use crate::domain::{cert_status_from_expiry, Certificate, CERT_ERROR, CERT_UNKNOWN};
use crate::error::AppResult;
use crate::repositories::{certificates, domains, subdomains};
use chrono::Utc;
use sqlx::SqlitePool;
use rustls::{ClientConfig, RootCertStore};
use rustls::pki_types::ServerName;
use std::net::ToSocketAddrs;
use std::sync::Arc;
use tokio::net::TcpStream;
use tokio::time::{timeout, Duration as TokioDuration};
use tokio_rustls::TlsConnector;
use x509_parser::prelude::FromDer;

pub async fn list_certificates(pool: &SqlitePool, status: Option<&str>) -> AppResult<Vec<Certificate>> {
    certificates::list(pool, status).await
}

pub async fn get_certificate(pool: &SqlitePool, id: i64) -> AppResult<Certificate> {
    certificates::get(pool, id).await
}

pub async fn check_hostname(hostname: &str) -> (Option<chrono::DateTime<Utc>>, Option<String>) {
    let addr = match format!("{hostname}:443").to_socket_addrs() {
        Ok(mut addrs) => match addrs.next() {
            Some(a) => a,
            None => return (None, Some("cannot resolve host".into())),
        },
        Err(e) => return (None, Some(e.to_string())),
    };

    let stream = match timeout(TokioDuration::from_secs(10), TcpStream::connect(addr)).await {
        Ok(Ok(s)) => s,
        Ok(Err(e)) => return (None, Some(e.to_string())),
        Err(_) => return (None, Some("connection timeout".into())),
    };

    let mut root_store = RootCertStore::empty();
    root_store.extend(webpki_roots::TLS_SERVER_ROOTS.iter().cloned());

    let config = ClientConfig::builder()
        .with_root_certificates(root_store)
        .with_no_client_auth();

    let connector = TlsConnector::from(Arc::new(config));
    let server_name = match ServerName::try_from(hostname.to_string()) {
        Ok(n) => n,
        Err(e) => return (None, Some(e.to_string())),
    };

    let tls = match connector.connect(server_name, stream).await {
        Ok(s) => s,
        Err(e) => return (None, Some(e.to_string())),
    };

    let (_, session) = tls.into_inner();
    let certs = session.peer_certificates();
    let Some(chain) = certs else {
        return (None, Some("no peer certificates".into()));
    };
    let Some(leaf) = chain.first() else {
        return (None, Some("empty cert chain".into()));
    };

    match x509_parser::certificate::X509Certificate::from_der(leaf.as_ref()) {
        Ok((_, cert)) => {
            let not_after = cert.validity().not_after.timestamp();
            let expires = chrono::DateTime::from_timestamp(not_after, 0);
            (expires, None)
        }
        Err(e) => (None, Some(e.to_string())),
    }
}

pub async fn check_and_store(
    pool: &SqlitePool,
    domain_id: i64,
    subdomain_id: Option<i64>,
    hostname: &str,
) -> AppResult<Certificate> {
    let (expires_at, err) = check_hostname(hostname).await;
    let status = if let Some(err_msg) = &err {
        certificates::upsert_check(
            pool,
            domain_id,
            subdomain_id,
            hostname,
            expires_at.map(|e| e.to_rfc3339()).as_deref(),
            CERT_ERROR,
            Some(err_msg),
        )
        .await?
    } else if let Some(exp) = expires_at {
        let days = (exp - Utc::now()).num_days();
        let st = cert_status_from_expiry(days);
        certificates::upsert_check(
            pool,
            domain_id,
            subdomain_id,
            hostname,
            Some(&exp.to_rfc3339()),
            st,
            None,
        )
        .await?
    } else {
        certificates::upsert_check(
            pool,
            domain_id,
            subdomain_id,
            hostname,
            None,
            CERT_UNKNOWN,
            Some("unknown expiry"),
        )
        .await?
    };
    Ok(status)
}

pub async fn run_all_checks(pool: &SqlitePool) -> AppResult<usize> {
    let mut count = 0usize;
    let all_domains = domains::list_all(pool).await?;
    for domain in all_domains {
        check_and_store(pool, domain.id, None, &domain.zone_name).await?;
        count += 1;
    }
    let subs = subdomains::list_all(pool).await?;
    for sub in subs {
        check_and_store(pool, sub.domain_id, Some(sub.id), &sub.fqdn).await?;
        count += 1;
    }
    Ok(count)
}

pub async fn status_summary(pool: &SqlitePool) -> AppResult<Vec<(String, i64)>> {
    certificates::count_by_status(pool).await
}