feat: expose current date and time via HTTP and MCP

Adds GET /datetime and an MCP get_current_datetime tool returning the
current date/time in Europe/Paris, alongside the existing calendar
endpoints. Both share the same CurrentDateTime payload shape.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hu8wwahgecuCGfesTKCfEd

cmd/domogeek/datetime_test.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestDateTimeHandler_ServeHTTP(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/datetime", nil)
+	rec := httptest.NewRecorder()
+
+	(&DateTimeHandler{}).ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var got CurrentDateTime
+	if err := json.Unmarshal(rec.Body.Bytes(), &got); err != nil {
+		t.Fatalf("unable to decode response: %v", err)
+	}
+
+	now := time.Now().In(location)
+	if diff := now.Sub(got.DateTime); diff < -time.Second || diff > time.Second {
+		t.Errorf("DateTime = %v, want close to %v", got.DateTime, now)
+	}
+	_, wantOffset := now.Zone()
+	_, gotOffset := got.DateTime.Zone()
+	if gotOffset != wantOffset {
+		t.Errorf("DateTime UTC offset = %d, want %d", gotOffset, wantOffset)
+	}
+}

cmd/domogeek/domogeek.go

@@ -88,6 +88,26 @@ func (c *CalendarHandler) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
 	}
 }
 
+type CurrentDateTime struct {
+	DateTime time.Time `json:"date_time"`
+}
+
+type DateTimeHandler struct{}
+
+func (d *DateTimeHandler) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
+	content, err := json.Marshal(CurrentDateTime{DateTime: time.Now().In(location)})
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		zap.S().Errorf("unable to marshall response %v, %v", content, err)
+	} else {
+		_, err = w.Write(content)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			zap.S().Errorf("unable to marshall response %v, :%v", content, err)
+		}
+	}
+}
+
 func main() {
 	var port int
 	var host string
@@ -173,6 +193,7 @@ func main() {
 	)
 	http.Handle("/status", healthz.Handler())
 	http.Handle("/mcp", newMCPHandler())
+	http.Handle("/datetime", &DateTimeHandler{})
 
 	signChan := make(chan os.Signal, 1)
 	go func() {

cmd/domogeek/mcp.go

@@ -38,6 +38,10 @@ func calendarDayFor(day time.Time) CalendarDay {
 	}
 }
 
+func handleCurrentDateTime(_ context.Context, _ *mcp.CallToolRequest, _ struct{}) (*mcp.CallToolResult, CurrentDateTime, error) {
+	return nil, CurrentDateTime{DateTime: time.Now().In(location)}, nil
+}
+
 func handleCalendarToday(_ context.Context, _ *mcp.CallToolRequest, _ struct{}) (*mcp.CallToolResult, CalendarDay, error) {
 	return nil, calendarDayFor(time.Now().In(location)), nil
 }
@@ -64,6 +68,11 @@ func newMCPHandler() http.Handler {
 		Version: "1.0.0",
 	}, nil)
 
+	mcp.AddTool(server, &mcp.Tool{
+		Name:        "get_current_datetime",
+		Description: "Get the current date and time",
+	}, handleCurrentDateTime)
+
 	mcp.AddTool(server, &mcp.Tool{
 		Name:        "get_calendar_today",
 		Description: "Get calendar information for today: working day, French public holiday (ferie), personal holiday (from CalDAV) and weekday",

cmd/domogeek/mcp_e2e_test.go

@@ -26,13 +26,24 @@ func TestMCPEndToEnd(t *testing.T) {
 	if err != nil {
 		t.Fatalf("list tools failed: %v", err)
 	}
-	if len(tools.Tools) != 3 {
-		t.Fatalf("got %d tools, want 3", len(tools.Tools))
+	if len(tools.Tools) != 4 {
+		t.Fatalf("got %d tools, want 4", len(tools.Tools))
 	}
 	for _, tool := range tools.Tools {
 		t.Logf("tool: %s - %s", tool.Name, tool.Description)
 	}
 
+	now, err := session.CallTool(ctx, &mcp.CallToolParams{
+		Name: "get_current_datetime",
+	})
+	if err != nil {
+		t.Fatalf("call get_current_datetime failed: %v", err)
+	}
+	if now.IsError {
+		t.Fatalf("get_current_datetime returned an error result: %v", now.Content)
+	}
+	t.Logf("current datetime structured content: %+v", now.StructuredContent)
+
 	result, err := session.CallTool(ctx, &mcp.CallToolParams{
 		Name:      "get_calendar_for_date",
 		Arguments: map[string]any{"date": "2020-01-01"},

cmd/domogeek/mcp_test.go

@@ -66,6 +66,18 @@ func TestCalendarDayFor(t *testing.T) {
 	}
 }
 
+func TestHandleCurrentDateTime(t *testing.T) {
+	_, dt, err := handleCurrentDateTime(context.Background(), nil, struct{}{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	now := time.Now().In(location)
+	if diff := now.Sub(dt.DateTime); diff < -time.Second || diff > time.Second {
+		t.Errorf("DateTime = %v, want close to %v", dt.DateTime, now)
+	}
+}
+
 func TestHandleCalendarToday(t *testing.T) {
 	withTestCalendar(t)