package tools

import (
	"ai_scheduler/internal/config"
	"ai_scheduler/internal/entitys"
	"ai_scheduler/internal/pkg/l_request"
	"bufio"
	"encoding/json"
	"fmt"
	"github.com/gofiber/fiber/v2/log"
	"github.com/gofiber/websocket/v2"
	"net/http"
	"strings"
)

// 知识库工具
type KnowledgeBaseTool struct {
	config config.ToolConfig
}

// NewKnowledgeBaseTool 创建知识库工具
func NewKnowledgeBaseTool(config config.ToolConfig) *KnowledgeBaseTool {
	return &KnowledgeBaseTool{config: config}
}

func (k *KnowledgeBaseTool) GetConfig() config.ToolConfig {
	return k.config
}

// Name 返回工具名称
func (k *KnowledgeBaseTool) Name() string {
	return "knowledgeBase"
}

// Description 返回工具描述
func (k *KnowledgeBaseTool) Description() string {
	return "请求知识库"
}

// Definition 返回工具定义
func (k *KnowledgeBaseTool) Definition() entitys.ToolDefinition {
	return entitys.ToolDefinition{
		Type: "function",
		Function: entitys.FunctionDef{
			Name:        k.Name(),
			Description: k.Description(),
			Parameters: map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"query": map[string]interface{}{
						"type":        "string",
						"description": "知识库查询条件",
					},
				},
				"required": []string{"query"},
			},
		},
	}
}

// Execute 执行知识库查询
func (k *KnowledgeBaseTool) Execute(channel chan entitys.ResponseData, c *websocket.Conn, args json.RawMessage) error {

	var params KnowledgeBaseRequest
	if err := json.Unmarshal(args, &params); err != nil {
		return fmt.Errorf("unmarshal args failed: %w", err)
	}
	log.Info("开始执行知识库 KnowledgeBaseTool Execute, params: %v", params)

	return k.chat(channel, c, params)

}

type KnowledgeBaseRequest struct {
	Session string // 知识库会话id
	ApiKey  string // 知识库apiKey
	Query   string // 用户输入
}

// Message 表示解析后的 SSE 消息
type Message struct {
	Event string // 事件类型（默认 "message"）
	Data  string // 消息内容（可能多行）
	ID    string // 消息 ID（可选）
}

type MsgContent struct {
	Id                  string      `json:"id"`
	ResponseType        string      `json:"response_type"`
	Content             string      `json:"content"`
	Done                bool        `json:"done"`
	KnowledgeReferences interface{} `json:"knowledge_references"`
}

// 解析知识库响应内容,并把通过channel结果返回
func msgContentParse(input string, channel chan entitys.ResponseData) (msgContent MsgContent, err error) {
	err = json.Unmarshal([]byte(input), &msgContent)
	if err != nil {
		err = fmt.Errorf("unmarshal input failed: %w", err)
	}

	channel <- entitys.ResponseData{
		Done:    msgContent.Done,
		Content: msgContent.Content,
		Type:    entitys.ResponseStream,
	}

	return
}

// 请求知识库聊天
func (this *KnowledgeBaseTool) chat(channel chan entitys.ResponseData, c *websocket.Conn, param KnowledgeBaseRequest) (err error) {

	req := l_request.Request{
		Method: "post",
		Url:    this.config.BaseURL + "/api/v1/knowledge-chat/" + param.Session,
		Params: nil,
		Headers: map[string]string{
			"Content-Type": "application/json",
			"X-API-Key":    param.ApiKey,
		},
		Cookies: nil,
		Data:    nil,
		Json: map[string]interface{}{
			"query": param.Query,
		},
		Files:    nil,
		Raw:      "",
		JsonByte: nil,
		Xml:      nil,
	}

	rsp, err := req.SendNoParseResponse()
	if err != nil {
		return
	}
	defer rsp.Body.Close()

	err = connectAndReadSSE(rsp, channel)
	if err != nil {
		return
	}

	return
}

// 连接 SSE 并读取数据
func connectAndReadSSE(resp *http.Response, channel chan entitys.ResponseData) error {

	// 验证响应状态和格式
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("非 200 状态码: %d", resp.StatusCode)
	}
	contentType := resp.Header.Get("Content-Type")
	if !strings.Contains(contentType, "text/event-stream") {
		return fmt.Errorf("不支持的 Content-Type: %s", contentType)
	}

	// 逐行读取响应流
	scanner := bufio.NewScanner(resp.Body)
	var currentMsg Message // 当前正在组装的消息

	for scanner.Scan() {
		line := scanner.Text()
		if line == "" {
			// 空行表示一条消息结束，处理当前消息
			if currentMsg.Data != "" || currentMsg.Event != "" || currentMsg.ID != "" {
				_, err := msgContentParse(currentMsg.Data, channel)
				if err != nil {
					return fmt.Errorf("msgContentParse failed: %w", err)
				}
				currentMsg = Message{} // 重置消息
			}
			continue
		}

		// 解析字段（格式："field: value"）
		parts := strings.SplitN(line, ":", 2)
		if len(parts) < 2 {
			continue // 无效行（无冒号），跳过
		}
		field := strings.TrimSpace(parts[0])
		value := strings.TrimSpace(parts[1])

		switch field {
		case "event":
			currentMsg.Event = value
		case "data":
			// data 可能多行，用换行符拼接（最后一条消息可能无结尾空行）
			currentMsg.Data += value + ""
		default:
			// 忽略未知字段
		}
	}

	// 检查扫描错误（如连接断开）
	if err := scanner.Err(); err != nil {
		return fmt.Errorf("读取流失败: %w", err)
	}

	// 处理最后一条未结束的消息（无结尾空行）
	if currentMsg.Data != "" || currentMsg.Event != "" || currentMsg.ID != "" {
		_, err := msgContentParse(currentMsg.Data, channel)
		if err != nil {
			return fmt.Errorf("msgContentParse failed: %w", err)
		}
	}

	return nil
}

// 获取知识库 session
func GetKnowledgeBaseSession(host, baseId, apiKey string) (string, error) {
	req := l_request.Request{
		Method: "post",
		Url:    host + "/api/v1/sessions",
		Params: nil,
		Headers: map[string]string{
			"Content-Type": "application/json",
			"X-API-Key":    apiKey,
		},
		Cookies: nil,
		Data:    nil,
		Json: map[string]interface{}{
			"knowledge_base_id": baseId,
		},
		Files:    nil,
		Raw:      "",
		JsonByte: nil,
		Xml:      nil,
	}

	rsp, err := req.Send()
	if err != nil {
		return "", err
	}

	var result sessionRsp
	err = json.Unmarshal(rsp.Content, &result)

	return result.Data.Id, err
}

type sessionRsp struct {
	Data struct {
		Id               string  `json:"id"`
		Title            string  `json:"title"`
		Description      string  `json:"description"`
		TenantId         int     `json:"tenant_id"`
		KnowledgeBaseId  string  `json:"knowledge_base_id"`
		MaxRounds        int     `json:"max_rounds"`
		EnableRewrite    bool    `json:"enable_rewrite"`
		FallbackStrategy string  `json:"fallback_strategy"`
		FallbackResponse string  `json:"fallback_response"`
		EmbeddingTopK    int     `json:"embedding_top_k"`
		KeywordThreshold float64 `json:"keyword_threshold"`
		VectorThreshold  float64 `json:"vector_threshold"`
		RerankModelId    string  `json:"rerank_model_id"`
		RerankTopK       int     `json:"rerank_top_k"`
		RerankThreshold  float64 `json:"rerank_threshold"`
		SummaryModelId   string  `json:"summary_model_id"`
	} `json:"data"`
	Success bool `json:"success"`
}