Working on email templating, updating with swagger

api/src/smtp/mod.rs

@@ -0,0 +1,103 @@
+use crate::error::ApiResult;
+use chrono::{Datelike, Utc};
+use handlebars::Handlebars;
+use lettre::message::header::ContentType;
+use lettre::message::{Mailbox, MultiPart, SinglePart};
+use lettre::transport::smtp::authentication::Credentials;
+use lettre::{Address, Message, SmtpTransport, Transport};
+use serde::Serialize;
+use std::env;
+use std::sync::OnceLock;
+
+static MAILER: OnceLock<SmtpTransport> = OnceLock::new();
+static FROM_ADDRESS: OnceLock<Mailbox> = OnceLock::new();
+static REGISTRY: OnceLock<Handlebars> = OnceLock::new();
+
+fn mailer() -> &'static SmtpTransport {
+  MAILER.get_or_init(|| {
+    let server = env::var("SMTP_SERVER").expect("SMTP_SERVER missing");
+    let username = env::var("SMTP_USERNAME").expect("SMTP_USERNAME missing");
+    let password = env::var("SMTP_PASSWORD").expect("SMTP_PASSWORD missing");
+    let creds = Credentials::new(username, password);
+    SmtpTransport::relay(&server)
+      .expect("invalid SMTP_SERVER")
+      .credentials(creds)
+      .build()
+  })
+}
+
+fn from_address() -> &'static Mailbox {
+  FROM_ADDRESS.get_or_init(|| {
+    let raw = env::var("SMTP_FROM").expect("SMTP_FROM missing");
+    let addr = raw.parse().expect("SMTP_FROM invalid");
+    Mailbox::new(Some("Aviation Data".into()), addr)
+  })
+}
+
+fn registry() -> &'static Handlebars<'static> {
+  REGISTRY.get_or_init(|| Handlebars::new())
+}
+
+#[derive(Serialize)]
+struct PasswordResetCtx {
+  logo_url: String,
+  link: String,
+  domain: String,
+  year: i32,
+}
+
+pub fn send_password_reset(to: &str, token: &str) -> ApiResult<()> {
+  let base_url = env::var("EXTERNAL_URL")?.trim_end_matches('/').to_string();
+  let link = format!("{base_url}/profile/reset?token={token}");
+  let subject = "Reset your password";
+
+  let plain = format!(
+    "Hello,\n\n\
+    We received a password reset request. Click the link below:\n\n\
+    {link}\n\n\
+    This link expires in 24 hours. If you didn't request this, please ignore.\n\n\
+    Cheers,\n\
+    \tAviation Data",
+    link = link
+  );
+
+  let ctx = PasswordResetCtx {
+    logo_url: format!("{}/logo.svg", base_url),
+    link: link.clone(),
+    domain: base_url,
+    year: Utc::now().year(),
+  };
+
+  let template_html = include_str!("../.././templates/password_reset.html");
+  let html = registry().render_template(template_html, &ctx).unwrap();
+
+  send_email(to, subject, plain, html)
+}
+
+pub fn send_email(to: &str, subject: &str, header: String, html: String) -> ApiResult<()> {
+  let to_address = to.parse::<Address>()?;
+  let to_mailbox = Mailbox::new(None, to_address);
+
+  // Build the email
+  let email = Message::builder()
+    .from(from_address().clone())
+    .to(to_mailbox)
+    .subject(subject)
+    .multipart(
+      MultiPart::alternative()
+        .singlepart(
+          SinglePart::builder()
+            .header(ContentType::TEXT_PLAIN)
+            .body(header),
+        )
+        .singlepart(
+          SinglePart::builder()
+            .header(ContentType::TEXT_HTML)
+            .body(html),
+        ),
+    )?;
+
+  // Send the email
+  mailer().send(&email)?;
+  Ok(())
+}