projax/mcp/timeline_test.go

package mcp

import (
	"context"
	"io"
	"log/slog"
	"testing"
	"time"

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

func mustTime(t *testing.T, s string) time.Time {
	t.Helper()
	tt, err := time.Parse(time.RFC3339, s)
	if err != nil {
		t.Fatalf("mustTime: %v", err)
	}
	return tt
}

// stubStore is a minimal LinkLister + ListByFilters-aware shim for unit
// tests. We embed the absence of *store.Store fields the timeline tool
// needs and surface only ListByFilters via a fake — the rest of mcp tests
// pass nil because they don't exercise this path.
type stubLinkLister struct{}

func (stubLinkLister) LinksByType(_ context.Context, _, _ string) ([]*store.ItemLink, error) {
	return nil, nil
}
func (stubLinkLister) DatedLinksRange(_ context.Context, _, _ time.Time) ([]*store.ItemLinkWithItem, error) {
	return nil, nil
}
func (stubLinkLister) ItemsCreatedInRange(_ context.Context, _, _ time.Time) ([]*store.Item, error) {
	return nil, nil
}

func newToolServer(t *testing.T, agg *aggregate.Aggregator) *Server {
	t.Helper()
	srv := New("projax-test", "0.0.1", "tok", slog.New(slog.NewTextHandler(io.Discard, nil)))
	// Pass a nil *store.Store — the timeline tool's store-backed paths
	// short-circuit cleanly on errors in this test surface (we just probe
	// registration + arg parsing here).
	RegisterProjaxTools(srv, nil, agg)
	return srv
}

func newAggregator() *aggregate.Aggregator {
	return aggregate.New(stubLinkLister{}, nil, nil, nil, slog.New(slog.NewTextHandler(io.Discard, nil)))
}

// TestTimelineToolUnregisteredWhenAggregatorNil proves passing nil yields a
// missing "timeline" tool — same kill-switch contract as the pre-Phase-5a
// TimelineBuilder=nil case.
func TestTimelineToolUnregisteredWhenAggregatorNil(t *testing.T) {
	srv := newToolServer(t, nil)
	if _, ok := srv.tools["timeline"]; ok {
		t.Fatalf("expected timeline tool to be absent when agg is nil")
	}
}

// TestTimelineToolRegisteredWhenAggregatorSet proves the tool shows up when
// an aggregator is plumbed through.
func TestTimelineToolRegisteredWhenAggregatorSet(t *testing.T) {
	srv := newToolServer(t, newAggregator())
	tool, ok := srv.tools["timeline"]
	if !ok {
		t.Fatalf("expected timeline tool to be registered")
	}
	if tool.Description == "" {
		t.Errorf("timeline tool should carry a Description")
	}
	if len(tool.InputSchema) == 0 {
		t.Errorf("timeline tool should carry an InputSchema")
	}
}

// TestTimelineToolBadDateReturnsError proves a malformed `from` rejects with
// a tool-level error rather than panicking.
func TestTimelineToolBadDateReturnsError(t *testing.T) {
	srv := newToolServer(t, newAggregator())
	_, err := srv.tools["timeline"].Handler(context.Background(), []byte(`{"from":"not-a-date"}`))
	if err == nil {
		t.Fatalf("expected timeline tool to error on bad date")
	}
}

// TestTimelineToolBadJSONReturnsError proves a malformed args body produces
// a tool-level error rather than panicking.
func TestTimelineToolBadJSONReturnsError(t *testing.T) {
	srv := newToolServer(t, newAggregator())
	_, err := srv.tools["timeline"].Handler(context.Background(), []byte(`not-json`))
	if err == nil {
		t.Fatalf("expected timeline tool to error on bad JSON")
	}
}

// TestTimelineViewSerializesTimes proves the buildTimelineView helper emits
// the expected stringified time shape so the JSON-RPC envelope stays
// language-agnostic.
func TestTimelineViewSerializesTimes(t *testing.T) {
	now := mustTime(t, "2026-05-17T10:30:00Z")
	v := buildTimelineView(nil, now.AddDate(0, 0, -3), now.AddDate(0, 0, 4), "desc", []string{aggregate.KindTodo}, 0, now)
	if v.From != "2026-05-14" {
		t.Errorf("From should be YYYY-MM-DD, got %q", v.From)
	}
	if v.To != "2026-05-21" {
		t.Errorf("To should be YYYY-MM-DD, got %q", v.To)
	}
	if v.ToInclusive != "2026-05-20" {
		t.Errorf("ToInclusive should be exclusive-To minus one day, got %q", v.ToInclusive)
	}
	if v.BuiltAt != "2026-05-17T10:30:00Z" {
		t.Errorf("BuiltAt should be ISO-8601 UTC, got %q", v.BuiltAt)
	}
	if v.Days == nil {
		t.Errorf("Days slice should be initialised (empty array), not nil")
	}
}

// TestResolveTimelineKindsSanitises proves resolveTimelineKinds drops
// unknown values, dedupes, and sorts.
func TestResolveTimelineKindsSanitises(t *testing.T) {
	got := resolveTimelineKinds([]string{"todo", "junk", "event", "todo", "DOC"})
	want := []string{"doc", "event", "todo"}
	if len(got) != len(want) {
		t.Fatalf("got %v, want %v", got, want)
	}
	for i := range got {
		if got[i] != want[i] {
			t.Fatalf("pos %d: got %q, want %q", i, got[i], want[i])
		}
	}
}

// TestResolveTimelineWindowDefaults proves no args → default 30/+90 window.
func TestResolveTimelineWindowDefaults(t *testing.T) {
	now := mustTime(t, "2026-05-21T12:00:00Z")
	from, to, err := resolveTimelineWindow(TimelineArgs{}, now)
	if err != nil {
		t.Fatalf("default window: %v", err)
	}
	wantFrom := now.AddDate(0, 0, -timelineDefaultPastDays).Format("2006-01-02")
	if from.Format("2006-01-02") != wantFrom {
		t.Errorf("from = %s, want %s", from.Format("2006-01-02"), wantFrom)
	}
	wantTo := now.AddDate(0, 0, timelineDefaultFutureDays).Format("2006-01-02")
	if to.Format("2006-01-02") != wantTo {
		t.Errorf("to = %s, want %s", to.Format("2006-01-02"), wantTo)
	}
}