import "github.com/krasun/paddle"

var paddleClient *paddle.Client
switch environment {
case "sandbox":
    paddleClient, err = paddle.NewSandboxClient(paddle.Authentication{paddleVendorID, paddleVendorAuthCode})
    if err != nil {
        log.Fatalf("failed to instantiate paddle %s client: %s", environment, err)
        return
    }
case "production":
    paddleClient, err = paddle.NewProductionClient(paddle.Authentication{paddleVendorID, paddleVendorAuthCode})
    if err != nil {
        log.Fatalf("failed to instantiate paddle %s client: %s", environment, err)
        return
    }
default:
    log.Fatalf("unsupported Paddle environment: %s", environment)
    return
}

options := &paddle.UpdateUserOptions{
    // ... 
    Prorate:         true,
    BillImmediately: true,
    // ...
}
response, _, err := paddleClient.Users.Update(ctx, options)
if err != nil {
    log.Error(err)
    return
}

webhooks, err := paddle.NewWebhooks(paddlePublicKey)
if err != nil {
    log.Fatalf("failed to instantiate Paddle webhooks client: %s", err)
    return
}

func handlePaddleWebhooks(webhooks *paddle.Webhooks, payments *payments) func(http.ResponseWriter, *http.Request) {
    return func(w http.ResponseWriter, r *http.Request) {
        ctx := r.Context()

        alert, err := webhooks.ParseRequest(r)
        if err != nil {
            log.Error(err)
            http.Error(w, "Sorry, something went wrong", http.StatusInternalServerError)
            return
        }

        switch alert := alert.(type) {
        // ... 
        case *paddle.SubscriptionCreatedAlert:
            err := payments.processSubscriptionCreated(ctx, alert)
            if err != nil {
                log.Error(err)
                http.Error(w, "Sorry, something went wrong", http.StatusInternalServerError)
                return
            }
        case *paddle.SubscriptionUpdatedAlert:
            // ... 
            return
        case *paddle.SubscriptionCancelledAlert:
            // ... 
            return
        // ...
        }
    }
}