package handler

import (
	"context"
	"log"
	"strings"
	"time"

	"carrot_bbs/internal/config"
	"carrot_bbs/internal/model"
	"carrot_bbs/internal/pkg/gorse"
	"carrot_bbs/internal/pkg/response"

	gorseio "github.com/gorse-io/gorse-go"
	"github.com/gin-gonic/gin"
)

// GorseHandler Gorse推荐处理器
type GorseHandler struct {
	importPassword string
	gorseConfig    config.GorseConfig
}

// NewGorseHandler 创建Gorse处理器
func NewGorseHandler(cfg config.GorseConfig) *GorseHandler {
	return &GorseHandler{
		importPassword: cfg.ImportPassword,
		gorseConfig:    cfg,
	}
}

// ImportRequest 导入请求
type ImportRequest struct {
	Password string `json:"password"`
}

// ImportData 导入数据到Gorse
// POST /api/v1/gorse/import
func (h *GorseHandler) ImportData(c *gin.Context) {
	// 验证密码
	if h.importPassword == "" {
		response.BadRequest(c, "Gorse import is disabled")
		return
	}

	var req ImportRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "invalid request body")
		return
	}

	if req.Password != h.importPassword {
		response.Unauthorized(c, "invalid password")
		return
	}

	ctx, cancel := context.WithTimeout(c.Request.Context(), 10*time.Minute)
	defer cancel()

	stats, err := h.importAllData(ctx)
	if err != nil {
		log.Printf("[ERROR] gorse import failed: %v", err)
		response.InternalServerError(c, "gorse import failed: "+err.Error())
		return
	}

	response.Success(c, gin.H{
		"message": "import completed",
		"status":  "done",
		"stats":   stats,
	})
}

// GetStatus 获取Gorse状态
// GET /api/v1/gorse/status
func (h *GorseHandler) GetStatus(c *gin.Context) {
	// 返回Gorse连接状态和配置信息
	hasPassword := h.importPassword != ""
	response.Success(c, gin.H{
		"enabled":      h.gorseConfig.Enabled,
		"has_password": hasPassword,
		"address":      h.gorseConfig.Address,
		"api_key":      strings.Repeat("*", 8), // 不返回实际APIKey
	})
}

func (h *GorseHandler) importAllData(ctx context.Context) (gin.H, error) {
	gorseClient := gorseio.NewGorseClient(h.gorseConfig.Address, h.gorseConfig.APIKey)
	gorse.InitEmbeddingWithConfig(h.gorseConfig.EmbeddingAPIKey, h.gorseConfig.EmbeddingURL, h.gorseConfig.EmbeddingModel)

	stats := gin.H{
		"items":     0,
		"users":     0,
		"likes":     0,
		"favorites": 0,
		"comments":  0,
	}

	// 导入帖子
	var posts []model.Post
	if err := model.DB.Find(&posts).Error; err != nil {
		return nil, err
	}
	for _, post := range posts {
		embedding, err := gorse.GetEmbedding(strings.TrimSpace(post.Title + " " + post.Content))
		if err != nil {
			log.Printf("[WARN] get embedding failed for post %s: %v", post.ID, err)
			embedding = make([]float64, 1024)
		}
		_, err = gorseClient.InsertItem(ctx, gorseio.Item{
			ItemId:     post.ID,
			IsHidden:   post.DeletedAt.Valid,
			Categories: buildPostCategories(&post),
			Comment:    post.Title,
			Timestamp:  post.CreatedAt.UTC().Truncate(time.Second),
			Labels: map[string]any{
				"embedding": embedding,
			},
		})
		if err != nil {
			log.Printf("[WARN] import item failed (%s): %v", post.ID, err)
			continue
		}
		stats["items"] = stats["items"].(int) + 1
	}

	// 导入用户
	var users []model.User
	if err := model.DB.Find(&users).Error; err != nil {
		return nil, err
	}
	for _, user := range users {
		_, err := gorseClient.InsertUser(ctx, gorseio.User{
			UserId: user.ID,
			Labels: map[string]any{
				"posts_count":     user.PostsCount,
				"followers_count": user.FollowersCount,
				"following_count": user.FollowingCount,
			},
			Comment: user.Nickname,
		})
		if err != nil {
			log.Printf("[WARN] import user failed (%s): %v", user.ID, err)
			continue
		}
		stats["users"] = stats["users"].(int) + 1
	}

	// 导入点赞
	var likes []model.PostLike
	if err := model.DB.Find(&likes).Error; err != nil {
		return nil, err
	}
	for _, like := range likes {
		_, err := gorseClient.InsertFeedback(ctx, []gorseio.Feedback{{
			FeedbackType: string(gorse.FeedbackTypeLike),
			UserId:       like.UserID,
			ItemId:       like.PostID,
			Timestamp:    like.CreatedAt.UTC().Truncate(time.Second),
		}})
		if err != nil {
			log.Printf("[WARN] import like failed (%s/%s): %v", like.UserID, like.PostID, err)
			continue
		}
		stats["likes"] = stats["likes"].(int) + 1
	}

	// 导入收藏
	var favorites []model.Favorite
	if err := model.DB.Find(&favorites).Error; err != nil {
		return nil, err
	}
	for _, fav := range favorites {
		_, err := gorseClient.InsertFeedback(ctx, []gorseio.Feedback{{
			FeedbackType: string(gorse.FeedbackTypeStar),
			UserId:       fav.UserID,
			ItemId:       fav.PostID,
			Timestamp:    fav.CreatedAt.UTC().Truncate(time.Second),
		}})
		if err != nil {
			log.Printf("[WARN] import favorite failed (%s/%s): %v", fav.UserID, fav.PostID, err)
			continue
		}
		stats["favorites"] = stats["favorites"].(int) + 1
	}

	// 导入评论（按用户-帖子去重）
	var comments []model.Comment
	if err := model.DB.Where("status = ?", model.CommentStatusPublished).Find(&comments).Error; err != nil {
		return nil, err
	}
	seen := make(map[string]struct{})
	for _, cm := range comments {
		key := cm.UserID + ":" + cm.PostID
		if _, ok := seen[key]; ok {
			continue
		}
		seen[key] = struct{}{}
		_, err := gorseClient.InsertFeedback(ctx, []gorseio.Feedback{{
			FeedbackType: string(gorse.FeedbackTypeComment),
			UserId:       cm.UserID,
			ItemId:       cm.PostID,
			Timestamp:    cm.CreatedAt.UTC().Truncate(time.Second),
		}})
		if err != nil {
			log.Printf("[WARN] import comment failed (%s/%s): %v", cm.UserID, cm.PostID, err)
			continue
		}
		stats["comments"] = stats["comments"].(int) + 1
	}

	return stats, nil
}

func buildPostCategories(post *model.Post) []string {
	var categories []string
	if post.ViewsCount > 1000 {
		categories = append(categories, "hot_high")
	} else if post.ViewsCount > 100 {
		categories = append(categories, "hot_medium")
	}
	if post.LikesCount > 100 {
		categories = append(categories, "likes_100+")
	} else if post.LikesCount > 10 {
		categories = append(categories, "likes_10+")
	}
	age := time.Since(post.CreatedAt)
	if age < 24*time.Hour {
		categories = append(categories, "today")
	} else if age < 7*24*time.Hour {
		categories = append(categories, "this_week")
	}
	return categories
}