projax/internal/itemwrite/itemwrite_test.go

package itemwrite

import (
	"context"
	"errors"
	"testing"

	"github.com/m/projax/store"
)

// stubReader fulfils the Reader interface for table-driven tests.
type stubReader struct {
	items   []*store.Item
	listErr error
}

func (s *stubReader) GetByID(_ context.Context, id string) (*store.Item, error) {
	for _, it := range s.items {
		if it.ID == id {
			return it, nil
		}
	}
	return nil, store.ErrNotFound
}

func (s *stubReader) ListAll(_ context.Context) ([]*store.Item, error) {
	if s.listErr != nil {
		return nil, s.listErr
	}
	out := make([]*store.Item, len(s.items))
	copy(out, s.items)
	return out, nil
}

func mkItem(id, slug string, parentIDs ...string) *store.Item {
	return &store.Item{ID: id, Slug: slug, Title: slug, ParentIDs: parentIDs, Paths: []string{slug}}
}

// --- ValidateFormat ---

func TestValidateFormatMissing(t *testing.T) {
	cases := []struct {
		name string
		in   Input
	}{
		{"missing title", Input{Slug: "x"}},
		{"missing slug", Input{Title: "X"}},
		{"whitespace title", Input{Title: "   ", Slug: "x"}},
		{"whitespace slug", Input{Title: "X", Slug: "  "}},
	}
	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			err := ValidateFormat(c.in)
			if err == nil {
				t.Fatalf("expected ValidationError, got nil")
			}
			if err.Kind != KindMissingRequired {
				t.Errorf("kind = %q, want %q", err.Kind, KindMissingRequired)
			}
		})
	}
}

func TestValidateFormatSlugFormat(t *testing.T) {
	cases := []struct {
		slug string
		bad  bool
	}{
		{"prjx", false},
		{"spring-clean", false},
		{"work.paliad", true},  // dot
		{"Work", true},         // upper-case
		{"my slug", true},      // whitespace
		{"123-numeric", false}, // numeric prefix is fine
	}
	for _, c := range cases {
		t.Run(c.slug, func(t *testing.T) {
			err := ValidateFormat(Input{Title: "x", Slug: c.slug})
			if c.bad && err == nil {
				t.Errorf("expected reject")
			}
			if !c.bad && err != nil {
				t.Errorf("unexpected reject: %v", err)
			}
			if c.bad && err != nil && err.Kind != KindInvalidSlugFormat {
				t.Errorf("kind = %q, want %q", err.Kind, KindInvalidSlugFormat)
			}
		})
	}
}

func TestValidateFormatStatus(t *testing.T) {
	if err := ValidateFormat(Input{Title: "x", Slug: "x", Status: "weird"}); err == nil || err.Kind != KindInvalidStatus {
		t.Fatalf("expected invalid-status, got %v", err)
	}
	for _, ok := range []string{"active", "done", "archived", ""} {
		if err := ValidateFormat(Input{Title: "x", Slug: "x", Status: ok}); err != nil {
			t.Errorf("status %q should be valid, got %v", ok, err)
		}
	}
}

func TestValidateFormatSelfParent(t *testing.T) {
	err := ValidateFormat(Input{ID: "self", Title: "x", Slug: "x", ParentIDs: []string{"other", "self"}})
	if err == nil || err.Kind != KindSelfParent {
		t.Fatalf("expected self-parent reject, got %v", err)
	}
	// Create paths (ID empty) must not flag self-parent — there's no self yet.
	if err := ValidateFormat(Input{Title: "x", Slug: "x", ParentIDs: []string{"any"}}); err != nil {
		t.Errorf("Create with no ID should not flag self-parent, got %v", err)
	}
}

func TestValidateFormatHappyPath(t *testing.T) {
	in := Input{Title: "X", Slug: "x", Status: "active", ParentIDs: []string{"pid"}}
	if err := ValidateFormat(in); err != nil {
		t.Fatalf("happy path rejected: %v", err)
	}
}

// --- ValidateAgainstStore ---

func TestValidateStoreUnknownParent(t *testing.T) {
	r := &stubReader{items: []*store.Item{mkItem("real", "real")}}
	err := ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "x", ParentIDs: []string{"ghost"}})
	if err == nil || err.Kind != KindUnknownParent {
		t.Fatalf("expected unknown-parent, got %v", err)
	}
}

func TestValidateStoreSlugCollisionRoot(t *testing.T) {
	r := &stubReader{items: []*store.Item{mkItem("a", "shared"), mkItem("b", "other")}}
	// New root with same slug as 'a' — should reject.
	err := ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "shared"})
	if err == nil || err.Kind != KindSlugCollision {
		t.Fatalf("expected slug-collision, got %v", err)
	}
	// Updating 'a' to itself isn't a collision.
	err = ValidateAgainstStore(context.Background(), r, Input{ID: "a", Title: "x", Slug: "shared"})
	if err != nil {
		t.Fatalf("self-update should not collide, got %v", err)
	}
	// A different root slug is fine.
	err = ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "novel"})
	if err != nil {
		t.Errorf("novel slug should pass, got %v", err)
	}
}

func TestValidateStoreSlugCollisionPerUser(t *testing.T) {
	// Phase 6 / Q6=a: slug uniqueness is per-user-global, not per-parent.
	r := &stubReader{items: []*store.Item{
		mkItem("parent", "parent"),
		mkItem("child1", "kid", "parent"),
		mkItem("other", "other"),
	}}
	// New child under the same parent with the same slug — reject.
	err := ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "kid", ParentIDs: []string{"parent"}})
	if err == nil || err.Kind != KindSlugCollision {
		t.Fatalf("expected slug-collision under common parent, got %v", err)
	}
	// Same slug under a DIFFERENT parent now also collides — the old
	// per-parent escape ("two paliads under different roots") is gone.
	err = ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "kid", ParentIDs: []string{"other"}})
	if err == nil || err.Kind != KindSlugCollision {
		t.Fatalf("expected per-user slug-collision regardless of parent, got %v", err)
	}
	// A novel slug under any parent is fine.
	err = ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "novel", ParentIDs: []string{"other"}})
	if err != nil {
		t.Errorf("novel slug should pass, got %v", err)
	}
	// Updating the existing child to keep its own slug is not a collision.
	err = ValidateAgainstStore(context.Background(), r, Input{ID: "child1", Title: "x", Slug: "kid", ParentIDs: []string{"parent"}})
	if err != nil {
		t.Errorf("self-update keeping own slug should pass, got %v", err)
	}
}

func TestValidateStoreCycle(t *testing.T) {
	r := &stubReader{items: []*store.Item{
		mkItem("root", "root"),
		mkItem("mid", "mid", "root"),
		mkItem("leaf", "leaf", "mid"),
	}}
	// Reparent 'root' under 'leaf' — closure of leaf reaches root. Cycle.
	err := ValidateAgainstStore(context.Background(), r, Input{ID: "root", Title: "root", Slug: "root", ParentIDs: []string{"leaf"}})
	if err == nil || err.Kind != KindCycle {
		t.Fatalf("expected cycle, got %v", err)
	}
	// Reparent 'mid' under 'leaf' — closure of leaf reaches mid. Cycle.
	err = ValidateAgainstStore(context.Background(), r, Input{ID: "mid", Title: "mid", Slug: "mid", ParentIDs: []string{"leaf"}})
	if err == nil || err.Kind != KindCycle {
		t.Fatalf("expected cycle, got %v", err)
	}
	// Adding 'leaf' under 'root' (its existing ancestor again — same already) is no cycle but
	// would duplicate; we don't gate that. Sanity-check no false positives:
	err = ValidateAgainstStore(context.Background(), r, Input{ID: "leaf", Title: "leaf", Slug: "leaf", ParentIDs: []string{"mid"}})
	if err != nil {
		t.Errorf("existing acyclic parentage should pass, got %v", err)
	}
}

func TestValidateStoreReadErrorIsNotValidationError(t *testing.T) {
	r := &stubReader{listErr: errors.New("db down")}
	// DB read failure surfaces as nil here — callers see the underlying
	// error later when they attempt the store call. Validator is not in the
	// business of masking infra errors.
	if err := ValidateAgainstStore(context.Background(), r, Input{Title: "x", Slug: "x"}); err != nil {
		t.Errorf("expected nil on read error (caller's responsibility), got %v", err)
	}
}

func TestValidateStoreHappyPath(t *testing.T) {
	r := &stubReader{items: []*store.Item{mkItem("parent", "parent")}}
	if err := ValidateAgainstStore(context.Background(), r, Input{Title: "X", Slug: "novel", ParentIDs: []string{"parent"}}); err != nil {
		t.Fatalf("happy path rejected: %v", err)
	}
}

func TestValidationErrorString(t *testing.T) {
	e := &ValidationError{Kind: KindCycle, Path: "dev.paliad", Detail: "cycle"}
	got := e.Error()
	want := "itemwrite: cycle at dev.paliad: cycle"
	if got != want {
		t.Errorf("got %q, want %q", got, want)
	}
	e2 := &ValidationError{Kind: KindMissingRequired, Detail: "title is required"}
	got = e2.Error()
	want = "itemwrite: missing-required: title is required"
	if got != want {
		t.Errorf("got %q, want %q", got, want)
	}
}