Update API to handle payment via Stripe.

Basically the same user handling as MapIt.

.travis.yml

@@ -20,6 +20,7 @@ matrix:
 
 services:
   - memcached
+  - redis-server
 
 notifications:
   email: false

classes/Redis.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace MySociety\TheyWorkForYou;
+
+class Redis extends \Predis\Client {
+    public function __construct() {
+        $redis_args = [
+            'host' => REDIS_DB_HOST,
+            'port' => REDIS_DB_PORT,
+            'db' => REDIS_DB_NUMBER,
+        ];
+        if (REDIS_DB_PASSWORD) {
+            $redis_args['password'] = REDIS_DB_PASSWORD;
+        }
+        parent::__construct($redis_args);
+    }
+}

classes/Stripe.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace MySociety\TheyWorkForYou;
+
+class Stripe {
+    static private $instance;
+
+    public function __construct($stripeSecretKey) {
+        if (self::$instance) {
+            throw new \RuntimeException('Stripe could not be instantiate more than once. Check PHP implementation : https://github.com/stripe/stripe-php');
+        }
+        self::$instance = $this;
+
+        \Stripe\Stripe::setApiKey($stripeSecretKey);
+    }
+
+    public function getSubscription($args) {
+        return \Stripe\Subscription::retrieve($args);
+    }
+
+    public function getUpcomingInvoice($args) {
+        return \Stripe\Invoice::upcoming($args);
+    }
+
+    public function createCustomer($args) {
+        return \Stripe\Customer::create($args);
+    }
+
+    public function createSubscription($args) {
+        return \Stripe\Subscription::create($args);
+    }
+}

classes/Subscription.php

@@ -0,0 +1,245 @@
+<?php
+
+namespace MySociety\TheyWorkForYou;
+
+function add_vat($pence) {
+    return round($pence * 1.2 / 100, 2);
+}
+
+class Subscription {
+    public $stripe;
+    public $upcoming;
+    public $has_payment_data = false;
+
+    private static $plans = ['twfy-1k', 'twfy-5k', 'twfy-10k', 'twfy-0k'];
+
+    public function __construct($arg) {
+        # User ID
+        if (is_int($arg)) {
+            $user = new \USER;
+            $user->init($arg);
+            $arg = $user;
+        }
+
+        $this->db = new \ParlDB;
+        $this->redis = new Redis;
+        if (defined('TESTING')) {
+            $this->api = new TestStripe("");
+        } else {
+            $this->api = new Stripe(STRIPE_SECRET_KEY);
+        }
+
+        if (is_a($arg, 'User')) {
+            # User object
+            $this->user = $arg;
+            $this->redis_prefix = "user:{$this->user->user_id}:quota:" . REDIS_API_NAME;
+            $q = $this->db->query('SELECT * FROM api_subscription WHERE user_id = :user_id', [
+                ':user_id' => $this->user->user_id()]);
+            if ($q->rows > 0) {
+                $id = $q->field(0, 'stripe_id');
+            } else {
+                return;
+            }
+        } else {
+            # Assume Stripe ID string
+            $id = $arg;
+            $q = $this->db->query('SELECT * FROM api_subscription WHERE stripe_id = :stripe_id', [
+                ':stripe_id' => $id]);
+            if ($q->rows > 0) {
+                $user = new \USER;
+                $user->init($q->field(0, 'user_id'));
+                $this->user = $user;
+                $this->redis_prefix = "user:{$this->user->user_id}:quota:" . REDIS_API_NAME;
+            } else {
+                return;
+            }
+        }
+
+        try {
+            $this->stripe = $this->api->getSubscription([
+                'id' => $id,
+                'expand' => ['customer.default_source'],
+            ]);
+        } catch (\Stripe\Error\InvalidRequest $e) {
+            $this->db->query('DELETE FROM api_subscription WHERE stripe_id = :stripe_id', [':stripe_id' => $id]);
+            $this->delete_from_redis();
+            return;
+        }
+
+        $this->has_payment_data = $this->stripe->customer->default_source;
+
+        $data = $this->stripe;
+        if ($data->discount && $data->discount->coupon && $data->discount->coupon->percent_off) {
+            $this->actual_paid = add_vat(floor(
+                $data->plan->amount * (100 - $data->discount->coupon->percent_off) / 100));
+            $data->plan->amount = add_vat($data->plan->amount);
+        } else {
+            $data->plan->amount = add_vat($data->plan->amount);
+            $this->actual_paid = $data->plan->amount;
+        }
+
+        try {
+            $this->upcoming = $this->api->getUpcomingInvoice(["customer" => $this->stripe->customer->id]);
+        } catch (\Stripe\Error\Base $e) {
+        }
+    }
+
+    private function update_subscription($form_data) {
+        if ($form_data['stripeToken']) {
+            $this->stripe->customer->source = $form_data['stripeToken'];
+            $this->stripe->customer->save();
+        }
+
+        # Update Stripe subscription
+        $this->stripe->plan = $form_data['plan'];
+        if ($form_data['coupon']) {
+            $this->stripe->coupon = $form_data['coupon'];
+        } elseif ($this->stripe->discount) {
+            $this->stripe->deleteDiscount();
+        }
+        $this->stripe->metadata = $form_data['metadata'];
+        $this->stripe->cancel_at_period_end = false; # Needed in Stripe 2018-02-28
+        $this->stripe->save();
+    }
+
+    private function add_subscription($form_data) {
+        # Create new Stripe customer and subscription
+        $cust_params = ['email' => $this->user->email()];
+        if ($form_data['stripeToken']) {
+            $cust_params['source'] = $form_data['stripeToken'];
+        }
+        $obj = $this->api->createCustomer($cust_params);
+        $customer = $obj->id;
+
+        if (!$form_data['stripeToken'] && !($form_data['plan'] == $this::$plans[0] && $form_data['coupon'] == 'charitable100')) {
+            exit(1); # Should never reach here!
+        }
+
+        $obj = $this->api->createSubscription([
+            'tax_percent' => 20,
+            'customer' => $customer,
+            'plan' => $form_data['plan'],
+            'coupon' => $form_data['coupon'],
+            'metadata' => $form_data['metadata']
+        ]);
+        $stripe_id = $obj->id;
+
+        $this->db->query('INSERT INTO api_subscription (user_id, stripe_id) VALUES (:user_id, :stripe_id)', [
+            ':user_id' => $this->user->user_id(),
+            ':stripe_id' => $stripe_id,
+        ]);
+    }
+
+    private function getFields() {
+        $fields = ['plan', 'charitable_tick', 'charitable', 'charity_number', 'description', 'tandcs_tick', 'stripeToken'];
+        $this->form_data = [];
+        foreach ($fields as $field) {
+            $this->form_data[$field] = get_http_var($field);
+        }
+    }
+
+    private function checkValidPlan() {
+        return ($this->form_data['plan'] && in_array($this->form_data['plan'], $this::$plans));
+    }
+
+    private function checkPaymentGivenIfNeeded() {
+        return ($this->has_payment_data || $this->form_data['stripeToken'] || (
+                    $this->form_data['plan'] == $this::$plans[0]
+                && in_array($this->form_data['charitable'], ['c', 'i'])
+                ));
+    }
+
+    public function checkForErrors() {
+        $this->getFields();
+        $form_data = &$this->form_data;
+
+        $errors = [];
+        if ($form_data['charitable'] && !in_array($form_data['charitable'], ['c', 'i', 'o'])) {
+            $form_data['charitable'] = '';
+        }
+
+        if (!$this->checkValidPlan()) {
+            $errors[] = 'Please pick a plan';
+        }
+
+        if (!$this->checkPaymentGivenIfNeeded()) {
+            $errors[] = 'You need to submit payment';
+        }
+
+        if (!$this->stripe && !$form_data['tandcs_tick']) {
+            $errors[] = 'Please agree to the terms and conditions';
+        }
+
+        if (!$form_data['charitable_tick']) {
+            $form_data['charitable'] = '';
+            $form_data['charity_number'] = '';
+            $form_data['description'] = '';
+            return $errors;
+        }
+
+        if ($form_data['charitable'] == 'c' && !$form_data['charity_number']) {
+            $errors[] = 'Please provide your charity number';
+        }
+        if ($form_data['charitable'] == 'i' && !$form_data['description']) {
+            $errors[] = 'Please provide details of your project';
+        }
+
+        return $errors;
+    }
+
+    public function createOrUpdateFromForm() {
+        $form_data = $this->form_data;
+
+        $form_data['coupon'] = null;
+        if (in_array($form_data['charitable'], ['c', 'i'])) {
+            $form_data['coupon'] = 'charitable50';
+            if ($form_data['plan'] == $this::$plans[0]) {
+                $form_data['coupon'] = 'charitable100';
+            }
+        }
+
+        $form_data['metadata'] = [
+            'charitable' => $form_data['charitable'],
+            'charity_number' => $form_data['charity_number'],
+            'description' => $form_data['description'],
+        ];
+
+        if ($this->stripe) {
+            $this->update_subscription($form_data);
+        } else {
+            $this->add_subscription($form_data);
+        }
+
+        $this->redis_update_max($form_data['plan']);
+    }
+
+    public function redis_update_max($plan) {
+        preg_match('#^twfy-(\d+)k#', $plan, $m);
+        $max = $m[1] * 1000;
+        $this->redis->set("$this->redis_prefix:max", $max);
+        $this->redis->del("$this->redis_prefix:blocked");
+    }
+
+    public function redis_reset_quota() {
+        $count = $this->redis->getset("$this->redis_prefix:count", 0);
+        if ($count !== null) {
+            $this->redis->rpush("$this->redis_prefix:history", $count);
+        }
+        $this->redis->del("$this->redis_prefix:blocked");
+    }
+
+    public function delete_from_redis() {
+        $this->redis->del("$this->redis_prefix:max");
+        $this->redis->del("$this->redis_prefix:count");
+        $this->redis->del("$this->redis_prefix:blocked");
+    }
+
+    public function quota_status() {
+        return [
+            'count' => floor($this->redis->get("$this->redis_prefix:count")),
+            'blocked' => floor($this->redis->get("$this->redis_prefix:blocked")),
+            'quota' => floor($this->redis->get("$this->redis_prefix:max")),
+            'history' => $this->redis->lrange("$this->redis_prefix:history", 0, -1),
+        ];
+    }
+}

classes/TestStripe.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace MySociety\TheyWorkForYou;
+
+class TestStripe extends Stripe {
+    public function getSubscription($args) {
+        if ($args['id'] == 'sub_123') {
+            return \Stripe\Util\Util::convertToStripeObject([
+                'id' => 'sub_123',
+                'discount' => [
+                    'coupon' => ['percent_off' => 100],
+                    'end' => null
+                ],
+                'plan' => [
+                    'amount' => '2000',
+                    'id' => 'twfy-1k',
+                    'name' => 'Some calls per month',
+                ],
+                'cancel_at_period_end' => false,
+                'created' => time(),
+                'current_period_end' => time(),
+                'customer' => [
+                    'id' => 'cus_123',
+                    'account_balance' => 0,
+                    'default_source' => [],
+                ],
+            ], null);
+        }
+        return \Stripe\Util\Util::convertToStripeObject([], null);
+    }
+
+    public function getUpcomingInvoice($args) {
+        return \Stripe\Util\Util::convertToStripeObject([], null);
+    }
+
+    public function createCustomer($args) {
+        return \Stripe\Util\Util::convertToStripeObject([
+            'id' => 'cus_123',
+            'email' => 'test@example.org',
+        ], null);
+    }
+
+    public function createSubscription($args) {
+        return \Stripe\Util\Util::convertToStripeObject([
+            'id' => 'sub_123',
+        ], null);
+    }
+}

classes/Utility/Session.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace MySociety\TheyWorkForYou\Utility;
+
+class Session {
+    public static function start() {
+        if (session_status() !== PHP_SESSION_ACTIVE) {
+            session_start();
+        }
+    }
+}

composer.json

@@ -8,7 +8,10 @@
         "php": ">=5.4",
         "filp/whoops": "1.*",
         "ircmaxell/password-compat": "1.0.4",
-        "facebook/graph-sdk": "^5.6"
+        "facebook/graph-sdk": "^5.6",
+        "stripe/stripe-php": "^6.10",
+        "predis/predis": "^1.1",
+        "volnix/csrf": "^1.2"
     },
     "require-dev": {
         "phpunit/phpunit": "4.8.*",