package ws

import (
	"context"
	"fmt"
	"log"
	"os/exec"
	"strconv"
	"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 "tunnel_open":
		// Legacy: wird nicht mehr verwendet, aber fuer Kompatibilitaet
		response.Status = "ok"
		response.Data = map[string]interface{}{"message": "tunnel_open deprecated, use tunnel_connect"}
	case "tunnel_connect":
		response = h.handleTunnelConnect(msg)
	case "tunnel_disconnect":
		h.handleTunnelDisconnect(msg)
		return // Keine Response noetig
	case "tunnel_close":
		// Legacy: alle Sessions fuer diesen Tunnel schliessen
		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)
	}
}

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
			}
		}
	}

	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()

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

	return response
}

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 == "" {
		return
	}

	h.client.tunnelManager.DisconnectSession(sessionID)
}

// SendSessionData schickt 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)
}