package user

import (
	"context"
	"testing"
	"time"

	domain "knowfoolery/backend/services/user-service/internal/domain/user"
	sharederrors "knowfoolery/backend/shared/domain/errors"
	sharedtypes "knowfoolery/backend/shared/domain/types"
)

// fakeRepo is an in-memory repository stub used by service unit tests.
type fakeRepo struct {
	usersByID      map[string]*domain.User
	usersByEmail   map[string]*domain.User
	usersByZitadel map[string]*domain.User
	audit          []domain.AuditLogEntry
}

// newFakeRepo creates a fake repository with empty stores.
func newFakeRepo() *fakeRepo {
	return &fakeRepo{
		usersByID:      map[string]*domain.User{},
		usersByEmail:   map[string]*domain.User{},
		usersByZitadel: map[string]*domain.User{},
	}
}

// EnsureSchema is a no-op for the in-memory fake repository.
func (r *fakeRepo) EnsureSchema(ctx context.Context) error { return nil }

// Create stores a user and assigns deterministic timestamps and ID for tests.
func (r *fakeRepo) Create(ctx context.Context, user *domain.User) (*domain.User, error) {
	user.ID = "u-1"
	now := time.Now().UTC()
	user.CreatedAt = now
	user.UpdatedAt = now
	r.usersByID[user.ID] = user
	r.usersByEmail[user.Email] = user
	r.usersByZitadel[user.ZitadelUserID] = user
	return user, nil
}

// GetByID returns a non-deleted user by ID.
func (r *fakeRepo) GetByID(ctx context.Context, id string) (*domain.User, error) {
	if u, ok := r.usersByID[id]; ok && !u.IsDeleted() {
		return u, nil
	}
	return nil, sharederrors.Wrap(sharederrors.CodeUserNotFound, "user not found", nil)
}

// GetByEmail returns a non-deleted user by email.
func (r *fakeRepo) GetByEmail(ctx context.Context, email string) (*domain.User, error) {
	if u, ok := r.usersByEmail[email]; ok && !u.IsDeleted() {
		return u, nil
	}
	return nil, sharederrors.Wrap(sharederrors.CodeUserNotFound, "user not found", nil)
}

// GetByZitadelUserID returns a non-deleted user by Zitadel subject.
func (r *fakeRepo) GetByZitadelUserID(ctx context.Context, zid string) (*domain.User, error) {
	if u, ok := r.usersByZitadel[zid]; ok && !u.IsDeleted() {
		return u, nil
	}
	return nil, sharederrors.Wrap(sharederrors.CodeUserNotFound, "user not found", nil)
}

// UpdateProfile updates mutable user profile fields in place.
func (r *fakeRepo) UpdateProfile(
	ctx context.Context,
	id, displayName string,
	consent domain.ConsentRecord,
) (*domain.User, error) {
	u, err := r.GetByID(ctx, id)
	if err != nil {
		return nil, err
	}
	u.DisplayName = displayName
	u.ConsentVersion = consent.Version
	u.ConsentGivenAt = consent.GivenAt
	u.ConsentSource = consent.Source
	u.UpdatedAt = time.Now().UTC()
	return u, nil
}

// MarkEmailVerified marks a user as verified in the fake store.
func (r *fakeRepo) MarkEmailVerified(ctx context.Context, id string) (*domain.User, error) {
	u, err := r.GetByID(ctx, id)
	if err != nil {
		return nil, err
	}
	u.EmailVerified = true
	u.UpdatedAt = time.Now().UTC()
	return u, nil
}

// SoftDelete marks a user as deleted and records an audit entry.
func (r *fakeRepo) SoftDelete(ctx context.Context, id string, actorUserID string) error {
	u, err := r.GetByID(ctx, id)
	if err != nil {
		return err
	}
	now := time.Now().UTC()
	u.DeletedAt = &now
	r.audit = append(
		r.audit,
		domain.AuditLogEntry{
			Action:       domain.AuditActionGDPRDelete,
			TargetUserID: id,
			ActorUserID:  actorUserID,
		},
	)
	return nil
}

// List returns users while honoring include-deleted filtering.
func (r *fakeRepo) List(
	ctx context.Context,
	pagination sharedtypes.Pagination,
	filter domain.ListFilter,
) ([]*domain.User, int64, error) {
	items := make([]*domain.User, 0, len(r.usersByID))
	for _, u := range r.usersByID {
		if !filter.IncludeDeleted && u.IsDeleted() {
			continue
		}
		items = append(items, u)
	}
	return items, int64(len(items)), nil
}

// AuditLogsByUserID returns audit entries associated with a target user.
func (r *fakeRepo) AuditLogsByUserID(ctx context.Context, id string) ([]domain.AuditLogEntry, error) {
	out := make([]domain.AuditLogEntry, 0)
	for _, a := range r.audit {
		if a.TargetUserID == id {
			out = append(out, a)
		}
	}
	return out, nil
}

// WriteAuditLog appends an audit entry to the fake repository.
func (r *fakeRepo) WriteAuditLog(ctx context.Context, entry domain.AuditLogEntry) error {
	r.audit = append(r.audit, entry)
	return nil
}

// TestRegisterIdempotent verifies repeated registration returns the same existing user.
func TestRegisterIdempotent(t *testing.T) {
	repo := newFakeRepo()
	svc := NewService(repo)

	first, err := svc.Register(context.Background(), RegisterInput{
		ActorZitadelUserID: "zitadel-1",
		ActorEmail:         "player@example.com",
		DisplayName:        "Player One",
		ConsentVersion:     "v1",
		ConsentSource:      "web",
	})
	if err != nil {
		t.Fatalf("first register failed: %v", err)
	}

	second, err := svc.Register(context.Background(), RegisterInput{
		ActorZitadelUserID: "zitadel-1",
		ActorEmail:         "player@example.com",
		DisplayName:        "Player One",
		ConsentVersion:     "v1",
		ConsentSource:      "web",
	})
	if err != nil {
		t.Fatalf("second register failed: %v", err)
	}

	if first.ID != second.ID {
		t.Fatalf("expected idempotent register, got %s and %s", first.ID, second.ID)
	}
}

// TestDeleteAndExport verifies a deleted user can no longer be fetched.
func TestDeleteAndExport(t *testing.T) {
	repo := newFakeRepo()
	svc := NewService(repo)

	u, err := svc.Register(context.Background(), RegisterInput{
		ActorZitadelUserID: "zitadel-1",
		ActorEmail:         "player@example.com",
		DisplayName:        "Player One",
		ConsentVersion:     "v1",
		ConsentSource:      "web",
	})
	if err != nil {
		t.Fatalf("register failed: %v", err)
	}

	if err := svc.DeleteUser(context.Background(), u.ID, "admin-1"); err != nil {
		t.Fatalf("delete failed: %v", err)
	}

	_, err = svc.GetProfile(context.Background(), u.ID)
	if err == nil {
		t.Fatal("expected deleted user to be unavailable")
	}
}