// Copyright 2021 Datafuse Labs.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! After running this, you should be able to run:
//!
//! ```console
//! $ echo "SELECT * FROM foo" | mysql -h 127.0.0.1 --table --ssl-mode=REQUIRED
//! ```

#[cfg(feature = "tls")]
mod tls {

    use rustls_pemfile::{certs, pkcs8_private_keys};
    use rustls_pki_types::{CertificateDer, PrivateKeyDer};
    use std::{
        fs::File,
        io::{self, BufReader, ErrorKind},
        sync::Arc,
    };
    use tokio::io::AsyncWrite;
    use tokio_rustls::rustls::ServerConfig;

    use opensrv_mysql::*;
    use tokio::net::TcpListener;

    struct Backend;

    #[async_trait::async_trait]
    impl<W: AsyncWrite + Send + Unpin> AsyncMysqlShim<W> for Backend {
        type Error = io::Error;

        async fn on_prepare<'a>(
            &'a mut self,
            _: &'a str,
            info: StatementMetaWriter<'a, W>,
        ) -> io::Result<()> {
            info.reply(42, &[], &[]).await
        }

        async fn on_execute<'a>(
            &'a mut self,
            _: u32,
            _: opensrv_mysql::ParamParser<'a>,
            results: QueryResultWriter<'a, W>,
        ) -> io::Result<()> {
            results.completed(OkResponse::default()).await
        }

        async fn on_close(&mut self, _: u32) {}

        async fn on_query<'a>(
            &'a mut self,
            sql: &'a str,
            results: QueryResultWriter<'a, W>,
        ) -> io::Result<()> {
            println!("execute sql {:?}", sql);
            results.start(&[]).await?.finish().await
        }
    }

    fn setup_tls() -> Result<ServerConfig, io::Error> {
        let cert = certs(&mut BufReader::new(File::open(
            "mysql/tests/ssl/server.crt",
        )?))
        .collect::<Result<Vec<CertificateDer>, io::Error>>()?;

        let key = pkcs8_private_keys(&mut BufReader::new(File::open(
            "mysql/tests/ssl/server.key",
        )?))
        .map(|key| key.map(PrivateKeyDer::from))
        .collect::<Result<Vec<PrivateKeyDer>, io::Error>>()?
        .remove(0);

        let config = ServerConfig::builder()
            .with_no_client_auth()
            .with_single_cert(cert, key)
            .map_err(|err| io::Error::new(ErrorKind::InvalidInput, err))?;

        Ok(config)
    }

    pub async fn main() -> Result<(), Box<dyn std::error::Error>> {
        let listener = TcpListener::bind("0.0.0.0:3306").await?;

        loop {
            let (stream, _) = listener.accept().await?;
            let (mut r, mut w) = stream.into_split();

            tokio::spawn(async move {
                let tls_config = setup_tls().unwrap();
                let tls_config = Arc::new(tls_config);
                let mut shim = Backend;
                let ops = IntermediaryOptions::default();

                let (is_ssl, init_params) = opensrv_mysql::AsyncMysqlIntermediary::init_before_ssl(
                    &mut shim,
                    &mut r,
                    &mut w,
                    &Some(tls_config.clone()),
                )
                .await
                .unwrap();

                if is_ssl {
                    opensrv_mysql::secure_run_with_options(shim, w, ops, tls_config, init_params)
                        .await
                } else {
                    opensrv_mysql::plain_run_with_options(shim, w, ops, init_params).await
                }
            });
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    #[cfg(feature = "tls")]
    tls::main().await?;
    println!(" cargo run --example serve_secure --features tls ");
    Ok(())
}