package handler

import (
	"context"
	"fmt"
	"net/http"

	"cyberstrike-ai/internal/database"
	"cyberstrike-ai/internal/knowledge"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

// KnowledgeHandler 知识库处理器
type KnowledgeHandler struct {
	manager  *knowledge.Manager
	retriever *knowledge.Retriever
	indexer  *knowledge.Indexer
	db       *database.DB
	logger   *zap.Logger
}

// NewKnowledgeHandler 创建新的知识库处理器
func NewKnowledgeHandler(
	manager *knowledge.Manager,
	retriever *knowledge.Retriever,
	indexer *knowledge.Indexer,
	db *database.DB,
	logger *zap.Logger,
) *KnowledgeHandler {
	return &KnowledgeHandler{
		manager:   manager,
		retriever: retriever,
		indexer:   indexer,
		db:        db,
		logger:    logger,
	}
}

// GetCategories 获取所有分类
func (h *KnowledgeHandler) GetCategories(c *gin.Context) {
	categories, err := h.manager.GetCategories()
	if err != nil {
		h.logger.Error("获取分类失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"categories": categories})
}

// GetItems 获取知识项列表
func (h *KnowledgeHandler) GetItems(c *gin.Context) {
	category := c.Query("category")

	items, err := h.manager.GetItems(category)
	if err != nil {
		h.logger.Error("获取知识项失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"items": items})
}

// GetItem 获取单个知识项
func (h *KnowledgeHandler) GetItem(c *gin.Context) {
	id := c.Param("id")

	item, err := h.manager.GetItem(id)
	if err != nil {
		h.logger.Error("获取知识项失败", zap.Error(err))
		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, item)
}

// CreateItem 创建知识项
func (h *KnowledgeHandler) CreateItem(c *gin.Context) {
	var req struct {
		Category string `json:"category" binding:"required"`
		Title    string `json:"title" binding:"required"`
		Content  string `json:"content" binding:"required"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	item, err := h.manager.CreateItem(req.Category, req.Title, req.Content)
	if err != nil {
		h.logger.Error("创建知识项失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	// 异步索引
	go func() {
		ctx := context.Background()
		if err := h.indexer.IndexItem(ctx, item.ID); err != nil {
			h.logger.Warn("索引知识项失败", zap.String("itemId", item.ID), zap.Error(err))
		}
	}()

	c.JSON(http.StatusOK, item)
}

// UpdateItem 更新知识项
func (h *KnowledgeHandler) UpdateItem(c *gin.Context) {
	id := c.Param("id")

	var req struct {
		Category string `json:"category" binding:"required"`
		Title    string `json:"title" binding:"required"`
		Content  string `json:"content" binding:"required"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	item, err := h.manager.UpdateItem(id, req.Category, req.Title, req.Content)
	if err != nil {
		h.logger.Error("更新知识项失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	// 异步重新索引
	go func() {
		ctx := context.Background()
		if err := h.indexer.IndexItem(ctx, item.ID); err != nil {
			h.logger.Warn("重新索引知识项失败", zap.String("itemId", item.ID), zap.Error(err))
		}
	}()

	c.JSON(http.StatusOK, item)
}

// DeleteItem 删除知识项
func (h *KnowledgeHandler) DeleteItem(c *gin.Context) {
	id := c.Param("id")

	if err := h.manager.DeleteItem(id); err != nil {
		h.logger.Error("删除知识项失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "删除成功"})
}

// RebuildIndex 重建索引
func (h *KnowledgeHandler) RebuildIndex(c *gin.Context) {
	// 异步重建索引
	go func() {
		ctx := context.Background()
		if err := h.indexer.RebuildIndex(ctx); err != nil {
			h.logger.Error("重建索引失败", zap.Error(err))
		}
	}()

	c.JSON(http.StatusOK, gin.H{"message": "索引重建已开始，将在后台进行"})
}

// ScanKnowledgeBase 扫描知识库
func (h *KnowledgeHandler) ScanKnowledgeBase(c *gin.Context) {
	if err := h.manager.ScanKnowledgeBase(); err != nil {
		h.logger.Error("扫描知识库失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	// 异步重建索引
	go func() {
		ctx := context.Background()
		if err := h.indexer.RebuildIndex(ctx); err != nil {
			h.logger.Error("重建索引失败", zap.Error(err))
		}
	}()

	c.JSON(http.StatusOK, gin.H{"message": "扫描完成，索引重建已开始"})
}

// GetRetrievalLogs 获取检索日志
func (h *KnowledgeHandler) GetRetrievalLogs(c *gin.Context) {
	conversationID := c.Query("conversationId")
	messageID := c.Query("messageId")
	limit := 50 // 默认50条

	if limitStr := c.Query("limit"); limitStr != "" {
		if parsed, err := parseInt(limitStr); err == nil && parsed > 0 {
			limit = parsed
		}
	}

	logs, err := h.manager.GetRetrievalLogs(conversationID, messageID, limit)
	if err != nil {
		h.logger.Error("获取检索日志失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"logs": logs})
}

// DeleteRetrievalLog 删除检索日志
func (h *KnowledgeHandler) DeleteRetrievalLog(c *gin.Context) {
	id := c.Param("id")

	if err := h.manager.DeleteRetrievalLog(id); err != nil {
		h.logger.Error("删除检索日志失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "删除成功"})
}

// GetIndexStatus 获取索引状态
func (h *KnowledgeHandler) GetIndexStatus(c *gin.Context) {
	status, err := h.manager.GetIndexStatus()
	if err != nil {
		h.logger.Error("获取索引状态失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, status)
}

// Search 搜索知识库（用于API调用，Agent内部使用Retriever）
func (h *KnowledgeHandler) Search(c *gin.Context) {
	var req knowledge.SearchRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	results, err := h.retriever.Search(c.Request.Context(), &req)
	if err != nil {
		h.logger.Error("搜索知识库失败", zap.Error(err))
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"results": results})
}

// 辅助函数：解析整数
func parseInt(s string) (int, error) {
	var result int
	_, err := fmt.Sscanf(s, "%d", &result)
	return result, err
}