//! SMTP server configuration.

use serde::{Deserialize, Serialize};

/// Configuration for an SMTP server instance.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SmtpServerConfig {
    /// Server hostname for greeting and EHLO responses.
    pub hostname: String,
    /// Ports to listen on (e.g. [25, 587]).
    pub ports: Vec<u16>,
    /// Port for implicit TLS (e.g. 465). None = no implicit TLS port.
    pub secure_port: Option<u16>,
    /// TLS certificate chain in PEM format.
    pub tls_cert_pem: Option<String>,
    /// TLS private key in PEM format.
    pub tls_key_pem: Option<String>,
    /// Maximum message size in bytes.
    pub max_message_size: u64,
    /// Maximum number of concurrent connections.
    pub max_connections: u32,
    /// Maximum recipients per message.
    pub max_recipients: u32,
    /// Connection timeout in seconds.
    pub connection_timeout_secs: u64,
    /// Data phase timeout in seconds.
    pub data_timeout_secs: u64,
    /// Whether authentication is available.
    pub auth_enabled: bool,
    /// Maximum authentication failures before disconnect.
    pub max_auth_failures: u32,
    /// Socket timeout in seconds (idle timeout for the entire connection).
    pub socket_timeout_secs: u64,
    /// Timeout in seconds waiting for TS to respond to email processing.
    pub processing_timeout_secs: u64,
}

impl Default for SmtpServerConfig {
    fn default() -> Self {
        Self {
            hostname: "mail.example.com".to_string(),
            ports: vec![25],
            secure_port: None,
            tls_cert_pem: None,
            tls_key_pem: None,
            max_message_size: 10 * 1024 * 1024, // 10 MB
            max_connections: 100,
            max_recipients: 100,
            connection_timeout_secs: 30,
            data_timeout_secs: 60,
            auth_enabled: false,
            max_auth_failures: 3,
            socket_timeout_secs: 300,
            processing_timeout_secs: 30,
        }
    }
}

impl SmtpServerConfig {
    /// Check if TLS is configured.
    pub fn has_tls(&self) -> bool {
        self.tls_cert_pem.is_some() && self.tls_key_pem.is_some()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_defaults() {
        let cfg = SmtpServerConfig::default();
        assert_eq!(cfg.max_message_size, 10 * 1024 * 1024);
        assert_eq!(cfg.max_connections, 100);
        assert!(!cfg.has_tls());
    }

    #[test]
    fn test_has_tls() {
        let mut cfg = SmtpServerConfig::default();
        cfg.tls_cert_pem = Some("cert".into());
        assert!(!cfg.has_tls()); // need both
        cfg.tls_key_pem = Some("key".into());
        assert!(cfg.has_tls());
    }
}