package admin

import (
	"context"
	"time"

	"github.com/google/uuid"

	"knowfoolery/backend/services/admin-service/internal/domain/audit"
)

// Service provides admin use-cases.
type Service struct {
	auditRepo audit.Repository
	retention time.Duration
}

// NewService builds an admin service with a retention period in days.
func NewService(auditRepo audit.Repository, retentionDays int) *Service {
	if retentionDays <= 0 {
		retentionDays = 90
	}
	return &Service{
		auditRepo: auditRepo,
		retention: time.Duration(retentionDays) * 24 * time.Hour,
	}
}

func (s *Service) AppendAudit(ctx context.Context, actorID, actorEmail, action, resource string, details any) error {
	return s.auditRepo.Append(ctx, audit.Entry{
		ID:         uuid.NewString(),
		At:         time.Now().UTC(),
		ActorID:    actorID,
		ActorEmail: actorEmail,
		Action:     action,
		Resource:   resource,
		Details:    details,
	})
}

func (s *Service) ListAudit(ctx context.Context, limit, offset int) ([]audit.Entry, error) {
	return s.auditRepo.List(ctx, limit, offset)
}

func (s *Service) Dashboard(ctx context.Context) (map[string]any, error) {
	auditCount, err := s.auditRepo.Count(ctx)
	if err != nil {
		return nil, err
	}
	return map[string]any{
		"audit_entries_total": auditCount,
		"generated_at":        time.Now().UTC(),
	}, nil
}

func (s *Service) PruneAudit(ctx context.Context) (int64, error) {
	before := time.Now().UTC().Add(-s.retention)
	return s.auditRepo.PruneBefore(ctx, before)
}