gemini-banlancer/internal/service/apikey_service.go

// Filename: internal/service/apikey_service.go

package service

import (
	"encoding/json"
	"errors"
	"fmt"
	"gemini-balancer/internal/channel"
	CustomErrors "gemini-balancer/internal/errors"
	"gemini-balancer/internal/models"
	"gemini-balancer/internal/repository"
	"gemini-balancer/internal/settings"
	"gemini-balancer/internal/store"
	"gemini-balancer/internal/task"
	"math"
	"sort"
	"strings"
	"sync"
	"time"

	"github.com/sirupsen/logrus"
	"gorm.io/gorm"
)

const (
	TaskTypeRestoreAllBannedInGroup = "restore_all_banned_in_group"
	TaskTypeRestoreSpecificKeys     = "restore_specific_keys_in_group"
	TaskTypeUpdateStatusByFilter    = "update_status_by_filter"
)

// DTOs & Constants
const (
	TestEndpoint = "https://generativelanguage.googleapis.com/v1beta/models"
)

type BatchRestoreResult struct {
	RestoredCount int              `json:"restored_count"`
	SkippedCount  int              `json:"skipped_count"`
	SkippedKeys   []SkippedKeyInfo `json:"skipped_keys"`
}

type SkippedKeyInfo struct {
	KeyID  uint   `json:"key_id"`
	Reason string `json:"reason"`
}

type PaginatedAPIKeys struct {
	Items      []*models.APIKeyDetails `json:"items"`
	Total      int64                   `json:"total"`
	Page       int                     `json:"page"`
	PageSize   int                     `json:"page_size"`
	TotalPages int                     `json:"total_pages"`
}

type KeyTestResult struct {
	Key     string `json:"key"`
	Status  string `json:"status"`
	Message string `json:"message"`
}

type APIKeyService struct {
	db                *gorm.DB
	keyRepo           repository.KeyRepository
	channel           channel.ChannelProxy
	store             store.Store
	SettingsManager   *settings.SettingsManager
	taskService       task.Reporter
	logger            *logrus.Entry
	stopChan          chan struct{}
	validationService *KeyValidationService
	groupManager      *GroupManager
}

func NewAPIKeyService(
	db *gorm.DB,
	repo repository.KeyRepository,
	ch channel.ChannelProxy,
	s store.Store,
	sm *settings.SettingsManager,
	ts task.Reporter,
	vs *KeyValidationService,
	gm *GroupManager,
	logger *logrus.Logger,
) *APIKeyService {
	logger.Debugf("[FORENSIC PROBE | INJECTION | APIKeyService] Received a KeyRepository. Fingerprint: %p", repo)
	return &APIKeyService{
		db:                db,
		keyRepo:           repo,
		channel:           ch,
		store:             s,
		SettingsManager:   sm,
		taskService:       ts,
		logger:            logger.WithField("component", "APIKeyService🔑"),
		stopChan:          make(chan struct{}),
		validationService: vs,
		groupManager:      gm,
	}
}

func (s *APIKeyService) Start() {
	requestSub, err := s.store.Subscribe(models.TopicRequestFinished)
	if err != nil {
		s.logger.Fatalf("Failed to subscribe to topic %s: %v", models.TopicRequestFinished, err)
		return
	}
	masterKeySub, err := s.store.Subscribe(models.TopicMasterKeyStatusChanged)
	if err != nil {
		s.logger.Fatalf("Failed to subscribe to topic %s: %v", models.TopicMasterKeyStatusChanged, err)
		return
	}
	keyStatusSub, err := s.store.Subscribe(models.TopicKeyStatusChanged)
	if err != nil {
		s.logger.Fatalf("Failed to subscribe to topic %s: %v", models.TopicKeyStatusChanged, err)
		return
	}
	importSub, err := s.store.Subscribe(models.TopicImportGroupCompleted)
	if err != nil {
		s.logger.Fatalf("Failed to subscribe to topic %s: %v", models.TopicImportGroupCompleted, err)
		return
	}
	s.logger.Info("Started and subscribed to request, master key, health check, and import events.")

	go func() {
		defer requestSub.Close()
		defer masterKeySub.Close()
		defer keyStatusSub.Close()
		defer importSub.Close()
		for {
			select {
			case msg := <-requestSub.Channel():
				var event models.RequestFinishedEvent
				if err := json.Unmarshal(msg.Payload, &event); err != nil {
					s.logger.Errorf("Failed to unmarshal event for key status update: %v", err)
					continue
				}
				s.handleKeyUsageEvent(&event)

			case msg := <-masterKeySub.Channel():
				var event models.MasterKeyStatusChangedEvent
				if err := json.Unmarshal(msg.Payload, &event); err != nil {
					s.logger.Errorf("Failed to unmarshal MasterKeyStatusChangedEvent: %v", err)
					continue
				}
				s.handleMasterKeyStatusChangeEvent(&event)
			case msg := <-keyStatusSub.Channel():
				var event models.KeyStatusChangedEvent
				if err := json.Unmarshal(msg.Payload, &event); err != nil {
					s.logger.Errorf("Failed to unmarshal KeyStatusChangedEvent: %v", err)
					continue
				}
				s.handleKeyStatusChangeEvent(&event)

			case msg := <-importSub.Channel():
				var event models.ImportGroupCompletedEvent
				if err := json.Unmarshal(msg.Payload, &event); err != nil {
					s.logger.WithError(err).Error("Failed to unmarshal ImportGroupCompletedEvent.")
					continue
				}
				s.logger.Infof("Received ImportGroupCompletedEvent for group %d, triggering validation for %d keys.", event.GroupID, len(event.KeyIDs))

				go s.handlePostImportValidation(&event)

			case <-s.stopChan:
				s.logger.Info("Stopping event listener.")
				return
			}
		}
	}()
}

func (s *APIKeyService) Stop() {
	close(s.stopChan)
}

func (s *APIKeyService) handleKeyUsageEvent(event *models.RequestFinishedEvent) {
	if event.RequestLog.KeyID == nil || event.RequestLog.GroupID == nil {
		return
	}
	if event.RequestLog.IsSuccess {
		mapping, err := s.keyRepo.GetMapping(*event.RequestLog.GroupID, *event.RequestLog.KeyID)
		if err != nil {
			s.logger.Warnf("[%s] Could not find mapping for G:%d K:%d on successful request: %v", event.CorrelationID, *event.RequestLog.GroupID, *event.RequestLog.KeyID, err)
			return
		}
		statusChanged := false
		oldStatus := mapping.Status
		if mapping.Status != models.StatusActive {
			mapping.Status = models.StatusActive
			mapping.ConsecutiveErrorCount = 0
			mapping.LastError = ""
			statusChanged = true
		}

		now := time.Now()
		mapping.LastUsedAt = &now
		if err := s.keyRepo.UpdateMapping(mapping); err != nil {
			s.logger.Errorf("[%s] Failed to update mapping for G:%d K:%d after successful request: %v", event.CorrelationID, *event.RequestLog.GroupID, *event.RequestLog.KeyID, err)
			return
		}
		if statusChanged {
			go s.publishStatusChangeEvent(*event.RequestLog.GroupID, *event.RequestLog.KeyID, oldStatus, models.StatusActive, "key_recovered_after_use")
		}
		return
	}
	if event.Error != nil {
		s.judgeKeyErrors(
			event.CorrelationID,
			*event.RequestLog.GroupID,
			*event.RequestLog.KeyID,
			event.Error,
			event.IsPreciseRouting,
		)
	}
}

func (s *APIKeyService) handleKeyStatusChangeEvent(event *models.KeyStatusChangedEvent) {
	log := s.logger.WithFields(logrus.Fields{
		"group_id":   event.GroupID,
		"key_id":     event.KeyID,
		"new_status": event.NewStatus,
		"reason":     event.ChangeReason,
	})
	log.Info("Received KeyStatusChangedEvent, will update polling caches.")
	s.keyRepo.HandleCacheUpdateEvent(event.GroupID, event.KeyID, event.NewStatus)
	log.Info("Polling caches updated based on health check event.")
}

func (s *APIKeyService) publishStatusChangeEvent(groupID, keyID uint, oldStatus, newStatus models.APIKeyStatus, reason string) {
	changeEvent := models.KeyStatusChangedEvent{
		KeyID:        keyID,
		GroupID:      groupID,
		OldStatus:    oldStatus,
		NewStatus:    newStatus,
		ChangeReason: reason,
		ChangedAt:    time.Now(),
	}
	eventData, _ := json.Marshal(changeEvent)
	if err := s.store.Publish(models.TopicKeyStatusChanged, eventData); err != nil {
		s.logger.Errorf("Failed to publish key status changed event for group %d: %v", groupID, err)
	}
}

func (s *APIKeyService) ListAPIKeys(params *models.APIKeyQueryParams) (*PaginatedAPIKeys, error) {
	// --- Path 1: High-performance DB pagination (no keyword) ---
	if params.Keyword == "" {
		items, total, err := s.keyRepo.GetPaginatedKeysAndMappingsByGroup(params)
		if err != nil {
			return nil, err
		}
		totalPages := 0
		if total > 0 && params.PageSize > 0 {
			totalPages = int(math.Ceil(float64(total) / float64(params.PageSize)))
		}
		return &PaginatedAPIKeys{
			Items:      items,
			Total:      total,
			Page:       params.Page,
			PageSize:   params.PageSize,
			TotalPages: totalPages,
		}, nil
	}
	// --- Path 2: In-memory search (keyword present) ---
	s.logger.Infof("Performing heavy in-memory search for group %d with keyword '%s'", params.KeyGroupID, params.Keyword)
	// To get all keys, we fetch all IDs first, then get their full details.
	var statusesToFilter []string
	if params.Status != "" {
		statusesToFilter = append(statusesToFilter, params.Status)
	} else {
		statusesToFilter = append(statusesToFilter, "all") // "all" gets every status
	}
	allKeyIDs, err := s.keyRepo.FindKeyIDsByStatus(params.KeyGroupID, statusesToFilter)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch all key IDs for search: %w", err)
	}
	if len(allKeyIDs) == 0 {
		return &PaginatedAPIKeys{Items: []*models.APIKeyDetails{}, Total: 0, Page: 1, PageSize: params.PageSize, TotalPages: 0}, nil
	}

	// This is the heavy operation: getting all keys and decrypting them.
	allKeys, err := s.keyRepo.GetKeysByIDs(allKeyIDs)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch all key details for in-memory search: %w", err)
	}
	// We also need mappings to build the final `APIKeyDetails`.
	var allMappings []models.GroupAPIKeyMapping
	err = s.db.Where("key_group_id = ? AND api_key_id IN ?", params.KeyGroupID, allKeyIDs).Find(&allMappings).Error
	if err != nil {
		return nil, fmt.Errorf("failed to fetch mappings for in-memory search: %w", err)
	}
	mappingMap := make(map[uint]*models.GroupAPIKeyMapping)
	for i := range allMappings {
		mappingMap[allMappings[i].APIKeyID] = &allMappings[i]
	}
	// Filter the results in memory.
	var filteredItems []*models.APIKeyDetails
	for _, key := range allKeys {
		if strings.Contains(key.APIKey, params.Keyword) {
			if mapping, ok := mappingMap[key.ID]; ok {
				filteredItems = append(filteredItems, &models.APIKeyDetails{
					ID:                    key.ID,
					CreatedAt:             key.CreatedAt,
					UpdatedAt:             key.UpdatedAt,
					APIKey:                key.APIKey,
					MasterStatus:          key.MasterStatus,
					Status:                mapping.Status,
					LastError:             mapping.LastError,
					ConsecutiveErrorCount: mapping.ConsecutiveErrorCount,
					LastUsedAt:            mapping.LastUsedAt,
					CooldownUntil:         mapping.CooldownUntil,
				})
			}
		}
	}
	// Sort the filtered results to ensure consistent pagination (by ID descending).
	sort.Slice(filteredItems, func(i, j int) bool {
		return filteredItems[i].ID > filteredItems[j].ID
	})
	// Manually paginate the filtered results.
	total := int64(len(filteredItems))
	start := (params.Page - 1) * params.PageSize
	end := start + params.PageSize
	if start < 0 {
		start = 0
	}
	if start >= len(filteredItems) {
		return &PaginatedAPIKeys{
			Items:      []*models.APIKeyDetails{},
			Total:      total,
			Page:       params.Page,
			PageSize:   params.PageSize,
			TotalPages: int(math.Ceil(float64(total) / float64(params.PageSize))),
		}, nil
	}
	if end > len(filteredItems) {
		end = len(filteredItems)
	}
	paginatedItems := filteredItems[start:end]
	return &PaginatedAPIKeys{
		Items:      paginatedItems,
		Total:      total,
		Page:       params.Page,
		PageSize:   params.PageSize,
		TotalPages: int(math.Ceil(float64(total) / float64(params.PageSize))),
	}, nil
}

func (s *APIKeyService) GetKeysByIds(ids []uint) ([]models.APIKey, error) {
	return s.keyRepo.GetKeysByIDs(ids)
}

func (s *APIKeyService) UpdateAPIKey(key *models.APIKey) error {
	go func() {
		var oldKey models.APIKey
		if err := s.db.First(&oldKey, key.ID).Error; err != nil {
			s.logger.Errorf("Failed to find old key state for ID %d before update: %v", key.ID, err)
			return
		}
		if err := s.keyRepo.Update(key); err != nil {
			s.logger.Errorf("Failed to asynchronously update key ID %d: %v", key.ID, err)
			return
		}
	}()
	return nil
}

func (s *APIKeyService) HardDeleteAPIKeyByID(id uint) error {
	// Get all associated groups before deletion to publish correct events
	groups, err := s.keyRepo.GetGroupsForKey(id)
	if err != nil {
		s.logger.Warnf("Could not get groups for key ID %d before hard deletion (key might be orphaned): %v", id, err)
	}

	err = s.keyRepo.HardDeleteByID(id)
	if err == nil {
		// Publish events for each group the key was a part of
		for _, groupID := range groups {
			event := models.KeyStatusChangedEvent{
				KeyID:        id,
				GroupID:      groupID,
				ChangeReason: "key_hard_deleted",
			}
			eventData, _ := json.Marshal(event)
			go s.store.Publish(models.TopicKeyStatusChanged, eventData)
		}
	}
	return err
}

func (s *APIKeyService) UpdateMappingStatus(groupID, keyID uint, newStatus models.APIKeyStatus) (*models.GroupAPIKeyMapping, error) {
	key, err := s.keyRepo.GetKeyByID(keyID)
	if err != nil {
		return nil, CustomErrors.ParseDBError(err)
	}

	if key.MasterStatus != models.MasterStatusActive && newStatus == models.StatusActive {
		return nil, CustomErrors.ErrStateConflictMasterRevoked
	}
	mapping, err := s.keyRepo.GetMapping(groupID, keyID)
	if err != nil {
		return nil, err
	}
	oldStatus := mapping.Status
	if oldStatus == newStatus {
		return mapping, nil
	}
	mapping.Status = newStatus
	if newStatus == models.StatusActive {
		mapping.ConsecutiveErrorCount = 0
		mapping.LastError = ""
	}
	if err := s.keyRepo.UpdateMapping(mapping); err != nil {
		return nil, err
	}
	go s.publishStatusChangeEvent(groupID, keyID, oldStatus, newStatus, "manual_update")
	return mapping, nil
}

func (s *APIKeyService) handleMasterKeyStatusChangeEvent(event *models.MasterKeyStatusChangedEvent) {
	s.logger.Infof("Received MasterKeyStatusChangedEvent for Key ID %d: %s -> %s", event.KeyID, event.OldMasterStatus, event.NewMasterStatus)
	if event.NewMasterStatus != models.MasterStatusRevoked {
		return
	}
	affectedGroupIDs, err := s.keyRepo.GetGroupsForKey(event.KeyID)
	if err != nil {
		s.logger.WithError(err).Errorf("Failed to get groups for key ID %d to propagate revoked status.", event.KeyID)
		return
	}
	if len(affectedGroupIDs) == 0 {
		s.logger.Infof("Key ID %d is revoked, but it's not associated with any group. No action needed.", event.KeyID)
		return
	}
	s.logger.Infof("Propagating REVOKED astatus for Key ID %d to %d groups.", event.KeyID, len(affectedGroupIDs))
	for _, groupID := range affectedGroupIDs {
		_, err := s.UpdateMappingStatus(groupID, event.KeyID, models.StatusBanned)
		if err != nil {
			if !errors.Is(err, gorm.ErrRecordNotFound) {
				s.logger.WithError(err).Errorf("Failed to update mapping status to BANNED for Key ID %d in Group ID %d.", event.KeyID, groupID)
			}
		}
	}
}

func (s *APIKeyService) StartRestoreKeysTask(groupID uint, keyIDs []uint) (*task.Status, error) {
	if len(keyIDs) == 0 {
		return nil, CustomErrors.NewAPIError(CustomErrors.ErrBadRequest, "No key IDs provided for restoration.")
	}
	resourceID := fmt.Sprintf("group-%d", groupID)
	taskStatus, err := s.taskService.StartTask(groupID, TaskTypeRestoreSpecificKeys, resourceID, len(keyIDs), time.Hour)
	if err != nil {
		return nil, err
	}
	go s.runRestoreKeysTask(taskStatus.ID, resourceID, groupID, keyIDs)
	return taskStatus, nil
}

func (s *APIKeyService) runRestoreKeysTask(taskID string, resourceID string, groupID uint, keyIDs []uint) {
	defer func() {
		if r := recover(); r != nil {
			s.logger.Errorf("Panic recovered in runRestoreKeysTask: %v", r)
			s.taskService.EndTaskByID(taskID, resourceID, nil, fmt.Errorf("panic in restore keys task: %v", r))
		}
	}()
	var mappingsToProcess []models.GroupAPIKeyMapping
	err := s.db.Preload("APIKey").
		Where("key_group_id = ? AND api_key_id IN ?", groupID, keyIDs).
		Find(&mappingsToProcess).Error
	if err != nil {
		s.taskService.EndTaskByID(taskID, resourceID, nil, err)
		return
	}
	result := &BatchRestoreResult{
		SkippedKeys: make([]SkippedKeyInfo, 0),
	}
	var successfulMappings []*models.GroupAPIKeyMapping
	processedCount := 0
	for _, mapping := range mappingsToProcess {
		processedCount++
		_ = s.taskService.UpdateProgressByID(taskID, processedCount)
		if mapping.APIKey == nil {
			result.SkippedCount++
			result.SkippedKeys = append(result.SkippedKeys, SkippedKeyInfo{KeyID: mapping.APIKeyID, Reason: "Associated APIKey entity not found."})
			continue
		}
		if mapping.APIKey.MasterStatus != models.MasterStatusActive {
			result.SkippedCount++
			result.SkippedKeys = append(result.SkippedKeys, SkippedKeyInfo{KeyID: mapping.APIKeyID, Reason: fmt.Sprintf("Master status is '%s'.", mapping.APIKey.MasterStatus)})
			continue
		}
		oldStatus := mapping.Status
		if oldStatus != models.StatusActive {
			mapping.Status = models.StatusActive
			mapping.ConsecutiveErrorCount = 0
			mapping.LastError = ""
			// Use the version that doesn't trigger individual cache updates.
			if err := s.keyRepo.UpdateMappingWithoutCache(&mapping); err != nil {
				s.logger.WithError(err).Warn("Failed to update mapping in DB during restore task.")
				result.SkippedCount++
				result.SkippedKeys = append(result.SkippedKeys, SkippedKeyInfo{KeyID: mapping.APIKeyID, Reason: "DB update failed."})
			} else {
				result.RestoredCount++
				successfulMappings = append(successfulMappings, &mapping) // Collect for batch cache update.
				go s.publishStatusChangeEvent(groupID, mapping.APIKeyID, oldStatus, models.StatusActive, "batch_restore")
			}
		} else {
			result.RestoredCount++ // Already active, count as success.
		}
	}
	// After the loop, perform one single, efficient cache update.
	if err := s.keyRepo.HandleCacheUpdateEventBatch(successfulMappings); err != nil {
		s.logger.WithError(err).Error("Failed to perform batch cache update after restore task.")
		// This is not a task-fatal error, so we just log it and continue.
	}
	// Account for keys that were requested but not found in the initial DB query.
	result.SkippedCount += (len(keyIDs) - len(mappingsToProcess))
	s.taskService.EndTaskByID(taskID, resourceID, result, nil)
}

func (s *APIKeyService) StartRestoreAllBannedTask(groupID uint) (*task.Status, error) {
	var bannedKeyIDs []uint
	err := s.db.Model(&models.GroupAPIKeyMapping{}).
		Where("key_group_id = ? AND status = ?", groupID, models.StatusBanned).
		Pluck("api_key_id", &bannedKeyIDs).Error
	if err != nil {
		return nil, CustomErrors.ParseDBError(err)
	}
	if len(bannedKeyIDs) == 0 {
		return nil, CustomErrors.NewAPIError(CustomErrors.ErrBadRequest, "No banned keys to restore in this group.")
	}
	return s.StartRestoreKeysTask(groupID, bannedKeyIDs)
}

func (s *APIKeyService) handlePostImportValidation(event *models.ImportGroupCompletedEvent) {
	group, ok := s.groupManager.GetGroupByID(event.GroupID)
	if !ok {
		s.logger.Errorf("Group with id %d not found during post-import validation, aborting.", event.GroupID)
		return
	}
	opConfig, err := s.groupManager.BuildOperationalConfig(group)
	if err != nil {
		s.logger.Errorf("Failed to build operational config for group %d, aborting validation: %v", event.GroupID, err)
		return
	}
	endpoint, err := s.groupManager.BuildKeyCheckEndpoint(event.GroupID)
	if err != nil {
		s.logger.Errorf("Failed to build key check endpoint for group %d, aborting validation: %v", event.GroupID, err)
		return
	}
	globalSettings := s.SettingsManager.GetSettings()
	concurrency := globalSettings.BaseKeyCheckConcurrency
	if opConfig.KeyCheckConcurrency != nil {
		concurrency = *opConfig.KeyCheckConcurrency
	}
	if concurrency <= 0 {
		concurrency = 10 // Safety fallback
	}
	timeout := time.Duration(globalSettings.KeyCheckTimeoutSeconds) * time.Second
	keysToValidate, err := s.keyRepo.GetKeysByIDs(event.KeyIDs)
	if err != nil {
		s.logger.Errorf("Failed to get key models for validation in group %d: %v", event.GroupID, err)
		return
	}
	s.logger.Infof("Validating %d keys for group %d with concurrency %d against endpoint %s", len(keysToValidate), event.GroupID, concurrency, endpoint)
	var wg sync.WaitGroup
	jobs := make(chan models.APIKey, len(keysToValidate))
	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			for key := range jobs {
				validationErr := s.validationService.ValidateSingleKey(&key, timeout, endpoint)
				if validationErr == nil {
					s.logger.Infof("Key ID %d PASSED validation. Status -> ACTIVE.", key.ID)
					if _, err := s.UpdateMappingStatus(event.GroupID, key.ID, models.StatusActive); err != nil {
						s.logger.Errorf("Failed to update status to ACTIVE for Key ID %d in group %d: %v", key.ID, event.GroupID, err)
					}
				} else {
					var apiErr *CustomErrors.APIError
					if !CustomErrors.As(validationErr, &apiErr) {
						apiErr = &CustomErrors.APIError{Message: validationErr.Error()}
					}
					s.judgeKeyErrors("", event.GroupID, key.ID, apiErr, false)
				}
			}
		}()
	}
	for _, key := range keysToValidate {
		jobs <- key
	}
	close(jobs)
	wg.Wait()
	s.logger.Infof("Finished post-import validation for group %d.", event.GroupID)
}

// [NEW] StartUpdateStatusByFilterTask starts a background job to update the status of keys
// that match a specific set of source statuses within a group.
func (s *APIKeyService) StartUpdateStatusByFilterTask(groupID uint, sourceStatuses []string, newStatus models.APIKeyStatus) (*task.Status, error) {
	s.logger.Infof("Starting task to update status to '%s' for keys in group %d matching statuses: %v", newStatus, groupID, sourceStatuses)

	// 1. Find key IDs using the new repository method. Using IDs is more efficient for updates.
	keyIDs, err := s.keyRepo.FindKeyIDsByStatus(groupID, sourceStatuses)
	if err != nil {
		return nil, CustomErrors.ParseDBError(err)
	}
	if len(keyIDs) == 0 {
		now := time.Now()
		return &task.Status{
			IsRunning: false, // The "task" is not running.
			Processed: 0,
			Total:     0,
			Result: map[string]string{ // We use the flexible Result field to pass the message.
				"message": "没有找到任何符合当前过滤条件的Key可供操作。",
			},
			Error:      "", // There is no error.
			StartedAt:  now,
			FinishedAt: &now, // It started and finished at the same time.
		}, nil // Return nil for the error, signaling a 200 OK.
	}
	// 2. Start a new task using the TaskService, following existing patterns.
	resourceID := fmt.Sprintf("group-%d-status-update", groupID)
	taskStatus, err := s.taskService.StartTask(groupID, TaskTypeUpdateStatusByFilter, resourceID, len(keyIDs), 30*time.Minute)
	if err != nil {
		return nil, err // Pass up errors like "task already in progress".
	}

	// 3. Run the core logic in a separate goroutine.
	go s.runUpdateStatusByFilterTask(taskStatus.ID, resourceID, groupID, keyIDs, newStatus)
	return taskStatus, nil
}

// [NEW] runUpdateStatusByFilterTask is the private worker function for the above task.
func (s *APIKeyService) runUpdateStatusByFilterTask(taskID, resourceID string, groupID uint, keyIDs []uint, newStatus models.APIKeyStatus) {
	defer func() {
		if r := recover(); r != nil {
			s.logger.Errorf("Panic recovered in runUpdateStatusByFilterTask: %v", r)
			s.taskService.EndTaskByID(taskID, resourceID, nil, fmt.Errorf("panic in update status task: %v", r))
		}
	}()
	type BatchUpdateResult struct {
		UpdatedCount int `json:"updated_count"`
		SkippedCount int `json:"skipped_count"`
	}
	result := &BatchUpdateResult{}
	var successfulMappings []*models.GroupAPIKeyMapping
	// 1. Fetch all key master statuses in one go. This is efficient.
	keys, err := s.keyRepo.GetKeysByIDs(keyIDs)
	if err != nil {
		s.logger.WithError(err).Error("Failed to fetch keys for bulk status update, aborting task.")
		s.taskService.EndTaskByID(taskID, resourceID, nil, err)
		return
	}
	masterStatusMap := make(map[uint]models.MasterAPIKeyStatus)
	for _, key := range keys {
		masterStatusMap[key.ID] = key.MasterStatus
	}
	// 2. [THE REFINEMENT] Fetch all relevant mappings directly using s.db,
	// avoiding the need for a new repository method. This pattern is
	// already used in other parts of this service.
	var mappings []*models.GroupAPIKeyMapping
	if err := s.db.Where("key_group_id = ? AND api_key_id IN ?", groupID, keyIDs).Find(&mappings).Error; err != nil {
		s.logger.WithError(err).Error("Failed to fetch mappings for bulk status update, aborting task.")
		s.taskService.EndTaskByID(taskID, resourceID, nil, err)
		return
	}
	processedCount := 0
	for _, mapping := range mappings {
		processedCount++
		// The progress update should reflect the number of items *being processed*, not the final count.
		_ = s.taskService.UpdateProgressByID(taskID, processedCount)
		masterStatus, ok := masterStatusMap[mapping.APIKeyID]
		if !ok {
			result.SkippedCount++
			continue
		}
		if masterStatus != models.MasterStatusActive && newStatus == models.StatusActive {
			result.SkippedCount++
			continue
		}
		oldStatus := mapping.Status
		if oldStatus != newStatus {
			mapping.Status = newStatus
			if newStatus == models.StatusActive {
				mapping.ConsecutiveErrorCount = 0
				mapping.LastError = ""
			}
			if err := s.keyRepo.UpdateMappingWithoutCache(mapping); err != nil {
				result.SkippedCount++
			} else {
				result.UpdatedCount++
				successfulMappings = append(successfulMappings, mapping)
				go s.publishStatusChangeEvent(groupID, mapping.APIKeyID, oldStatus, newStatus, "batch_status_update")
			}
		} else {
			result.UpdatedCount++ // Already in desired state, count as success.
		}
	}
	result.SkippedCount += (len(keyIDs) - len(mappings))
	if err := s.keyRepo.HandleCacheUpdateEventBatch(successfulMappings); err != nil {
		s.logger.WithError(err).Error("Failed to perform batch cache update after status update task.")
	}
	s.logger.Infof("Finished bulk status update task '%s' for group %d. Updated: %d, Skipped: %d.", taskID, groupID, result.UpdatedCount, result.SkippedCount)
	s.taskService.EndTaskByID(taskID, resourceID, result, nil)
}

func (s *APIKeyService) HandleRequestResult(group *models.KeyGroup, key *models.APIKey, success bool, apiErr *CustomErrors.APIError) {
	if success {
		if group.PollingStrategy == models.StrategyWeighted {
			go s.keyRepo.UpdateKeyUsageTimestamp(group.ID, key.ID)
		}
		return
	}
	if apiErr == nil {
		s.logger.Warnf("Request failed for KeyID %d in GroupID %d but no specific API error was provided. No action taken.", key.ID, group.ID)
		return
	}
	errMsg := apiErr.Message
	if CustomErrors.IsPermanentUpstreamError(errMsg) || CustomErrors.IsTemporaryUpstreamError(errMsg) {
		s.logger.Warnf("Request for KeyID %d in GroupID %d failed with a key-specific error: %s. Issuing order to move to cooldown.", key.ID, group.ID, errMsg)
		go s.keyRepo.SyncKeyStatusInPollingCaches(group.ID, key.ID, models.StatusCooldown)
	} else {
		s.logger.Infof("Request for KeyID %d in GroupID %d failed with a non-key-specific error. No punitive action taken. Error: %s", key.ID, group.ID, errMsg)
	}
}

// sanitizeForLog truncates long error messages and removes JSON-like content for cleaner Info/Error logs.
func sanitizeForLog(errMsg string) string {
	// Find the start of any potential JSON blob or detailed structure.
	jsonStartIndex := strings.Index(errMsg, "{")
	var cleanMsg string
	if jsonStartIndex != -1 {
		// If a '{' is found, take everything before it as the summary
		// and append a simple placeholder.
		cleanMsg = strings.TrimSpace(errMsg[:jsonStartIndex]) + " {...}"
	} else {
		// If no JSON-like structure is found, use the original message.
		cleanMsg = errMsg
	}
	// Always apply a final length truncation as a safeguard against extremely long non-JSON errors.
	const maxLen = 250
	if len(cleanMsg) > maxLen {
		return cleanMsg[:maxLen] + "..."
	}
	return cleanMsg
}

func (s *APIKeyService) judgeKeyErrors(
	correlationID string,
	groupID, keyID uint,
	apiErr *CustomErrors.APIError,
	isPreciseRouting bool,
) {
	logger := s.logger.WithFields(logrus.Fields{"group_id": groupID, "key_id": keyID, "correlation_id": correlationID})
	mapping, err := s.keyRepo.GetMapping(groupID, keyID)
	if err != nil {
		logger.WithError(err).Warn("Cannot apply consequences for error: mapping not found.")
		return
	}
	now := time.Now()
	mapping.LastUsedAt = &now
	errorMessage := apiErr.Message
	if CustomErrors.IsPermanentUpstreamError(errorMessage) {
		logger.Errorf("Permanent error detected. Banning mapping and revoking master key. Reason: %s", sanitizeForLog(errorMessage))
		logger.WithField("full_error_details", errorMessage).Debug("Full details of the permanent error.")
		if mapping.Status != models.StatusBanned {
			oldStatus := mapping.Status
			mapping.Status = models.StatusBanned
			mapping.LastError = errorMessage
			if err := s.keyRepo.UpdateMapping(mapping); err != nil {
				logger.WithError(err).Error("Failed to update mapping status to BANNED.")
			} else {
				go s.publishStatusChangeEvent(groupID, keyID, oldStatus, mapping.Status, "permanent_error_banned")
				go s.revokeMasterKey(keyID, "permanent_upstream_error")
			}
		}
		return
	}
	if CustomErrors.IsTemporaryUpstreamError(errorMessage) {
		mapping.LastError = errorMessage
		mapping.ConsecutiveErrorCount++
		var threshold int
		if isPreciseRouting {
			group, ok := s.groupManager.GetGroupByID(groupID)
			opConfig, err := s.groupManager.BuildOperationalConfig(group)
			if !ok || err != nil {
				logger.Warnf("Could not build operational config for group %d in Precise Routing mode. Falling back to global settings.", groupID)
				threshold = s.SettingsManager.GetSettings().BlacklistThreshold
			} else {
				threshold = *opConfig.KeyBlacklistThreshold
			}
		} else {
			threshold = s.SettingsManager.GetSettings().BlacklistThreshold
		}
		logger.Warnf("Temporary error detected. Incrementing error count. New count: %d (Threshold: %d). Reason: %s", mapping.ConsecutiveErrorCount, threshold, sanitizeForLog(errorMessage))
		logger.WithField("full_error_details", errorMessage).Debug("Full details of the temporary error.")
		oldStatus := mapping.Status
		newStatus := oldStatus
		if mapping.ConsecutiveErrorCount >= threshold && oldStatus == models.StatusActive {
			newStatus = models.StatusCooldown
			logger.Errorf("Putting mapping into COOLDOWN due to reaching temporary error threshold (%d)", threshold)
		}
		if oldStatus != newStatus {
			mapping.Status = newStatus
		}
		if err := s.keyRepo.UpdateMapping(mapping); err != nil {
			logger.WithError(err).Error("Failed to update mapping after temporary error.")
			return
		}
		if oldStatus != newStatus {
			go s.publishStatusChangeEvent(groupID, keyID, oldStatus, newStatus, "error_threshold_reached")
		}
		return
	}
	logger.Infof("Ignored truly ignorable upstream error. Only updating LastUsedAt. Reason: %s", sanitizeForLog(errorMessage))
	logger.WithField("full_error_details", errorMessage).Debug("Full details of the ignorable error.")
	if err := s.keyRepo.UpdateMapping(mapping); err != nil {
		logger.WithError(err).Error("Failed to update LastUsedAt for ignorable error.")
	}
}

func (s *APIKeyService) revokeMasterKey(keyID uint, reason string) {
	key, err := s.keyRepo.GetKeyByID(keyID)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			s.logger.Warnf("Attempted to revoke non-existent key ID %d.", keyID)
		} else {
			s.logger.Errorf("Failed to get key by ID %d for master status revocation: %v", keyID, err)
		}
		return
	}
	if key.MasterStatus == models.MasterStatusRevoked {
		return
	}
	oldMasterStatus := key.MasterStatus
	newMasterStatus := models.MasterStatusRevoked
	if err := s.keyRepo.UpdateMasterStatusByID(keyID, newMasterStatus); err != nil {
		s.logger.Errorf("Failed to update master status to REVOKED for key ID %d: %v", keyID, err)
		return
	}
	masterKeyEvent := models.MasterKeyStatusChangedEvent{
		KeyID:           keyID,
		OldMasterStatus: oldMasterStatus,
		NewMasterStatus: newMasterStatus,
		ChangeReason:    reason,
		ChangedAt:       time.Now(),
	}
	eventData, _ := json.Marshal(masterKeyEvent)
	_ = s.store.Publish(models.TopicMasterKeyStatusChanged, eventData)
}

func (s *APIKeyService) GetAPIKeyStringsForExport(groupID uint, statuses []string) ([]string, error) {
	return s.keyRepo.GetKeyStringsByGroupAndStatus(groupID, statuses)
}