// Email invitation functions
#[cfg(feature = "mail")]
use log::warn;
#[cfg(feature = "mail")]
use uuid::Uuid;
#[cfg(feature = "mail")]
use lettre::{
    message::{header::ContentType, Message},
    transport::smtp::authentication::Credentials,
    SmtpTransport, Transport,
};

/// Send invitation email
#[cfg(feature = "mail")]
pub async fn send_invitation_email(
    to_email: String,
    role: String,
    custom_message: Option<String>,
    invitation_id: Uuid,
) -> Result<(), String> {
    let smtp = crate::core::secrets::SecretsManager::get()
        .ok()
        .and_then(|sm| {
            let sm_owned = sm.clone();
            let (tx, rx) = std::sync::mpsc::channel();
            std::thread::spawn(move || {
                let rt = tokio::runtime::Builder::new_current_thread()
                    .enable_all()
                    .build();
                let result = if let Ok(rt) = rt {
                    rt.block_on(async move { sm_owned.get_secret(crate::core::secrets::SecretPaths::EMAIL).await.ok() })
                } else {
                    None
                };
                let _ = tx.send(result);
            });
            rx.recv().ok().flatten()
        });

    let smtp_host = smtp.as_ref()
        .and_then(|s| s.get("smtp_host").cloned())
        .unwrap_or_else(|| "localhost".to_string());
    let smtp_user = smtp.as_ref().and_then(|s| s.get("smtp_user").cloned());
    let smtp_pass = smtp.as_ref().and_then(|s| s.get("smtp_password").cloned());
    let smtp_from = smtp.as_ref()
        .and_then(|s| s.get("smtp_from").cloned())
        .unwrap_or_else(|| "noreply@generalbots.com".to_string());
    let app_url = smtp.as_ref()
        .and_then(|s| s.get("app_url").cloned())
        .unwrap_or_else(|| "https://app.generalbots.com".to_string());

    let custom_msg = custom_message.unwrap_or_default();

    let accept_url = format!("{}/accept-invitation?token={}", app_url, invitation_id);

    let body = format!(
        r#"You have been invited to join our organization as a {}.

{}

Click on link below to accept the invitation:
{}

This invitation will expire in 7 days.

If you did not expect this invitation, you can safely ignore this email.

Best regards,
The General Bots Team"#,
        role,
        if custom_msg.is_empty() { "".to_string() } else { format!("\n{}\n", custom_msg) },
        accept_url
    );

    let email = Message::builder()
        .from(smtp_from.parse().map_err(|e| format!("Invalid from address: {}", e))?)
        .to(to_email.parse().map_err(|e| format!("Invalid to address: {}", e))?)
        .subject("You've been invited to join our organization")
        .header(ContentType::TEXT_PLAIN)
        .body(body)
        .map_err(|e| format!("Failed to build email: {}", e))?;

    let mailer = if let (Some(user), Some(pass)) = (smtp_user, smtp_pass) {
        let creds = Credentials::new(user, pass);
        SmtpTransport::relay(&smtp_host)
            .map_err(|e| format!("SMTP relay error: {}", e))?
            .credentials(creds)
            .build()
    } else {
        SmtpTransport::builder_dangerous(&smtp_host).build()
    };

    mailer.send(&email).map_err(|e| format!("Failed to send email: {}", e))?;
    warn!("Invitation email sent successfully to {}", to_email);
    Ok(())
}

/// Send invitation email by fetching details from database
#[cfg(feature = "mail")]
pub async fn send_invitation_email_by_id(invitation_id: Uuid) -> Result<(), String> {
    // TODO: Implement when invitations table is available in schema
    warn!("send_invitation_email_by_id called for {} - not fully implemented", invitation_id);
    Err(format!("Invitation with id {} not found", invitation_id))
}