payrail-paypal 0.1.0

PayPal connector for PayRail
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
use async_trait::async_trait;
use payrail_core::{
    CapturablePaymentConnector, CaptureRequest, CaptureResponse, CreatePaymentRequest, NextAction,
    PaymentConnector, PaymentError, PaymentEvent, PaymentMethod, PaymentProvider, PaymentSession,
    PaymentStatusResponse, ProviderErrorDetails, ProviderReference, RefundRequest, RefundResponse,
    WebhookRequest,
};
use url::Url;

use crate::{
    auth::TokenCache,
    config::PayPalConfig,
    mapper::map_order_status,
    models::{PayPalOrder, VerifyWebhookSignatureRequest, VerifyWebhookSignatureResponse},
    orders::{approval_url, create_order_body},
    webhook::parse_event,
};

/// PayPal PayRail connector.
#[derive(Debug)]
pub struct PayPalConnector {
    config: PayPalConfig,
    client: reqwest::Client,
    tokens: TokenCache,
}

impl PayPalConnector {
    /// Creates a PayPal connector.
    ///
    /// # Errors
    ///
    /// Returns an error when the HTTP client cannot be built.
    pub fn new(config: PayPalConfig) -> Result<Self, PaymentError> {
        let client = reqwest::Client::builder()
            .user_agent("payrail-rs/0.1 (+https://github.com/boniface/payrail)")
            .timeout(config.request_timeout_value())
            .build()?;
        Ok(Self {
            config,
            client,
            tokens: TokenCache::default(),
        })
    }

    fn endpoint(&self, path: &str) -> Result<Url, PaymentError> {
        self.config
            .base_url_value()
            .join(path)
            .map_err(|error| PaymentError::InvalidConfiguration(error.to_string()))
    }

    async fn access_token(&self) -> Result<String, PaymentError> {
        self.tokens.access_token(&self.client, &self.config).await
    }

    async fn parse_response<T: serde::de::DeserializeOwned>(
        &self,
        response: reqwest::Response,
    ) -> Result<T, PaymentError> {
        let status = response.status();
        if status.is_success() {
            return Ok(response.json::<T>().await?);
        }

        Err(PaymentError::ProviderDetails {
            details: ProviderErrorDetails {
                provider: PaymentProvider::PayPal,
                status: status.as_u16(),
                code: None,
                request_id: None,
                message: "paypal request failed".to_owned(),
            },
        })
    }

    async fn verify_webhook_signature(
        &self,
        request: &WebhookRequest<'_>,
    ) -> Result<(), PaymentError> {
        let webhook_id = self.config.webhook_id_value().ok_or_else(|| {
            PaymentError::InvalidConfiguration("missing paypal webhook id".to_owned())
        })?;
        let body = VerifyWebhookSignatureRequest {
            auth_algo: header_value(&request.headers, "paypal-auth-algo")?,
            cert_url: header_value(&request.headers, "paypal-cert-url")?,
            transmission_id: header_value(&request.headers, "paypal-transmission-id")?,
            transmission_sig: header_value(&request.headers, "paypal-transmission-sig")?,
            transmission_time: header_value(&request.headers, "paypal-transmission-time")?,
            webhook_id,
            webhook_event: serde_json::from_slice(request.payload)?,
        };
        let token = self.access_token().await?;
        let response: VerifyWebhookSignatureResponse = self
            .parse_response(
                self.client
                    .post(self.endpoint("/v1/notifications/verify-webhook-signature")?)
                    .bearer_auth(token)
                    .json(&body)
                    .send()
                    .await?,
            )
            .await?;

        if response.verification_status == "SUCCESS" {
            return Ok(());
        }

        Err(PaymentError::WebhookVerificationFailed)
    }
}

fn header_value<'a>(headers: &'a http::HeaderMap, name: &str) -> Result<&'a str, PaymentError> {
    headers
        .get(name)
        .and_then(|value| value.to_str().ok())
        .ok_or(PaymentError::WebhookVerificationFailed)
}

#[async_trait]
impl PaymentConnector for PayPalConnector {
    fn provider(&self) -> PaymentProvider {
        PaymentProvider::PayPal
    }

    async fn create_payment(
        &self,
        request: CreatePaymentRequest,
    ) -> Result<PaymentSession, PaymentError> {
        if !matches!(request.payment_method(), PaymentMethod::PayPal(_)) {
            return Err(PaymentError::UnsupportedPaymentMethod(
                "paypal connector only supports paypal routes".to_owned(),
            ));
        }

        let token = self.access_token().await?;
        let mut builder = self
            .client
            .post(self.endpoint("/v2/checkout/orders")?)
            .bearer_auth(token)
            .json(&create_order_body(&request));
        if let Some(key) = request.idempotency_key() {
            builder = builder.header("PayPal-Request-Id", key.as_str());
        }

        tracing::debug!(
            provider = "paypal",
            operation = "create_payment",
            has_idempotency_key = request.idempotency_key().is_some(),
            "sending provider request"
        );
        let order: PayPalOrder = self.parse_response(builder.send().await?).await?;
        let url = approval_url(&order)?;

        PaymentSession::new(
            PaymentProvider::PayPal,
            ProviderReference::new(&order.id)?,
            request.reference().clone(),
            map_order_status(&order.status),
            Some(NextAction::RedirectToUrl { url }),
        )
    }

    async fn get_payment_status(
        &self,
        provider_reference: &ProviderReference,
    ) -> Result<PaymentStatusResponse, PaymentError> {
        let token = self.access_token().await?;
        let path = format!("/v2/checkout/orders/{}", provider_reference.as_str());
        tracing::debug!(
            provider = "paypal",
            operation = "get_payment_status",
            "sending provider request"
        );
        let order: PayPalOrder = self
            .parse_response(
                self.client
                    .get(self.endpoint(&path)?)
                    .bearer_auth(token)
                    .send()
                    .await?,
            )
            .await?;

        Ok(PaymentStatusResponse {
            provider: PaymentProvider::PayPal,
            provider_reference: ProviderReference::new(order.id)?,
            status: map_order_status(&order.status),
        })
    }

    async fn refund_payment(
        &self,
        _request: RefundRequest,
    ) -> Result<RefundResponse, PaymentError> {
        Err(PaymentError::UnsupportedOperation(
            "paypal refunds are not implemented in v1".to_owned(),
        ))
    }

    async fn parse_webhook(
        &self,
        request: WebhookRequest<'_>,
    ) -> Result<PaymentEvent, PaymentError> {
        tracing::debug!(
            provider = "paypal",
            operation = "parse_webhook",
            payload_len = request.payload.len(),
            "verifying webhook signature"
        );
        self.verify_webhook_signature(&request).await?;
        parse_event(request.payload)
    }
}

#[async_trait]
impl CapturablePaymentConnector for PayPalConnector {
    async fn capture_payment(
        &self,
        request: CaptureRequest,
    ) -> Result<CaptureResponse, PaymentError> {
        let token = self.access_token().await?;
        let path = format!(
            "/v2/checkout/orders/{}/capture",
            request.provider_reference.as_str()
        );
        tracing::debug!(
            provider = "paypal",
            operation = "capture_payment",
            "sending provider request"
        );
        let order: PayPalOrder = self
            .parse_response(
                self.client
                    .post(self.endpoint(&path)?)
                    .bearer_auth(token)
                    .header("PayPal-Request-Id", request.idempotency_key.as_str())
                    .json(&serde_json::json!({}))
                    .send()
                    .await?,
            )
            .await?;

        Ok(CaptureResponse {
            provider: PaymentProvider::PayPal,
            provider_reference: ProviderReference::new(order.id)?,
            status: map_order_status(&order.status),
        })
    }
}

#[cfg(test)]
mod tests {
    use payrail_core::{Money, PaymentMethod};
    use secrecy::SecretString;
    use serde_json::json;
    use wiremock::{
        Mock, MockServer, ResponseTemplate,
        matchers::{body_string_contains, header, method, path},
    };

    use super::*;

    #[tokio::test]
    async fn create_order_fetches_token_and_returns_approval_url() {
        let server = MockServer::start().await;
        Mock::given(method("POST"))
            .and(path("/v1/oauth2/token"))
            .and(body_string_contains("grant_type=client_credentials"))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "access_token": "token_test",
                "expires_in": 3600
            })))
            .mount(&server)
            .await;
        Mock::given(method("POST"))
            .and(path("/v2/checkout/orders"))
            .and(body_string_contains("\"reference_id\":\"ORDER-1\""))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "id": "PAYPAL-ORDER-1",
                "status": "CREATED",
                "links": [{
                    "href": "https://paypal.example/approve",
                    "rel": "approve"
                }]
            })))
            .mount(&server)
            .await;
        let config = PayPalConfig::sandbox(
            SecretString::from("client_id".to_owned()),
            SecretString::from("client_secret".to_owned()),
        )
        .expect("config should be valid")
        .base_url(Url::parse(&server.uri()).expect("mock url should parse"));
        let connector = PayPalConnector::new(config).expect("connector should build");
        let request = CreatePaymentRequest::builder()
            .amount(Money::new_minor(1_000, "USD").expect("money should be valid"))
            .reference("ORDER-1")
            .expect("reference should be valid")
            .payment_method(PaymentMethod::paypal())
            .return_url("https://example.com/return")
            .expect("return url should be valid")
            .cancel_url("https://example.com/cancel")
            .expect("cancel url should be valid")
            .build()
            .expect("request should be valid");

        let session = connector
            .create_payment(request)
            .await
            .expect("session should be created");

        assert_eq!(session.provider_reference.as_str(), "PAYPAL-ORDER-1");
        assert!(matches!(
            session.next_action,
            Some(NextAction::RedirectToUrl { .. })
        ));
    }

    #[tokio::test]
    async fn status_capture_and_webhook_are_normalized() {
        let server = MockServer::start().await;
        Mock::given(method("POST"))
            .and(path("/v1/oauth2/token"))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "access_token": "token_test",
                "expires_in": 3600
            })))
            .mount(&server)
            .await;
        Mock::given(method("GET"))
            .and(path("/v2/checkout/orders/PAYPAL-ORDER-1"))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "id": "PAYPAL-ORDER-1",
                "status": "APPROVED",
                "links": []
            })))
            .mount(&server)
            .await;
        Mock::given(method("POST"))
            .and(path("/v2/checkout/orders/PAYPAL-ORDER-1/capture"))
            .and(header("paypal-request-id", "ORDER-1:capture"))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "id": "PAYPAL-ORDER-1",
                "status": "COMPLETED",
                "links": []
            })))
            .mount(&server)
            .await;
        Mock::given(method("POST"))
            .and(path("/v1/notifications/verify-webhook-signature"))
            .and(body_string_contains("\"webhook_id\":\"WH-CONFIGURED\""))
            .and(body_string_contains(
                "\"transmission_id\":\"transmission-1\"",
            ))
            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
                "verification_status": "SUCCESS"
            })))
            .mount(&server)
            .await;
        let config = PayPalConfig::sandbox(
            SecretString::from("client_id".to_owned()),
            SecretString::from("client_secret".to_owned()),
        )
        .expect("config should be valid")
        .webhook_id("WH-CONFIGURED")
        .expect("webhook id should be valid")
        .base_url(Url::parse(&server.uri()).expect("mock url should parse"));
        let connector = PayPalConnector::new(config).expect("connector should build");
        let reference =
            ProviderReference::new("PAYPAL-ORDER-1").expect("reference should be valid");

        let status = connector
            .get_payment_status(&reference)
            .await
            .expect("status should parse");
        let capture = connector
            .capture_payment(CaptureRequest {
                provider: PaymentProvider::PayPal,
                provider_reference: reference.clone(),
                idempotency_key: payrail_core::IdempotencyKey::new("ORDER-1:capture")
                    .expect("key should be valid"),
            })
            .await
            .expect("capture should parse");
        let mut headers = http::HeaderMap::new();
        headers.insert("paypal-auth-algo", "SHA256withRSA".parse().expect("header"));
        headers.insert(
            "paypal-cert-url",
            "https://paypal.example/cert".parse().expect("header"),
        );
        headers.insert(
            "paypal-transmission-id",
            "transmission-1".parse().expect("header"),
        );
        headers.insert(
            "paypal-transmission-sig",
            "signature".parse().expect("header"),
        );
        headers.insert(
            "paypal-transmission-time",
            "2026-04-26T00:00:00Z".parse().expect("header"),
        );
        let payload = br#"{
            "id":"WH-1",
            "event_type":"CHECKOUT.ORDER.COMPLETED",
            "resource":{"id":"PAYPAL-ORDER-1"}
        }"#;
        let event = connector
            .parse_webhook(WebhookRequest::new(payload, headers))
            .await
            .expect("webhook should parse");

        assert_eq!(status.status, payrail_core::PaymentStatus::Authorized);
        assert_eq!(capture.status, payrail_core::PaymentStatus::Succeeded);
        assert_eq!(event.provider_reference.as_str(), "PAYPAL-ORDER-1");
    }
}