package api

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"time"

	"github.com/cynfo/rmm-backend/db"
	"github.com/cynfo/rmm-backend/ws"
)

type TaskScheduler struct {
	db  *db.Database
	hub *ws.Hub
}

func NewTaskScheduler(database *db.Database, hub *ws.Hub) *TaskScheduler {
	return &TaskScheduler{db: database, hub: hub}
}

func (s *TaskScheduler) Run() {
	log.Println("Task-Scheduler gestartet (30s Intervall)")
	ticker := time.NewTicker(30 * time.Second)
	defer ticker.Stop()

	// Run once immediately
	s.processDueTasks()

	for range ticker.C {
		s.processDueTasks()
	}
}

func (s *TaskScheduler) processDueTasks() {
	tasks, err := s.db.GetDueTasks()
	if err != nil {
		log.Printf("Scheduler: Fehler beim Laden faelliger Tasks: %v", err)
		return
	}

	for _, task := range tasks {
		go s.executeTask(task.ID, task.AgentID, task.Action, task.WebhookURL, task.AgentName, task.CustomerName, task.ScheduledAt)
	}
}

func (s *TaskScheduler) executeTask(taskID int, agentID, action, webhookURL, agentName, customerName, scheduledAt string) {
	log.Printf("Scheduler: Starte Task #%d (%s) fuer Agent %s", taskID, action, agentID)

	// Set status to running
	s.db.UpdateTaskStatus(taskID, "running", nil)

	var result interface{}
	var taskErr error

	switch action {
	case "backup":
		result, taskErr = s.executeBackup(agentID)
	case "update":
		result, taskErr = s.executeUpdate(agentID)
	default:
		taskErr = fmt.Errorf("unbekannte Aktion: %s", action)
	}

	// Update status
	status := "completed"
	if taskErr != nil {
		status = "failed"
		result = map[string]string{"error": taskErr.Error()}
		log.Printf("Scheduler: Task #%d fehlgeschlagen: %v", taskID, taskErr)
	} else {
		log.Printf("Scheduler: Task #%d erfolgreich abgeschlossen", taskID)
	}

	s.db.UpdateTaskStatus(taskID, status, result)

	// Re-read task for webhook payload
	task, _ := s.db.GetTask(taskID)

	// Send webhook if configured
	if webhookURL != "" && task != nil {
		s.sendWebhook(taskID, webhookURL, task)
	}
}

func (s *TaskScheduler) executeBackup(agentID string) (interface{}, error) {
	if !s.hub.IsAgentConnected(agentID) {
		return nil, fmt.Errorf("Agent nicht verbunden")
	}

	cmdID := generateID()
	cmd := map[string]interface{}{
		"type":    "command",
		"id":      cmdID,
		"command": "backup",
		"params":  map[string]interface{}{},
	}

	responseCh := s.hub.RegisterResponseWaiter(cmdID)
	defer s.hub.UnregisterResponseWaiter(cmdID)

	cmdJSON, _ := json.Marshal(cmd)
	if err := s.hub.SendToAgent(agentID, cmdJSON); err != nil {
		return nil, fmt.Errorf("Command senden fehlgeschlagen: %w", err)
	}

	select {
	case resp := <-responseCh:
		respStatus, _ := resp["status"].(string)
		if respStatus != "ok" {
			errMsg, _ := resp["error"].(string)
			return resp, fmt.Errorf("Backup fehlgeschlagen: %s", errMsg)
		}

		data, ok := resp["data"].(map[string]interface{})
		if !ok {
			return resp, fmt.Errorf("ungueltiges Response-Format")
		}

		// Save backup to DB (same logic as triggerBackup handler)
		configB64, _ := data["config"].(string)
		hash, _ := data["hash"].(string)
		sizeFloat, _ := data["size"].(float64)
		size := int(sizeFloat)

		configXML, err := base64.StdEncoding.DecodeString(configB64)
		if err != nil {
			return nil, fmt.Errorf("Base64-Dekodierung fehlgeschlagen")
		}

		backupID, isNew, err := s.db.SaveConfigBackup(agentID, hash, size, string(configXML))
		if err != nil {
			return nil, fmt.Errorf("Backup speichern fehlgeschlagen: %w", err)
		}

		msg := "Backup gespeichert"
		if !isNew {
			msg = "Config unveraendert (Hash identisch)"
		}

		return map[string]interface{}{
			"message":   msg,
			"backup_id": backupID,
			"sha256":    hash,
			"size":      size,
			"new":       isNew,
		}, nil

	case <-time.After(60 * time.Second):
		return nil, fmt.Errorf("Timeout: Agent hat nicht rechtzeitig geantwortet")
	}
}

func (s *TaskScheduler) executeUpdate(agentID string) (interface{}, error) {
	if !s.hub.IsAgentConnected(agentID) {
		return nil, fmt.Errorf("Agent nicht verbunden")
	}

	// First: update_check
	checkCmdID := generateID()
	checkCmd := map[string]interface{}{
		"type":    "command",
		"id":      checkCmdID,
		"command": "update_check",
	}

	checkCh := s.hub.RegisterResponseWaiter(checkCmdID)
	defer s.hub.UnregisterResponseWaiter(checkCmdID)

	checkJSON, _ := json.Marshal(checkCmd)
	if err := s.hub.SendToAgent(agentID, checkJSON); err != nil {
		return nil, fmt.Errorf("Update-Check senden fehlgeschlagen: %w", err)
	}

	var checkResult map[string]interface{}
	select {
	case resp := <-checkCh:
		checkResult = resp
	case <-time.After(120 * time.Second):
		return nil, fmt.Errorf("Timeout beim Update-Check")
	}

	// Then: update
	updateCmdID := generateID()
	updateCmd := map[string]interface{}{
		"type":    "command",
		"id":      updateCmdID,
		"command": "update",
		"params":  map[string]interface{}{"reboot": false},
	}

	updateCh := s.hub.RegisterResponseWaiter(updateCmdID)
	defer s.hub.UnregisterResponseWaiter(updateCmdID)

	updateJSON, _ := json.Marshal(updateCmd)
	if err := s.hub.SendToAgent(agentID, updateJSON); err != nil {
		return nil, fmt.Errorf("Update-Command senden fehlgeschlagen: %w", err)
	}

	select {
	case resp := <-updateCh:
		respStatus, _ := resp["status"].(string)
		if respStatus != "ok" {
			errMsg, _ := resp["error"].(string)
			return resp, fmt.Errorf("Update fehlgeschlagen: %s", errMsg)
		}
		return map[string]interface{}{
			"message":      "Update ausgefuehrt",
			"check_result": checkResult,
			"update_result": resp,
		}, nil
	case <-time.After(900 * time.Second):
		return nil, fmt.Errorf("Timeout beim Update")
	}
}

func (s *TaskScheduler) sendWebhook(taskID int, url string, task interface{}) {
	payload, err := json.Marshal(task)
	if err != nil {
		log.Printf("Scheduler: Webhook-Payload fuer Task #%d serialisieren fehlgeschlagen: %v", taskID, err)
		s.db.SetTaskWebhookResult(taskID, false, fmt.Sprintf("JSON-Fehler: %v", err))
		return
	}

	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Post(url, "application/json", bytes.NewReader(payload))
	if err != nil {
		log.Printf("Scheduler: Webhook fuer Task #%d fehlgeschlagen: %v", taskID, err)
		s.db.SetTaskWebhookResult(taskID, false, fmt.Sprintf("Fehler: %v", err))
		return
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
	response := fmt.Sprintf("HTTP %d: %s", resp.StatusCode, string(body))

	sent := resp.StatusCode >= 200 && resp.StatusCode < 300
	s.db.SetTaskWebhookResult(taskID, sent, response)
	log.Printf("Scheduler: Webhook fuer Task #%d gesendet (Status: %d)", taskID, resp.StatusCode)
}