package automation

import (
	"context"
	"fmt"

	applogger "github.com/gochat/gochat/pkg/logger"
	"gorm.io/gorm"
)

// BotRuleService provides CRUD + condition matching + action execution for bot rules.
// Reference: Chatwoot AutomationRules pattern adapted for AgentBot scope.
// BotRuleService reuses ConditionsFilterService.MatchConditions and ActionService.Execute
// to avoid duplicating condition matching and action execution logic.
type BotRuleService struct {
	db DBProvider
}

// NewBotRuleService creates a new BotRuleService.
func NewBotRuleService(db DBProvider) *BotRuleService {
	return &BotRuleService{db: db}
}

// GetByID retrieves a bot rule by ID.
func (s *BotRuleService) GetByID(ctx context.Context, id uint) (*BotRule, error) {
	var rule BotRule
	if err := s.db.DB().WithContext(ctx).First(&rule, id).Error; err != nil {
		return nil, err
	}
	return &rule, nil
}

// ListByAccount retrieves all bot rules for an account.
func (s *BotRuleService) ListByAccount(ctx context.Context, accountID uint) ([]BotRule, error) {
	var rules []BotRule
	if err := s.db.DB().WithContext(ctx).
		Where("account_id = ?", accountID).
		Order("id ASC").
		Find(&rules).Error; err != nil {
		return nil, err
	}
	return rules, nil
}

// ListByAgentBot retrieves all bot rules for a specific AgentBot.
func (s *BotRuleService) ListByAgentBot(ctx context.Context, accountID uint, agentBotID uint) ([]BotRule, error) {
	var rules []BotRule
	if err := s.db.DB().WithContext(ctx).
		Where("account_id = ? AND agent_bot_id = ?", accountID, agentBotID).
		Order("id ASC").
		Find(&rules).Error; err != nil {
		return nil, err
	}
	return rules, nil
}

// ListActiveByAccountAndEvent retrieves active bot rules for a given account and event.
// Reference: mirrors AutomationRuleService.ListActiveByAccountAndEvent
func (s *BotRuleService) ListActiveByAccountAndEvent(ctx context.Context, accountID uint, eventName string) ([]BotRule, error) {
	var rules []BotRule
	if err := s.db.DB().WithContext(ctx).
		Where("account_id = ? AND event_name = ? AND status = ?", accountID, eventName, BotRuleStatusActive).
		Order("id ASC").
		Find(&rules).Error; err != nil {
		return nil, err
	}
	return rules, nil
}

// Create creates a new bot rule.
// New rules default to active status unless explicitly set to inactive.
func (s *BotRuleService) Create(ctx context.Context, rule *BotRule) error {
	// Validate conditions before saving
	if err := ValidateConditions(rule.Conditions); err != nil {
		return fmt.Errorf("invalid conditions: %w", err)
	}
	// Use Select to force all fields including zero-value fields
	return s.db.DB().WithContext(ctx).Select(
		"AccountID", "AgentBotID", "EventName", "Name", "Description",
		"Conditions", "Actions", "Status",
	).Create(rule).Error
}

// Update updates an existing bot rule.
func (s *BotRuleService) Update(ctx context.Context, rule *BotRule) error {
	// Validate conditions before saving
	if err := ValidateConditions(rule.Conditions); err != nil {
		return fmt.Errorf("invalid conditions: %w", err)
	}
	return s.db.DB().WithContext(ctx).Save(rule).Error
}

// Delete soft-deletes a bot rule.
func (s *BotRuleService) Delete(ctx context.Context, id uint) error {
	return s.db.DB().WithContext(ctx).Delete(&BotRule{}, id).Error
}

// Clone duplicates a bot rule, creating a new copy with "(copy)" appended to the name.
func (s *BotRuleService) Clone(ctx context.Context, id uint) (*BotRule, error) {
	original, err := s.GetByID(ctx, id)
	if err != nil {
		return nil, err
	}

	cloned := &BotRule{
		AccountID:   original.AccountID,
		AgentBotID:  original.AgentBotID,
		EventName:   original.EventName,
		Name:        original.Name + " (copy)",
		Description: original.Description,
		Conditions:  original.Conditions,
		Actions:     original.Actions,
		Status:      original.Status,
	}

	if err := s.db.DB().WithContext(ctx).Create(cloned).Error; err != nil {
		return nil, err
	}
	return cloned, nil
}

// ToggleStatus toggles the active/inactive status of a bot rule.
func (s *BotRuleService) ToggleStatus(ctx context.Context, id uint, status BotRuleStatus) error {
	return s.db.DB().WithContext(ctx).
		Model(&BotRule{}).
		Where("id = ?", id).
		Update("status", status).Error
}

// MatchAndExecute checks all active bot rules for the given event and account,
// runs condition filters for each rule, and executes actions for matching rules.
// Reference: mirrors AutomationRuleService.MatchAndExecute but for BotRule scope.
// Reuses ConditionsFilterService.MatchConditions and ActionService.Execute.
func (s *BotRuleService) MatchAndExecute(ctx context.Context, accountID uint, eventName string, conversationID uint, eventData map[string]interface{}) error {
	rules, err := s.ListActiveByAccountAndEvent(ctx, accountID, eventName)
	if err != nil {
		return fmt.Errorf("failed to load bot rules: %w", err)
	}

	if len(rules) == 0 {
		applogger.L().Debugf("no active bot rules for account %d event %s", accountID, eventName)
		return nil
	}

	// Load the conversation for condition matching
	conversation, err := loadConversationForFilter(ctx, s.db.DB(), conversationID)
	if err != nil {
		return fmt.Errorf("failed to load conversation %d: %w", conversationID, err)
	}

	actionSvc := NewActionService(s.db)

	for _, rule := range rules {
		matched, err := MatchConditions(ctx, s.db.DB(), rule.Conditions, conversation, eventData)
		if err != nil {
			applogger.L().Errorf("condition matching failed for bot rule %d: %v", rule.ID, err)
			continue
		}
		if !matched {
			applogger.L().Debugf("bot rule %d did not match conditions for conversation %d", rule.ID, conversationID)
			continue
		}

		applogger.L().Infof("bot rule %d matched for conversation %d, executing %d actions", rule.ID, conversationID, len(rule.Actions))

		// Execute actions — stamp source as "bot_rule" with rule.ID for audit trail
		actionsExecuted := 0
		actionsFailed := 0
		var firstErrorMsg string
		for _, action := range rule.Actions {
			if err := actionSvc.Execute(ctx, accountID, conversationID, action, ActionSourceBotRule, rule.ID); err != nil {
				applogger.L().Errorf("action %s failed for bot rule %d on conversation %d: %v", action.ActionName, rule.ID, conversationID, err)
				actionsFailed++
				if firstErrorMsg == "" {
					firstErrorMsg = err.Error()
				}
			} else {
				actionsExecuted++
			}
		}

		if actionsFailed > 0 {
			applogger.L().Warnf("bot rule %d: %d/%d actions executed, %d failed (first error: %s)",
				rule.ID, actionsExecuted, len(rule.Actions), actionsFailed, firstErrorMsg)
		} else {
			applogger.L().Infof("bot rule %d: all %d actions executed successfully", rule.ID, actionsExecuted)
		}
	}

	return nil
}

// loadConversationForFilter loads a conversation for condition matching.
// Standalone helper shared by BotRuleService and BotTriggerConfigService.
// Reference: mirrors AutomationRuleService.loadConversation
func loadConversationForFilter(ctx context.Context, db *gorm.DB, conversationID uint) (*ConversationForFilter, error) {
	var conv ConversationForFilter
	if err := db.WithContext(ctx).
		Table("conversations").
		Where("id = ?", conversationID).
		First(&conv).Error; err != nil {
		return nil, err
	}
	return &conv, nil
}