add FCMBatch main file

Author: HakamRaza

src/FCMBatch.php

@@ -0,0 +1,300 @@
+<?php
+
+namespace Quantomtech\LaravelFirebaseBatchMessaging;
+
+use Exception;
+use Firebase\JWT\JWT;
+use Illuminate\Http\Client\Response;
+use Illuminate\Support\Arr;
+use Illuminate\Support\Str;
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Storage;
+
+class FCMBatch
+{
+    /**
+     * Maximum payload that can be per API call as per documented
+     */
+    const MAX_PAYLOAD = 500;
+
+    /**
+     * Batch file folder path
+     * 
+     */
+    protected $tempFolderPath;
+
+    /**
+     * JSON file downloaded when creating Google Cloud Service Account
+     * 
+     * @var string
+     */
+    protected $credentialFilePath;
+
+    /**
+     * Notification sound file name
+     * 
+     * @var string
+     */
+    protected $soundFileName;
+
+    /**
+     * Batch file unique name 
+     * 
+     * @var string
+     */
+    protected $batchFileTempName;
+
+
+    /**
+     * Payload array to be map
+     * 
+     */
+    public $payload = [];
+
+    /**
+     * 
+     */
+    public function __construct()
+    {
+        $this->credentialFilePath = config('fcm-batch.credential_path');
+        $this->tempFolderPath = config('fcm-batch.temp_file_path');
+        $this->soundFileName = config('fcm-batch.fcm_sound');
+
+        $this->batchFileTempName = 'batch_request_' . Str::random(5) . '.txt';
+    }
+
+    /**
+     * Append boundry to request file
+     * 
+     */
+    private function appendBoundry(): void
+    {
+        Storage::disk('local')->append($this->tempFolderPath . $this->batchFileTempName, "\n--subrequest_boundary");
+    }
+
+    /**
+     * Append payload to request file
+     * 
+     */
+    private function appendPayload(string $json):void
+    {
+        Storage::disk('local')->append($this->tempFolderPath . $this->batchFileTempName, "\n--subrequest_boundary\nContent-Type: application/http\nContent-Transfer-Encoding: binary\n\nPOST /v1/projects/meniaga-app/messages:send\nContent-Type: application/json\naccept: application/json\n\n" . $json);
+    }
+
+    /**
+     * Remove generated request file
+     */
+    private function removeTempRequestFile(): void
+    {
+        Storage::disk('local')->delete($this->tempFolderPath . $this->batchFileTempName);
+    }
+
+    /**
+     * Create OAuth JWT Token
+     * Maximum validity is 1 Hour
+     * 
+     * @param int $periodSeconds
+     */
+    public function createJWTToken(int $periodSeconds = 3600): string
+    {
+        if($periodSeconds > 3600) {
+            throw new Exception('Valid JWT period cannot more than 1 Hour.');
+        }
+
+        $content = file_get_contents($this->credentialFilePath);
+        $jsonObj = json_decode($content);
+
+        $iat = time();
+        $exp = $iat + $periodSeconds;
+
+        return  JWT::encode([
+                    "iss" => $jsonObj->client_email,
+                    "aud" => $jsonObj->token_uri,
+                    "scope" => 'https://www.googleapis.com/auth/firebase.messaging',
+                    'iat' => $iat,
+                    'exp' => $exp
+                ], $jsonObj->private_key, "RS256");
+    }
+
+    /**
+     * Fetch API access token
+     */
+    private function getAccessToken(): string
+    {
+        $jwtToken = $this->createJWTToken();
+
+        $res =  Http::acceptJson()
+                ->asForm()
+                ->post('https://oauth2.googleapis.com/token', [
+                    'grant_type' => 'urn:ietf:params:oauth:grant-type:jwt-bearer',
+                    'assertion' => $jwtToken
+                ]);
+
+        if($res->successful()) {
+
+            /**
+             * Sometimes, trailing dots returned, need to trim
+             * https://stackoverflow.com/questions/68654502/why-am-i-getting-a-jwt-with-a-bunch-of-periods-dots-back-from-google-oauth
+             * 
+             */
+            $body = $res->json();
+
+            return rtrim($body["access_token"], '.');
+        }
+
+        throw new Exception('Failed to fetch access token. Body: ' . $res->body());
+    }
+
+
+    /**
+     * Construct IOS Payload
+     * 
+     * @return $this
+     */
+    private function addIosPayload(
+        string $fcmToken, 
+        string $title, 
+        string $body, 
+        ?array $data
+    ){
+        $setPayload = [
+            'message' =>[
+                'token' => $fcmToken,
+                'notification' =>[
+                    'title' => $title,
+                    'body' => $body
+                ],
+            ]
+        ];
+
+        if($data){
+            $setPayload['message']['data'] = $data;
+        }
+
+        $this->payload[] = $setPayload;
+
+        return $this;
+    }
+
+    /**
+     * Construct Android Payload
+     * 
+     * @return $this
+     */
+    private function addAndroidPayload(
+        string $fcmToken, 
+        string $title, 
+        string $body, 
+        ?array $data
+    ){
+        $setPayload = [
+            'message' =>[
+                'token' => $fcmToken,
+                'notification' =>[
+                    'title' => $title,
+                    'body' => $body
+                ],
+                'android' => [
+                    'collapse_key' => $title,
+                    'priority' => 'high',
+                    'ttl' => '0s',
+                    'notification' => [
+                        "sound" => $this->soundFileName
+                    ]
+                ]
+            ]
+        ];
+
+        if($data){
+            $setPayload['message']['data'] = $data;
+        }
+
+        $this->payload[] = $setPayload;
+
+        return $this;
+    }
+
+    /**
+     * Add payload
+     * https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages
+     * 
+     * @param  string title
+     * @param string body
+     * @param array data
+     * 
+     * @return $this
+     */
+    public function addPayload(
+        string $fcmToken,
+        string $title,
+        string $body,
+        array $data = null,
+        bool $IosPayload = false
+    ) {
+        if($IosPayload) {
+            return $this->addIosPayload( $fcmToken, $title, $body, $data);
+        } 
+        
+        return $this->addAndroidPayload( $fcmToken, $title, $body, $data);
+    }
+
+    /**
+     * Add custom payload data
+     * https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages
+     * 
+     * @param array $data    require 'title', 'body' in array
+     * 
+     * @return $this
+     */
+    public function addCustomPayload(array $payload)
+    {
+        $token = Arr::get($payload, 'message.token', null);
+        $title = Arr::get($payload, 'message.notification.title', null);
+        $body = Arr::get($payload, 'message.notification.body', null);
+
+        if(is_null($token) || is_null($title) || is_null($body)){
+            throw new Exception('"fcm token", "body" and "title" are required');
+        }
+
+        $this->payload[] = $payload;
+
+        return $this;
+    }
+
+    /**
+     * Send batch payload
+     * 
+     */
+    public function send(): Response
+    {        
+        // check total payload
+        if(count($this->payload) > self::MAX_PAYLOAD) {
+            throw new Exception("Total Payload per API call cannot exceed ". self::MAX_PAYLOAD ." messages");
+        }
+
+        // patch payload to file
+        foreach ($this->payload as $payload) {
+            $this->appendPayload(json_encode($payload));
+        }
+
+        $this->appendBoundry();
+
+        // send
+        $accessToken = $this->getAccessToken();
+
+        $contents = Storage::disk('local')->get($this->tempFolderPath . $this->batchFileTempName);
+
+        $res =  Http::attach('attachment', $contents)
+                ->withHeaders([
+                    'Authorization' => "Bearer " . $accessToken,
+                    'Content-Type' => 'multipart/mixed; boundary="subrequest_boundary"'
+                ])
+                ->post('https://fcm.googleapis.com/batch');
+
+
+        // remove temp file
+        $this->removeTempRequestFile();
+
+        return $res;
+    }
+}