use lettre::{
    message::{Mailbox, MultiPart, SinglePart},
    AsyncTransport, Message,
};
use rinja::Template;

use crate::{models::User, utils::ApplicationError};

use super::Mailer;

impl Mailer {
    pub async fn send_forgot_password_mail(
        &self,
        user: &User,
        token: &str,
    ) -> Result<(), ApplicationError> {
        let message = build(&self.hostname, &user.name, &user.email, token)?;
        self.transport.send(message).await?;

        Ok(())
    }
}

#[derive(Template)]
#[template(path = "emails/forgot_password.txt")]
struct ForgotPasswordMailTemplatePlain<'a> {
    name: &'a str,
    reset_url: &'a str,
}

#[derive(Template)]
#[template(path = "emails/forgot_password.html")]
struct ForgotPasswordMailTemplateHtml<'a> {
    name: &'a str,
    reset_url: &'a str,
}

fn build(
    hostname: &str,
    name: &str,
    email: &str,
    token: &str,
) -> Result<Message, ApplicationError> {
    let reset_url = format!("https://{hostname}/reset-password?token={token}");

    let plain = ForgotPasswordMailTemplatePlain {
        name,
        reset_url: &reset_url,
    }
    .to_string();

    let html = ForgotPasswordMailTemplateHtml {
        name,
        reset_url: &reset_url,
    }
    .to_string();

    let message = Message::builder()
        .from("noreply <noreply@brasiwa-leipzig.de>".parse()?)
        .reply_to("noreply <noreply@brasiwa-leipzig.de>".parse()?)
        .to(Mailbox::new(Some(name.to_string()), email.parse()?))
        .subject("Brass: Zurücksetzen des Passworts angefordert")
        .multipart(
            MultiPart::alternative()
                .singlepart(SinglePart::plain(plain))
                .singlepart(SinglePart::html(html)),
        )
        .unwrap();

    Ok(message)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::utils::test_helper::assert_mail_snapshot;
    use lettre::{transport::stub::StubTransport, Transport};

    #[test]
    fn build_mail_snapshot() {
        let message = build(
            "brasiwa-leipzig.de",
            "Max Mustermann",
            "max@example.com",
            "123456789",
        )
        .unwrap();

        let sender = StubTransport::new_ok();
        sender.send(&message).unwrap();
        let messages = sender.messages();
        let (_, sent_message) = messages.first().unwrap();

        assert_mail_snapshot!(sent_message);
    }
}