/*
    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2023 metamuffin <metamuffin.org>
*/
use log::debug;
use markup::Render;
use rocket::{
    futures::FutureExt,
    http::{ContentType, Header, Status},
    response::{self, Responder},
    Request, Response,
};
use std::{
    collections::hash_map::DefaultHasher,
    future::Future,
    hash::{Hash, Hasher},
    io::Cursor,
    os::unix::prelude::MetadataExt,
    pin::Pin,
};
use tokio::{fs::File, io::AsyncRead};

pub mod account;
pub mod browser;
pub mod error;
pub mod home;
pub mod layout;
pub mod node;
pub mod player;
pub mod style;
pub mod assets;

pub struct HtmlTemplate<'a>(pub markup::DynRender<'a>);

impl<'r> Responder<'r, 'static> for HtmlTemplate<'_> {
    fn respond_to(self, _req: &'r Request<'_>) -> response::Result<'static> {
        let mut out = String::new();
        self.0.render(&mut out).unwrap();
        Response::build()
            .header(ContentType::HTML)
            .sized_body(out.as_bytes().len(), Cursor::new(out))
            .ok()
    }
}

pub struct Defer(Pin<Box<dyn Future<Output = String> + Send>>);

impl AsyncRead for Defer {
    fn poll_read(
        mut self: std::pin::Pin<&mut Self>,
        cx: &mut std::task::Context<'_>,
        buf: &mut tokio::io::ReadBuf<'_>,
    ) -> std::task::Poll<std::io::Result<()>> {
        match self.0.poll_unpin(cx) {
            std::task::Poll::Ready(r) => {
                buf.put_slice(r.as_bytes());
                std::task::Poll::Ready(Ok(()))
            }
            std::task::Poll::Pending => std::task::Poll::Pending,
        }
    }
}

pub struct CacheControlFile(File, String);
impl CacheControlFile {
    pub async fn new(f: File) -> Self {
        let meta = f.metadata().await.unwrap();
        let modified = meta.mtime();
        let mut h = DefaultHasher::new();
        modified.hash(&mut h);
        let tag = format!("{:0>16x}", h.finish());
        Self(f, tag)
    }
}
impl<'r> Responder<'r, 'static> for CacheControlFile {
    fn respond_to(self, req: &'r Request<'_>) -> response::Result<'static> {
        let Self(file, tag) = self;
        if req.headers().get_one("if-none-match") == Some(&tag) {
            debug!("file cache: not modified");
            Response::build()
                .status(Status::NotModified)
                .header(Header::new("cache-control", "private"))
                .ok()
        } else {
            debug!("file cache: transfer");
            Response::build()
                .status(Status::Ok)
                .header(Header::new("cache-control", "private"))
                .header(Header::new("etag", tag))
                .streamed_body(file)
                .ok()
        }
    }
}