#![feature(split_inclusive)]

#![allow(dead_code)]

#[macro_use] extern crate log;

use chain::{
    Chain,
};
use warp::{
    Filter,
    Buf,
    reply::Response,
};
use hyper::Body;
use std::{
    sync::Arc,
    fmt,
    error,
    net::{
	SocketAddr,
	IpAddr,
    },
};
use tokio::{
    sync::{
	RwLock,
	mpsc,
	Notify,
    },
    stream::{Stream,StreamExt,},
};
use serde::{
    Serialize,
    Deserialize
};
use futures::{
    future::{
	FutureExt,
	BoxFuture,
	join_all,
    },
};
use lazy_static::lazy_static;
use cfg_if::cfg_if;

macro_rules! if_debug {
    ($($tt:tt)*) => {
	cfg_if::cfg_if!{
	    if #[cfg(debug_assertions)] {
		$($tt)*
	    }
	}
    }
}

macro_rules! status {
    ($code:expr) => {
	::warp::http::status::StatusCode::from_u16($code).unwrap()
    };
}

mod ext;
use ext::*;
mod util;
mod sanitise;
mod bytes;
mod chunking;
#[cfg(feature="api")]
mod api;
#[cfg(target_family="unix")]
mod signals;
mod config;
mod state;
use state::State;
mod save;
mod forwarded_list;
use forwarded_list::XForwardedFor;

mod feed;
mod gen;
mod sentance;

const DEFAULT_LOG_LEVEL: &str = "warn";

fn init_log()
{
    let level = match std::env::var_os("RUST_LOG") {
	None => {
	    std::env::set_var("RUST_LOG", DEFAULT_LOG_LEVEL);
	    std::borrow::Cow::Borrowed(std::ffi::OsStr::new(DEFAULT_LOG_LEVEL))
	},
	Some(w) => std::borrow::Cow::Owned(w),
    };
    pretty_env_logger::init();
    trace!("Initialising `genmarkov` ({}) v{} with log level {:?}.\n\tMade by {} with <3.\n\tLicensed with GPL v3 or later",
	   std::env::args().next().unwrap(),
	   env!("CARGO_PKG_VERSION"),
	   level,
	   env!("CARGO_PKG_AUTHORS"));
}

#[tokio::main]
async fn main() {
    init_log();
    
    let config = match config::load().await {
	Some(v) => v,
	_ => {
	    let cfg = config::Config::default();
	    #[cfg(debug_assertions)]
	    {
		if let Err(err) = cfg.save(config::DEFAULT_FILE_LOCATION).await {
		    error!("Failed to create default config file: {}", err);
		}
	    }
	    cfg
	},
    };	
    trace!("Using config {:?}", config);
    
    let chain = Arc::new(RwLock::new(match save::load(&config.file).await {
	Ok(chain) => {
	    info!("Loaded chain from {:?}", config.file);
	    chain
	},
	Err(e) => {
	    warn!("Failed to load chain, creating new");
	    trace!("Error: {}", e);
	    Chain::new()
	},
    }));
    {
	let mut tasks = Vec::<BoxFuture<'static, ()>>::new();
	let (state, chain) = {
	    let save_when = Arc::new(Notify::new());
	    
	    let state = State::new(config,
				   Arc::clone(&chain),
				   Arc::clone(&save_when));
	    let state2 = state.clone();
	    let saver = tokio::spawn(save::host(state.clone()));
	    let chain = warp::any().map(move || state.clone());

	    tasks.push(saver.map(|res| res.expect("Saver panicked")).boxed());
	    (state2, chain)
	};

	let client_ip = if state.config().trust_x_forwarded_for {
	    warp::header("x-forwarded-for")
		.map(|ip: XForwardedFor| ip)
		.and_then(|x: XForwardedFor| async move { x.into_first().ok_or_else(|| warp::reject::not_found()) })
		.or(warp::filters::addr::remote()
		    .and_then(|x: Option<SocketAddr>| async move { x.map(|x| x.ip()).ok_or_else(|| warp::reject::not_found()) }))
		.unify().boxed()
	} else {
	    warp::filters::addr::remote().and_then(|x: Option<SocketAddr>| async move {x.map(|x| x.ip()).ok_or_else(|| warp::reject::not_found())}).boxed()
	};
	
	let push = warp::put()
	    .and(warp::path("put"))
	    .and(chain.clone())
	    .and(client_ip.clone())
	    .and(warp::body::content_length_limit(state.config().max_content_length))
	    .and(warp::body::stream())
	    .and_then(|state: State, host: IpAddr, buf| {
		async move {
		    feed::full(&host, state, buf).await
			.map(|_| warp::reply::with_status(warp::reply(), status!(201)))
			.map_err(|_| warp::reject::not_found()) //(warp::reject::custom) //TODO: Recover rejection filter down below for custom error return
		}
	    })
	    .with(warp::log("markov::put"));

	
	cfg_if!{
	    if #[cfg(feature="api")] {
		let api = {
		    let single = {
			let msz = state.config().max_gen_size;
			warp::post()
			    .and(warp::path("single"))
			    .and(client_ip.clone())
			    .and(warp::path::param()
				 .map(move |sz: usize| {
				     if sz == 0 || (2..=msz).contains(&sz) {
					 Some(sz)
				     } else {
					 None
				     }
				 })
				 .or(warp::any().map(|| None))
				 .unify())
			    .and(warp::body::content_length_limit(state.config().max_content_length))
			    .and(warp::body::aggregate())
			    .and_then(api::single)
			    .with(warp::log("markov::api::single"))
		    };
		    warp::path("api")
			.and(single)
			.recover(api::error::rejection)
		};
	    }
	}
	
	
	let read = warp::get()
	    .and(chain.clone())
	    .and(client_ip.clone())
	    .and(warp::path::param().map(|opt: usize| Some(opt))
		 .or(warp::path::end().map(|| Option::<usize>::None)).unify())
	    .and_then(|state: State, host: IpAddr, num: Option<usize>| {
		async move {
		    let (tx, rx) = mpsc::channel(state.config().max_gen_size);
		    tokio::spawn(gen::body(state, num, tx));
		    Ok::<_, std::convert::Infallible>(Response::new(Body::wrap_stream(rx.filter_map(move |mut x| {
			if x.trim_in_place().len() != 0 {
			    info!("{} <- {:?}", host, x);
			    x.push('\n');
			    Some(Ok::<_, std::convert::Infallible>(x))
			} else {
			    None
			}
		    }))))
		}
	    })
	    .with(warp::log("markov::read"));
	
	let sentance = warp::get()
	    .and(warp::path("sentance")) //TODO: sanitise::Sentance::new_iter the body line
	    .and(chain.clone())
            .and(client_ip.clone())
	    .and(warp::path::param().map(|opt: usize| Some(opt))
		 .or(warp::path::end().map(|| Option::<usize>::None)).unify())
	    .and_then(|state: State, host: IpAddr, num: Option<usize>| {
		async move {
		    let (tx, rx) = mpsc::channel(state.config().max_gen_size);
		    tokio::spawn(sentance::body(state, num, tx));
		    Ok::<_, std::convert::Infallible>(Response::new(Body::wrap_stream(rx.filter_map(move |mut x| {
			if x.trim_in_place().len() != 0 {
			    info!("{} (sentance) <- {:?}", host, x);
			    x.push(' ');
			    Some(Ok::<_, std::convert::Infallible>(x))
			} else {
			    None
			}
		    }))))
		}
	    })
	    .with(warp::log("markov::read::sentance"));

	let read = warp::path("get").and(read.or(sentance));
	#[cfg(feature="api")]
	let read = read.or(api);

	#[cfg(target_family="unix")]
	tasks.push(tokio::spawn(signals::handle(state.clone())).map(|res| res.expect("Signal handler panicked")).boxed());

	require_send(async {
	    let server = {
		let s2 = AssertNotSend::new(state.clone()); //temp clone the Arcs here for shutdown if server fails to bind, assert they cannot remain cloned across an await boundary.
		match bind::try_serve(warp::serve(push
						  .or(read)),
				      state.config().bindpoint.clone(),
				      async move {
					  tokio::signal::ctrl_c().await.unwrap();
					  state.shutdown();
				      }) {
		    Ok((addr, server)) => {
			info!("Server bound on {:?}", addr);
			server
		    },
		    Err(err) => {
			error!("Failed to bind server: {}", err);
			s2.into_inner().shutdown();
			return;
		    },
		}
	    };
	    server.await;
	}).await;
	
	// Cleanup
	async move {
	    trace!("Cleanup");

	    join_all(tasks).await;
	}
    }.await;
    info!("Shut down gracefully")
}

mod bind;