chatrpg-api/src/controllers/webhook/stripe.rs

use actix_web::{HttpResponse, HttpRequest, web, post};
use stripe::{Event, EventType, EventObject, Webhook};
use sqlx::PgPool;
use crate::{
    http_error::HttpError,
    models::{
        purchase::{Purchase, Status},
        user::User
    },
    STRIPE_WEBHOOK_SECRET
};

#[post("/webhook/stripe")]
pub async fn route(
    req: HttpRequest,
    db: web::Data<PgPool>,
    body: web::Bytes
) -> Result<HttpResponse, HttpError> {
    let payload = std::str::from_utf8(&body).unwrap();
    let signature = get_signature(&req)?;
    let secret = STRIPE_WEBHOOK_SECRET.get().unwrap();
    let event = Webhook::construct_event(payload, &signature, secret)
        .map_err(|_| HttpError::InvalidInput("Failed to verify webhook".into()))?;

    match event.type_ {
        EventType::PaymentIntentSucceeded => {handle_success(event, &db).await?},
        EventType::PaymentIntentPaymentFailed => {handle_failure(event, &db).await?},
        _ => ()
    };

    Ok(HttpResponse::Ok().finish())
}

fn get_signature(req: &HttpRequest) -> Result<String, HttpError> {
    let signature = req.headers()
        .get("stripe-signature")
        .and_then(|v| v.to_str().ok())
        .ok_or_else(|| HttpError::InvalidInput("No signature".into()))?
        .to_string();

    Ok(signature)
}

async fn handle_success(event: Event, db: &PgPool) -> Result<(), HttpError> {
    let id = match event.data.object {
        EventObject::PaymentIntent(pi) => pi.id.to_string(),
        _ => {return Err(HttpError::InvalidInput("No payment intent ID".into()))}
    };

    let p = Purchase::update_status(db, id, Status::Succeeded).await?;
    User::add_tokens(db, p.user_id, p.pack_count * p.tokens_per_pack).await?;

    Ok(())
}

async fn handle_failure(event: Event, db: &PgPool) -> Result<(), HttpError> {
    let id = match event.data.object {
        EventObject::PaymentIntent(pi) => pi.id.to_string(),
        _ => {return Err(HttpError::InvalidInput("No payment intent ID".into()))}
    };

    Purchase::update_status(db, id, Status::Succeeded).await?;
    Ok(())
}