package ws

import (
	"context"
	"fmt"
	"log"
	"os/exec"
	"strconv"
	"strings"
	"time"
)

type Handler struct {
	client *Client
}

func NewHandler(client *Client) *Handler {
	return &Handler{client: client}
}

func (h *Handler) HandleCommand(msg Message) {
	log.Printf("Command erhalten: %s (ID: %s)", msg.Command, msg.ID)

	var response Message
	response.Type = "response"
	response.ID = msg.ID

	switch msg.Command {
	case "exec":
		response = h.handleExec(msg)
	case "update":
		response = h.handleUpdate(msg)
	case "major_update":
		response = h.handleMajorUpdate(msg)
	case "update_check":
		response = h.handleUpdateCheck(msg)
	case "reboot":
		response = h.handleReboot(msg)
	case "tunnel_connect":
		response = h.handleTunnelConnect(msg)
	case "tunnel_disconnect":
		h.handleTunnelDisconnect(msg)
		return
	case "tunnel_open":
		response.Status = "ok"
		response.Data = map[string]interface{}{"message": "tunnel_open deprecated, use tunnel_connect"}
	case "tunnel_close":
		response.Status = "ok"
	default:
		response.Status = "error"
		response.Error = fmt.Sprintf("Unbekanntes Command: %s", msg.Command)
	}

	if err := h.client.SendMessage(response); err != nil {
		log.Printf("Response senden fehlgeschlagen: %v", err)
	}
}

// handleExec fuehrt einen beliebigen Befehl aus
func (h *Handler) handleExec(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}

	command, ok := msg.Params["command"].(string)
	if !ok || command == "" {
		response.Status = "error"
		response.Error = "Parameter 'command' erforderlich"
		return response
	}

	timeoutSec := 30
	if t, ok := msg.Params["timeout"]; ok {
		if ts, ok := t.(float64); ok {
			timeoutSec = int(ts)
		} else if ts, ok := t.(string); ok {
			if parsed, err := strconv.Atoi(ts); err == nil {
				timeoutSec = parsed
			}
		}
	}

	output, err := h.runCommand(command, timeoutSec)

	if err != nil {
		response.Status = "error"
		response.Error = err.Error()
		response.Data = map[string]interface{}{"output": output}
	} else {
		response.Status = "ok"
		response.Data = map[string]interface{}{"output": output}
	}

	return response
}

// handleUpdateCheck prueft ob Updates verfuegbar sind
func (h *Handler) handleUpdateCheck(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}
	log.Println("Update-Check gestartet...")

	result := map[string]interface{}{}

	// 1. OPNsense Core Update pruefen
	coreOutput, coreErr := h.runCommand("/usr/local/sbin/opnsense-update -c", 60)
	if coreErr != nil {
		// Exit 1 = Update verfuegbar
		result["core_update_available"] = true
		result["core_update_info"] = strings.TrimSpace(coreOutput)
	} else {
		result["core_update_available"] = false
		result["core_update_info"] = "Kein Core-Update verfuegbar"
	}

	// 2. Paket-Updates pruefen
	pkgOutput, _ := h.runCommand("/usr/sbin/pkg upgrade -n", 60)
	pendingPackages := h.parsePkgUpgrade(pkgOutput)
	result["package_update_available"] = len(pendingPackages) > 0
	result["pending_packages"] = pendingPackages
	result["pending_count"] = len(pendingPackages)

	response.Status = "ok"
	response.Data = result
	log.Printf("Update-Check abgeschlossen: Core=%v, Packages=%d",
		result["core_update_available"], len(pendingPackages))
	return response
}

// handleUpdate fuehrt ein normales Update durch (Core + Packages)
func (h *Handler) handleUpdate(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}
	log.Println("Normales Update gestartet...")

	reboot := false
	if r, ok := msg.Params["reboot"].(bool); ok {
		reboot = r
	}

	result := map[string]interface{}{
		"steps": []map[string]interface{}{},
	}
	var steps []map[string]interface{}

	// Schritt 1: opnsense-update (Core + Firmware)
	log.Println("Update Schritt 1: opnsense-update")
	coreOutput, coreErr := h.runCommand("/usr/local/sbin/opnsense-update", 600)
	step1 := map[string]interface{}{
		"step":   "opnsense-update",
		"output": coreOutput,
		"ok":     coreErr == nil,
	}
	if coreErr != nil {
		step1["error"] = coreErr.Error()
	}
	steps = append(steps, step1)

	// Schritt 2: pkg upgrade -y (Paket-Updates)
	log.Println("Update Schritt 2: pkg upgrade -y")
	pkgOutput, pkgErr := h.runCommand("/usr/sbin/pkg upgrade -y", 600)
	step2 := map[string]interface{}{
		"step":   "pkg upgrade",
		"output": pkgOutput,
		"ok":     pkgErr == nil,
	}
	if pkgErr != nil {
		step2["error"] = pkgErr.Error()
	}
	steps = append(steps, step2)

	// Schritt 3: opnsense-update -c (Nachpruefung)
	log.Println("Update Schritt 3: Nachpruefung")
	checkOutput, checkErr := h.runCommand("/usr/local/sbin/opnsense-update -c", 60)
	stillPending := checkErr != nil
	step3 := map[string]interface{}{
		"step":            "verify",
		"output":          checkOutput,
		"updates_pending": stillPending,
	}
	steps = append(steps, step3)

	result["steps"] = steps
	result["reboot_requested"] = reboot

	// Gesamtstatus
	if coreErr == nil && pkgErr == nil {
		response.Status = "ok"
		result["message"] = "Update erfolgreich abgeschlossen"
	} else {
		response.Status = "ok" // Nicht "error" — teilweise Updates sind OK
		result["message"] = "Update mit Warnungen abgeschlossen"
	}

	// Reboot wenn gewuenscht
	if reboot {
		log.Println("Reboot nach Update angefordert...")
		result["reboot"] = "Reboot in 5 Sekunden..."
		response.Data = result

		// Response erst senden, dann rebooten
		go func() {
			time.Sleep(5 * time.Second)
			log.Println("Reboot wird ausgefuehrt...")
			exec.Command("/sbin/shutdown", "-r", "now").Run()
		}()

		return response
	}

	response.Data = result
	log.Println("Update abgeschlossen")
	return response
}

// handleMajorUpdate fuehrt ein Major-Upgrade durch
func (h *Handler) handleMajorUpdate(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}

	targetVersion, ok := msg.Params["version"].(string)
	if !ok || targetVersion == "" {
		response.Status = "error"
		response.Error = "Parameter 'version' erforderlich (z.B. '26.7')"
		return response
	}

	reboot := false
	if r, ok := msg.Params["reboot"].(bool); ok {
		reboot = r
	}

	log.Printf("Major-Update auf Version %s gestartet...", targetVersion)

	result := map[string]interface{}{
		"target_version": targetVersion,
	}
	var steps []map[string]interface{}

	// Schritt 1: opnsense-update -r <version> (Release wechseln)
	log.Printf("Major-Update Schritt 1: opnsense-update -r %s", targetVersion)
	releaseCmd := fmt.Sprintf("/usr/local/sbin/opnsense-update -r %s", targetVersion)
	releaseOutput, releaseErr := h.runCommand(releaseCmd, 300)
	step1 := map[string]interface{}{
		"step":   fmt.Sprintf("opnsense-update -r %s", targetVersion),
		"output": releaseOutput,
		"ok":     releaseErr == nil,
	}
	if releaseErr != nil {
		step1["error"] = releaseErr.Error()
		steps = append(steps, step1)

		// Bei Fehler im Release-Wechsel abbrechen
		result["steps"] = steps
		result["message"] = "Release-Wechsel fehlgeschlagen"
		response.Status = "error"
		response.Error = "Release-Wechsel fehlgeschlagen"
		response.Data = result
		return response
	}
	steps = append(steps, step1)

	// Schritt 2: opnsense-update (eigentliches Update laden)
	log.Println("Major-Update Schritt 2: opnsense-update")
	updateOutput, updateErr := h.runCommand("/usr/local/sbin/opnsense-update", 900)
	step2 := map[string]interface{}{
		"step":   "opnsense-update",
		"output": updateOutput,
		"ok":     updateErr == nil,
	}
	if updateErr != nil {
		step2["error"] = updateErr.Error()
	}
	steps = append(steps, step2)

	// Schritt 3: pkg upgrade -y
	log.Println("Major-Update Schritt 3: pkg upgrade -y")
	pkgOutput, pkgErr := h.runCommand("/usr/sbin/pkg upgrade -y", 600)
	step3 := map[string]interface{}{
		"step":   "pkg upgrade",
		"output": pkgOutput,
		"ok":     pkgErr == nil,
	}
	if pkgErr != nil {
		step3["error"] = pkgErr.Error()
	}
	steps = append(steps, step3)

	result["steps"] = steps
	result["reboot_requested"] = reboot

	if updateErr == nil {
		result["message"] = fmt.Sprintf("Major-Update auf %s abgeschlossen", targetVersion)
	} else {
		result["message"] = fmt.Sprintf("Major-Update auf %s mit Warnungen", targetVersion)
	}

	response.Status = "ok"

	if reboot {
		log.Println("Reboot nach Major-Update angefordert...")
		result["reboot"] = "Reboot in 5 Sekunden..."
		response.Data = result

		go func() {
			time.Sleep(5 * time.Second)
			log.Println("Reboot wird ausgefuehrt...")
			exec.Command("/sbin/shutdown", "-r", "now").Run()
		}()

		return response
	}

	response.Data = result
	log.Printf("Major-Update auf %s abgeschlossen", targetVersion)
	return response
}

// handleReboot fuehrt einen Reboot durch
func (h *Handler) handleReboot(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}

	delaySec := 5
	if d, ok := msg.Params["delay"].(float64); ok && d > 0 {
		delaySec = int(d)
	}

	log.Printf("Reboot angefordert (Verzoegerung: %ds)", delaySec)

	response.Status = "ok"
	response.Data = map[string]interface{}{
		"message": fmt.Sprintf("Reboot in %d Sekunden", delaySec),
	}

	go func() {
		time.Sleep(time.Duration(delaySec) * time.Second)
		log.Println("Reboot wird ausgefuehrt...")
		exec.Command("/sbin/shutdown", "-r", "now").Run()
	}()

	return response
}

// --- Tunnel Handlers ---

func (h *Handler) handleTunnelConnect(msg Message) Message {
	response := Message{Type: "response", ID: msg.ID}

	sessionID, _ := msg.Params["session_id"].(string)
	tunnelID, _ := msg.Params["tunnel_id"].(string)
	targetHost, _ := msg.Params["target_host"].(string)
	targetPortFloat, _ := msg.Params["target_port"].(float64)
	targetPort := int(targetPortFloat)

	if sessionID == "" || targetHost == "" || targetPort <= 0 {
		response.Status = "error"
		response.Error = "session_id, target_host und target_port erforderlich"
		return response
	}

	if err := h.client.tunnelManager.ConnectSession(sessionID, tunnelID, targetHost, targetPort); err != nil {
		response.Status = "error"
		response.Error = fmt.Sprintf("Session-Connect fehlgeschlagen: %v", err)
		return response
	}

	response.Status = "ok"
	response.Data = map[string]interface{}{"session_id": sessionID}
	return response
}

func (h *Handler) handleTunnelDisconnect(msg Message) {
	sessionID, _ := msg.Params["session_id"].(string)
	if sessionID != "" {
		h.client.tunnelManager.DisconnectSession(sessionID)
	}
}

// --- Helper ---

// runCommand fuehrt einen Shell-Befehl mit Timeout aus
func (h *Handler) runCommand(command string, timeoutSec int) (string, error) {
	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(timeoutSec)*time.Second)
	defer cancel()

	cmd := exec.CommandContext(ctx, "/bin/sh", "-c", command)
	output, err := cmd.CombinedOutput()
	return string(output), err
}

// parsePkgUpgrade parst die Ausgabe von "pkg upgrade -n"
func (h *Handler) parsePkgUpgrade(output string) []map[string]string {
	var packages []map[string]string

	inUpgradeBlock := false
	for _, line := range strings.Split(output, "\n") {
		trimmed := strings.TrimSpace(line)

		if strings.Contains(trimmed, "packages to be UPGRADED") ||
			strings.Contains(trimmed, "will be affected") {
			inUpgradeBlock = true
			continue
		}

		if inUpgradeBlock && strings.Contains(trimmed, "->") {
			parts := strings.SplitN(trimmed, ":", 2)
			if len(parts) == 2 {
				pkg := strings.TrimSpace(parts[0])
				versions := strings.TrimSpace(parts[1])

				arrowParts := strings.SplitN(versions, "->", 2)
				if len(arrowParts) == 2 {
					packages = append(packages, map[string]string{
						"package":         pkg,
						"current_version": strings.TrimSpace(arrowParts[0]),
						"new_version":     strings.TrimSpace(arrowParts[1]),
					})
				}
			}
		}

		if inUpgradeBlock && (trimmed == "" || strings.HasPrefix(trimmed, "Number of")) {
			if !strings.HasPrefix(trimmed, "Number of") {
				inUpgradeBlock = false
			}
		}
	}

	return packages
}

// SendSessionData schickt Tunnel-Daten als Binary-Message zurueck zum Backend
func (h *Handler) SendSessionData(sessionID string, data []byte) error {
	idBytes := []byte(sessionID)
	if len(idBytes) > 255 {
		return fmt.Errorf("session_id zu lang")
	}

	message := make([]byte, 1+len(idBytes)+len(data))
	message[0] = byte(len(idBytes))
	copy(message[1:], idBytes)
	copy(message[1+len(idBytes):], data)

	return h.client.SendBinaryData(message)
}