package service

import (
	"context"
	"fmt"
	"testing"

	"github.com/google/uuid"
	"github.com/igodwin/notifier/internal/auth"
	"github.com/igodwin/notifier/internal/domain"
)

// ctxForClient builds a context carrying an auth.Context for the given
// client and roles, as REST/gRPC middleware would attach after authenticating
// a request.
func ctxForClient(clientID string, roles ...string) context.Context {
	return auth.ContextWithAuth(context.Background(), &auth.Context{
		ClientID: clientID,
		Roles:    roles,
	})
}

// TestTenantScopingNonAdminSeesOnlyOwnNotifications verifies that a
// non-admin caller only sees notifications stamped with their own ClientID.
func TestTenantScopingNonAdminSeesOnlyOwnNotifications(t *testing.T) {
	svc := createTestService(t)

	tenantA := &domain.Notification{
		ID:         uuid.New().String(),
		Type:       domain.TypeStdout,
		Status:     domain.StatusSent,
		Recipients: []string{"a@example.com"},
		ClientID:   "tenant-a",
	}
	tenantB := &domain.Notification{
		ID:         uuid.New().String(),
		Type:       domain.TypeStdout,
		Status:     domain.StatusSent,
		Recipients: []string{"b@example.com"},
		ClientID:   "tenant-b",
	}

	svc.storeNotification(tenantA)
	svc.storeNotification(tenantB)

	ctxA := ctxForClient("tenant-a", "user")

	list, err := svc.ListNotifications(ctxA, &domain.NotificationFilter{})
	if err != nil {
		t.Fatalf("ListNotifications failed: %v", err)
	}
	if len(list) != 1 || list[0].ID != tenantA.ID {
		t.Fatalf("expected tenant-a to see only its own notification, got %d results", len(list))
	}

	if _, err := svc.GetNotification(ctxA, tenantA.ID); err != nil {
		t.Errorf("tenant-a should be able to get its own notification: %v", err)
	}

	if _, err := svc.GetNotification(ctxA, tenantB.ID); err == nil {
		t.Error("tenant-a should not be able to get tenant-b's notification")
	}

	stats, err := svc.GetStats(ctxA)
	if err != nil {
		t.Fatalf("GetStats failed: %v", err)
	}
	if stats.TotalSent != 1 {
		t.Errorf("expected tenant-a stats to count only its own notification, got %d", stats.TotalSent)
	}
}

// TestTenantScopingAdminSeesAll verifies that a caller with the admin role
// can see notifications belonging to any tenant.
func TestTenantScopingAdminSeesAll(t *testing.T) {
	svc := createTestService(t)

	tenantA := &domain.Notification{ID: uuid.New().String(), Type: domain.TypeStdout, Status: domain.StatusSent, Recipients: []string{"a@example.com"}, ClientID: "tenant-a"}
	tenantB := &domain.Notification{ID: uuid.New().String(), Type: domain.TypeStdout, Status: domain.StatusSent, Recipients: []string{"b@example.com"}, ClientID: "tenant-b"}

	svc.storeNotification(tenantA)
	svc.storeNotification(tenantB)

	adminCtx := ctxForClient("admin-client", "admin")

	list, err := svc.ListNotifications(adminCtx, &domain.NotificationFilter{})
	if err != nil {
		t.Fatalf("ListNotifications failed: %v", err)
	}
	if len(list) != 2 {
		t.Fatalf("expected admin to see both notifications, got %d", len(list))
	}

	if _, err := svc.GetNotification(adminCtx, tenantA.ID); err != nil {
		t.Errorf("admin should be able to get tenant-a's notification: %v", err)
	}
	if _, err := svc.GetNotification(adminCtx, tenantB.ID); err != nil {
		t.Errorf("admin should be able to get tenant-b's notification: %v", err)
	}

	stats, err := svc.GetStats(adminCtx)
	if err != nil {
		t.Fatalf("GetStats failed: %v", err)
	}
	if stats.TotalSent != 2 {
		t.Errorf("expected admin stats to count both notifications, got %d", stats.TotalSent)
	}
}

// TestTenantScopingAuthDisabledUnchanged verifies that when no auth context
// is present (auth disabled), behavior is unchanged: every notification is
// visible regardless of ClientID.
func TestTenantScopingAuthDisabledUnchanged(t *testing.T) {
	svc := createTestService(t)

	tenantA := &domain.Notification{ID: uuid.New().String(), Type: domain.TypeStdout, Status: domain.StatusSent, Recipients: []string{"a@example.com"}, ClientID: "tenant-a"}
	tenantB := &domain.Notification{ID: uuid.New().String(), Type: domain.TypeStdout, Status: domain.StatusSent, Recipients: []string{"b@example.com"}, ClientID: ""}

	svc.storeNotification(tenantA)
	svc.storeNotification(tenantB)

	ctx := context.Background() // no auth context attached

	list, err := svc.ListNotifications(ctx, &domain.NotificationFilter{})
	if err != nil {
		t.Fatalf("ListNotifications failed: %v", err)
	}
	if len(list) != 2 {
		t.Fatalf("expected both notifications visible when auth is disabled, got %d", len(list))
	}

	if _, err := svc.GetNotification(ctx, tenantA.ID); err != nil {
		t.Errorf("expected to get tenant-a's notification with auth disabled: %v", err)
	}
	if _, err := svc.GetNotification(ctx, tenantB.ID); err != nil {
		t.Errorf("expected to get tenant-b's notification with auth disabled: %v", err)
	}
}

// TestTenantScopingCrossTenantAccessReturnsNotFound verifies that
// Get/Cancel/Retry on another tenant's notification return the exact same
// not-found error as a genuinely missing ID, so existence isn't leaked.
func TestTenantScopingCrossTenantAccessReturnsNotFound(t *testing.T) {
	svc := createTestService(t)

	tenantA := &domain.Notification{
		ID:         uuid.New().String(),
		Type:       domain.TypeStdout,
		Status:     domain.StatusPending,
		Recipients: []string{"a@example.com"},
		MaxRetries: 3,
		ClientID:   "tenant-a",
	}
	svc.storeNotification(tenantA)

	ctxB := ctxForClient("tenant-b", "user")

	wantMsg := fmt.Sprintf("notification not found: %s", tenantA.ID)

	_, getErr := svc.GetNotification(ctxB, tenantA.ID)
	if getErr == nil {
		t.Fatal("expected not-found error for cross-tenant Get")
	}
	if getErr.Error() != wantMsg {
		t.Errorf("expected cross-tenant Get error %q, got %q", wantMsg, getErr.Error())
	}

	_, missingErr := svc.GetNotification(ctxB, "does-not-exist")
	if missingErr == nil {
		t.Fatal("expected not-found error for missing ID")
	}

	cancelErr := svc.CancelNotification(ctxB, tenantA.ID)
	if cancelErr == nil {
		t.Fatal("expected not-found error for cross-tenant Cancel")
	}
	if cancelErr.Error() != wantMsg {
		t.Errorf("expected cross-tenant Cancel error %q, got %q", wantMsg, cancelErr.Error())
	}

	_, retryErr := svc.RetryNotification(ctxB, tenantA.ID)
	if retryErr == nil {
		t.Fatal("expected not-found error for cross-tenant Retry")
	}
	if retryErr.Error() != wantMsg {
		t.Errorf("expected cross-tenant Retry error %q, got %q", wantMsg, retryErr.Error())
	}

	// The owning tenant should still be able to see and act on it.
	ctxA := ctxForClient("tenant-a", "user")
	if _, err := svc.GetNotification(ctxA, tenantA.ID); err != nil {
		t.Errorf("tenant-a should still be able to get its own notification: %v", err)
	}
}