trigger <-chan struct{}) {
	// Interval: default 1s, floor 250ms.
	interval := time.Second
	if keyCfg.Refresh != "" {
		if d, err := time.ParseDuration(keyCfg.Refresh); err == nil && d > 0 {
			interval = d
		} else if err != nil {
			log.Printf("key %d: invalid refresh %q, using 1s", keyIdx, keyCfg.Refresh)
		}
	}
	if interval < 250*time.Millisecond {
		interval = 250 * time.Millisecond
	}

	// Preload immutable base image(s). An empty name yields a black background.
	load := func(name string) (image.Image, bool) {
		if name == "" {
			return image.NewRGBA(image.Rect(0, 0, sd.ImageWidth(), sd.ImageHeight())), true
		}
		img, err := loadImage(filepath.Join(iconsDir, name))
		if err != nil {
			log.Printf("key %d: load icon %q: %v", keyIdx, name, err)
			return nil, false
		}
		return img, true
	}

	pollMode := keyCfg.Poll != nil && keyCfg.IconTrue != "" && keyCfg.IconFalse != ""
	var baseImg, imgTrue, imgFalse image.Image
	if pollMode {
		var ok1, ok2 bool
		imgTrue, ok1 = load(keyCfg.IconTrue)
		imgFalse, ok2 = load(keyCfg.IconFalse)
		if !ok1 || !ok2 {
			return
		}
	} else {
		var ok bool
		baseImg, ok = load(keyCfg.Icon) // "" → black background
		if !ok {
			return
		}
	}

	render := func() {
		text := runTextCommand(keyCfg.TextCommand)
		if text == "" {
			text = keyCfg.Text // static fallback
		}
		base := baseImg
		if pollMode {
			if queryPollState(keyCfg.Poll) == 1 {
				base = imgTrue
			} else {
				base = imgFalse
			}
		}
		img := overlayText(base, text, keyCfg.TextColor, sd.ImageWidth())
		if err := sd.SetKeyImage(keyIdx, img); err != nil {
			log.Printf("key %d: set dynamic text image: %v", keyIdx, err)
		}
	}

	render() // set immediately on startup

	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			render()
		case <-trigger:
			// Wait briefly for a press-triggered command to take effect, then re-render.
			select {
			case <-ctx.Done():
				return
			case <-time.After(300 * time.Millisecond):
			}
			render()
		}
	}
}

// runTextCommand runs cmd via sh -c and returns its stdout with trailing
// whitespace/newlines trimmed. Stderr is dropped so it can't pollute the label.
func runTextCommand(cmd string) string {
	out, err := exec.Command("sh", "-c", cmd).Output()
	if err != nil {
		log.Printf("text_command %q: %v", cmd, err)
	}
	return strings.TrimRight(string(out), " \t\r\n")
}

// unwrapCmdSubst returns the inner command if s is exactly "$( ... )".
func unwrapCmdSubst(s string) (string, bool) {
	s = strings.TrimSpace(s)
	if strings.HasPrefix(s, "$(") && strings.HasSuffix(s, ")") {
		inner := strings.TrimSpace(s[2 : len(s)-1])
		if inner != "" {
			return inner, true
		}
	}
	return "", false
}

// mustConnect blocks until the device opens successfully.
//
// Strategy: try quickly at first (device may just be enumerating), then settle
// into a short fixed interval. We deliberately avoid long exponential backoff
// because in KVM setups the device is guaranteed to come back — we just don't
// know when. A 2s poll means the deck is live within ~2s of switching back.
func mustConnect(vendorID, productID uint16) *device.StreamDeck {
	const (
		quickRetries  = 5
		quickInterval = 500 * time.Millisecond
		pollInterval  = 2 * time.Second
	)
	for i := 0; ; i++ {
		sd, err := device.Open(vendorID, productID)
		if err == nil {
			return sd
		}
		wait := pollInterval
		if i < quickRetries {
			wait = quickInterval
		}
		log.Printf("could not open device: %v — retrying in %s", err, wait)
		time.Sleep(wait)
	}
}

// animateKey cycles pre-encoded GIF frames on a key until ctx is cancelled.
//
// Transient HID write errors (USB bus contention, especially with multiple
// concurrent GIFs) are suppressed after the first occurrence to avoid log spam.
// A summary is logged when errors stop or when they become persistent enough
// to indicate a real device problem.
func animateKey(ctx context.Context, sd *device.StreamDeck, keyIdx int, frames [][]byte, delays []time.Duration) {
	var writeErrors int // consecutive HID write failures

	for {
		for i, frame := range frames {
			select {
			case <-ctx.Done():
				return
			default:
			}
			if err := sd.SetKeyFrame(keyIdx, frame); err != nil {
				writeErrors++
				if writeErrors == 50 {
					log.Printf("key %d: %d consecutive frame write errors — device may be unhealthy", keyIdx, writeErrors)
				}
			} else if writeErrors > 0 {
				writeErrors = 0
			}
			select {
			case <-ctx.Done():
				return
			case <-time.After(delays[i]):
			}
		}
	}
}

// loadGIF decodes a GIF and pre-encodes every frame as JPEG bytes.
func loadGIF(sd *device.StreamDeck, path string) (frames [][]byte, delays []time.Duration, err error) {
	f, err := os.Open(path)
	if err != nil {
		return nil, nil, err
	}
	defer f.Close()

	g, err := gif.DecodeAll(f)
	if err != nil {
		return nil, nil, err
	}

	canvas := image.NewRGBA(image.Rect(0, 0, g.Config.Width, g.Config.Height))
	for i, frame := range g.Image {
		draw.Draw(canvas, frame.Bounds(), frame, frame.Bounds().Min, draw.Over)
		encoded, err := sd.EncodeFrame(canvas)
		if err != nil {
			return nil, nil, err
		}
		frames = append(frames, encoded)
		d := g.Delay[i]
		if d <= 0 {
			d = 10
		}
		delays = append(delays, time.Duration(d)*10*time.Millisecond)
	}
	return frames, delays, nil
}

// --- Text overlay ---

var (
	parsedFont *opentype.Font
	fontOnce   sync.Once
)

func getFont() *opentype.Font {
	fontOnce.Do(func() {
		f, err := opentype.Parse(gobold.TTF)
		if err != nil {
			log.Fatalf("parse embedded font: %v", err)
		}
		parsedFont = f
	})
	return parsedFont
}

// parseTextColor converts a color name or hex string to a color.Color.
// Supported names: white (default), black, red, blue. Hex: "#RRGGBB".
func parseTextColor(s string) color.Color {
	switch strings.ToLower(strings.TrimSpace(s)) {
	case "", "white":
		return color.White
	case "black":
		return color.Black
	case "red":
		return color.RGBA{R: 255, A: 255}
	case "blue":
		return color.RGBA{B: 255, A: 255}
	default:
		s = strings.TrimPrefix(s, "#")
		if len(s) == 6 {
			b, err := hex.DecodeString(s)
			if err == nil && len(b) == 3 {
				return color.RGBA{R: b[0], G: b[1], B: b[2], A: 255}
			}
		}
		log.Printf("unknown text_color %q, using white", s)
		return color.White
	}
}

// contrastColor returns black or white depending on which contrasts better
// with the given color. Used for the text outline/shadow.
func contrastColor(c color.Color) color.Color {
	r, g, b, _ := c.RGBA()
	// Perceived luminance (values are 16-bit, so divide by 257 to get 8-bit).
	lum := 0.299*float64(r/257) + 0.587*float64(g/257) + 0.114*float64(b/257)
	if lum > 128 {
		return color.Black
	}
	return color.White
}

// splitLines splits text on explicit newlines only. No automatic word wrapping.
func splitLines(text string) []string {
	return strings.Split(text, "\n")
}

// overlayText renders text onto img at keySize resolution with auto-sizing.
// The image is first scaled to keySize×keySize so font sizes are consistent
// regardless of source image dimensions.
// textColor is parsed from the config; shadow/outline uses the contrasting color.
func overlayText(img image.Image, text, textColorStr string, keySize int) image.Image {
	if text == "" {
		return img
	}

	// Scale to key resolution so font sizing is consistent.
	dst := image.NewRGBA(image.Rect(0, 0, keySize, keySize))
	xdraw.BiLinear.Scale(dst, dst.Bounds(), img, img.Bounds(), xdraw.Over, nil)
	w, h := keySize, keySize

	f := getFont()
	marginX := int(float64(w) * 0.06)
	marginY := int(float64(h) * 0.06)
	availW := w - 2*marginX
	availH := h - 2*marginY

	// Split on explicit newlines only — no automatic word wrapping.
	lines := splitLines(text)

	// Find the largest font size where all lines fit.
	// Cap at h*0.16 (~15pt on 96px key) so text stays label-sized.
	var bestFace font.Face
	maxSize := float64(h) * 0.16
	const minSize = 6.0

	for size := maxSize; size >= minSize; size -= 0.5 {
		face, err := opentype.NewFace(f, &opentype.FaceOptions{
			Size:    size,
			DPI:     72,
			Hinting: font.HintingFull,
		})
		if err != nil {
			continue
		}
		lineH := face.Metrics().Height.Ceil()
		fits := lineH*len(lines) <= availH
		if fits {
			for _, line := range lines {
				if font.MeasureString(face, line).Ceil() > availW {
					fits = false
					break
				}
			}
		}
		if fits {
			bestFace = face
			break
		}
	}
	if bestFace == nil {
		bestFace, _ = opentype.NewFace(f, &opentype.FaceOptions{
			Size: minSize, DPI: 72, Hinting: font.HintingFull,
		})
	}

	metrics := bestFace.Metrics()
	lineH := metrics.Height.Ceil()
	totalH := lineH * len(lines)
	// Bottom-align so the icon stays visible above.
	startY := h - marginY - totalH + metrics.Ascent.Ceil()

	txtColor := parseTextColor(textColorStr)
	shadow := contrastColor(txtColor)

	// Outline offsets for readability on any background.
	offsets := [8]image.Point{
		{-1, -1},
		{0, -1},
		{1, -1},
		{-1, 0},
		{1, 0},
		{-1, 1},
		{0, 1},
		{1, 1},
	}

	for i, line := range lines {
		adv := font.MeasureString(bestFace, line)
		x := (w - adv.Ceil()) / 2
		y := startY + i*lineH

		// Draw outline.
		for _, off := range offsets {
			d := &font.Drawer{
				Dst:  dst,
				Src:  image.NewUniform(shadow),
				Face: bestFace,
				Dot:  fixed.P(x+off.X, y+off.Y),
			}
			d.DrawString(line)
		}
		// Draw text.
		d := &font.Drawer{
			Dst:  dst,
			Src:  image.NewUniform(txtColor),
			Face: bestFace,
			Dot:  fixed.P(x, y),
		}
		d.DrawString(line)
	}

	return dst
}

func loadImage(path string) (image.Image, error) {
	if strings.ToLower(filepath.Ext(path)) == ".svg" {
		return loadSVG(path)
	}
	f, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	img, _, err := image.Decode(f)
	return img, err
}

func loadSVG(path string) (image.Image, error) {
	icon, err := oksvg.ReadIcon(path, oksvg.IgnoreErrorMode)
	if err != nil {
		return nil, err
	}
	const size = 96
	icon.SetTarget(0, 0, size, size)
	rgba := image.NewRGBA(image.Rect(0, 0, size, size))
	scanner := rasterx.NewScannerGV(size, size, rgba, rgba.Bounds())
	raster := rasterx.NewDasher(size, size, scanner)
	icon.Draw(raster, 1.0)
	return rgba, nil
}

func runCommand(cmd string) {
	if strings.HasPrefix(cmd, "priv:") {
		name := strings.TrimPrefix(cmd, "priv:")
		if err := runPrivileged(name); err != nil {
			log.Printf("privileged command %q: %v", name, err)
		}
		return
	}
	c := exec.Command("sh", "-c", cmd)
	c.Stdout = os.Stdout
	c.Stderr = os.Stderr
	if err := c.Run(); err != nil {
		log.Printf("command %q: %v", cmd, err)
	}
}

// runPrivileged dispatches a named privileged command.
// On macOS: reads the user's local whitelist and runs via osascript (admin auth dialog).
// On Linux: sends to the root helper daemon over its Unix socket.
func runPrivileged(name string) error {
	if runtime.GOOS == "darwin" {
		return runPrivilegedDarwin(name)
	}
	return runPrivilegedHelper(name)
}

// runPrivilegedDarwin looks up name in ~/.config/streamdeck-go/privileged.yaml
// and executes it via osascript, which shows the standard macOS admin auth dialog.
func runPrivilegedDarwin(name string) error {
	wlPath := darwinWhitelistPath()
	commands, err := loadPrivilegedCommands(wlPath)
	if err != nil {
		return fmt.Errorf("load whitelist %q: %w", wlPath, err)
	}
	shell, ok := commands[name]
	if !ok {
		return fmt.Errorf("unknown command %q — add it to %s", name, wlPath)
	}
	script := fmt.Sprintf(`do shell script %q with administrator privileges`, shell)
	out, err := exec.Command("osascript", "-e", script).CombinedOutput()
	if err != nil {
		return fmt.Errorf("%w: %s", err, out)
	}
	return nil
}

// runPrivilegedHelper sends a named command to the root helper daemon over its Unix socket.
func runPrivilegedHelper(name string) error {
	conn, err := net.Dial("unix", helperSocketPath())
	if err != nil {
		return fmt.Errorf("helper unavailable (is streamdeck-go-helper.service running?): %w", err)
	}
	defer conn.Close()

	req, _ := json.Marshal(map[string]string{"command": name})
	if _, err := fmt.Fprintf(conn, "%s\n", req); err != nil {
		return fmt.Errorf("send: %w", err)
	}

	scanner := bufio.NewScanner(conn)
	if !scanner.Scan() {
		return fmt.Errorf("no response from helper")
	}

	var resp struct {
		OK    bool   `json:"ok"`
		Error string `json:"error"`
	}
	if err := json.Unmarshal(scanner.Bytes(), &resp); err != nil {
		return fmt.Errorf("bad response: %w", err)
	}
	if !resp.OK {
		return fmt.Errorf("%s", resp.Error)
	}
	return nil
}

func darwinWhitelistPath() string {
	base := os.Getenv("XDG_CONFIG_HOME")
	if base == "" {
		home, _ := os.UserHomeDir()
		base = filepath.Join(home, ".config")
	}
	return filepath.Join(base, "streamdeck-go", "privileged.yaml")
}

func loadPrivilegedCommands(path string) (map[string]string, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}
	var wl struct {
		Commands map[string]string `yaml:"commands"`
	}
	if err := yaml.Unmarshal(data, &wl); err != nil {
		return nil, err
	}
	if wl.Commands == nil {
		return map[string]string{}, nil
	}
	return wl.Commands, nil
}

// loadEnvFile reads a .env file and sets each KEY=VALUE pair in the process
// environment. Blank lines and lines starting with # are ignored. Quoted values
// (single or double) are unquoted. A missing file is silently ignored.
func loadEnvFile(path string) error {
	data, err := os.ReadFile(path)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return fmt.Errorf("load env %q: %w", path, err)
	}
	for _, line := range strings.Split(string(data), "\n") {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		key, val, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}
		key = strings.TrimSpace(key)
		val = strings.TrimSpace(val)
		// Strip matching quotes around value.
		if len(val) >= 2 &&
			((val[0] == '"' && val[len(val)-1] == '"') ||
				(val[0] == '\'' && val[len(val)-1] == '\'')) {
			val = val[1 : len(val)-1]
		}
		os.Setenv(key, val)
	}
	return nil
}

func defaultConfigPath() string {
	return config.DefaultConfigPath()
}

func ensureConfigDir(cfgPath string) error {
	dir := filepath.Dir(cfgPath)
	iconsDir := filepath.Join(dir, "icons")
	if err := os.MkdirAll(iconsDir, 0o755); err != nil {
		return err
	}
	if _, err := os.Stat(cfgPath); os.IsNotExist(err) {
		return os.WriteFile(cfgPath, []byte(defaultConfig(iconsDir)), 0o644)
	}
	return nil
}

func defaultConfig(iconsDir string) string {
	return `# streamdeck-go configuration
# https://git.i0t.app/lwoodard/streamdeck-go

icons_dir: ` + iconsDir + `
brightness: 70

# USB IDs — defaults match Stream Deck XL v2.
# Run: lsusb | grep Elgato
device:
  vendor_id: 0x0fd9
  product_id: 0x00ba

# Keys are 0-indexed, left-to-right, top-to-bottom.
# Stream Deck XL layout (8 columns x 4 rows):
#
#  0  1  2  3  4  5  6  7
#  8  9 10 11 12 13 14 15
# 16 17 18 19 20 21 22 23
# 24 25 26 27 28 29 30 31
#
# icon: filename inside icons_dir (PNG, JPEG, or GIF)
# command: shell command to run on press

keys: {}
`
}