use std::{sync::{self, Arc}, net::SocketAddr, convert::Infallible, pin::Pin, task::{Context, Poll}, io::{BufWriter, Write}, fs::{File, self}, collections::HashMap};

use crate::web_server::{Factories, ChiteyError};

use super::util::{TlsCertsKey, throw_chitey_internal_server_error};
use bytes::{BytesMut, BufMut, Bytes};
use futures_util::{ready, Future, TryStreamExt};
use http::{Request, Response, StatusCode, HeaderValue};
use hyper::{server::{conn::{AddrIncoming, AddrStream}, accept::Accept}, service::{make_service_fn, service_fn}, Server, Body};
use mime::Mime;
use rustls::ServerConfig;
use tokio::io::{AsyncRead, ReadBuf, self, AsyncWrite};
use urlpattern::UrlPatternMatchInput;

// HTTP/2 TLS など  chromeなどのブラウザはこちらに最初にアクセスしてくる
// https://github.com/quic-go/quic-go/issues/3890
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Alt-Svc#browser_compatibility
// https://http3-explained.haxx.se/ja/h3/h3-altsvc

#[derive(Clone)]
pub struct HttpsServerOpt {
    pub listen: SocketAddr,
}

pub async fn launch_https_server (tls_cert_key: TlsCertsKey, https_server_opt: HttpsServerOpt, factories: Factories) -> Result<(), ChiteyError> {
    let TlsCertsKey{certs, key} = tls_cert_key;
    let HttpsServerOpt{listen} = https_server_opt;

    let tls_config = {
        // Do not use client certificate authentication.
        let mut cfg = rustls::ServerConfig::builder()
            .with_safe_defaults()
            .with_no_client_auth()
            .with_single_cert(certs, key).unwrap();        // Configure ALPN to accept HTTP/2, HTTP/1.1 in that order.

        // cfg.alpn_protocols = b"\x02h2\x08http/1.1";
        cfg.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
        sync::Arc::new(cfg)
    };

    let incoming = AddrIncoming::bind(&listen)
        .map_err(|e| ChiteyError::InternalServerError(format!("Incoming failed: {:?}", e))).expect("error");
    let make_service = make_service_fn(move |_| {
        let factories = factories.clone();
        let service = service_fn(move |req| {
            handle_https_service(req, factories.clone())
        });

        async move { Ok::<_, Infallible>(service) }
    });
    let https_server = Server::builder(HyperAcceptor::new(tls_config, incoming)).serve(make_service);

    // Prepare a long-running future stream to accept and serve clients.

    // handle incoming connections and requests

    println!("Starting to serve on https://{}.", listen);
    match https_server.await {
        Ok(_) => Ok(()),
        Err(e) => Err(ChiteyError::InternalServerError(e.to_string())),
    }
}

pub struct HyperAcceptor {
    config: Arc<ServerConfig>,
    incoming: AddrIncoming,
}

impl HyperAcceptor {
    #[inline]
    pub fn new(config: Arc<ServerConfig>, incoming: AddrIncoming) -> HyperAcceptor {
        HyperAcceptor { config, incoming }
    }
}

enum State {
    Handshaking(tokio_rustls::Accept<AddrStream>),
    Streaming(tokio_rustls::server::TlsStream<AddrStream>),
}

// tokio_rustls::server::TlsStream doesn't expose constructor methods,
// so we have to TlsAcceptor::accept and handshake to have access to it
// TlsStream implements AsyncRead/AsyncWrite handshaking tokio_rustls::Accept first
pub struct HyperStream {
    state: State,
}

impl HyperStream {
    #[inline]
    fn new(stream: AddrStream, config: Arc<ServerConfig>) -> HyperStream {
        let accept = tokio_rustls::TlsAcceptor::from(config).accept(stream);
        HyperStream {
            state: State::Handshaking(accept),
        }
    }
}

impl AsyncRead for HyperStream {
    #[inline]
    fn poll_read(
        self: Pin<&mut Self>,
        cx: &mut Context,
        buf: &mut ReadBuf,
    ) -> Poll<io::Result<()>> {
        // info!("impl AsyncRead for HyperStream");
        let pin = self.get_mut();
        match pin.state {
            State::Handshaking(ref mut accept) => match ready!(Pin::new(accept).poll(cx)) {
                Ok(mut stream) => {
                    let result = Pin::new(&mut stream).poll_read(cx, buf);
                    pin.state = State::Streaming(stream);
                    result
                }
                Err(err) => Poll::Ready(Err(err)),
            },
            State::Streaming(ref mut stream) => Pin::new(stream).poll_read(cx, buf),
        }
    }
}

impl AsyncWrite for HyperStream {
    #[inline]
    fn poll_write(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        buf: &[u8],
    ) -> Poll<io::Result<usize>> {
        let pin = self.get_mut();
        match pin.state {
            State::Handshaking(ref mut accept) => match ready!(Pin::new(accept).poll(cx)) {
                Ok(mut stream) => {
                    let result = Pin::new(&mut stream).poll_write(cx, buf);
                    pin.state = State::Streaming(stream);
                    result
                }
                Err(err) => Poll::Ready(Err(err)),
            },
            State::Streaming(ref mut stream) => Pin::new(stream).poll_write(cx, buf),
        }
    }

    #[inline]
    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
        match self.state {
            State::Handshaking(_) => Poll::Ready(Ok(())),
            State::Streaming(ref mut stream) => Pin::new(stream).poll_flush(cx),
        }
    }

    #[inline]
    fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
        match self.state {
            State::Handshaking(_) => Poll::Ready(Ok(())),
            State::Streaming(ref mut stream) => Pin::new(stream).poll_shutdown(cx),
        }
    }
}

impl Accept for HyperAcceptor {
    type Conn = HyperStream;
    type Error = io::Error;

    #[inline]
    fn poll_accept(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<Option<Result<Self::Conn, Self::Error>>> {
        let pin = self.get_mut();
        match ready!(Pin::new(&mut pin.incoming).poll_accept(cx)) {
            Some(Ok(sock)) => Poll::Ready(Some(Ok(HyperStream::new(sock, pin.config.clone())))),
            Some(Err(e)) => Poll::Ready(Some(Err(e))),
            None => Poll::Ready(None),
        }
    }
}

#[inline]
async fn handle_https_service(req: Request<Body>, factories: Factories) -> Result<Response<Body>, ChiteyError> {
    if req.uri().path().contains("..") {
        let builder = Response::builder()
        .header("Alt-Svc", "h3=\":443\"; ma=2592000")
        .status(StatusCode::NOT_FOUND);
        return match builder.body(Body::empty()) {
            Ok(v) => Ok(v),
            Err(e) => Err(ChiteyError::InternalServerError(e.to_string())),
        }
    }

    let url = throw_chitey_internal_server_error(req.uri().to_string().parse())?;
    let input = UrlPatternMatchInput::Url(url);
    {
        let method = req.method().clone();
        let req_contain_key = req.headers().contains_key("Another-Header");
        for (res, factory) in factories.factories {
            // GET && POST
            if res.guard == method {
                if let Ok(Some(_)) = res.rdef.exec(input.clone()) {
                    let factory_loc = factory.lock().await;
                    if factory_loc.analyze_types(input.clone()) {
                        return match factory_loc.handler_func(input.clone(), (req, false)).await {
                            Ok(mut resp) => {
                                if req_contain_key {
                                    resp.headers_mut().append("Another-Header", HeaderValue::from_static("Ack"));
                                }
                                resp.headers_mut().append("Alt-Svc", HeaderValue::from_static("h3=\":443\"; ma=2592000"));
                                Ok(resp)
                            },
                            Err(e) => Err(ChiteyError::InternalServerError(e.to_string())),
                        }
                    }
                };
            }
        }
    }

    let builder = Response::builder()
        .header("Alt-Svc", "h3=\":443\"; ma=2592000")
        .status(StatusCode::NOT_FOUND);

    match builder.body(Body::from(Bytes::copy_from_slice(b"page not found"))) {
        // match builder.body(Body::empty()) {
        Ok(v) => Ok(v),
        Err(e) => Err(ChiteyError::InternalServerError(e.to_string())),
    }
}

//uploadIDを表示させる関数
pub async fn process_upload(id:String, builder:http::response::Builder, req: Request<Body>) -> Result<Response<Body>, http::Error>{
    // println!("uploadID: {}",id);
    let content_type_option = req.headers().get("content-type");
    if content_type_option.is_none() {
        return builder.body(Body::from(""));
    }
    let content_type = content_type_option.unwrap();
    let mime_type_result: Result<mime::Mime, _> = match content_type.to_str() {
        Ok(s) => s
            .parse()
            .map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err)),
        Err(err) => Err(std::io::Error::new(std::io::ErrorKind::Other, err)),
    };
    if mime_type_result.is_err() {
        return builder.body(Body::from(""));
    }
    let mime_type = mime_type_result.unwrap();
    if mime_type.essence_str() != "multipart/form-data" {
        return builder.body(Body::from(""));
    }
    let a = parse_mpart(req, mime_type).await;
    dbg!(&a);
    builder.status(StatusCode::OK).body(Body::from(format!("uploadID: {}",id)))
}

// multipartをパースしてhashmapにして返す関数
// ファイルがアップロードされたときはuploadフォルダに保存しhashmapにはそのファイル名を入れる
// アップロードされたファイル名は元のファイル名は使わずに年月日時分秒のファイル名としている
async fn parse_mpart(req: Request<Body>, mime_type: Mime) -> HashMap<String, String>{
    let mut a = HashMap::new();
    let boundary = mime_type.get_param("boundary").map(|v| v.to_string()).ok_or_else(|| std::io::Error::new(std::io::ErrorKind::Other, "boundary not found")).unwrap();
    let (_parts, body) = req.into_parts();
    let mut multipart_stream = mpart_async::server::MultipartStream::new(boundary, body);
    while let Ok(Some(mut field)) = multipart_stream.try_next().await {
        let name = field.name().unwrap().to_string();
        if let Ok(_filename) = field.filename() {
        const UPLOAD_DIRNAME: &str = "upload";
        if fs::create_dir_all(UPLOAD_DIRNAME).is_err(){
            // println!("** ディレクトリの作成失敗 **");
            continue;
        }
        let filename = chrono::Utc::now().format("%Y%m%d%H%M%S").to_string();
        let filename = format!("{UPLOAD_DIRNAME}/{filename}.dat");
        let mut writer = BufWriter::new(File::create(&filename).unwrap());
        // let mut bufferlen: i64 = 0;
        while let Ok(Some(bytes)) = field.try_next().await {
            // bufferlen += bytes.len() as i64;
            writer.write_all(&bytes).unwrap();
        }
        // println!("{bufferlen}");
        a.insert(name, filename);
        }else{
        let mut buffer = BytesMut::new();
        while let Ok(Some(bytes)) = field.try_next().await {
            buffer.put(bytes);
        }
        let value = String::from_utf8(buffer.to_vec()).unwrap();
        a.insert(name, value);
        }

    }
    a
}