package plant

import (
	"context"
	"errors"
	"fmt"
	"io"
	"strings"

	"github.com/google/uuid"
	qdrant "github.com/qdrant/go-client/qdrant"
	openai "github.com/sashabaranov/go-openai"
	"go.uber.org/zap"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/metadata"
	"sundynix-go/global"
	plantModel "sundynix-go/model/plant"
	"sundynix-go/model/system"
	systemService "sundynix-go/service/system"
)

type AiRagService struct{}

var sysAiConfigService = systemService.SysAiConfigService{}

// ──────────────────────────────────────────────────────────────
// OpenAI 客户端构建
// ──────────────────────────────────────────────────────────────

func getChatClient(cfg *system.SysAiConfig) *openai.Client {
	config := openai.DefaultConfig(cfg.ChatApiKey)
	if cfg.ChatApiUrl != "" {
		config.BaseURL = cfg.ChatApiUrl
	}
	return openai.NewClientWithConfig(config)
}

func getEmbeddingClient(cfg *system.SysAiConfig) *openai.Client {
	config := openai.DefaultConfig(cfg.EmbeddingApiKey)
	if cfg.EmbeddingApiUrl != "" {
		config.BaseURL = cfg.EmbeddingApiUrl
	}
	return openai.NewClientWithConfig(config)
}

// ──────────────────────────────────────────────────────────────
// Qdrant gRPC 连接
// ──────────────────────────────────────────────────────────────

func newQdrantConn(cfg *system.SysAiConfig) (*grpc.ClientConn, context.Context, error) {
	addr := strings.TrimPrefix(cfg.QdrantUrl, "http://")
	addr = strings.TrimPrefix(addr, "https://")
	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, nil, fmt.Errorf("qdrant grpc dial failed: %w", err)
	}
	ctx := context.Background()
	if cfg.QdrantApiKey != "" {
		ctx = metadata.NewOutgoingContext(ctx, metadata.Pairs("api-key", cfg.QdrantApiKey))
	}
	return conn, ctx, nil
}

// EnsureCollection 确保 Collection 存在，不存在则创建
func EnsureCollection(cfg *system.SysAiConfig) error {
	conn, ctx, err := newQdrantConn(cfg)
	if err != nil {
		return err
	}
	defer conn.Close()
	dim := uint64(cfg.VectorDimension)
	if dim == 0 {
		dim = 104
	}
	collClient := qdrant.NewCollectionsClient(conn)
	if _, getErr := collClient.Get(ctx, &qdrant.GetCollectionInfoRequest{CollectionName: cfg.QdrantCollection}); getErr == nil {
		return nil // 已存在
	}
	_, err = collClient.Create(ctx, &qdrant.CreateCollection{
		CollectionName: cfg.QdrantCollection,
		VectorsConfig: &qdrant.VectorsConfig{
			Config: &qdrant.VectorsConfig_Params{
				Params: &qdrant.VectorParams{Size: dim, Distance: qdrant.Distance_Cosine},
			},
		},
	})
	if err != nil {
		return fmt.Errorf("qdrant create collection failed: %w", err)
	}
	global.Logger.Info("Qdrant collection created", zap.String("collection", cfg.QdrantCollection))
	return nil
}

// wikiID → Qdrant point UUID（确保幂等）
func wikiToQdrantID(wikiId string) string {
	return uuid.NewMD5(uuid.NameSpaceOID, []byte(wikiId)).String()
}

// buildWikiText 拼接用于向量化的文本语料
func buildWikiText(w plantModel.Wiki) string {
	return fmt.Sprintf(
		"植物名字:%s. 拉丁名:%s. 科属:%s. 生命周期:%s. 生长习性:%s. 病虫害:%s. 光照类型:%s. 最佳温度:%s.",
		w.Name, w.LatinName, w.Genus, w.LifeCycle, w.GrowthHabit,
		w.PestsDiseases, w.LightType, w.OptimalTempPeriod,
	)
}

// ──────────────────────────────────────────────────────────────
// SyncSingleWikiAsync 异步同步单条百科到 Qdrant（新增/更新时调用）
// 同步成功后将 is_vector_synced 置为 1
// ──────────────────────────────────────────────────────────────
func (s *AiRagService) SyncSingleWikiAsync(wikiId string) {
	go func() {
		if err := s.syncSingleWiki(wikiId); err != nil {
			global.Logger.Error("Async sync wiki to Qdrant failed", zap.String("wiki_id", wikiId), zap.Error(err))
		}
	}()
}

// SyncSingleWiki 同步同步单条百科到 Qdrant（用于API直接调用）
func (s *AiRagService) SyncSingleWiki(wikiId string) error {
	return s.syncSingleWiki(wikiId)
}

func (s *AiRagService) syncSingleWiki(wikiId string) error {
	cfg, err := sysAiConfigService.GetActiveAiConfig()
	if err != nil {
		return fmt.Errorf("no active ai config: %w", err)
	}
	if err = EnsureCollection(cfg); err != nil {
		global.Logger.Warn("EnsureCollection warn", zap.Error(err))
	}

	var w plantModel.Wiki
	if err = global.DB.Where("id = ?", wikiId).First(&w).Error; err != nil {
		return fmt.Errorf("wiki not found: %w", err)
	}

	text := buildWikiText(w)
	embClient := getEmbeddingClient(cfg)
	embResp, err := embClient.CreateEmbeddings(context.Background(), openai.EmbeddingRequest{
		Input: []string{text},
		Model: openai.EmbeddingModel(cfg.EmbeddingModelName),
	})
	if err != nil {
		return fmt.Errorf("embedding failed: %w", err)
	}

	conn, qdCtx, err := newQdrantConn(cfg)
	if err != nil {
		return err
	}
	defer conn.Close()
	ptsClient := qdrant.NewPointsClient(conn)

	_, err = ptsClient.Upsert(qdCtx, &qdrant.UpsertPoints{
		CollectionName: cfg.QdrantCollection,
		Points: []*qdrant.PointStruct{{
			Id:      qdrant.NewID(wikiToQdrantID(wikiId)),
			Vectors: qdrant.NewVectors(embResp.Data[0].Embedding...),
			Payload: map[string]*qdrant.Value{
				"wiki_id":   qdrant.NewValueString(w.Id),
				"name":      qdrant.NewValueString(w.Name),
				"full_text": qdrant.NewValueString(text),
			},
		}},
	})
	if err != nil {
		return fmt.Errorf("qdrant upsert failed: %w", err)
	}

	// 更新同步状态
	_ = global.DB.Model(&plantModel.Wiki{}).Where("id = ?", wikiId).Update("is_vector_synced", 1).Error
	global.Logger.Info("Wiki synced to Qdrant", zap.String("wiki_id", wikiId))
	return nil
}

// ──────────────────────────────────────────────────────────────
// DeleteFromQdrant 从 Qdrant 删除单条植物的向量点位
// 删除成功后将 is_vector_synced 置为 0
// ──────────────────────────────────────────────────────────────
func (s *AiRagService) DeleteFromQdrant(wikiId string) error {
	cfg, err := sysAiConfigService.GetActiveAiConfig()
	if err != nil {
		return fmt.Errorf("no active ai config: %w", err)
	}
	conn, qdCtx, err := newQdrantConn(cfg)
	if err != nil {
		return err
	}
	defer conn.Close()
	ptsClient := qdrant.NewPointsClient(conn)

	qID := wikiToQdrantID(wikiId)
	_, err = ptsClient.Delete(qdCtx, &qdrant.DeletePoints{
		CollectionName: cfg.QdrantCollection,
		Points: &qdrant.PointsSelector{
			PointsSelectorOneOf: &qdrant.PointsSelector_Points{
				Points: &qdrant.PointsIdsList{
					Ids: []*qdrant.PointId{qdrant.NewID(qID)},
				},
			},
		},
	})
	if err != nil {
		return fmt.Errorf("qdrant delete failed: %w", err)
	}
	_ = global.DB.Model(&plantModel.Wiki{}).Where("id = ?", wikiId).Update("is_vector_synced", 0).Error
	global.Logger.Info("Wiki deleted from Qdrant", zap.String("wiki_id", wikiId))
	return nil
}

// DeleteFromQdrantBatch 批量从 Qdrant 删除（用于批量删除百科时）
func (s *AiRagService) DeleteFromQdrantBatch(wikiIds []string) {
	go func() {
		cfg, err := sysAiConfigService.GetActiveAiConfig()
		if err != nil {
			global.Logger.Warn("No active ai config for batch qdrant delete", zap.Error(err))
			return
		}
		conn, qdCtx, err := newQdrantConn(cfg)
		if err != nil {
			global.Logger.Warn("Qdrant connect failed for batch delete", zap.Error(err))
			return
		}
		defer conn.Close()
		ptsClient := qdrant.NewPointsClient(conn)

		var ids []*qdrant.PointId
		for _, wid := range wikiIds {
			ids = append(ids, qdrant.NewID(wikiToQdrantID(wid)))
		}
		_, err = ptsClient.Delete(qdCtx, &qdrant.DeletePoints{
			CollectionName: cfg.QdrantCollection,
			Points: &qdrant.PointsSelector{
				PointsSelectorOneOf: &qdrant.PointsSelector_Points{
					Points: &qdrant.PointsIdsList{Ids: ids},
				},
			},
		})
		if err != nil {
			global.Logger.Error("Qdrant batch delete failed", zap.Error(err))
		} else {
			global.Logger.Info("Qdrant batch delete done", zap.Int("count", len(wikiIds)))
		}
	}()
}

// ──────────────────────────────────────────────────────────────
// SyncWikiToQdrant 全量同步（后台操作/手动触发）
// ──────────────────────────────────────────────────────────────
func (s *AiRagService) SyncWikiToQdrant() error {
	cfg, err := sysAiConfigService.GetActiveAiConfig()
	if err != nil {
		return err
	}
	if err = EnsureCollection(cfg); err != nil {
		global.Logger.Warn("EnsureCollection failed, continuing", zap.Error(err))
	}

	var wikis []plantModel.Wiki
	if err = global.DB.Find(&wikis).Error; err != nil {
		return err
	}

	embClient := getEmbeddingClient(cfg)
	conn, qdCtx, err := newQdrantConn(cfg)
	if err != nil {
		return err
	}
	defer conn.Close()
	ptsClient := qdrant.NewPointsClient(conn)

	var successIds []string
	for _, w := range wikis {
		text := buildWikiText(w)
		embResp, embErr := embClient.CreateEmbeddings(context.Background(), openai.EmbeddingRequest{
			Input: []string{text},
			Model: openai.EmbeddingModel(cfg.EmbeddingModelName),
		})
		if embErr != nil {
			global.Logger.Error("Embedding failed", zap.String("wiki_id", w.Id), zap.Error(embErr))
			continue
		}
		_, upsertErr := ptsClient.Upsert(qdCtx, &qdrant.UpsertPoints{
			CollectionName: cfg.QdrantCollection,
			Points: []*qdrant.PointStruct{{
				Id:      qdrant.NewID(wikiToQdrantID(w.Id)),
				Vectors: qdrant.NewVectors(embResp.Data[0].Embedding...),
				Payload: map[string]*qdrant.Value{
					"wiki_id":   qdrant.NewValueString(w.Id),
					"name":      qdrant.NewValueString(w.Name),
					"full_text": qdrant.NewValueString(text),
				},
			}},
		})
		if upsertErr != nil {
			global.Logger.Error("Qdrant upsert failed", zap.String("wiki_id", w.Id), zap.Error(upsertErr))
		} else {
			successIds = append(successIds, w.Id)
		}
	}

	// 批量更新同步状态
	if len(successIds) > 0 {
		_ = global.DB.Model(&plantModel.Wiki{}).Where("id IN ?", successIds).Update("is_vector_synced", 1).Error
	}
	global.Logger.Info("SyncWikiToQdrant done", zap.Int("total", len(wikis)), zap.Int("success", len(successIds)))
	return nil
}

// ──────────────────────────────────────────────────────────────
// PlantChatStreamRAG 向量检索 + 大模型流式对话
// ──────────────────────────────────────────────────────────────
func (s *AiRagService) PlantChatStreamRAG(ctx context.Context, userQuery string, onData func(chunk string) error) error {
	cfg, err := sysAiConfigService.GetActiveAiConfig()
	if err != nil {
		return err
	}

	embClient := getEmbeddingClient(cfg)
	chatClient := getChatClient(cfg)

	embResp, err := embClient.CreateEmbeddings(ctx, openai.EmbeddingRequest{
		Input: []string{userQuery},
		Model: openai.EmbeddingModel(cfg.EmbeddingModelName),
	})
	if err != nil {
		return fmt.Errorf("向量化查询失败: %w", err)
	}

	conn, qdCtx, connErr := newQdrantConn(cfg)
	var contextText string
	if connErr == nil {
		defer conn.Close()
		ptsClient := qdrant.NewPointsClient(conn)
		limit := uint64(3)
		searchRes, searchErr := ptsClient.Search(qdCtx, &qdrant.SearchPoints{
			CollectionName: cfg.QdrantCollection,
			Vector:         embResp.Data[0].Embedding,
			Limit:          limit,
			WithPayload: &qdrant.WithPayloadSelector{
				SelectorOptions: &qdrant.WithPayloadSelector_Enable{Enable: true},
			},
		})
		if searchErr != nil {
			global.Logger.Warn("Qdrant search failed, using empty context", zap.Error(searchErr))
		} else {
			for _, pt := range searchRes.GetResult() {
				if txt, ok := pt.GetPayload()["full_text"]; ok {
					contextText += txt.GetStringValue() + "\n"
				}
			}
		}
	} else {
		global.Logger.Warn("Qdrant connect failed, skipping RAG", zap.Error(connErr))
	}

	systemPrompt := "你是一个专业的植物百科助手，请基于以下知识库信息回答用户问题。如果知识库无相关信息，结合你的通用知识作答。\n"
	if contextText != "" {
		systemPrompt += "--- 知识库 ---\n" + contextText + "\n--------------\n"
	}

	stream, err := chatClient.CreateChatCompletionStream(ctx, openai.ChatCompletionRequest{
		Model: cfg.ChatModelName,
		Messages: []openai.ChatCompletionMessage{
			{Role: openai.ChatMessageRoleSystem, Content: systemPrompt},
			{Role: openai.ChatMessageRoleUser, Content: userQuery},
		},
		Stream: true,
	})
	if err != nil {
		return fmt.Errorf("大模型调用失败: %w", err)
	}
	defer stream.Close()

	for {
		resp, recvErr := stream.Recv()
		if errors.Is(recvErr, io.EOF) {
			break
		}
		if recvErr != nil {
			return recvErr
		}
		if len(resp.Choices) > 0 {
			if content := resp.Choices[0].Delta.Content; content != "" {
				if writeErr := onData(content); writeErr != nil {
					return writeErr
				}
			}
		}
	}
	return nil
}