adding in firebase cloud message. ref #61

fcm/README.md

@@ -0,0 +1,41 @@
+# FCM
+
+A Firebase Cloud Messaging client written in Go. For more information checkout
+[their docs](https://firebase.google.com/docs/cloud-messaging/).
+
+## Installation
+
+```bash
+go get -u github.com/zabawaba99/firego/fcm
+```
+
+## Usage
+
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/zabawaba99/firego/fcm"
+)
+
+func main() {
+	client := fcm.New("my-api-key", nil)
+
+	msg := fcm.Message{
+		RegistrationIDs: []string{"foo", "bar"},
+		Data: &fcm.Data{
+			"hello": "world",
+		},
+	}
+	resp, err := client.Send(msg)
+	if err != nil {
+		log.Fatalf("Error sending msg %s", err)
+	}
+
+	if resp.Failure != 0 {
+		log.Fatal("All these reuslts failed to send %s", resp.Failures())
+	}
+}
+```

fcm/fcm.go

@@ -0,0 +1,241 @@
+package fcm
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+// Endpoint is the URL where all Firebase Cloud Messages are sent to.
+const Endpoint = "https://fcm.googleapis.com/fcm/send"
+
+// FCM represents the Firebase Cloud Messaging service.
+type FCM struct {
+	apiKey string
+	client *http.Client
+}
+
+// New returns a new instance of the Firebase Cloud Message service.
+func New(apiKey string, client *http.Client) *FCM {
+	if client == nil {
+		client = http.DefaultClient
+	}
+
+	return &FCM{
+		apiKey: apiKey,
+		client: client,
+	}
+}
+
+// Send posts a message to the Firebase Cloud Messaging service.
+func (f *FCM) Send(msg Message) (*Response, error) {
+	b, err := json.Marshal(msg)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequest("POST", Endpoint, bytes.NewReader(b))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Add("Authorization", fmt.Sprintf("key=%s", f.apiKey))
+	req.Header.Add("Content-Type", "application/json")
+
+	resp, err := f.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var response Response
+	return &response, json.NewDecoder(resp.Body).Decode(&response)
+}
+
+// Response represents the FCM server's response to the application
+// server's sent message.
+type Response struct {
+	MulticastID  int64    `json:"multicast_id"`
+	Success      int      `json:"success"`
+	Failure      int      `json:"failure"`
+	CanonicalIDs int      `json:"canonical_ids"`
+	Results      []Result `json:"results"`
+}
+
+// Failures collects and returns all failed results.
+func (r *Response) Failures() []Result {
+	results := make([]Result, r.Failure)
+	resultIndex := 0
+
+	for _, result := range r.Results {
+		if result.Error == "" {
+			continue
+		}
+		results[resultIndex] = result
+		resultIndex++
+	}
+
+	return results
+}
+
+// Result represents the status of a processed message.
+type Result struct {
+	MessageID      string `json:"message_id"`
+	RegistrationID string `json:"registration_id"`
+	Error          string `json:"error"`
+}
+
+// Message represents the payload that is sent to the Firebase Cloud Messaging
+// service.
+// Ref https://firebase.google.com/docs/cloud-messaging/http-server-ref#downstream-http-messages-json
+// Message represents list of targets, options, and payload for HTTP JSON messages.
+type Message struct {
+	// Token specifies the recipient of a message. The value must be a
+	// registration token, notification key, or topic. Do not set this
+	// field when sending to multiple topics. See condition.
+	Token string `json:"to,omitempty"`
+
+	// RegistrationIDs specifies a list of devices (registration tokens, or IDs)
+	// receiving a multicast message. It must contain at least 1 and at most 1000 registration tokens.
+	//
+	// Use this parameter only for multicast messaging, not for single recipients.
+	RegistrationIDs []string `json:"registration_ids,omitempty"`
+
+	// Condition specifies a logical expression of conditions that determine the message target.
+	// Supported condition: Topic, formatted as "'yourTopic' in topics". This value is case-insensitive.
+	// Supported operators: &&, ||. Maximum two operators per topic message supported.
+	Condition string `json:"condition,omitempty"`
+
+	// CollapseKey identifies a group of messages (e.g., with collapse_key: "Updates Available")
+	// that can be collapsed, so that only the last message gets sent when delivery can be resumed.
+	// This is intended to avoid sending too many of the same messages when the device comes back online or becomes active.
+	//
+	// Note that there is no guarantee of the order in which messages get sent.
+	//
+	// Note: A maximum of 4 different collapse keys is allowed at any given time.
+	// This means a FCM connection server can simultaneously store 4 different send-to-sync
+	// messages per client app. If you exceed this number, there is no guarantee which 4 collapse
+	// keys the FCM connection server will keep.
+
+	CollapseKey string `json:"collapse_key,omitempty"`
+
+	// Priority sets the priority of the message. Valid values are "normal" and "high."
+	// On iOS, these correspond to APNs priorities 5 and 10.
+	// By default, messages are sent with normal priority. Normal priority optimizes
+	// the client app's battery consumption and should be used unless immediate delivery
+	// is required. For messages with normal priority, the app may receive the message with unspecified delay.
+	//
+	// When a message is sent with high priority, it is sent immediately, and the app can
+	// wake a sleeping device and open a network connection to your server.
+	Priority string `json:"priority,omitempty"`
+
+	// ContentAvailable signifies whether or not content is avaliable as part of the message.
+	//
+	// On iOS, use this field to represent content-available in the APNs payload.
+	// When a notification or message is sent and this is set to true, an inactive client
+	// app is awoken.
+	//
+	// On Android, data messages wake the app by default.
+	//
+	// On Chrome, currently not supported.
+	ContentAvailable bool `json:"content_available,omitempty"`
+
+	// TimeToLive specifies how long (in seconds) the message should be kept in
+	// FCM storage if the device is offline. The maximum time to live supported
+	// is 4 weeks, and the default value is 4 weeks
+	TimeToLive int `json:"time_to_live,omitempty"`
+
+	// RestrictedPackageName specifies the package name of the application where the
+	// registration tokens must match in order to receive the message.
+	RestrictedPackageName string `json:"restricted_package_name,omitempty"`
+
+	// DryRun allows developers to test a request without actuallin sending it.
+	//
+	// The default value is false.
+	DryRun bool `json:"dry_run,omitempty"`
+
+	// Notification specifies the predefined, user-visible key-value pairs of
+	// the notification payload. See Notification payload support for detail.
+	Notification *Notification `json:"notification,omitempty"`
+
+	// Data specifies the custom key-value pairs of the message's payload.
+	//
+	// For example, with data:{"score":"3x1"}:
+	//
+	// On iOS, if the message is sent via APNS, it represents the custom data fields.
+	// If it is sent via FCM connection server, it would be represented as key value
+	// dictionary in AppDelegate application:didReceiveRemoteNotification:.
+	//
+	// On Android, this would result in an intent extra named score with the string value 3x1.
+	//
+	// The key should not be a reserved word ("from" or any word starting with "google" or "gcm").
+	// Do not use any of the words defined in this table (such as collapse_key).
+	//
+	// Values in string types are recommended. You have to convert values in objects or other
+	// non-string data types (e.g., integers or booleans) to string.
+	Data *Data `json:"data,omitempty"`
+}
+
+// Notification specifies the predefined, user-visible key-value pairs
+// of the notification payload
+type Notification struct {
+	// Title indicates the notification title. This field is not visible on iOS phones and tablets.
+	Title string `json:"title,omitempty"`
+
+	// Body indicates the notification body text.
+	Body string `json:"body,omitempty"`
+
+	// Icon indicates notification icon.
+	// On Android sets value to myicon for drawable resource myicon.
+	// On Web it is the URL for a notification icon.
+	Icon string `json:"icon,omitempty"`
+
+	// Sound indicates the sound to play when the device receives a notification.
+	// Sound files can be in the main bundle of the client app or in the Library/Sounds
+	// folder of the app's data container.
+	// Only used for iOS and Android
+	Sound string `json:"sound,omitempty"`
+
+	// Badge indicates the badge on the client app home icon.
+	// Only used for iOS
+	Badge string `json:"badge,omitempty"`
+
+	// Tag indicates whether each notification results in a new entry in the notification drawer on Android.
+	// If not set, each request creates a new notification.
+	// If set, and a notification with the same tag is already being shown, the new
+	// notification replaces the existing one in the notification drawer.
+	// Only used for Android
+	Tag string `json:"tag,omitempty"`
+
+	// Color indicates color of the icon, expressed in #rrggbb format
+	// Only used for Android
+	Color string `json:"color,omitempty"`
+
+	// ClickAction indicates the action associated with a user click on the notification.
+	// On iOS it corresponds to category in the APNs payload.
+	// On Android when this is set, an activity with a matching intent filter is launched when user clicks the notification.
+	// On Web all URL values, secure HTTPS is required.
+	ClickAction string `json:"click_action,omitempty"`
+
+	// BodyLocKey indicates the key to the body string for localization.
+	// On iOS it corresponds to "loc-key" in the APNs payload.
+	// On Android it is the key in the app's string resources when populating this value.
+	BodyLocKey string `json:"body_loc_key,omitempty"`
+
+	// BodyLocArgs indicates the string value to replace format specifiers in the body string for localization.
+	// On iOS it corresponds to "loc-args" in the APNs payload.
+	// On Android for more information, see http://developer.android.com/guide/topics/resources/string-resource.html#FormattingAndStyling
+	BodyLocArgs string `json:"body_loc_args,omitempty"`
+
+	// TitleLocKey indicates the key to the title string for localization.
+	// On iOS it corresponds to "title-loc-key" in the APNs payload.
+	// On Android it is the key in the app's string resources when populating this value.
+	TitleLocKey string `json:"title_loc_key,omitempty"`
+
+	// TitleLocArgs indicates the string value to replace format specifiers in the title string for localization.
+	// On iOS it corresponds to "title-loc-args" in the APNs payload.
+	// On Android for more information, see http://developer.android.com/guide/topics/resources/string-resource.html#FormattingAndStyling
+	TitleLocArgs string `json:"title_loc_args,omitempty"`
+}
+
+// Data specifies the custom key-value pairs of the message's payload.
+type Data map[string]interface{}