package service

import (
	"baron-sso-backend/internal/domain"
	"baron-sso-backend/internal/repository"
	"context"
	"fmt"
	"log/slog"
)

type RelyingPartyService interface {
	Create(ctx context.Context, tenantID string, client domain.HydraClient) (*domain.RelyingParty, error)
	Get(ctx context.Context, clientID string) (*domain.RelyingParty, *domain.HydraClient, error)
	List(ctx context.Context, tenantID string) ([]domain.RelyingParty, error)
	ListAll(ctx context.Context) ([]domain.RelyingParty, error)
	ListByTenantIDs(ctx context.Context, tenantIDs []string) ([]domain.RelyingParty, error)
	Update(ctx context.Context, clientID string, client domain.HydraClient) (*domain.RelyingParty, error)
	Delete(ctx context.Context, clientID string) error
}

func (s *relyingPartyService) ListAll(ctx context.Context) ([]domain.RelyingParty, error) {
	return s.repo.ListAll(ctx)
}

func (s *relyingPartyService) ListByTenantIDs(ctx context.Context, tenantIDs []string) ([]domain.RelyingParty, error) {
	// Simple implementation for now, repository could be optimized with IN clause
	var allRps []domain.RelyingParty
	for _, tid := range tenantIDs {
		rps, _ := s.repo.ListByTenantID(ctx, tid)
		allRps = append(allRps, rps...)
	}
	return allRps, nil
}

type relyingPartyService struct {
	repo         repository.RelyingPartyRepository
	hydraService *HydraAdminService
	ketoService  KetoService
}

func NewRelyingPartyService(
	repo repository.RelyingPartyRepository,
	hydraService *HydraAdminService,
	ketoService KetoService,
) RelyingPartyService {
	return &relyingPartyService{
		repo:         repo,
		hydraService: hydraService,
		ketoService:  ketoService,
	}
}

func (s *relyingPartyService) Create(ctx context.Context, tenantID string, client domain.HydraClient) (*domain.RelyingParty, error) {
	// 1. Create Client in Hydra
	// Ensure metadata contains tenant_id for reference
	if client.Metadata == nil {
		client.Metadata = make(map[string]interface{})
	}
	client.Metadata["tenant_id"] = tenantID

	createdClient, err := s.hydraService.CreateClient(ctx, client)
	if err != nil {
		return nil, fmt.Errorf("failed to create hydra client: %w", err)
	}

	// 2. Create Record in DB
	rp := &domain.RelyingParty{
		ClientID:    createdClient.ClientID,
		TenantID:    tenantID,
		Name:        createdClient.ClientName,
		Description: "", // Hydra doesn't have description field standard, maybe in metadata?
	}

	if err := s.repo.Create(ctx, rp); err != nil {
		// Rollback: Delete Hydra Client
		_ = s.hydraService.DeleteClient(ctx, createdClient.ClientID)
		return nil, fmt.Errorf("failed to create relying party in db: %w", err)
	}

	// 3. Create Relation in Keto
	// RelyingParty:<client_id>#parent_tenant@Tenant:<tenant_id>
	err = s.ketoService.CreateRelation(ctx, "RelyingParty", createdClient.ClientID, "parent_tenant", "Tenant:"+tenantID)
	if err != nil {
		slog.Error("Failed to create keto relation for relying party", "error", err, "client_id", createdClient.ClientID)
		// We don't rollback here, but we should probably have a background job to fix this.
		// Or return error and let caller decide? For MVP, logging error is acceptable as per issue discussion (Eventual Consistency preferred).
	}

	return rp, nil
}

func (s *relyingPartyService) Get(ctx context.Context, clientID string) (*domain.RelyingParty, *domain.HydraClient, error) {
	// Get from DB
	rp, err := s.repo.FindByID(ctx, clientID)
	if err != nil {
		return nil, nil, err
	}

	// Get from Hydra
	hydraClient, err := s.hydraService.GetClient(ctx, clientID)
	if err != nil {
		return nil, nil, err
	}

	return rp, hydraClient, nil
}

func (s *relyingPartyService) List(ctx context.Context, tenantID string) ([]domain.RelyingParty, error) {
	return s.repo.ListByTenantID(ctx, tenantID)
}

func (s *relyingPartyService) Update(ctx context.Context, clientID string, client domain.HydraClient) (*domain.RelyingParty, error) {
	// Update Hydra
	updatedClient, err := s.hydraService.UpdateClient(ctx, clientID, client)
	if err != nil {
		return nil, err
	}

	// Update DB
	rp, err := s.repo.FindByID(ctx, clientID)
	if err != nil {
		return nil, err
	}
	rp.Name = updatedClient.ClientName
	// Update other fields if necessary

	if err := s.repo.Update(ctx, rp); err != nil {
		return nil, err
	}

	return rp, nil
}

func (s *relyingPartyService) Delete(ctx context.Context, clientID string) error {
	// Delete from DB
	if err := s.repo.Delete(ctx, clientID); err != nil {
		return err
	}

	// Delete from Hydra
	if err := s.hydraService.DeleteClient(ctx, clientID); err != nil {
		slog.Error("Failed to delete hydra client", "error", err, "client_id", clientID)
		// Proceeding...
	}

	// Delete from Keto (Optional, but good practice to clean up)
	// We might not know the tenant ID here without querying DB first, but if DB is deleted, we might miss it.
	//Ideally, we should query DB first.
	// But `DeleteRelation` requires specific object/relation/subject.
	// If we want to delete ALL relations for this object, Keto API supports that?
	// `DeleteRelation` in our service wrapper is specific.
	// We can skip explicit Keto deletion for now as orphaned tuples are less critical than orphaned resources.

	return nil
}