mod middleware;
mod codec;

use std::net::SocketAddr;
use std::sync::Arc;

use anyhow::{anyhow, bail, Result};
use hyper::service::service_fn;
use hyper::{Request, Response, body::Bytes};
use hyper::server::conn::http1 as http;
use hyper::rt::{Read, Write};
use hyper::body::Incoming;
use hyper_util::rt::TokioIo;
use futures::stream::{FuturesUnordered, StreamExt};
use tokio::net::TcpListener;
use tokio::sync::watch;
use tokio_rustls::TlsAcceptor;
use tokio::net::TcpStream;
use tokio::io::{AsyncRead, AsyncWrite};
use rustls_pemfile::{certs, private_key};

use aero_user::config::{DavConfig, DavUnsecureConfig};
use aero_user::login::ArcLoginProvider;
use aero_collections::{user::User, calendar::Calendar, davdag::BlobId};
use aero_dav::types as dav;
use aero_dav::caltypes as cal;
use aero_dav::acltypes as acl;
use aero_dav::realization::{All, self as all};

use crate::dav::codec::{serialize, deserialize, depth, text_body};

type ArcUser = std::sync::Arc<User>;

pub struct Server {
    bind_addr: SocketAddr,
    login_provider: ArcLoginProvider,
    tls: Option<TlsAcceptor>,
}

pub fn new_unsecure(config: DavUnsecureConfig, login: ArcLoginProvider) -> Server {
    Server {
        bind_addr: config.bind_addr,
        login_provider: login,
        tls: None,
    }
}

pub fn new(config: DavConfig, login: ArcLoginProvider) -> Result<Server> {
    let loaded_certs = certs(&mut std::io::BufReader::new(std::fs::File::open(
        config.certs,
    )?))
    .collect::<Result<Vec<_>, _>>()?;
    let loaded_key = private_key(&mut std::io::BufReader::new(std::fs::File::open(
        config.key,
    )?))?
    .unwrap();

    let tls_config = rustls::ServerConfig::builder()
        .with_no_client_auth()
        .with_single_cert(loaded_certs, loaded_key)?;
    let acceptor = TlsAcceptor::from(Arc::new(tls_config));

    Ok(Server {
        bind_addr: config.bind_addr,
        login_provider: login,
        tls: Some(acceptor),
    })
}

trait Stream: Read + Write + Send + Unpin {}
impl<T: Unpin + AsyncRead + AsyncWrite + Send> Stream for TokioIo<T> {}

impl Server {
    pub async fn run(self: Self, mut must_exit: watch::Receiver<bool>) -> Result<()> {
        let tcp = TcpListener::bind(self.bind_addr).await?;
        tracing::info!("DAV server listening on {:#}", self.bind_addr);

        let mut connections = FuturesUnordered::new();
        while !*must_exit.borrow() {
            let wait_conn_finished = async {
                if connections.is_empty() {
                    futures::future::pending().await
                } else {
                    connections.next().await
                }
            };
            let (socket, remote_addr) = tokio::select! {
                a = tcp.accept() => a?,
                _ = wait_conn_finished => continue,
                _ = must_exit.changed() => continue,
            };
            tracing::info!("Accepted connection from {}", remote_addr);
            let stream = match self.build_stream(socket).await {
                Ok(v) => v,
                Err(e) => {
                    tracing::error!(err=?e, "TLS acceptor failed");
                    continue
                }
            };

            let login = self.login_provider.clone();
            let conn = tokio::spawn(async move {
                //@FIXME should create a generic "public web" server on which "routers" could be
                //abitrarily bound
                //@FIXME replace with a handler supporting http2 and TLS

                match http::Builder::new().serve_connection(stream, service_fn(|req: Request<hyper::body::Incoming>| {
                    let login = login.clone();
                    tracing::info!("{:?} {:?}", req.method(), req.uri());
                    async {
                        match middleware::auth(login, req, |user, request| async { router(user, request).await }.boxed()).await {
                            Ok(v) => Ok(v),
                            Err(e) => {
                                tracing::error!(err=?e, "internal error");
                                Response::builder()
                                    .status(500)
                                    .body(codec::text_body("Internal error"))
                            },
                        }
                    }
                })).await {
                    Err(e) => tracing::warn!(err=?e, "connection failed"),
                    Ok(()) => tracing::trace!("connection terminated with success"),
                }
            });
            connections.push(conn);
        }
        drop(tcp);

        tracing::info!("Server shutting down, draining remaining connections...");
        while connections.next().await.is_some() {}

        Ok(())
    }

    async fn build_stream(&self, socket: TcpStream) -> Result<Box<dyn Stream>> {
        match self.tls.clone() {
            Some(acceptor) => {
                let stream = acceptor.accept(socket).await?;
                Ok(Box::new(TokioIo::new(stream)))
            }
            None => Ok(Box::new(TokioIo::new(socket))),
        }
    }
}

use http_body_util::BodyExt;

//@FIXME We should not support only BasicAuth


/// Path is a voluntarily feature limited
/// compared to the expressiveness of a UNIX path
/// For example getting parent with ../ is not supported, scheme is not supported, etc.
/// More complex support could be added later if needed by clients
enum Path<'a> {
    Abs(Vec<&'a str>),
    Rel(Vec<&'a str>),
}
impl<'a> Path<'a> {
    fn new(path: &'a str) -> Result<Self> {
        // This check is naive, it does not aim at detecting all fully qualified
        // URL or protect from any attack, its only goal is to help debugging.
        if path.starts_with("http://") || path.starts_with("https://") {
            anyhow::bail!("Full URL are not supported")
        }

        let path_segments: Vec<_> = path.split("/").filter(|s| *s != "" && *s != ".").collect();
        if path.starts_with("/") {
            return Ok(Path::Abs(path_segments))
        }
        Ok(Path::Rel(path_segments))
    }
}

async fn router(user: std::sync::Arc<User>, req: Request<Incoming>) -> Result<Response<BoxBody<Bytes, std::io::Error>>> {
    let path = req.uri().path().to_string();
    let path_segments: Vec<_> = path.split("/").filter(|s| *s != "").collect();
    let method = req.method().as_str().to_uppercase();

    let node = match (RootNode {}).fetch(&user, &path_segments).await {
        Ok(v) => v,
        Err(e) => {
            tracing::warn!(err=?e, "dav node fetch failed");
            return Ok(Response::builder()
                .status(404)
                .body(codec::text_body("Resource not found"))?)
        }
    };
    let response = DavResponse { node, user, req };

    match method.as_str() {
        "OPTIONS" => return Ok(Response::builder()
            .status(200)
            .header("DAV", "1")
            .header("Allow", "HEAD,GET,PUT,OPTIONS,DELETE,PROPFIND,PROPPATCH,MKCOL,COPY,MOVE,LOCK,UNLOCK,MKCALENDAR,REPORT")
            .body(codec::text_body(""))?),
        "HEAD" | "GET" => {
            tracing::warn!("HEAD+GET not correctly implemented");
            return Ok(Response::builder()
                .status(404)
                .body(codec::text_body(""))?)
        },
        "PUT" => {
            todo!();
        },
        "DELETE" => {
            todo!();
        },
        "PROPFIND" => response.propfind().await,
        "REPORT" => response.report().await,
        _ => return Ok(Response::builder()
            .status(501)
            .body(codec::text_body("HTTP Method not implemented"))?),
    }
}

const ALLPROP: [dav::PropertyRequest<All>; 10] = [
    dav::PropertyRequest::CreationDate,
    dav::PropertyRequest::DisplayName,
    dav::PropertyRequest::GetContentLanguage,
    dav::PropertyRequest::GetContentLength,
    dav::PropertyRequest::GetContentType,
    dav::PropertyRequest::GetEtag,
    dav::PropertyRequest::GetLastModified,
    dav::PropertyRequest::LockDiscovery,
    dav::PropertyRequest::ResourceType,
    dav::PropertyRequest::SupportedLock,
];

// ---------- Building objects

// ---- HTTP DAV Binding
use futures::stream::TryStreamExt;
use http_body_util::BodyStream;
use http_body_util::StreamBody;
use http_body_util::combinators::BoxBody;
use hyper::body::Frame;
use tokio_util::sync::PollSender;
use std::io::{Error, ErrorKind};
use futures::sink::SinkExt;
use tokio_util::io::{SinkWriter, CopyToBytes};



//---
use futures::{future, future::BoxFuture, future::FutureExt};

/// A DAV node should implement the following methods
/// @FIXME not satisfied by BoxFutures but I have no better idea currently
trait DavNode: Send {
    // recurence, filesystem hierarchy
    /// This node direct children
    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>>;
    /// Recursively fetch a child (progress inside the filesystem hierarchy)
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>>;

    // node properties
    /// Get the path
    fn path(&self, user: &ArcUser) -> String;
    /// Get the supported WebDAV properties
    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All>;
    /// Get the values for the given properties
    fn properties(&self, user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>>;

    //@FIXME maybe add etag, maybe add a way to set content

    /// Utility function to get a propname response from a node
    fn response_propname(&self, user: &ArcUser) -> dav::Response<All> {
        dav::Response {
            status_or_propstat: dav::StatusOrPropstat::PropStat(
                dav::Href(self.path(user)), 
                vec![
                    dav::PropStat {
                        status: dav::Status(hyper::StatusCode::OK), 
                        prop: dav::AnyProp(self.supported_properties(user).0.into_iter().map(dav::AnyProperty::Request).collect()),
                        error: None,
                        responsedescription: None,
                    }
                ],
            ),
            error: None,
            location: None,
            responsedescription: None
        }
    }

    /// Utility function to get a prop response from a node & a list of propname
    fn response_props(&self, user: &ArcUser, props: dav::PropName<All>) -> dav::Response<All> {
        let mut prop_desc = vec![];
        let (found, not_found): (Vec<_>, Vec<_>) = self.properties(user, props).into_iter().partition(|v| matches!(v, dav::AnyProperty::Value(_)));

        // If at least one property has been found on this object, adding a HTTP 200 propstat to
        // the response
        if !found.is_empty() {
            prop_desc.push(dav::PropStat { 
                status: dav::Status(hyper::StatusCode::OK), 
                prop: dav::AnyProp(found),
                error: None,
                responsedescription: None,
            });
        }

        // If at least one property can't be found on this object, adding a HTTP 404 propstat to
        // the response
        if !not_found.is_empty() {
            prop_desc.push(dav::PropStat { 
                status: dav::Status(hyper::StatusCode::NOT_FOUND), 
                prop: dav::AnyProp(not_found),
                error: None,
                responsedescription: None,
            })
        }

        // Build the finale response
        dav::Response {
            status_or_propstat: dav::StatusOrPropstat::PropStat(dav::Href(self.path(user)), prop_desc),
            error: None,
            location: None,
            responsedescription: None
        }
    }
}

struct DavResponse {
    node: Box<dyn DavNode>,
    user: std::sync::Arc<User>,
    req: Request<Incoming>,
}
impl DavResponse {
    // --- Public API ---

    /// REPORT has been first described in the "Versioning Extension" of WebDAV
    /// It allows more complex queries compared to PROPFIND
    ///
    /// Note: current implementation is not generic at all, it is heavily tied to CalDAV.
    /// A rewrite would be required to make it more generic (with the extension system that has
    /// been introduced in aero-dav)
    async fn report(self) -> Result<Response<BoxBody<Bytes, std::io::Error>>> { 
        let status = hyper::StatusCode::from_u16(207)?;

        let report = match deserialize::<cal::Report<All>>(self.req).await {
            Ok(v) => v,
            Err(e) => {
                tracing::error!(err=?e, "unable to decode REPORT body");
                return Ok(Response::builder()
                          .status(400)
                          .body(text_body("Bad request"))?)
            }
        };

        // Multiget is really like a propfind where Depth: 0|1|Infinity is replaced by an arbitrary
        // list of URLs
        let multiget = match report {
            cal::Report::Multiget(m) => m,
            _ => return Ok(Response::builder()
                           .status(501)
                           .body(text_body("Not implemented"))?),
        };

        // Getting the list of nodes
        let (mut ok_node, mut not_found) = (Vec::new(), Vec::new());
        for h in multiget.href.into_iter() {
            let maybe_collected_node = match Path::new(h.0.as_str()) {
                Ok(Path::Abs(p)) => RootNode{}.fetch(&self.user, p.as_slice()).await.or(Err(h)),
                Ok(Path::Rel(p)) => self.node.fetch(&self.user, p.as_slice()).await.or(Err(h)),
                Err(_) => Err(h),
            };

            match maybe_collected_node {
                Ok(v) => ok_node.push(v),
                Err(h) => not_found.push(h),
            };
        }

        // Getting props
        let props = match multiget.selector {
            None | Some(cal::CalendarSelector::AllProp) => Some(dav::PropName(ALLPROP.to_vec())),
            Some(cal::CalendarSelector::PropName) => None,
            Some(cal::CalendarSelector::Prop(inner)) => Some(inner),
        };

        serialize(status, Self::multistatus(&self.user, ok_node, not_found, props))
    }

    /// PROPFIND is the standard way to fetch WebDAV properties
    async fn propfind(self) -> Result<Response<BoxBody<Bytes, std::io::Error>>> { 
        let depth = depth(&self.req);
        if matches!(depth, dav::Depth::Infinity) {
            return Ok(Response::builder()
                .status(501)
                .body(text_body("Depth: Infinity not implemented"))?)    
        }

        let status = hyper::StatusCode::from_u16(207)?;

        // A client may choose not to submit a request body.  An empty PROPFIND
        // request body MUST be treated as if it were an 'allprop' request.
        // @FIXME here we handle any invalid data as an allprop, an empty request is thus correctly
        // handled, but corrupted requests are also silently handled as allprop.
        let propfind = deserialize::<dav::PropFind<All>>(self.req).await.unwrap_or_else(|_| dav::PropFind::<All>::AllProp(None));
        tracing::debug!(recv=?propfind, "inferred propfind request");

        // Collect nodes as PROPFIND is not limited to the targeted node
        let mut nodes = vec![];
        if matches!(depth, dav::Depth::One | dav::Depth::Infinity) {
            nodes.extend(self.node.children(&self.user).await);
        }
        nodes.push(self.node);

        // Expand properties request
        let propname = match propfind {
            dav::PropFind::PropName => None,
            dav::PropFind::AllProp(None) => Some(dav::PropName(ALLPROP.to_vec())),
            dav::PropFind::AllProp(Some(dav::Include(mut include))) => {
                include.extend_from_slice(&ALLPROP);
                Some(dav::PropName(include))
            },
            dav::PropFind::Prop(inner) => Some(inner),
        };

        // Not Found is currently impossible considering the way we designed this function
        let not_found = vec![];
        serialize(status, Self::multistatus(&self.user, nodes, not_found, propname))
    }

    // --- Internal functions ---
    /// Utility function to build a multistatus response from 
    /// a list of DavNodes
    fn multistatus(user: &ArcUser, nodes: Vec<Box<dyn DavNode>>, not_found: Vec<dav::Href>, props: Option<dav::PropName<All>>) -> dav::Multistatus<All> {
        // Collect properties on existing objects
        let mut responses: Vec<dav::Response<All>> = match props {
            Some(props) => nodes.into_iter().map(|n| n.response_props(user, props.clone())).collect(),
            None => nodes.into_iter().map(|n| n.response_propname(user)).collect(),
        };

        // Register not found objects only if relevant
        if !not_found.is_empty() {
            responses.push(dav::Response {
                status_or_propstat: dav::StatusOrPropstat::Status(not_found, dav::Status(hyper::StatusCode::NOT_FOUND)),
                error: None,
                location: None,
                responsedescription: None,
            });
        }

        // Build response
        dav::Multistatus::<All> {
            responses,
            responsedescription: None,
        }
    }
}

#[derive(Clone)]
struct RootNode {}
impl DavNode for RootNode {
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>> {
        if path.len() == 0 {
            let this = self.clone();
            return async { Ok(Box::new(this) as Box<dyn DavNode>) }.boxed();
        }

        if path[0] == user.username {
            let child = Box::new(HomeNode {});
            return child.fetch(user, &path[1..]);
        }

        async { Err(anyhow!("Not found")) }.boxed()
    }

    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>> {
        async { vec![Box::new(HomeNode { }) as Box<dyn DavNode>] }.boxed()
    }

    fn path(&self, user: &ArcUser) -> String {
        "/".into()
    }

    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All> {
        dav::PropName(vec![
            dav::PropertyRequest::DisplayName,
            dav::PropertyRequest::ResourceType,
            dav::PropertyRequest::GetContentType,
            dav::PropertyRequest::Extension(all::PropertyRequest::Acl(acl::PropertyRequest::CurrentUserPrincipal)),
        ])
    }
    fn properties(&self, user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>> {
        prop.0.into_iter().map(|n| match n {
            dav::PropertyRequest::DisplayName => dav::AnyProperty::Value(dav::Property::DisplayName("DAV Root".to_string())),
            dav::PropertyRequest::ResourceType => dav::AnyProperty::Value(dav::Property::ResourceType(vec![
                dav::ResourceType::Collection,
            ])),
            dav::PropertyRequest::GetContentType => dav::AnyProperty::Value(dav::Property::GetContentType("httpd/unix-directory".into())),
            dav::PropertyRequest::Extension(all::PropertyRequest::Acl(acl::PropertyRequest::CurrentUserPrincipal)) =>
                dav::AnyProperty::Value(dav::Property::Extension(all::Property::Acl(acl::Property::CurrentUserPrincipal(acl::User::Authenticated(dav::Href(HomeNode{}.path(user))))))),
            v => dav::AnyProperty::Request(v),
        }).collect()
    }
}

#[derive(Clone)]
struct HomeNode {}
impl DavNode for HomeNode {
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>> {
        if path.len() == 0 {
            let node = Box::new(self.clone()) as Box<dyn DavNode>;
            return async { Ok(node) }.boxed()
        }

        if path[0] == "calendar" {
            return async {
                let child = Box::new(CalendarListNode::new(user).await?);
                child.fetch(user, &path[1..]).await
            }.boxed();
        }

        async { Err(anyhow!("Not found")) }.boxed()
    }

    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>> {
        async { 
            CalendarListNode::new(user).await
                .map(|c| vec![Box::new(c) as Box<dyn DavNode>])
                .unwrap_or(vec![]) 
        }.boxed()
    }

    fn path(&self, user: &ArcUser) -> String {
        format!("/{}/", user.username)
    }

    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All> {
        dav::PropName(vec![
            dav::PropertyRequest::DisplayName,
            dav::PropertyRequest::ResourceType,
            dav::PropertyRequest::GetContentType,
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::CalendarHomeSet)),
        ])
    }
    fn properties(&self, user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>> {
        prop.0.into_iter().map(|n| match n {
            dav::PropertyRequest::DisplayName => dav::AnyProperty::Value(dav::Property::DisplayName(format!("{} home", user.username))),
            dav::PropertyRequest::ResourceType => dav::AnyProperty::Value(dav::Property::ResourceType(vec![
                dav::ResourceType::Collection,
                dav::ResourceType::Extension(all::ResourceType::Acl(acl::ResourceType::Principal)),
            ])),
            dav::PropertyRequest::GetContentType => dav::AnyProperty::Value(dav::Property::GetContentType("httpd/unix-directory".into())),
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::CalendarHomeSet)) => 
                dav::AnyProperty::Value(dav::Property::Extension(all::Property::Cal(cal::Property::CalendarHomeSet(dav::Href(/*CalendarListNode{}.path(user)*/ todo!()))))),
            v => dav::AnyProperty::Request(v),
        }).collect()
    }
}

#[derive(Clone)]
struct CalendarListNode {
    list: Vec<String>,
}
impl CalendarListNode {
    async fn new(user: &ArcUser) -> Result<Self> {
        let list = user.calendars.list(user).await?;
        Ok(Self { list })
    }
}
impl DavNode for CalendarListNode {
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>> {
        if path.len() == 0 {
            let node = Box::new(self.clone()) as Box<dyn DavNode>;
            return async { Ok(node) }.boxed();
        }

        async {
            let cal = user.calendars.open(user, path[0]).await?.ok_or(anyhow!("Not found"))?;
            let child = Box::new(CalendarNode { 
                col: cal,
                calname: path[0].to_string()
            });
            child.fetch(user, &path[1..]).await
        }.boxed()
    }

    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>> {
        let list = self.list.clone();
        async move {
            //@FIXME maybe we want to be lazy here?!
            futures::stream::iter(list.iter())
                .filter_map(|name| async move {
                    user.calendars.open(user, name).await
                        .ok()
                        .flatten()
                        .map(|v| (name, v))
                })
                .map(|(name, cal)| Box::new(CalendarNode { 
                    col: cal,
                    calname: name.to_string(),
                }) as Box<dyn DavNode>)
                .collect::<Vec<Box<dyn DavNode>>>()
                .await
        }.boxed()
    }

    fn path(&self, user: &ArcUser) -> String {
        format!("/{}/calendar/", user.username)
    }

    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All> {
        dav::PropName(vec![
            dav::PropertyRequest::DisplayName,
            dav::PropertyRequest::ResourceType,
            dav::PropertyRequest::GetContentType,
        ])
    }
    fn properties(&self, user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>> {
        prop.0.into_iter().map(|n| match n {
            dav::PropertyRequest::DisplayName => dav::AnyProperty::Value(dav::Property::DisplayName(format!("{} calendars", user.username))),
            dav::PropertyRequest::ResourceType => dav::AnyProperty::Value(dav::Property::ResourceType(vec![dav::ResourceType::Collection])),
            dav::PropertyRequest::GetContentType => dav::AnyProperty::Value(dav::Property::GetContentType("httpd/unix-directory".into())),
            v => dav::AnyProperty::Request(v),
        }).collect()
    }
}

#[derive(Clone)]
struct CalendarNode {
    col: Arc<Calendar>,
    calname: String,
}
impl DavNode for CalendarNode {
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>> {
        if path.len() == 0 {
            let node = Box::new(self.clone()) as Box<dyn DavNode>;
            return async { Ok(node) }.boxed()
        }

        let col = self.col.clone();
        let calname = self.calname.clone();
        async move {
            if let Some(blob_id) = col.dag().await.idx_by_filename.get(path[0]) {
                let child = Box::new(EventNode {
                    col: col.clone(),
                    calname,
                    filename: path[0].to_string(),
                    blob_id: *blob_id,
                });
                return child.fetch(user, &path[1..]).await
            }

            Err(anyhow!("Not found"))
        }.boxed()
    }

    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>> {
        let col = self.col.clone();
        let calname = self.calname.clone();

        async move {
            col.dag().await.idx_by_filename.iter().map(|(filename, blob_id)| {
                Box::new(EventNode { 
                    col: col.clone(),
                    calname: calname.clone(),
                    filename: filename.to_string(),
                    blob_id: *blob_id,
                }) as Box<dyn DavNode>
            }).collect()
        }.boxed()
    }

    fn path(&self, user: &ArcUser) -> String {
        format!("/{}/calendar/{}/", user.username, self.calname)
    }

    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All> {
        dav::PropName(vec![
            dav::PropertyRequest::DisplayName,
            dav::PropertyRequest::ResourceType,
            dav::PropertyRequest::GetContentType,
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::SupportedCalendarComponentSet)),
        ])
    }
    fn properties(&self, _user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>> {
        prop.0.into_iter().map(|n| match n {
            dav::PropertyRequest::DisplayName =>  dav::AnyProperty::Value(dav::Property::DisplayName(format!("{} calendar", self.calname))),
            dav::PropertyRequest::ResourceType =>  dav::AnyProperty::Value(dav::Property::ResourceType(vec![
                dav::ResourceType::Collection,
                dav::ResourceType::Extension(all::ResourceType::Cal(cal::ResourceType::Calendar)),
            ])),
            //dav::PropertyRequest::GetContentType => dav::AnyProperty::Value(dav::Property::GetContentType("httpd/unix-directory".into())),
            //@FIXME seems wrong but seems to be what Thunderbird expects...
            dav::PropertyRequest::GetContentType => dav::AnyProperty::Value(dav::Property::GetContentType("text/calendar".into())),
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::SupportedCalendarComponentSet))
                => dav::AnyProperty::Value(dav::Property::Extension(all::Property::Cal(cal::Property::SupportedCalendarComponentSet(vec![
                    cal::CompSupport(cal::Component::VEvent),
                ])))),
            v => dav::AnyProperty::Request(v),
        }).collect()
    }
}

const FAKE_ICS: &str = r#"BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Example Corp.//CalDAV Client//EN
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:US/Eastern
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20240406T001102Z
DTSTART;TZID=US/Eastern:20240406T100000
DURATION:PT1H
SUMMARY:Event #1
Description:Go Steelers!
UID:74855313FA803DA593CD579A@example.com
END:VEVENT
END:VCALENDAR"#;

#[derive(Clone)]
struct EventNode {
    col: Arc<Calendar>,
    calname: String,
    filename: String,
    blob_id: BlobId,
}
impl DavNode for EventNode {
    fn fetch<'a>(&self, user: &'a ArcUser, path: &'a [&str]) -> BoxFuture<'a, Result<Box<dyn DavNode>>> {
        if path.len() == 0 {
            let node = Box::new(self.clone()) as Box<dyn DavNode>;
            return async { Ok(node) }.boxed()
        }

        async { Err(anyhow!("Not found")) }.boxed()
    }

    fn children<'a>(&self, user: &'a ArcUser) -> BoxFuture<'a, Vec<Box<dyn DavNode>>> {
        async { vec![] }.boxed()
    }

    fn path(&self, user: &ArcUser) -> String {
        format!("/{}/calendar/{}/{}", user.username, self.calname, self.filename)
    }

    fn supported_properties(&self, user: &ArcUser) -> dav::PropName<All> {
        dav::PropName(vec![
            dav::PropertyRequest::DisplayName,
            dav::PropertyRequest::ResourceType,
            dav::PropertyRequest::GetEtag,
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::CalendarData(cal::CalendarDataRequest::default()))),
        ])
    }
    fn properties(&self, _user: &ArcUser, prop: dav::PropName<All>) -> Vec<dav::AnyProperty<All>> {
        prop.0.into_iter().map(|n| match n {
            dav::PropertyRequest::DisplayName => dav::AnyProperty::Value(dav::Property::DisplayName(format!("{} event", self.filename))),
            dav::PropertyRequest::ResourceType => dav::AnyProperty::Value(dav::Property::ResourceType(vec![])),
            dav::PropertyRequest::GetContentType =>  dav::AnyProperty::Value(dav::Property::GetContentType("text/calendar".into())),
            dav::PropertyRequest::GetEtag => dav::AnyProperty::Value(dav::Property::GetEtag("\"abcdefg\"".into())),
            dav::PropertyRequest::Extension(all::PropertyRequest::Cal(cal::PropertyRequest::CalendarData(req))) =>
                dav::AnyProperty::Value(dav::Property::Extension(all::Property::Cal(cal::Property::CalendarData(cal::CalendarDataPayload { 
                    mime: None, 
                    payload: FAKE_ICS.into() 
                })))),
            v => dav::AnyProperty::Request(v),
        }).collect()
    }
}



// <D:propfind xmlns:D='DAV:' xmlns:A='http://apple.com/ns/ical/'>
//   <D:prop>
//     <D:getcontenttype/>
//     <D:resourcetype/>
//     <D:displayname/>
//     <A:calendar-color/>
//   </D:prop>
// </D:propfind>


// <D:propfind xmlns:D='DAV:' xmlns:A='http://apple.com/ns/ical/' xmlns:C='urn:ietf:params:xml:ns:caldav'>
//   <D:prop>
//     <D:resourcetype/>
//     <D:owner/>
//     <D:displayname/>
//     <D:current-user-principal/>
//     <D:current-user-privilege-set/>
//     <A:calendar-color/>
//     <C:calendar-home-set/>
//   </D:prop>
// </D:propfind>

// <D:propfind xmlns:D='DAV:' xmlns:C='urn:ietf:params:xml:ns:caldav' xmlns:CS='http://calendarserver.org/ns/'>
//   <D:prop>
//     <D:resourcetype/>
//     <D:owner/>
//     <D:current-user-principal/>
//     <D:current-user-privilege-set/>
//     <D:supported-report-set/>
//     <C:supported-calendar-component-set/>
//     <CS:getctag/>
//   </D:prop>
// </D:propfind>

// <C:calendar-multiget xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
//   <D:prop>
//     <D:getetag/>
//     <C:calendar-data/>
//    </D:prop>
//    <D:href>/alice/calendar/personal/something.ics</D:href>
//  </C:calendar-multiget>