From 6e1fc993656bfccf906c7b15e3fe23c326694fe7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A0=20Cidre?= <adria.cidre@gmail.com>
Date: Tue, 8 May 2018 16:30:03 +0200
Subject: [PATCH] Notifier package to interact with gorush notifications (#910)

---
 notifier/notifier.go      | 100 ++++++++++++++++++++++++++++++++++++++
 notifier/notifier_test.go |  62 +++++++++++++++++++++++
 2 files changed, 162 insertions(+)
 create mode 100644 notifier/notifier.go
 create mode 100644 notifier/notifier_test.go

diff --git a/notifier/notifier.go b/notifier/notifier.go
new file mode 100644
index 000000000..634f3551c
--- /dev/null
+++ b/notifier/notifier.go
@@ -0,0 +1,100 @@
+package notifier
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"log"
+	"net/http"
+)
+
+const (
+	// IOS identifier for an iOS notification.
+	IOS = 1
+	// Android identifier for an android notification.
+	Android             = 2
+	failedPushErrorType = "failed-push"
+	pushEndpoint        = "/api/push"
+)
+
+// Notifier handles android and ios push notifications.
+type Notifier struct {
+	client *http.Client
+	url    string
+}
+
+// New notifier connected to the specified server.
+func New(url string) *Notifier {
+	client := &http.Client{}
+
+	return &Notifier{url: url, client: client}
+}
+
+// Notification details for gorush.
+type Notification struct {
+	Tokens   []string `json:"tokens"`
+	Platform float32  `json:"platform"`
+	Message  string   `json:"message"`
+}
+
+type request struct {
+	Notifications []*Notification `json:"notifications"`
+}
+
+// Response from gorush.
+type Response struct {
+	Logs []struct {
+		Type  string `json:"type"`
+		Error string `json:"error"`
+	} `json:"logs"`
+}
+
+// Send a push notification to given devices.
+func (n *Notifier) Send(notifications []*Notification) error {
+	url := n.url + pushEndpoint
+	r := request{Notifications: notifications}
+
+	body, err := json.Marshal(r)
+	if err != nil {
+		return err
+	}
+
+	res, err := n.doRequest(url, body)
+	if err != nil {
+		return err
+	}
+
+	if len(res.Logs) > 0 {
+		if res.Logs[0].Type == failedPushErrorType {
+			return errors.New(res.Logs[0].Error)
+		}
+	}
+
+	return err
+}
+
+func (n *Notifier) doRequest(url string, body []byte) (res Response, err error) {
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(body))
+	if err != nil {
+		return
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := n.client.Do(req)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if err := resp.Body.Close(); err != nil {
+			log.Println(err.Error())
+		}
+	}()
+
+	body, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return
+	}
+
+	return res, json.Unmarshal(body, &res)
+}
diff --git a/notifier/notifier_test.go b/notifier/notifier_test.go
new file mode 100644
index 000000000..c33e95a00
--- /dev/null
+++ b/notifier/notifier_test.go
@@ -0,0 +1,62 @@
+package notifier
+
+import (
+	"errors"
+	"log"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type NotifierTestSuite struct {
+	suite.Suite
+	url string
+	n   *Notifier
+}
+
+func (s *NotifierTestSuite) SetupTest() {
+	s.url = "http://localhost:3000"
+	s.n = New(s.url)
+}
+
+var flagtests = []struct {
+	response string
+	err      error
+}{
+	{
+		response: `{"counts":1,"logs":[{"type":"failed-push","platform":"android","token":"1111111","message":"Hello world","error":"invalid registration token"}],"success":"ok"}`,
+		err:      errors.New("invalid registration token"),
+	},
+	{
+		response: `{"counts":1,"success":"ok"}`,
+		err:      nil,
+	},
+}
+
+func (s *NotifierTestSuite) TestSendNotifications() {
+	for _, tt := range flagtests {
+		var apiStub = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusOK)
+			if _, err := w.Write([]byte(tt.response)); err != nil {
+				log.Println(err.Error())
+			}
+		}))
+		defer apiStub.Close()
+
+		s.n.url = apiStub.URL
+		notification := Notification{
+			Tokens:   []string{"t1", "t2"},
+			Platform: 2,
+			Message:  "hello world",
+		}
+
+		err := s.n.Send([]*Notification{&notification})
+		s.Equal(tt.err, err)
+	}
+}
+
+func TestNotifierTestSuite(t *testing.T) {
+	suite.Run(t, new(NotifierTestSuite))
+}