package service

import (
	"encoding/json"
	"fmt"
	"log"

	kafkago "github.com/segmentio/kafka-go"
)

// MessageHandler 处理 Kafka 消息
type MessageHandler struct {
	wsService *WebSocketService
	reader    *kafkago.Reader
}

// WebSocketMessage 定义 WebSocket 消息结构
type WebSocketMessage struct {
	Type    string          `json:"type"`
	Content string          `json:"content"`
	Payload json.RawMessage `json:"payload,omitempty"`
}

func NewMessageHandler(wsService *WebSocketService, reader *kafkago.Reader) *MessageHandler {
	return &MessageHandler{
		wsService: wsService,
		reader:    reader,
	}
}

// parseJSONMessage 解析并格式化 JSON 消息
func (h *MessageHandler) parseJSONMessage(message []byte) (string, error) {
	var jsonData interface{}
	if err := json.Unmarshal(message, &jsonData); err != nil {
		return "", fmt.Errorf("failed to parse JSON: %v", err)
	}

	prettyJSON, err := json.MarshalIndent(jsonData, "", "    ")
	if err != nil {
		return "", fmt.Errorf("failed to format JSON: %v", err)
	}

	return string(prettyJSON), nil
}

// parseWebSocketMessage 解析为 WebSocketMessage 结构
func (h *MessageHandler) parseWebSocketMessage(message []byte) (*WebSocketMessage, error) {
	var wsMsg WebSocketMessage
	if err := json.Unmarshal(message, &wsMsg); err != nil {
		return nil, fmt.Errorf("failed to parse WebSocket message: %v", err)
	}
	return &wsMsg, nil
}

func (h *MessageHandler) HandleMessage(message *kafkago.Message) error {
	// 解析并打印格式化的 JSON
	prettyJSON, err := h.parseJSONMessage(message.Value)
	if err != nil {
		log.Printf("Error parsing message: %v", err)
		return err
	}
	fmt.Printf("kafka parseJSONMessage:\n%s\n", prettyJSON)

	// 解析为 WebSocketMessage
	wsMsg, err := h.parseWebSocketMessage(message.Value)
	if err != nil {
		log.Printf("Error parsing WebSocket message: %v", err)
		return err
	}

	// 根据消息类型处理不同的业务逻辑
	var processErr error
	switch wsMsg.Type {
	case "message":
		// 处理普通消息
		processErr = h.wsService.Broadcast(message.Value)
	case "broadcast":
		// 广播消息给所有连接的客户端
		processErr = h.wsService.Broadcast(wsMsg.Payload)
	case "private":
		// 处理私聊消息
		processErr = h.wsService.SendPrivateMessage(wsMsg.Payload)
	default:
		log.Printf("Unknown message type: %s", wsMsg.Type)
	}

	if processErr != nil {
		log.Printf("Error processing message: %v", processErr)
	} else {
		log.Printf("Message processed successfully - Topic: %s, Partition: %d, Offset: %d",
			message.Topic, message.Partition, message.Offset)
	}

	return processErr
}