Add device pair

internal/device/device.go

@@ -146,6 +146,103 @@ func List(invocation api.Invocation, arguments []string) error {
 	return nil
 }
 
+func Pair(invocation api.Invocation, arguments []string) error {
+	if len(arguments) != 2 {
+		return errors.New("device pair takes an IMEI and a fleet id")
+	}
+
+	imei := arguments[0]
+
+	if !validImei(imei) {
+		return errors.New("the IMEI is the 15-digit number printed on the device")
+	}
+
+	fleetId, err := strconv.ParseInt(arguments[1], 10, 64)
+
+	if err != nil || fleetId < 1 {
+		return errors.New("the fleet id is the number shown by fleet list")
+	}
+
+	fleets, err := api.FetchFleets(invocation)
+
+	if err != nil {
+		return err
+	}
+
+	fleetName := ""
+
+	for _, fleet := range fleets {
+		if fleet.Id == fleetId {
+			fleetName = fleet.Name
+		}
+	}
+
+	if fleetName == "" {
+		return errors.New("no such fleet, fleet list shows yours")
+	}
+
+	body, err := json.Marshal(map[string]int64{"fleet_id": fleetId})
+
+	if err != nil {
+		return err
+	}
+
+	request, err := api.AuthenticatedRequest(invocation, http.MethodPost, "/devices/"+imei+"/pair", bytes.NewReader(body))
+
+	if err != nil {
+		return err
+	}
+
+	request.Header.Set("Content-Type", "application/json")
+
+	response, err := invocation.Client.Do(request)
+
+	if err != nil {
+		return errors.New("the server could not be reached, check your internet access")
+	}
+
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusAccepted {
+		return api.ServerError(response)
+	}
+
+	fmt.Fprintln(invocation.Out, "Press the pairing button on the device.")
+
+	// The server holds the pairing open for one minute.
+	deadline := time.Now().Add(75 * time.Second)
+
+	for {
+		time.Sleep(2 * time.Second)
+
+		devices, err := api.FetchDevices(invocation)
+
+		if err != nil {
+			return err
+		}
+
+		for _, device := range devices {
+			if device.Imei != imei || device.FleetId != fleetId {
+				continue
+			}
+
+			label := imei
+
+			if device.Name != nil && *device.Name != "" {
+				label = *device.Name
+			}
+
+			fmt.Fprintf(invocation.Out, "Paired device %q into fleet %q.\n", api.Printable(label), api.Printable(fleetName))
+
+			return nil
+		}
+
+		if time.Now().After(deadline) {
+			return errors.New("the pairing button was not pressed in time, run device pair again")
+		}
+	}
+}
+
 func Rename(invocation api.Invocation, arguments []string) error {
 	if len(arguments) != 2 {
 		return errors.New("device rename takes an IMEI and a new name, quoted if it has spaces")

internal/device/device_test.go

@@ -3,6 +3,7 @@ package device
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"strings"
 	"testing"
@@ -12,6 +13,107 @@ import (
 	"github.com/siliconwitchery/superstack-cli/internal/api/apitest"
 )
 
+func TestDevicePair(t *testing.T) {
+	fleets := `[{"id":3,"name":"pilot","owner":true}]`
+	unpaired := `[{"imei":"111111111111111","name":null,"fleet_id":0,"last_seen_at":null}]`
+	paired := `[{"imei":"111111111111111","name":"roof","fleet_id":3,"last_seen_at":null}]`
+
+	tests := []struct {
+		name          string
+		arguments     []string
+		pairStatus    int
+		pairRefusal   string
+		pollsToPair   int
+		wantShown     []string
+		wantError     string
+		wantPairCalls int
+	}{
+		{
+			name:          "pairing completes when the button is pressed",
+			arguments:     []string{"111111111111111", "3"},
+			pairStatus:    http.StatusAccepted,
+			pollsToPair:   2,
+			wantShown:     []string{"Press the pairing button on the device.", `Paired device "roof" into fleet "pilot".`},
+			wantPairCalls: 1,
+		},
+		{
+			name:          "a server refusal is shown",
+			arguments:     []string{"111111111111111", "3"},
+			pairStatus:    http.StatusConflict,
+			pairRefusal:   "the device is already paired, unpair it first",
+			wantError:     "already paired",
+			wantPairCalls: 1,
+		},
+		{name: "an unknown fleet is refused", arguments: []string{"111111111111111", "9"}, wantError: "no such fleet"},
+		{name: "a malformed IMEI is refused", arguments: []string{"roof", "3"}, wantError: "printed on the device"},
+		{name: "a wordy fleet id is refused", arguments: []string{"111111111111111", "pilot"}, wantError: "shown by fleet list"},
+		{name: "missing arguments", arguments: []string{"111111111111111"}, wantError: "takes an IMEI and a fleet id"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			pairCalls := 0
+			polls := 0
+
+			mux := http.NewServeMux()
+
+			mux.HandleFunc("GET /fleets", func(w http.ResponseWriter, r *http.Request) { fmt.Fprint(w, fleets) })
+
+			mux.HandleFunc("POST /devices/{imei}/pair", func(w http.ResponseWriter, r *http.Request) {
+				pairCalls++
+
+				body, err := io.ReadAll(r.Body)
+
+				if err != nil || string(body) != `{"fleet_id":3}` {
+					t.Errorf("the pairing sent body %q", body)
+				}
+
+				if test.pairRefusal != "" {
+					http.Error(w, test.pairRefusal, test.pairStatus)
+					return
+				}
+
+				w.WriteHeader(test.pairStatus)
+			})
+
+			mux.HandleFunc("GET /devices", func(w http.ResponseWriter, r *http.Request) {
+				polls++
+
+				if polls >= test.pollsToPair {
+					fmt.Fprint(w, paired)
+					return
+				}
+
+				fmt.Fprint(w, unpaired)
+			})
+
+			invocation, out := apitest.LoggedInInvocation(t, mux)
+
+			err := Pair(invocation, test.arguments)
+
+			printed := out.String()
+
+			if test.wantError != "" {
+				if err == nil || !strings.Contains(err.Error(), test.wantError) {
+					t.Fatalf("error = %v", err)
+				}
+			} else if err != nil {
+				t.Fatal(err)
+			}
+
+			for _, want := range test.wantShown {
+				if !strings.Contains(printed, want) {
+					t.Errorf("output %q omits %q", printed, want)
+				}
+			}
+
+			if pairCalls != test.wantPairCalls {
+				t.Errorf("the pairing route was called %d times, want %d", pairCalls, test.wantPairCalls)
+			}
+		})
+	}
+}
+
 func TestDeviceList(t *testing.T) {
 	now := time.Now()
 	devices := fmt.Sprintf(`[{"imei":"111111111111111","name":"roof","fleet_id":3,"last_seen_at":%q},`+

main.go

@@ -37,6 +37,7 @@ var sections = []dispatch.Section{
 		Title: "Devices",
 		Commands: []dispatch.Command{
 			{Name: "device list", Arguments: "[fleet_id] [--json]", Summary: "List devices and when they were last seen", Run: device.List},
+			{Name: "device pair", Arguments: "<imei> <fleet_id>", Summary: "Pair a device into a fleet", Run: device.Pair},
 			{Name: "device rename", Arguments: "<imei> <new_name>", Summary: "Rename a device", Run: device.Rename},
 			{Name: "device unpair", Arguments: "<imei>", Summary: "Remove a device from its fleet", Run: device.Unpair},
 			{Name: "device start", Arguments: "<imei>", Summary: "Start the code on a device"},

main_test.go

@@ -161,7 +161,7 @@ func TestNoPartImportsAnother(t *testing.T) {
 func TestTheTableWiresEveryCommandOffered(t *testing.T) {
 	wired := []string{
 		"account balance", "account delete", "account topup",
-		"device list", "device rename", "device unpair",
+		"device list", "device pair", "device rename", "device unpair",
 		"fleet create", "fleet delete", "fleet list", "fleet rename", "fleet transfer",
 		"key create", "key list", "key revoke",
 		"login", "logout",