zero2prod_axum/src/routes/subscriptions.rs

use crate::domain::SubscriberEmail;
use crate::domain::{NewSubscriber, SubscriberName};
use crate::email_client::EmailClient;
use crate::startup::AppState;
use axum::extract::State;
use axum::routing::post;
use axum::Form;
use axum::Router;
use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
};
use chrono::Utc;
use serde::Deserialize;
use sqlx::PgPool;
use uuid::Uuid;

#[derive(Debug, Deserialize)]
struct FormData {
    email: String,
    name: String,
}

impl TryFrom<FormData> for NewSubscriber {
    type Error = String;

    fn try_from(value: FormData) -> Result<Self, Self::Error> {
        let name = SubscriberName::parse(value.name)?;
        let email = SubscriberEmail::parse(value.email)?;
        Ok(Self { email, name })
    }
}

#[tracing::instrument(
    name = "Send a confirmation email to a new subscriber",
    skip(email_client, new_subscriber, base_url)
)]
pub async fn send_confirmation_email(
    email_client: &EmailClient,
    new_subscriber: NewSubscriber,
    base_url: &str,
) -> Result<(), reqwest::Error> {
    let confirmation_link = format!(
        "{}/subscriptions/confirm?subscription_token=mytoken",
        base_url
    );
    let plain_body = format!(
        "Welcome to our newsletter! Visit {} to confirm your subscription.",
        confirmation_link
    );
    let html_body = format!(
        "Welcome to our newsletter!<br />\
        Click <a href=\"{}\">here</a> to confirm your subscription.",
        confirmation_link
    );
    email_client
        .send_email(new_subscriber.email, "Welcome!", &html_body, &plain_body)
        .await
}

// TODO: remove request_id?
#[tracing::instrument(
    name = "Adding a new subscriber",
    skip(form, db_pool, email_client, base_url),
    fields(
        request_id = %Uuid::new_v4(),
        subscriber_email = %form.email,
        subscriber_name = %form.name
    )
)]
pub async fn subscribe(
    State(AppState {
        db_pool,
        email_client,
        base_url,
    }): State<AppState>,
    Form(form): Form<FormData>,
) -> Response {
    let new_subscriber = match form.try_into() {
        Ok(form) => form,
        Err(_) => {
            return (StatusCode::BAD_REQUEST, "Invalid subscription.").into_response();
        }
    };
    if insert_subscriber(&db_pool, &new_subscriber).await.is_err() {
        return (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong.").into_response();
    }
    if send_confirmation_email(&email_client, new_subscriber, &base_url.0)
        .await
        .is_err()
    {
        return (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong.").into_response();
    }
    return (StatusCode::OK,).into_response();
}

#[tracing::instrument(
    name = "Saving new subscriber details in the database",
    skip(new_subscriber, db_pool)
)]
pub async fn insert_subscriber(
    db_pool: &PgPool,
    new_subscriber: &NewSubscriber,
) -> Result<(), sqlx::Error> {
    let _ = sqlx::query!(
        r#"
            INSERT INTO subscriptions (id, email, name, subscribed_at, status)
            VALUES ($1, $2, $3, $4, 'pending_confirmation')
            "#,
        Uuid::new_v4(),
        new_subscriber.email.as_ref(),
        new_subscriber.name.as_ref(),
        Utc::now()
    )
    .execute(db_pool)
    .await
    .map_err(|e| {
        tracing::error!("Failed to execute query: {:?}", e);
        e
    });
    Ok(())
}

pub fn routes_subscriptions() -> Router<AppState> {
    Router::new().route("/subscriptions", post(subscribe))
}