fix: align canned coach timezone filtering

Author: wesm

internal/server/insights.go

@@ -526,9 +526,13 @@ func (s *Server) listCannedCoachSessions(
 	if req.Filters != nil {
 		filters = *req.Filters
 	}
+	loc := cannedCoachLocation(filters.Timezone)
+	dateFrom, dateTo := cannedCoachUTCDateBounds(
+		req.DateFrom, req.DateTo, loc,
+	)
 	filter := db.SessionFilter{
-		DateFrom:        req.DateFrom,
-		DateTo:          req.DateTo,
+		DateFrom:        dateFrom,
+		DateTo:          dateTo,
 		Project:         req.Project,
 		Machine:         filters.Machine,
 		Agent:           filters.Agent,
@@ -545,10 +549,91 @@ func (s *Server) listCannedCoachSessions(
 		if err != nil {
 			return nil, err
 		}
-		out = append(out, page.Sessions...)
+		for _, session := range page.Sessions {
+			if cannedCoachSessionInDateRange(
+				session, req.DateFrom, req.DateTo, loc,
+			) {
+				out = append(out, session)
+			}
+		}
 		if page.NextCursor == "" {
 			return out, nil
 		}
 		filter.Cursor = page.NextCursor
 	}
 }
+
+func cannedCoachLocation(name string) *time.Location {
+	loc, err := time.LoadLocation(name)
+	if err != nil {
+		return time.UTC
+	}
+	return loc
+}
+
+func cannedCoachUTCDateBounds(
+	from, to string,
+	loc *time.Location,
+) (string, string) {
+	start, err := time.ParseInLocation("2006-01-02", from, loc)
+	if err != nil {
+		return from, to
+	}
+	end, err := time.ParseInLocation("2006-01-02", to, loc)
+	if err != nil {
+		return from, to
+	}
+	end = end.AddDate(0, 0, 1).Add(-time.Nanosecond)
+	return start.UTC().Format("2006-01-02"),
+		end.UTC().Format("2006-01-02")
+}
+
+func cannedCoachSessionInDateRange(
+	session db.Session,
+	from, to string,
+	loc *time.Location,
+) bool {
+	date := cannedCoachSessionLocalDate(session, loc)
+	if date == "" {
+		return false
+	}
+	if from != "" && date < from {
+		return false
+	}
+	if to != "" && date > to {
+		return false
+	}
+	return true
+}
+
+func cannedCoachSessionLocalDate(
+	session db.Session,
+	loc *time.Location,
+) string {
+	ts := session.CreatedAt
+	if session.StartedAt != nil && *session.StartedAt != "" {
+		ts = *session.StartedAt
+	}
+	t, ok := cannedCoachLocalTime(ts, loc)
+	if !ok {
+		if len(ts) >= 10 {
+			return ts[:10]
+		}
+		return ""
+	}
+	return t.Format("2006-01-02")
+}
+
+func cannedCoachLocalTime(
+	ts string,
+	loc *time.Location,
+) (time.Time, bool) {
+	t, err := time.Parse(time.RFC3339Nano, ts)
+	if err != nil {
+		t, err = time.Parse("2006-01-02T15:04:05Z", ts)
+		if err != nil {
+			return time.Time{}, false
+		}
+	}
+	return t.In(loc), true
+}

internal/server/insights_test.go

@@ -663,6 +663,64 @@ func TestGenerateCannedInsight_UsesSessionFilterPayload(t *testing.T) {
 	assert.NotContains(t, generatedPrompts[1], codexPrompt)
 }
 
+func TestGenerateCannedInsight_CoachSummaryUsesFilterTimezone(t *testing.T) {
+	var generatedPrompt string
+	stubGen := func(
+		_ context.Context, _ string, prompt string, _ insight.LogFunc,
+	) (insight.Result, error) {
+		generatedPrompt = prompt
+		return insight.Result{
+			Agent: "claude",
+			Model: "test-model",
+			Content: `{
+				"schema_version":"llm_insight.v1",
+				"kind":"prompt_maturity_review",
+				"summary":"Prompt maturity evidence is scoped to the requested local day.",
+				"confidence":"medium",
+				"recommendations":[{
+					"title":"Keep local-day Coach scope aligned",
+					"rationale":"Coach prompt maturity uses the same local-date filter as the canned payload.",
+					"actions":["Generate recommendations from the selected local day"],
+					"evidence_refs":["coach:prompt_maturity"],
+					"impact":"medium",
+					"effort":"low"
+				}],
+				"risks":[],
+				"evidence_refs":["coach:prompt_maturity"]
+			}`,
+		}, nil
+	}
+	te := setupWithServerOpts(t, []server.Option{
+		server.WithGenerateStreamFunc(stubGen),
+	})
+
+	localDayPrompt := "Implement local-day filtering with acceptance criteria and verification steps"
+	previousLocalDayPrompt := "Implement previous-day filtering with acceptance criteria and verification steps"
+	te.seedSession(t, "local-day-match", "my-app", 4, func(s *db.Session) {
+		started := "2025-01-16T07:30:00Z"
+		ended := "2025-01-16T07:45:00Z"
+		s.StartedAt = &started
+		s.EndedAt = &ended
+		s.FirstMessage = &localDayPrompt
+	})
+	te.seedSession(t, "previous-local-day", "my-app", 4, func(s *db.Session) {
+		started := "2025-01-15T01:00:00Z"
+		ended := "2025-01-15T01:15:00Z"
+		s.StartedAt = &started
+		s.EndedAt = &ended
+		s.FirstMessage = &previousLocalDayPrompt
+	})
+
+	payload := `{"type":"llm_canned","kind":"prompt_maturity_review","date_from":"2025-01-15","date_to":"2025-01-15","project":"my-app","agent":"claude","llm_opt_in":true,"filters":{"timezone":"America/Los_Angeles","include_one_shot":false,"automated_scope":"human"}}`
+	w := te.post(t, "/api/v1/insights/generate", payload)
+	assertStatus(t, w, http.StatusOK)
+
+	assert.Contains(t, generatedPrompt, `"timezone":"America/Los_Angeles"`)
+	assert.Contains(t, generatedPrompt, `"session_count":1`)
+	assert.Contains(t, generatedPrompt, localDayPrompt)
+	assert.NotContains(t, generatedPrompt, previousLocalDayPrompt)
+}
+
 func TestGenerateCannedInsight_RejectsOversizedFocus(t *testing.T) {
 	te := setup(t)
 	longFocus := strings.Repeat("x", insight.MaxCannedFocusRunes+1)