package qq_napcat

import (
	"encoding/json"
	"fmt"
	"strings"

	"nukumizu-backend/config"
	"nukumizu-backend/internal/controller"
	"nukumizu-backend/internal/komari"
	"nukumizu-backend/internal/node"
	"nukumizu-backend/internal/template"
	"nukumizu-backend/postLog"
)

// oneBotEvent mirrors a OneBot 11 event pushed over the NapCat WebSocket.
// Only "message" events are handled; notice/request/meta_event are ignored.
type oneBotEvent struct {
	PostType    string          `json:"post_type"`
	MessageType string          `json:"message_type"`
	GroupID     int64           `json:"group_id"`
	UserID      int64           `json:"user_id"`
	RawMessage  string          `json:"raw_message"`
	Message     json.RawMessage `json:"message"`
	Sender      struct {
		UserID   int64  `json:"user_id"`
		Nickname string `json:"nickname"`
	} `json:"sender"`
	SelfID  int64  `json:"self_id"`
	SubType string `json:"sub_type"`
}

// QQController handles QQ Bot interactions by connecting directly to NapCat.
type QQController struct {
	cfg          config.QQConfig
	napcatClient *Client
}

// NewQQController creates a new QQ (Napcat) controller.
func NewQQController(cfg config.QQConfig) *QQController {
	q := &QQController{cfg: cfg}
	if cfg.Enabled {
		q.napcatClient = NewClient(cfg.NapcatAddr, cfg.NapcatPort, cfg.NapcatToken)
	}
	return q
}

// Name returns the controller name.
func (q *QQController) Name() string {
	return "qq(napcat)"
}

// Start initializes the QQ controller and starts the NapCat WebSocket listener.
func (q *QQController) Start() error {
	if !q.cfg.Enabled {
		// postLog.Info("QQ (Napcat) controller is disabled")
		return nil
	}
	if q.napcatClient == nil {
		postLog.Warning("QQ (Napcat) controller enabled but NapCat client is nil")
		return nil
	}

	postLog.Info("QQ (Napcat) controller started, connecting to NapCat WebSocket...")
	go func() {
		defer func() {
			if r := recover(); r != nil {
				postLog.Error(fmt.Sprintf("Napcat WS listener panic recovered: %v", r))
			}
		}()
		q.napcatClient.Listen(q.handleNapcatEvent)
	}()

	return nil
}

// Stop shuts down the QQ controller and its WebSocket listener.
func (q *QQController) Stop() {
	if q.napcatClient != nil {
		q.napcatClient.Stop()
	}
	postLog.Info("QQ (Napcat) controller stopped")
}

// IsEnabled returns whether the controller is enabled.
func (q *QQController) IsEnabled() bool {
	return q.cfg.Enabled
}

// handleNapcatEvent processes a raw OneBot event received from the NapCat WebSocket.
func (q *QQController) handleNapcatEvent(raw []byte) {
	var ev oneBotEvent
	if err := json.Unmarshal(raw, &ev); err != nil {
		postLog.Debug("Failed to parse NapCat WS event: " + err.Error())
		return
	}

	// Only handle message events; ignore notice/request/meta_event.
	if ev.PostType != "message" {
		return
	}

	// Ignore messages the bot itself sent (echo prevention).
	if q.isSelfMessage(ev) {
		return
	}

	// Determine chat information.
	chatID := ev.GroupID
	if ev.MessageType == "private" {
		chatID = ev.UserID
	}

	// Build a command from the raw message.
	cmd := controller.Command{
		RawText:  ev.RawMessage,
		ChatID:   chatID,
		ChatType: ev.MessageType,
		SenderID: ev.UserID,
	}

	response, err := q.HandleCommand(cmd)
	if err != nil {
		postLog.Error("Napcat command handling failed: " + err.Error())
		return
	}

	if response == "" {
		return
	}

	// Reply in the same chat.
	if ev.MessageType == "private" {
		if _, err := q.napcatClient.SendMsg("private", ev.UserID, response, false, 0); err != nil {
			postLog.Warning("Failed to send NapCat private reply: " + err.Error())
		}
	} else {
		if _, err := q.napcatClient.SendMsg("group", ev.GroupID, response, false, 0); err != nil {
			postLog.Warning("Failed to send NapCat group reply: " + err.Error())
		}
	}
}

// isSelfMessage returns true when the event was generated by the bot itself.
func (q *QQController) isSelfMessage(ev oneBotEvent) bool {
	if q.cfg.BotQQID > 0 && ev.SelfID == q.cfg.BotQQID {
		return true
	}
	if ev.UserID == ev.SelfID {
		return true
	}
	return false
}

// HandleCommand processes a bot command and returns a response string.
func (q *QQController) HandleCommand(cmd controller.Command) (string, error) {
	cfg := config.GetConfig()

	// Debug: when ShowNapcatMsg is enabled, echo the received message back in real-time.
	if cfg.Debug.ShowNapcatMsg {
		postLog.Debug("Napcat message received: " + cmd.RawText)
		return cmd.RawText, nil
	}

	text := cmd.RawText

	// Check listen method. In "at" mode the @mention must be stripped before
	// parsing, otherwise raw_message like "[CQ:at,qq=123] /list" fails the
	// "/" prefix check.
	if q.cfg.ListenMethod == "at" {
		atMention := fmt.Sprintf("[CQ:at,qq=%d]", q.cfg.BotQQID)
		if !strings.Contains(text, atMention) {
			return "", nil // Not mentioned, ignore.
		}
		text = strings.ReplaceAll(text, atMention, "")
	}

	parsed, ok := controller.ParseCommand(text)
	if !ok {
		// Not a command. In "global" mode, silently ignore.
		// In "at" mode, this would be an error - but at detection happens at the message level.
		return "", nil
	}

	parsed.ChatID = cmd.ChatID
	parsed.ChatType = cmd.ChatType
	parsed.SenderID = cmd.SenderID

	return q.executeCommand(parsed)
}

func (q *QQController) executeCommand(cmd controller.Command) (string, error) {
	// Validate against supported commands.
	switch cmd.Command {
	case "list":
		return q.handleList()
	case "status":
		return q.handleStatus(cmd)
	case "shutdown":
		return q.handleShutdown(cmd)
	case "reboot":
		return q.handleReboot(cmd)
	case "run":
		return q.handleRun(cmd)
	default:
		if q.cfg.ListenMethod == "at" {
			return "Unknown command: /" + cmd.Command, nil
		}
		return "", nil // Global mode: silently ignore unknown commands.
	}
}

func (q *QQController) isAdmin(senderID int64) bool {
	senderStr := fmt.Sprintf("%d", senderID)
	for _, admin := range q.cfg.Admins {
		if admin == senderStr {
			return true
		}
	}
	return false
}

func (q *QQController) handleList() (string, error) {
	cfg := config.GetConfig()
	params := template.BuildParamsFromServerList()
	return template.Render(cfg.ControllerMessage.ServerList, params), nil
}

func (q *QQController) handleStatus(cmd controller.Command) (string, error) {
	if len(cmd.Args) < 1 {
		return "Usage: /status <uuid>", nil
	}
	uuid := cmd.Args[0]
	tracker := node.GetTracker()
	n, exists := tracker.GetNode(uuid)
	if !exists {
		return fmt.Sprintf("Server with UUID %s not found", uuid), nil
	}

	statusStr := "Offline"
	if n.Online {
		statusStr = "Online"
	}

	var sb strings.Builder
	sb.WriteString(fmt.Sprintf("Server: %s (%s)\n", n.Name, n.UUID))
	sb.WriteString(fmt.Sprintf("Status: %s\n", statusStr))

	if n.LatestReport != nil {
		r := n.LatestReport
		sb.WriteString(fmt.Sprintf("CPU: %.2f%%\n", r.CPU.Usage))
		sb.WriteString(fmt.Sprintf("RAM: %d / %d\n", r.RAM.Used, r.RAM.Total))
		sb.WriteString(fmt.Sprintf("Disk: %d / %d\n", r.Disk.Used, r.Disk.Total))
		sb.WriteString(fmt.Sprintf("Network: ↑%d ↓%d\n", r.Network.Up, r.Network.Down))
		sb.WriteString(fmt.Sprintf("Uptime: %d seconds\n", r.Uptime))
		sb.WriteString(fmt.Sprintf("Processes: %d\n", r.Process))
		if r.Message != "" {
			sb.WriteString(fmt.Sprintf("Message: %s\n", r.Message))
		}
	}

	return sb.String(), nil
}

func (q *QQController) handleShutdown(cmd controller.Command) (string, error) {
	if !q.isAdmin(cmd.SenderID) {
		return "Permission denied: admin only", nil
	}
	if len(cmd.Args) < 1 {
		return "Usage: /shutdown <uuid>", nil
	}

	uuid := cmd.Args[0]
	client := komari.GetClient()
	if client == nil {
		return "Error: Komari client not initialized", nil
	}

	_, err := client.ExecTask([]string{uuid}, "shutdown")
	if err != nil {
		return fmt.Sprintf("Error: %v", err), nil
	}

	return fmt.Sprintf("Shutdown command sent to server %s", uuid), nil
}

func (q *QQController) handleReboot(cmd controller.Command) (string, error) {
	if !q.isAdmin(cmd.SenderID) {
		return "Permission denied: admin only", nil
	}
	if len(cmd.Args) < 1 {
		return "Usage: /reboot <uuid>", nil
	}

	uuid := cmd.Args[0]
	client := komari.GetClient()
	if client == nil {
		return "Error: Komari client not initialized", nil
	}

	_, err := client.ExecTask([]string{uuid}, "reboot")
	if err != nil {
		return fmt.Sprintf("Error: %v", err), nil
	}

	return fmt.Sprintf("Reboot command sent to server %s", uuid), nil
}

func (q *QQController) handleRun(cmd controller.Command) (string, error) {
	if !q.isAdmin(cmd.SenderID) {
		return "Permission denied: admin only", nil
	}
	if len(cmd.Args) < 2 {
		return "Usage: /run <uuid|all> <command>", nil
	}

	uuidArg := cmd.Args[0]
	command := cmd.Args[1]
	client := komari.GetClient()
	if client == nil {
		return "Error: Komari client not initialized", nil
	}

	var uuids []string
	if uuidArg == "all" {
		tracker := node.GetTracker()
		for _, n := range tracker.GetAllNodes() {
			uuids = append(uuids, n.UUID)
		}
	} else {
		uuids = []string{uuidArg}
	}

	taskID, err := client.ExecTask(uuids, command)
	if err != nil {
		return fmt.Sprintf("Error executing command: %v", err), nil
	}

	results, err := client.PollTaskResult(taskID)
	if err != nil {
		return fmt.Sprintf("Error getting results: %v", err), nil
	}

	cfg := config.GetConfig()
	params := template.BuildParamsFromExecResult(uuidArg, uuidArg, command, formatTaskResults(results))
	return template.Render(cfg.ControllerMessage.ServerExecuteResult, params), nil
}

func formatTaskResults(results []komari.TaskResult) string {
	var sb strings.Builder
	for _, r := range results {
		sb.WriteString(fmt.Sprintf("--- %s ---\n", r.Client))
		sb.WriteString(r.Result)
		sb.WriteString(fmt.Sprintf("\nExit code: %d\n", r.ExitCode))
	}
	return sb.String()
}

// SendStatusChange sends a status change notification via QQ.
func (q *QQController) SendStatusChange(change node.StatusChange) error {
	if !q.cfg.Enabled {
		return nil
	}

	cfg := config.GetConfig()
	params := template.BuildParamsFromStatusChange(change)
	message := template.Render(cfg.ControllerMessage.ServerStatusChanged, params)

	// Send to trusted groups.
	for _, groupID := range q.cfg.TrustedGroups {
		q.sendGroupMessage(groupID, message)
	}

	// Send to admins via private message.
	for _, adminID := range q.cfg.Admins {
		q.sendPrivateMessage(adminID, message)
	}

	return nil
}

// SendServerList sends the server list via QQ.
func (q *QQController) SendServerList(onlineServers, offlineServers string) error {
	if !q.cfg.Enabled {
		return nil
	}

	cfg := config.GetConfig()
	params := template.BuildParamsFromServerList()
	message := template.Render(cfg.ControllerMessage.ServerList, params)

	for _, groupID := range q.cfg.TrustedGroups {
		q.sendGroupMessage(groupID, message)
	}
	return nil
}

// SendExecuteResult sends a command execution result via QQ.
func (q *QQController) SendExecuteResult(serverName, serverUUID, command, result string) error {
	if !q.cfg.Enabled {
		return nil
	}

	cfg := config.GetConfig()
	params := template.BuildParamsFromExecResult(serverName, serverUUID, command, result)
	message := template.Render(cfg.ControllerMessage.ServerExecuteResult, params)

	for _, groupID := range q.cfg.TrustedGroups {
		q.sendGroupMessage(groupID, message)
	}
	return nil
}

func (q *QQController) sendGroupMessage(groupID string, message string) {
	if q.napcatClient == nil {
		postLog.Warning("Cannot send QQ group message: NapCat client not initialized")
		return
	}

	var groupIDInt int64
	if _, err := fmt.Sscanf(groupID, "%d", &groupIDInt); err != nil || groupIDInt == 0 {
		postLog.Warning(fmt.Sprintf("Invalid QQ group ID: %s", groupID))
		return
	}

	if _, err := q.napcatClient.SendMsg("group", groupIDInt, message, false, 0); err != nil {
		postLog.Warning(fmt.Sprintf("Failed to send QQ group message to %s: %v", groupID, err))
	}
}

func (q *QQController) sendPrivateMessage(userID string, message string) {
	if q.napcatClient == nil {
		postLog.Warning("Cannot send QQ private message: NapCat client not initialized")
		return
	}

	var userIDInt int64
	if _, err := fmt.Sscanf(userID, "%d", &userIDInt); err != nil || userIDInt == 0 {
		postLog.Warning(fmt.Sprintf("Invalid QQ user ID: %s", userID))
		return
	}

	if _, err := q.napcatClient.SendMsg("private", userIDInt, message, false, 0); err != nil {
		postLog.Warning(fmt.Sprintf("Failed to send QQ private message to %s: %v", userID, err))
	}
}