use lettre::message::Mailbox;
use lettre::transport::smtp::client::Tls;
use lettre::{Message, SmtpTransport, Transport};

pub fn send_notification(
    id: i64,
    question: &str,
    notify_email: &str,
) -> Result<(), Box<dyn std::error::Error>> {
    let truncated = if question.len() > 50 {
        format!("{}...", &question[..50])
    } else {
        question.to_string()
    };

    let from: Mailbox = "Q&A <qa@extremist.software>".parse()?;
    let reply_to: Mailbox = format!("qa+{id}@extremist.software").parse()?;
    let to: Mailbox = notify_email.parse()?;

    let email = Message::builder()
        .from(from)
        .reply_to(reply_to)
        .to(to)
        .subject(format!("Q&A #{id}: {truncated}"))
        .body(question.to_string())?;

    let mailer = SmtpTransport::builder_dangerous("localhost")
        .tls(Tls::None)
        .build();
    mailer.send(&email)?;

    Ok(())
}

pub fn strip_quoted_text(body: &str) -> String {
    let mut result = Vec::new();
    for line in body.lines() {
        if line.starts_with('>') {
            continue;
        }
        if line.starts_with("On ") && line.ends_with("wrote:") {
            break;
        }
        result.push(line);
    }
    result.join("\n").trim().to_string()
}

pub fn extract_id_from_address(to: &str) -> Result<i64, Box<dyn std::error::Error>> {
    let addr = to.trim();
    let addr = if let Some(start) = addr.find('<') {
        &addr[start + 1..addr.find('>').unwrap_or(addr.len())]
    } else {
        addr
    };
    let local = addr.split('@').next().unwrap_or("");
    let id_str = local
        .strip_prefix("qa+")
        .ok_or("No qa+ prefix in address")?;
    Ok(id_str.parse()?)
}