Upload photos / interacting with Picasa Web Albums / Google Photos via old API https://developers.google.com/picasa-web/docs/2.0/developers_guide_protocol

composer.json

{
    "name": "thewheat/code",
    "authors": [
        {
            "name": "Timothy Lim",
            "email": "tim.lim@intercom.io"
        }
    ],
    "require": {
        "google/apiclient": "^2.0"
    }
}

functions.php

<?php
/*
- Interacting with Picasa Web Albums / Google Photos via old API https://developers.google.com/picasa-web/docs/2.0/developers_guide_protocol
- Install depdencies via composer https://getcomposer.org/
- Get dependencies with `composer install`
- Minimal composer.json file below
===============================================================================
composer.json
===============================================================================
{
    "name": "thewheat/code",
    "authors": [
        {
            "name": "Timothy Lim",
            "email": "tim.lim@intercom.io"
        }
    ],
    "require": {
        "google/apiclient": "^2.0"
    }
}
===============================================================================
- Getting a service account key from https://console.developers.google.com/ 
- Specify $user_to_impersonate value to indicate user to upload as
*/


// include your composer dependencies
require_once 'vendor/autoload.php';
use GuzzleHttp\Psr7\Request;


// Get a service account key from https://console.developers.google.com/ 
putenv('GOOGLE_APPLICATION_CREDENTIALS=./auth.json');
$user_to_impersonate = "EMAIL@DOMAIN.COM"; // email address of the user to upload data with


$client = new Google_Client();
$client->useApplicationDefaultCredentials();
$client->setSubject($user_to_impersonate);
$client->addScope('https://picasaweb.google.com/data/');

// returns a Guzzle HTTP Client
$httpClient = $client->authorize();

// make an HTTP request
function debugResponse($response){
	print_r($response);
	echo "\ngetStatusCode: " . $response->getStatusCode();      // >>> 200
	echo "\ngetReasonPhrase: " . $response->getReasonPhrase();    // >>> OK
	echo "\nbody: " . $response->getBody();
	echo "\n";

}
function listAlbums($httpClient){
	echo "=======================================\n";
	echo "Listing albums\n";
	echo "---------------------------------------\n";
	$response = $httpClient->get('https://picasaweb.google.com/data/feed/api/user/default');
	$xml=simplexml_load_string($response->getBody());
	for($i = 0; $i < count($xml->entry); $i++){
		echo "$i. id: " . $xml->entry[$i]->id . "\n";
		echo "$i. title: " . $xml->entry[$i]->title . "\n";
	}
	echo "=======================================\n";
}
function createAlbum($httpClient, $name){
	echo "=======================================\n";
	echo "Creating album\n";
	echo "---------------------------------------\n";
	$xmlData =  "" .
	"<entry xmlns='http://www.w3.org/2005/Atom' xmlns:media='http://search.yahoo.com/mrss/' xmlns:gphoto='http://schemas.google.com/photos/2007'>
	  <title type='text'>1234123</title>
	  <category scheme='http://schemas.google.com/g/2005#kind' term='http://schemas.google.com/photos/2007#album'></category>
	</entry>";

	$xml=simplexml_load_string($xmlData);
	$xml->title = $name;
	$response = $httpClient->post('https://picasaweb.google.com/data/feed/api/user/default', [
		'headers' => ['Content-Type' => 'application/atom+xml'],
		'body' => $xml->asXML()
		]);
	$xml_response=simplexml_load_string($response->getBody());
	echo "id: " . $xml_response->id . "\n";
	echo "title: " . $xml_response->title . "\n";
	echo "=======================================\n";
}
function listAlbum($httpClient, $id){
	$response = $httpClient->get("https://picasaweb.google.com/data/feed/api/user/default/albumid/" . $id);
	$xml=simplexml_load_string($response->getBody());
	echo "=======================================\n";
	echo "Listing photos in album\n";
	echo "---------------------------------------\n";
	echo "Album id: " . $xml->id . "\n";
	echo "Album title: " . $xml->title . "\n";
	echo "---------------------------------------\n";
	for($i = 0; $i < count($xml->entry); $i++){
		echo "$i. id: " . $xml->entry[$i]->id . "\n";
		echo "$i. title: " . $xml->entry[$i]->title . "\n";
	}
	echo "=======================================\n";
}

function uploadPhoto($httpClient, $id, $image_path, $title = ""){
	echo "=======================================\n";
	echo "Upload photo to album\n";
	echo "---------------------------------------\n";
	echo "Album ID: " . $id . "\n";
	echo "Image Path: " . $image_path . "\n";
	if(file_exists($image_path)){
		echo "File exists. Upload it!\n";
		$body = fopen($image_path, 'r');
		$data = [
			'body' => $body
		];
		if($title != "") {
			$data['headers'] = ['Slug' => $title];
		}
		$response = $httpClient->post("https://picasaweb.google.com/data/feed/api/user/default/albumid/" . $id, $data);
		$xml_response=simplexml_load_string($response->getBody());
		echo "id: " . $xml_response->id . "\n";
		echo "title: " . $xml_response->title . "\n";
	}
	else{
		echo "File doesn't exist\n";
	}
	echo "=======================================\n";
}

//=============================================================================
// Example usage:
//=============================================================================
//listAlbums($httpClient);
//createAlbum($httpClient, "create album via PHP");
//listAlbum($httpClient, "6352386383096829777");
//uploadPhoto($httpClient, "6352386383096829777", "test.jpg", "title");
//=============================================================================