implement econet exporter

pkg/econet/econetmcp/server.go

@@ -0,0 +1,64 @@
+/*
+Package econetmcp exposes an MCP server, mounted as an HTTP handler at
+/api/mcp, whose tools wrap the EconetService gRPC API.
+*/
+package econetmcp
+
+import (
+	"context"
+	"net/http"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/rs/zerolog"
+
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/config"
+	"gitea.libretechconsulting.com/rmcguire/econet-exporter/pkg/econet/econetgrpc"
+)
+
+var EconetMCPImpl = &mcp.Implementation{
+	Name:  "Econet MCP Server",
+	Title: "Econet Exporter MCP",
+}
+
+type EconetMCPServer struct {
+	ctx        context.Context
+	cfg        *config.ServiceConfig
+	log        *zerolog.Logger
+	server     *mcp.Server
+	econetGRPC *econetgrpc.EconetGRPCServer
+}
+
+func NewEconetMCPServer(ctx context.Context, cfg *config.ServiceConfig,
+	grpc *econetgrpc.EconetGRPCServer,
+) *EconetMCPServer {
+	return &EconetMCPServer{
+		ctx:        ctx,
+		cfg:        cfg,
+		log:        zerolog.Ctx(ctx),
+		econetGRPC: grpc,
+		server: mcp.NewServer(EconetMCPImpl, &mcp.ServerOptions{
+			Instructions: "Use these tools to inspect Rheem EcoNet water heaters: " +
+				"current mode, setpoint, hot water availability, connectivity, and alerts.",
+			HasTools: true,
+		}),
+	}
+}
+
+func (m *EconetMCPServer) GetHandlers() []opts.HTTPHandler {
+	// NOTE: Add other tools here
+	m.addListDevicesTool()
+
+	handler := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
+		return m.server
+	}, &mcp.StreamableHTTPOptions{})
+
+	m.log.Debug().Msg("Econet MCP tools ready")
+
+	return []opts.HTTPHandler{
+		{
+			Prefix:  "/api/mcp",
+			Handler: handler,
+		},
+	}
+}

pkg/econet/econetmcp/tool.go

@@ -0,0 +1,76 @@
+package econetmcp
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"k8s.io/utils/ptr"
+
+	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
+)
+
+var ListDevicesTool = &mcp.Tool{
+	Name:        "list_water_heaters",
+	Title:       "List EcoNet Water Heaters",
+	Description: "Lists Rheem EcoNet devices and their current state (mode, setpoint, " +
+		"hot water availability, connectivity). Optionally filter to one serial number.",
+	Annotations: &mcp.ToolAnnotations{
+		ReadOnlyHint:  true,
+		OpenWorldHint: ptr.To(true),
+	},
+}
+
+type ListDevicesParams struct {
+	SerialNumber string `json:"serial_number,omitempty" jsonschema:"Optional device serial number to return a single device"`
+}
+
+func (m *EconetMCPServer) addListDevicesTool() {
+	mcp.AddTool(m.server, ListDevicesTool, m.listDevicesHandler)
+}
+
+func (m *EconetMCPServer) listDevicesHandler(ctx context.Context, _ *mcp.CallToolRequest, args *ListDevicesParams) (
+	*mcp.CallToolResult, any, error,
+) {
+	m.log.Debug().Str("serial", args.SerialNumber).Msg("list water heaters tool called")
+
+	devices, err := m.lookup(ctx, args.SerialNumber)
+	if err != nil {
+		return &mcp.CallToolResult{IsError: true, Meta: mcp.Meta{"error": err.Error()}}, nil, err
+	}
+
+	return &mcp.CallToolResult{
+		Content: []mcp.Content{&mcp.TextContent{Text: summarizeDevices(devices)}},
+	}, nil, nil
+}
+
+func (m *EconetMCPServer) lookup(ctx context.Context, serial string) ([]*pb.Device, error) {
+	if serial != "" {
+		resp, err := m.econetGRPC.GetDevice(ctx, &pb.GetDeviceRequest{SerialNumber: serial})
+		if err != nil {
+			return nil, err
+		}
+		return []*pb.Device{resp.GetDevice()}, nil
+	}
+
+	resp, err := m.econetGRPC.ListDevices(ctx, &pb.ListDevicesRequest{})
+	if err != nil {
+		return nil, err
+	}
+	return resp.GetDevices(), nil
+}
+
+func summarizeDevices(devices []*pb.Device) string {
+	if len(devices) == 0 {
+		return "No EcoNet devices found."
+	}
+	var b strings.Builder
+	for _, d := range devices {
+		fmt.Fprintf(&b, "%s (%s, serial %s): mode=%s setpoint=%d°F running=%t connected=%t hotWater=%d%% alerts=%d\n",
+			d.GetFriendlyName(), d.GetGenericType(), d.GetSerialNumber(),
+			d.GetMode(), d.GetSetpoint(), d.GetRunning(), d.GetConnected(),
+			d.GetHotWaterAvailability(), d.GetAlertCount())
+	}
+	return strings.TrimRight(b.String(), "\n")
+}

pkg/econet/econetmcp/tool_test.go

@@ -0,0 +1,38 @@
+package econetmcp
+
+import (
+	"strings"
+	"testing"
+
+	pb "gitea.libretechconsulting.com/rmcguire/econet-exporter/api/econet/v1alpha1"
+)
+
+func TestSummarizeDevices(t *testing.T) {
+	tests := []struct {
+		name    string
+		devices []*pb.Device
+		want    string // substring that must appear
+	}{
+		{"empty", nil, "No EcoNet devices found."},
+		{
+			name: "single",
+			devices: []*pb.Device{{
+				FriendlyName: "Garage",
+				GenericType:  "heatpumpWaterHeater",
+				SerialNumber: "ABC123",
+				Mode:         "heat-pump",
+				Setpoint:     125,
+			}},
+			want: "Garage (heatpumpWaterHeater, serial ABC123): mode=heat-pump setpoint=125",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := summarizeDevices(tt.devices)
+			if !strings.Contains(got, tt.want) {
+				t.Errorf("summarizeDevices() = %q, want substring %q", got, tt.want)
+			}
+		})
+	}
+}