package user

import (
	"context"
	"fmt"
	"strconv"
	"strings"

	"github.com/perfect-panel/server/internal/config"
	"github.com/perfect-panel/server/internal/svc"
)

func clearAllSessions(ctx context.Context, svcCtx *svc.ServiceContext, userID int64) error {
	userIDText := strconv.FormatInt(userID, 10)
	sessionSet := make(map[string]struct{})

	pattern := fmt.Sprintf("%s:*", config.SessionIdKey)
	var cursor uint64
	for {
		keys, nextCursor, err := svcCtx.Redis.Scan(ctx, cursor, pattern, 200).Result()
		if err != nil {
			return err
		}
		for _, sessionKey := range keys {
			value, err := svcCtx.Redis.Get(ctx, sessionKey).Result()
			if err != nil || value != userIDText {
				continue
			}
			sessionID := strings.TrimPrefix(sessionKey, config.SessionIdKey+":")
			if sessionID == "" || strings.HasPrefix(sessionID, "detail:") {
				continue
			}
			sessionSet[sessionID] = struct{}{}
		}
		cursor = nextCursor
		if cursor == 0 {
			break
		}
	}

	if len(sessionSet) == 0 {
		return nil
	}

	deviceKeySet := make(map[string]struct{})
	devicePattern := fmt.Sprintf("%s:*", config.DeviceCacheKeyKey)
	cursor = 0
	for {
		keys, nextCursor, err := svcCtx.Redis.Scan(ctx, cursor, devicePattern, 200).Result()
		if err != nil {
			return err
		}
		for _, deviceKey := range keys {
			sessionID, err := svcCtx.Redis.Get(ctx, deviceKey).Result()
			if err != nil {
				continue
			}
			if _, exists := sessionSet[sessionID]; exists {
				deviceKeySet[deviceKey] = struct{}{}
			}
		}
		cursor = nextCursor
		if cursor == 0 {
			break
		}
	}

	sessionsKey := fmt.Sprintf("%s%v", config.UserSessionsKeyPrefix, userID)
	pipe := svcCtx.Redis.TxPipeline()
	for sessionID := range sessionSet {
		pipe.Del(ctx, fmt.Sprintf("%v:%v", config.SessionIdKey, sessionID))
		pipe.Del(ctx, fmt.Sprintf("%s:detail:%s", config.SessionIdKey, sessionID))
		pipe.ZRem(ctx, sessionsKey, sessionID)
	}
	pipe.Del(ctx, sessionsKey)
	for deviceKey := range deviceKeySet {
		pipe.Del(ctx, deviceKey)
	}
	_, err := pipe.Exec(ctx)
	return err
}