package handler

import (
	"io"
	"net/http"
	"resume-platform/internal/service/chat"

	"github.com/gin-gonic/gin"
)

// ChatHandler 聊天对话处理器，基于文档向量库进行问答
type ChatHandler struct {
	chatService chat.ChatService
}

// NewChatHandler 创建聊天处理器实例
// @param chatService 聊天服务层
// @return *ChatHandler 处理器实例
// @author sunct
func NewChatHandler(chatService chat.ChatService) *ChatHandler {
	return &ChatHandler{chatService: chatService}
}

// Chat 流式对话接口，以 SSE 方式返回 AI 回答
// @param c Gin 上下文
// @author sunct
func (h *ChatHandler) Chat(c *gin.Context) {
	userID := c.Query("user_id")
	if userID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "user_id is required"})
		return
	}

	var request struct {
		Question string `json:"question"`
	}
	if err := c.ShouldBindJSON(&request); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}

	c.Stream(func(w io.Writer) bool {
		answer, err := h.chatService.Chat(c.Request.Context(), userID, request.Question)
		if err != nil {
			c.SSEvent("error", gin.H{"message": err.Error()})
			return false
		}

		c.SSEvent("message", answer)
		return true
	})
}

// GetChatHistory 获取用户聊天历史记录接口
// @param c Gin 上下文
// @author sunct
func (h *ChatHandler) GetChatHistory(c *gin.Context) {
	userID := c.Query("user_id")
	if userID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "user_id is required"})
		return
	}

	history, err := h.chatService.GetChatHistory(c.Request.Context(), userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, history)
}