feat(email): add email verification

src/email.rs

@@ -0,0 +1,38 @@
+use lettre::transport::smtp::authentication::Credentials;
+use lettre::{Message, SmtpTransport, Transport};
+use std::env;
+use std::fs;
+
+pub async fn send_verification_email(to: &str, code: i32, username: &str) -> Result<(), String> {
+    let smtp_user = env::var("SMTP_USER").map_err(|_| "SMTP_USER not set".to_string())?;
+    let smtp_pass = env::var("SMTP_PASS").map_err(|_| "SMTP_PASS not set".to_string())?;
+    let smtp_server = env::var("SMTP_SERVER").map_err(|_| "SMTP_SERVER not set".to_string())?;
+
+    // Load template
+    let template = fs::read_to_string("res/email/confirmationTemplate.html")
+        .map_err(|e| format!("Failed to read email template: {}", e))?;
+
+    // Replace placeholders
+    let body = template
+        .replace("{{username}}", username)
+        .replace("{{confirmation-code}}", &format!("{:06}", code));
+
+    let email = Message::builder()
+        .from(smtp_user.parse().unwrap())
+        .to(to.parse().unwrap())
+        .subject("Your Verification Code")
+        .header(lettre::message::header::ContentType::TEXT_HTML)
+        .body(body)
+        .map_err(|e| e.to_string())?;
+
+    let creds = Credentials::new(smtp_user, smtp_pass);
+
+    let mailer = SmtpTransport::relay(&smtp_server)
+        .map_err(|e| e.to_string())?
+        .credentials(creds)
+        .build();
+
+    mailer.send(&email).map_err(|e| e.to_string())?;
+
+    Ok(())
+}