// backend\server.go
package main

import (
	"bytes"
	"context"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"net"
	"net/http"
	"os"
	"os/exec"
	"os/signal"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/joho/godotenv"
)

var embeddedTLSOnce sync.Once
var embeddedTLSCertPath string
var embeddedTLSKeyPath string
var embeddedTLSErr error

func embeddedTLSPathsCached() (string, string, error) {
	embeddedTLSOnce.Do(func() {
		embeddedTLSCertPath, embeddedTLSKeyPath, embeddedTLSErr = embeddedTLSFilesDir()
	})

	return embeddedTLSCertPath, embeddedTLSKeyPath, embeddedTLSErr
}

func escapePowerShell(s string) string {
	return strings.ReplaceAll(s, "'", "''")
}

func escapeAppleScript(s string) string {
	s = strings.ReplaceAll(s, "\\", "\\\\")
	s = strings.ReplaceAll(s, `"`, `\"`)
	return s
}

func showAppNotification(title, message string) error {
	switch runtime.GOOS {
	case "windows":
		ps := fmt.Sprintf(`
			Add-Type -AssemblyName System.Windows.Forms
			Add-Type -AssemblyName System.Drawing

			$n = New-Object System.Windows.Forms.NotifyIcon
			$n.Icon = [System.Drawing.SystemIcons]::Information
			$n.BalloonTipTitle = '%s'
			$n.BalloonTipText  = '%s'
			$n.Visible = $true
			$n.ShowBalloonTip(3000)
			Start-Sleep -Milliseconds 3500
			$n.Dispose()
			`, escapePowerShell(title), escapePowerShell(message))

		cmd := exec.Command(
			"powershell",
			"-NoProfile",
			"-NonInteractive",
			"-WindowStyle", "Hidden",
			"-ExecutionPolicy", "Bypass",
			"-Command", ps,
		)

		cmd.SysProcAttr = &syscall.SysProcAttr{
			HideWindow:    true,
			CreationFlags: 0x08000000, // CREATE_NO_WINDOW
		}

		return cmd.Run()

	case "darwin":
		return exec.Command(
			"osascript",
			"-e",
			fmt.Sprintf(
				`display notification "%s" with title "%s"`,
				escapeAppleScript(message),
				escapeAppleScript(title),
			),
		).Run()

	case "linux":
		return exec.Command("notify-send", title, message).Run()

	default:
		return nil
	}
}

func buildStartupNotificationMessage() string {
	return "Die App läuft im Hintergrund."
}

type aiServerProcess struct {
	cmd *exec.Cmd
}

func aiServerAutostartEnabled() bool {
	raw := strings.ToLower(strings.TrimSpace(os.Getenv("AI_SERVER_AUTOSTART")))

	// Standard: aktiv.
	if raw == "" {
		return true
	}

	switch raw {
	case "0", "false", "no", "off":
		return false
	default:
		return true
	}
}

var aiServerTokenOnce sync.Once
var aiServerTokenValue string

func randomAISecretHex(bytesLen int) string {
	if bytesLen <= 0 {
		bytesLen = 32
	}

	b := make([]byte, bytesLen)
	if _, err := rand.Read(b); err != nil {
		fallback := fmt.Sprintf("%d-%d", time.Now().UnixNano(), os.Getpid())
		return hex.EncodeToString([]byte(fallback))
	}

	return hex.EncodeToString(b)
}

func aiServerToken() string {
	aiServerTokenOnce.Do(func() {
		token := strings.TrimSpace(os.Getenv("AI_SERVER_TOKEN"))

		if token == "" {
			token = randomAISecretHex(32)
			_ = os.Setenv("AI_SERVER_TOKEN", token)
			appLogln("🔐 AI_SERVER_TOKEN automatisch erzeugt.")
		}

		aiServerTokenValue = token
	})

	return aiServerTokenValue
}

func addAIServerAuth(req *http.Request) {
	if req == nil {
		return
	}

	token := strings.TrimSpace(aiServerToken())
	if token == "" {
		return
	}

	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("X-AI-Server-Token", token)
}

func aiServerURL() string {
	raw := strings.TrimSpace(os.Getenv("AI_SERVER_URL"))
	if raw == "" {
		raw = "http://127.0.0.1:8765"
	}

	return strings.TrimRight(raw, "/")
}

func aiServerPortFromURL() string {
	url := aiServerURL()

	if strings.Contains(url, ":8765") {
		return "8765"
	}

	// Einfacher Fallback. Wenn du später andere Ports willst,
	// setze AI_SERVER_PORT explizit.
	port := strings.TrimSpace(os.Getenv("AI_SERVER_PORT"))
	if port != "" {
		return port
	}

	return "8765"
}

func aiServerPythonPath() string {
	raw := strings.TrimSpace(os.Getenv("AI_SERVER_PYTHON"))
	if raw != "" {
		return raw
	}

	// Windows py launcher zuerst versuchen.
	if runtime.GOOS == "windows" {
		if _, err := exec.LookPath("py"); err == nil {
			return "py"
		}
	}

	if _, err := exec.LookPath("python"); err == nil {
		return "python"
	}

	if _, err := exec.LookPath("python3"); err == nil {
		return "python3"
	}

	return "python"
}

func findAIServerScriptDir() (string, error) {
	cwd, _ := os.Getwd()

	exePath, _ := os.Executable()
	exeDir := ""
	if exePath != "" {
		exeDir = filepath.Dir(exePath)
	}

	candidates := []string{
		filepath.Join(cwd, "backend", "ai_server.py"),
		filepath.Join(cwd, "ai_server.py"),
	}

	if exeDir != "" {
		candidates = append(candidates,
			filepath.Join(exeDir, "backend", "ai_server.py"),
			filepath.Join(exeDir, "ai_server.py"),
		)
	}

	for _, path := range candidates {
		cleanPath := filepath.Clean(path)

		if fi, err := os.Stat(cleanPath); err == nil && fi != nil && !fi.IsDir() {
			appLogln("✅ ai_server.py gefunden:", cleanPath)
			return filepath.Dir(cleanPath), nil
		}
	}

	embeddedDir, err := embeddedAIServerDir()
	if err != nil {
		return "", appErrorf("embedded ai_server.py konnte nicht extrahiert werden: %w", err)
	}

	appLogln("✅ embedded ai_server.py extrahiert:", filepath.Join(embeddedDir, "ai_server.py"))
	return embeddedDir, nil
}

func waitForAIServer(ctx context.Context, url string, timeout time.Duration) error {
	deadline := time.Now().Add(timeout)
	client := &http.Client{
		Timeout: 800 * time.Millisecond,
	}

	for {
		if time.Now().After(deadline) {
			return appErrorf("AI Server nicht rechtzeitig bereit")
		}

		req, err := http.NewRequestWithContext(ctx, http.MethodGet, url+"/health", nil)
		if err == nil {
			addAIServerAuth(req)

			res, err := client.Do(req)
			if err == nil {
				_ = res.Body.Close()

				if res.StatusCode >= 200 && res.StatusCode < 300 {
					return nil
				}
			}
		}

		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-time.After(300 * time.Millisecond):
		}
	}
}

func aiServerStatusHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Nur GET erlaubt", http.StatusMethodNotAllowed)
		return
	}

	url := aiServerURL()
	client := &http.Client{
		Timeout: 900 * time.Millisecond,
	}

	status := map[string]any{
		"ok":      false,
		"running": false,
		"url":     url,
	}

	req, err := http.NewRequestWithContext(r.Context(), http.MethodGet, url+"/health", nil)
	if err != nil {
		status["error"] = err.Error()
		writeJSON(w, http.StatusOK, status)
		return
	}

	addAIServerAuth(req)

	res, err := client.Do(req)
	if err != nil {
		status["error"] = err.Error()
		writeJSON(w, http.StatusOK, status)
		return
	}
	defer res.Body.Close()

	status["statusCode"] = res.StatusCode

	if res.StatusCode >= 200 && res.StatusCode < 300 {
		status["ok"] = true
		status["running"] = true
	}

	writeJSON(w, http.StatusOK, status)
}

func startAIServer(ctx context.Context) (*aiServerProcess, error) {
	if !aiServerAutostartEnabled() {
		appLogln("ℹ️ AI Server Autostart deaktiviert.")
		return nil, nil
	}

	scriptDir, err := findAIServerScriptDir()
	if err != nil {
		return nil, err
	}

	exePath, _ := os.Executable()
	exeDir := ""
	if exePath != "" {
		exeDir = filepath.Dir(exePath)
	}

	appBaseDir := exeDir
	if strings.TrimSpace(appBaseDir) == "" {
		appBaseDir, _ = os.Getwd()
	}

	trainingRoot := filepath.Join(appBaseDir, "generated", "training")
	detectionLabelsPath := filepath.Join(trainingRoot, "detection_labels.json")
	defaultModelPath := filepath.Join(trainingRoot, "detector", "model", "best.pt")

	pythonPath := aiServerPythonPath()
	port := aiServerPortFromURL()

	args := []string{}

	// Windows py launcher braucht meist -3.
	if runtime.GOOS == "windows" && filepath.Base(strings.ToLower(pythonPath)) == "py" {
		args = append(args, "-3")
	}

	args = append(args,
		"-m", "uvicorn",
		"ai_server:app",
		"--host", "0.0.0.0",
		"--port", port,
		"--log-level", "error",
	)

	cmd := exec.CommandContext(ctx, pythonPath, args...)
	cmd.Dir = scriptDir

	env := os.Environ()
	env = append(env,
		"PYTHONUNBUFFERED=1",
		"AI_SERVER_URL="+aiServerURL(),
	)

	env = upsertEnv(env, "AI_SERVER_AUTH_REQUIRED", "1")
	env = upsertEnv(env, "AI_SERVER_TOKEN", aiServerToken())

	appLogln("🔐 AI Server Auth aktiv.")

	// Immer App-Root/generated/training verwenden.
	env = upsertEnv(env, "APP_BASE_DIR", appBaseDir)
	env = upsertEnv(env, "TRAINING_ROOT", trainingRoot)
	env = upsertEnv(env, "DETECTION_LABELS_PATH", detectionLabelsPath)

	// Modell ebenfalls standardmäßig aus generated/training nehmen,
	// aber YOLO_MODEL darf weiterhin extern überschrieben werden.
	if strings.TrimSpace(os.Getenv("YOLO_MODEL")) == "" {
		env = upsertEnv(env, "YOLO_MODEL", defaultModelPath)
	}

	if fi, err := os.Stat(detectionLabelsPath); err != nil || fi == nil || fi.IsDir() {
		appLogln("⚠️ detection_labels.json nicht gefunden:", detectionLabelsPath)
	} else {
		appLogln("✅ detection_labels.json:", detectionLabelsPath)
	}

	if fi, err := os.Stat(defaultModelPath); err != nil || fi == nil || fi.IsDir() {
		appLogln("⚠️ YOLO Modell nicht gefunden:", defaultModelPath)
	} else {
		appLogln("✅ YOLO Modell:", defaultModelPath)
	}

	if strings.TrimSpace(os.Getenv("YOLO_IMGSZ")) == "" {
		env = append(env, "YOLO_IMGSZ=640")
	}
	if strings.TrimSpace(os.Getenv("YOLO_BATCH")) == "" {
		env = append(env, "YOLO_BATCH=16")
	}
	if strings.TrimSpace(os.Getenv("YOLO_CONF")) == "" {
		env = append(env, "YOLO_CONF=0.25")
	}

	cmd.Env = env

	logWriter := appLogWriter()
	cmd.Stdout = logWriter
	cmd.Stderr = logWriter

	if runtime.GOOS == "windows" {
		cmd.SysProcAttr = &syscall.SysProcAttr{
			HideWindow:    true,
			CreationFlags: 0x08000000, // CREATE_NO_WINDOW
		}
	}

	if err := cmd.Start(); err != nil {
		return nil, err
	}

	proc := &aiServerProcess{
		cmd: cmd,
	}

	go func() {
		err := cmd.Wait()

		if err != nil && ctx.Err() == nil {
			appLogf("⚠️ AI Server beendet: %v", err)
		} else {
			appLogln("🛑 AI Server beendet.")
		}
	}()

	waitCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
	defer cancel()

	if err := waitForAIServer(waitCtx, aiServerURL(), 30*time.Second); err != nil {
		appLogln("⚠️ AI Server noch nicht bereit:", err)
		// Nicht hart abbrechen. Deine Analyse kann auf den Fallback gehen.
		return proc, nil
	}

	appLogln("🧠 AI Server bereit:", aiServerURL())
	return proc, nil
}

func (p *aiServerProcess) Stop() {
	if p == nil {
		return
	}

	if p.cmd != nil && p.cmd.Process != nil {
		_ = p.cmd.Process.Kill()
	}
}

func setEnvIfMissing(key, value string) {
	key = strings.TrimSpace(key)
	value = strings.TrimSpace(value)

	if key == "" {
		return
	}

	if strings.TrimSpace(os.Getenv(key)) != "" {
		return
	}

	_ = os.Setenv(key, value)
}

func upsertEnv(env []string, key string, value string) []string {
	key = strings.TrimSpace(key)
	value = strings.TrimSpace(value)

	if key == "" {
		return env
	}

	prefix := strings.ToUpper(key) + "="
	out := make([]string, 0, len(env)+1)
	replaced := false

	for _, item := range env {
		if strings.HasPrefix(strings.ToUpper(item), prefix) {
			if !replaced && value != "" {
				out = append(out, key+"="+value)
				replaced = true
			}
			continue
		}

		out = append(out, item)
	}

	if !replaced && value != "" {
		out = append(out, key+"="+value)
	}

	return out
}

func loadEmbeddedDotEnv() {
	b, err := embeddedDotEnvBytes()
	if err != nil {
		appLogln("ℹ️ Keine eingebettete .env gefunden.")
		return
	}

	envMap, err := godotenv.Parse(bytes.NewReader(b))
	if err != nil {
		appLogln("⚠️ Eingebettete .env konnte nicht gelesen werden:", err)
		return
	}

	for k, v := range envMap {
		setEnvIfMissing(k, v)
	}

	appLogln("✅ Eingebettete .env geladen")
}

func loadExternalDotEnvNextToExe() {
	exePath, err := os.Executable()
	if err != nil {
		if err := godotenv.Overload(); err == nil {
			appLogln("✅ Externe .env geladen aus aktuellem Arbeitsverzeichnis")
		}
		return
	}

	exeDir := filepath.Dir(exePath)
	envPath := filepath.Join(exeDir, ".env")

	if err := godotenv.Overload(envPath); err == nil {
		appLogln("✅ Externe .env geladen und überschreibt embedded/env:", envPath)
		return
	}

	if err := godotenv.Overload(); err == nil {
		appLogln("✅ Externe .env geladen aus aktuellem Arbeitsverzeichnis und überschreibt embedded/env")
	}
}

func loadAppEnv() {
	loadEmbeddedDotEnv()
	loadExternalDotEnvNextToExe()
}

func httpsEnabled() bool {
	raw := strings.ToLower(strings.TrimSpace(os.Getenv("HTTPS_ENABLED")))
	return raw == "1" || raw == "true" || raw == "yes" || raw == "on"
}

func resolveMaybeRelativeToExe(path string) string {
	path = strings.TrimSpace(path)
	if path == "" {
		return ""
	}

	if filepath.IsAbs(path) {
		return path
	}

	exePath, err := os.Executable()
	if err != nil || exePath == "" {
		return path
	}

	return filepath.Join(filepath.Dir(exePath), path)
}

func tlsCertFile() string {
	raw := strings.TrimSpace(os.Getenv("TLS_CERT_FILE"))
	if raw != "" {
		return resolveMaybeRelativeToExe(raw)
	}

	certPath, _, err := embeddedTLSPathsCached()
	if err == nil && certPath != "" {
		return certPath
	}

	return resolveMaybeRelativeToExe("recorder-cert.pem")
}

func tlsKeyFile() string {
	raw := strings.TrimSpace(os.Getenv("TLS_KEY_FILE"))
	if raw != "" {
		return resolveMaybeRelativeToExe(raw)
	}

	_, keyPath, err := embeddedTLSPathsCached()
	if err == nil && keyPath != "" {
		return keyPath
	}

	return resolveMaybeRelativeToExe("recorder-key.pem")
}

func publicAppURL() string {
	scheme := "http"
	if httpsEnabled() {
		scheme = "https"
	}

	host := strings.TrimSpace(os.Getenv("APP_HOST"))
	if host == "" {
		host = "localhost"
	}

	port := strings.TrimSpace(os.Getenv("APP_PORT"))
	if port == "" {
		port = "9999"
	}

	return scheme + "://" + host + ":" + port
}

// --- main ---
func main() {
	clearAppLog()
	initAppLog()
	defer closeAppLog()

	loadAppEnv()

	loadSettings()

	appCtx, appCancel := context.WithCancel(context.Background())
	defer appCancel()

	// Nur eine Instanz erlauben:
	appLn, err := net.Listen("tcp", ":9999")
	if err != nil {
		_ = showAppNotification(
			"Recorder",
			"Die Anwendung wird bereits ausgeführt.",
		)
		appLogln("⚠️ Die App läuft bereits oder Port 9999 ist bereits belegt.")
		os.Exit(0)
	}
	defer appLn.Close()

	aiProc, err := startAIServer(appCtx)
	if err != nil {
		appLogln("⚠️ AI Server konnte nicht gestartet werden:", err)
	}

	// ✅ Hier: alte manuelle Autostart-Pause beim echten App-Start zurücksetzen.
	resetAutostartPauseOnStartup()

	fixKeepRootFilesIntoModelSubdirs()

	postWorkQ.StartWorkers(2)
	enrichQ.StartWorkers(1)
	startPostWorkStatusRefresher()
	startEnrichStatusRefresher()

	startPostworkLeftoverScanOnStartup()

	go startGeneratedGarbageCollector()

	// Altes NSFW-ONNX nicht mehr hart initialisieren.
	// Das neue Training-/YOLO-Modell wird über trainingPredictFrame genutzt.
	var closeNSFWOnce sync.Once
	closeNSFW := func() {
		closeNSFWOnce.Do(func() {
			_ = closeNSFWDetector()
		})
	}
	defer closeNSFW()

	mux := http.NewServeMux()

	auth, err := NewAuthManager()
	if err != nil {
		appLogln("❌ auth init:", err)
		closeNSFW()
		os.Exit(1)
	}

	store := registerRoutes(mux, auth)
	setChaturbateOnlineModelStore(store)

	if err := clearAllPendingAutoStartOnStartup(); err != nil {
		appLogln("⚠️ [pending-autostart] startup clear failed:", err)
	}

	// Hintergrund-Worker
	go startDiskSpaceGuard()
	go startChaturbateOnlinePoller(store)
	go startChaturbateAutoStartWorker(store)
	go startMyFreeCamsAutoStartWorker(store)

	// optional: Bootstrap nur im Hintergrund
	if getSettings().UseChaturbateAPI {
		go func() {
			ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
			defer cancel()

			if _, err := refreshChaturbateSnapshotNow(ctx); err != nil {
				appLogln("⚠️ Chaturbate API failed:", err)
			} else {
				appLogln("✅ Chaturbate API geladen")
			}
		}()
	}

	if _, err := ensureCoversDir(); err != nil {
		appLogln("⚠️ covers dir:", err)
	}

	if httpsEnabled() {
		appLogln("🌐 HTTPS-API aktiv:", publicAppURL())
		appLogln("🔐 TLS Cert:", tlsCertFile())
		appLogln("🔐 TLS Key: ", tlsKeyFile())
	} else {
		appLogln("🌐 HTTP-API aktiv: http://localhost:9999")
	}

	handler := withCORS(mux)
	srv := &http.Server{
		Addr:    ":9999",
		Handler: handler,
	}

	var shutdownOnce sync.Once
	shutdown := func() {
		shutdownOnce.Do(func() {
			if aiProc != nil {
				aiProc.Stop()
			}

			appCancel()

			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
			defer cancel()

			_ = srv.Shutdown(ctx)
			appLogln("🛑 Server beendet.")

			closeNSFW()
		})
	}

	stopSig := make(chan os.Signal, 1)
	signal.Notify(stopSig, os.Interrupt, syscall.SIGTERM)

	go func() {
		<-stopSig
		shutdown()
	}()

	serverErrCh := make(chan error, 1)

	go func() {
		var err error

		if httpsEnabled() {
			err = srv.ServeTLS(appLn, tlsCertFile(), tlsKeyFile())
		} else {
			err = srv.Serve(appLn)
		}

		if err != nil && err != http.ErrServerClosed {
			serverErrCh <- err
			return
		}

		serverErrCh <- nil
	}()

	go func() {
		_ = showAppNotification(
			"Recorder gestartet",
			buildStartupNotificationMessage(),
		)
	}()

	go func() {
		err := <-serverErrCh
		if err != nil {
			appLogln("❌ HTTP-Server Fehler:", err)
			shutdown()
		}
	}()

	runTray(shutdown, buildTrayStats)
	shutdown()
}