Add API to receive calendar update notification

README.md

@@ -9,6 +9,8 @@ Calendar Notifier provides event handler and actions triggered by Google Calenda
 
 ## Features
 
+![diagram](./docs/diagram.drawio.svg)
+
 - Events
   - [x] [Calendar Events List API](https://developers.google.com/calendar/v3/reference/events/list)
   - [ ] [Calendar Events Watch API](https://developers.google.com/calendar/v3/reference/events/watch)

config.sample.yml

@@ -1,7 +1,11 @@
-version: 1
+version: "1"
 
 mode: resident
+interval: "1m"
 calendar_id: ja.japanese#[email protected]
+calendar_webhook:
+  disable: true
+  address: "https://example.com/notify"
 
 handler:
   light:

domain/repository/calendar.go

@@ -10,4 +10,5 @@ import (
 // Calendar is the interface to control calendar service.
 type Calendar interface {
 	List(ctx context.Context, since, until time.Time) (model.Schedules, error)
+	Watch(ctx context.Context, address string, ttl time.Duration) error
 }

domain/repository/config.go

@@ -13,4 +13,5 @@ type Config interface {
 	RunningMode() model.RunningMode
 	SyncInterval() time.Duration
 	Calendar() string
+	CalendarWebhookURL() (string, bool)
 }

domain/service/sync.go

@@ -50,6 +50,12 @@ func (s *synchronizer) Sync(ctx context.Context) error {
 	}
 	log.Println("calendar.List:", len(schedules))
 
+	if address, ok := s.cnf.CalendarWebhookURL(); ok {
+		if err := s.cal.Watch(ctx, address, s.cnf.SyncInterval()); err != nil {
+			return fmt.Errorf("failed to register watch address: %w", err)
+		}
+	}
+
 	acm := s.cnf.ActionConfigMap()
 	am := make(map[model.ActionName]*action, len(acm))
 

go.mod

@@ -6,6 +6,7 @@ require (
 	cloud.google.com/go v0.58.0
 	cloud.google.com/go/pubsub v1.4.0
 	github.com/golang/protobuf v1.4.2
+	github.com/google/uuid v1.1.1
 	github.com/google/wire v0.4.0
 	golang.org/x/lint v0.0.0-20200302205851-738671d3881b
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d

go.sum

@@ -130,6 +130,8 @@ github.com/google/renameio v0.1.0 h1:GOZbcHa3HfsPKPlmyPyN2KEohoMXOhdMbHrvbpl2QaA
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/subcommands v1.0.1 h1:/eqq+otEXm5vhfBrbREPCSVQbvofip6kIz+mX5TUH7k=
 github.com/google/subcommands v1.0.1/go.mod h1:ZjhPrFU+Olkh9WazFPsl27BQ4UPiG37m3yTrtFlrHVk=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
+github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/wire v0.4.0 h1:kXcsA/rIGzJImVqPdhfnr6q0xsS9gU0515q1EPpJ9fE=
 github.com/google/wire v0.4.0/go.mod h1:ngWDr9Qvq3yZA10YrxfyGELY/AFWGVpy9c1LTRi1EoU=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=

interface/calendar/calendar.go

@@ -4,8 +4,10 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"strconv"
 	"time"
 
+	"github.com/google/uuid"
 	calendar "google.golang.org/api/calendar/v3"
 
 	"github.com/ww24/calendar-notifier/domain/model"
@@ -16,6 +18,7 @@ import (
 type Calendar struct {
 	calendarID string
 	newService func(ctx context.Context) (*calendar.Service, error)
+	token      syncToken
 }
 
 // New returns new calendar API wrapper.
@@ -45,6 +48,8 @@ func (c *Calendar) List(ctx context.Context, since, until time.Time) (model.Sche
 		return nil, err
 	}
 
+	c.token.update(events.NextSyncToken)
+
 	schedules := make([]model.Schedule, 0, len(events.Items))
 	for _, item := range events.Items {
 		s, err := toModelSchedule(item)
@@ -61,6 +66,42 @@ func (c *Calendar) List(ctx context.Context, since, until time.Time) (model.Sche
 	return schedules, nil
 }
 
+// Watch watches google calendar update event.
+func (c *Calendar) Watch(ctx context.Context, address string, ttl time.Duration) error {
+	svc, err := c.newService(ctx)
+	if err != nil {
+		return err
+	}
+
+	id, err := uuid.NewRandom()
+	if err != nil {
+		return fmt.Errorf("failed to generate UUIDv4 as channel id: %w", err)
+	}
+
+	channel := &calendar.Channel{
+		Address: address,
+		Id:      id.String(),
+		Params: map[string]string{
+			"ttl": strconv.Itoa(int(ttl.Seconds())),
+		},
+		Payload: true,
+		Token:   "", // TODO
+	}
+	watchCall := svc.Events.Watch(c.calendarID, channel).
+		Context(ctx).
+		SyncToken(c.token.get())
+
+	ch, err := watchCall.Do()
+	if err != nil {
+		return fmt.Errorf("failed to watch calendar events: %w", err)
+	}
+
+	// DEBUG
+	fmt.Printf("channel: %+v\n", ch)
+
+	return nil
+}
+
 func toModelSchedule(item *calendar.Event) (model.Schedule, error) {
 	s := model.Schedule{
 		ID:          item.Id,

interface/calendar/token.go

@@ -0,0 +1,22 @@
+package calendar
+
+import (
+	"sync"
+)
+
+type syncToken struct {
+	mu    sync.RWMutex
+	token string
+}
+
+func (c *syncToken) update(token string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.token = token
+}
+
+func (c *syncToken) get() string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.token
+}

interface/config/config.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"os"
 	"strings"
 	"time"
@@ -20,16 +21,47 @@ const (
 
 // Config represents a config.yml.
 type Config struct {
-	Version    string                      `yaml:"version"`
-	Mode       model.RunningMode           `yaml:"mode"`
-	Interval   time.Duration               `yaml:"interval"`
-	CalendarID string                      `yaml:"calendar_id"`
-	Handler    map[string]EventHandler     `yaml:"handler"`
-	Action     map[model.ActionName]Action `yaml:"action"`
+	Version         string                      `yaml:"version"`
+	Mode            model.RunningMode           `yaml:"mode"`
+	Interval        time.Duration               `yaml:"interval"`
+	CalendarID      string                      `yaml:"calendar_id"`
+	CalendarWebhook calendarWebhook             `yaml:"calendar_webhook"`
+	Handler         map[string]eventHandler     `yaml:"handler"`
+	Action          map[model.ActionName]Action `yaml:"action"`
 }
 
-// EventHandler is event handler which contains action names.
-type EventHandler struct {
+// calendarWebhook is settings for calendar update notification.
+type calendarWebhook struct {
+	Disable bool   `yaml:"disable"`
+	Address string `yaml:"address"`
+}
+
+func (c *calendarWebhook) validate() error {
+	if c.Disable {
+		return nil
+	}
+	u, err := url.Parse(c.Address)
+	if err != nil {
+		return err
+	}
+	if u.Scheme != "https" {
+		return errors.New("scheme must be \"https\"")
+	}
+	if u.Host != "example.com" {
+		return errors.New("must replace placeholder (example.com) with valid host")
+	}
+	return nil
+}
+
+func (c *calendarWebhook) url() (string, bool) {
+	if c.Disable {
+		return "", false
+	}
+	return c.Address, true
+}
+
+// eventHandler is event handler which contains action names.
+type eventHandler struct {
 	Start []model.ActionName `yaml:"start"`
 	End   []model.ActionName `yaml:"end"`
 }
@@ -130,6 +162,11 @@ func (c *Config) validate() error {
 			return fmt.Errorf("unsupported action type: %s", a.Type)
 		}
 	}
+
+	if err := c.CalendarWebhook.validate(); err != nil {
+		return fmt.Errorf("calendar_webhook is invalid: %w", err)
+	}
+
 	return nil
 }
 
@@ -192,3 +229,8 @@ func (c *Config) SyncInterval() time.Duration {
 func (c *Config) Calendar() string {
 	return c.CalendarID
 }
+
+// CalendarWebhookURL returns calendar webhook address and enabled status.
+func (c *Config) CalendarWebhookURL() (string, bool) {
+	return c.CalendarWebhook.url()
+}

interface/http/handler/handler.go

@@ -14,7 +14,8 @@ func New(sync usecase.Synchronizer) http.Handler {
 	mux := http.NewServeMux()
 	svc := newService(sync)
 	mux.HandleFunc("/", svc.defaultHandler)
-	mux.HandleFunc("/launch", svc.sync)
+	mux.HandleFunc("/launch", svc.sync) // TODO: change to sync
+	mux.HandleFunc("/notify", svc.notify)
 	return mux
 }
 
@@ -46,6 +47,8 @@ func (s *syncService) defaultHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *syncService) sync(w http.ResponseWriter, r *http.Request) {
+	// TODO: IAM 認証
+
 	switch r.Method {
 	case http.MethodOptions:
 		return
@@ -70,6 +73,22 @@ func (s *syncService) sync(w http.ResponseWriter, r *http.Request) {
 	w.Write(append(d, '\n'))
 }
 
+func (s *syncService) notify(w http.ResponseWriter, r *http.Request) {
+	// TODO: api key による認証
+
+	if r.Header.Get("content-type") != "application/json" {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	// FIXME: DEBUG出力
+	m := make(map[string]interface{})
+	json.NewDecoder(r.Body).Decode(&m)
+	fmt.Printf("%+v\n", m)
+
+	w.WriteHeader(http.StatusNoContent)
+}
+
 func sendError(w http.ResponseWriter, r *http.Request, err error) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusInternalServerError)