use std::str::FromStr;

use fltk::{
	app,
	button::Button, 
	enums::CallbackTrigger,
	frame::Frame,
	input::*,
	prelude::*, 
	window::Window
};
use structopt::StructOpt;
use tokio::runtime::Runtime;

use quic_demo::{
	client_proxy::*,
	prelude::*,
	protocol::PeerId,
};

#[derive (Debug, StructOpt)]
struct Opt {
	#[structopt (long)]
	window_title: Option <String>,
	#[structopt (long)]
	relay_addr: Option <String>,
	#[structopt (long)]
	client_id: Option <PeerId>,
	#[structopt (long)]
	cert_url: Option <String>,
}

#[derive (Clone, Copy)]
enum Message {
	OpenPort (usize),
	ClosePort (usize),
}

struct GuiClient <'a> {
	rt: &'a Runtime,
	frame_status: Frame,
	forwarding_instances: Vec <Option <ForwardingInstance>>,
	gui_ports: Vec <GuiPort>,
}

impl GuiClient <'_> {
	pub fn open_port (
		&mut self, 
		connection_p2_p3: quinn::Connection, 
		port_idx: usize,
	) -> anyhow::Result <()>
	{
		let params = self.gui_ports [port_idx].get_params ()?;
		
		let _guard = self.rt.enter ();
		self.forwarding_instances [port_idx].replace (ForwardingInstance::new (
			connection_p2_p3,
			params,
		));
		
		self.gui_ports [port_idx].set_forwarding (true);
		self.sync_status ();
		
		Ok (())
	}
	
	pub fn close_port (&mut self, port_idx: usize) -> anyhow::Result <()> {
		if let Some (old_instance) = self.forwarding_instances [port_idx].take () {
			self.rt.block_on (async {
				old_instance.close ()
				.await
				.context ("closing ForwardingInstance")?;
				
				Ok::<_, anyhow::Error> (())
			})?;
		}
		
		self.gui_ports [port_idx].set_forwarding (false);
		self.sync_status ();
		
		Ok (())
	}
	
	fn open_ports (&self) -> usize {
		self.forwarding_instances.iter ()
		.map (|x| if x.is_some () { 1 } else { 0 })
		.sum ()
	}
	
	fn sync_status (&mut self) {
		let open_ports = self.open_ports ();
		
		self.frame_status.set_label (&format! ("Forwarding {} ports", open_ports));
	}
}

fn main () -> anyhow::Result <()> {
	tracing_subscriber::fmt::init ();
	let rt = Runtime::new ()?;
	
	let opt = Opt::from_args ();
	
	let (fltk_tx, fltk_rx) = app::channel::<Message> ();
	
	let app = app::App::default ();
	let window_title = opt.window_title.clone ().unwrap_or_else (|| "PTTH client proxy".to_string ());
	let mut wind = Window::new (100, 100, 800, 600, None)
	.with_label (&window_title);
	
	let margin = 10;
	let h = 30;
	let mut x = margin;
	let mut y = margin;
	
	let frame_status = Frame::new (x, y, 800 - 20, h, "Forwarding 0 ports");
	
	y += h + margin;
	x = margin;
	
	{
		let w = 80;
		Frame::new (x, y, w, h, "Local port");
		x += w + margin;
		
		let w = 120;
		Frame::new (x, y, w, h, "Server ID");
		x += w + margin;
		
		let w = 80;
		Frame::new (x, y, w, h, "Server port");
		// x += w + margin;
	}
	
	y += h + margin;
	x = margin;
	
	let gui_port_0 = GuiPort::new (fltk_tx, &mut x, y, 0);
	y += h + margin;
	x = margin;
	
	let gui_port_1 = GuiPort::new (fltk_tx, &mut x, y, 1);
	y += h + margin;
	x = margin;
	
	let gui_port_2 = GuiPort::new (fltk_tx, &mut x, y, 2);
	// y += h + margin;
	// x = margin;
	
	let gui_ports = vec! [
		gui_port_0,
		gui_port_1,
		gui_port_2,
	];
	
	let forwarding_instances = vec! [
		None,
		None,
		None,
	];
	
	let mut gui_client = GuiClient {
		rt: &rt,
		frame_status,
		forwarding_instances,
		gui_ports,
	};
	
	// y += h + margin;
	
	wind.end ();
	wind.show ();
	
	let connection_p2_p3 = rt.block_on (async move {
		let server_cert = match opt.cert_url.as_ref () {
			Some (url) => reqwest::get (url).await?.bytes ().await?,
			None => tokio::fs::read ("ptth_quic_output/quic_server.crt").await?.into (),
		};
		
		let relay_addr = opt.relay_addr
		.unwrap_or_else (|| String::from ("127.0.0.1:30380"))
		.parse ()
		.context ("relay_addr should be like 127.0.0.1:30380")?;
		let endpoint = make_client_endpoint ("0.0.0.0:0".parse ()?, &[&server_cert])?;
		
		trace! ("Connecting to relay server");
		
		let client_id = opt.client_id.unwrap_or_else (|| "bogus_client".to_string ());
		
		let quinn::NewConnection {
			connection,
			..
		} = protocol::p2_connect_to_p3 (&endpoint, &relay_addr, &client_id).await
		.context ("P2 can't connect to P3")?;
		
		Ok::<_, anyhow::Error> (connection)
	})?;
	
	while app.wait () {
		match fltk_rx.recv () {
			Some (Message::OpenPort (port_idx)) => {
				match gui_client.open_port (connection_p2_p3.clone (), port_idx) {
					Err (e) => error! ("{:?}", e),
					_ => (),
				};
			},
			Some (Message::ClosePort (port_idx)) => {
				gui_client.close_port (port_idx)?;
			},
			None => (),
		}
	}
	
	Ok (())
}

fn set_active <W: WidgetExt> (w: &mut W, b: bool) {
	if b {
		w.activate ();
	}
	else {
		w.deactivate ();
	}
}

struct GuiPort {
	input_client_port: Input,
	input_server_id: Input,
	input_server_port: Input,
	but_open: Button,
	but_close: Button,
}

impl GuiPort {
	fn new (fltk_tx: fltk::app::Sender <Message>, x: &mut i32, y: i32, port_idx: usize) -> Self {
		let margin = 10;
		let h = 30;
		
		let w = 80;
		let mut input_client_port = Input::new (*x, y, w, h, "");
		*x += w + margin;
		
		let w = 120;
		let mut input_server_id = Input::new (*x, y, w, h, "");
		*x += w + margin;
		
		let w = 80;
		let mut input_server_port = Input::new (*x, y, w, h, "");
		*x += w + margin;
		
		let w = 80;
		let mut but_open = Button::new (*x, y, w, h, "Open");
		*x += w + margin;
		
		let w = 80;
		let mut but_close = Button::new (*x, y, w, h, "Close");
		// *x += w + margin;
		
		input_client_port.set_value ("5901");
		input_server_id.set_value ("bogus_server");
		input_server_port.set_value ("5900");
		
		but_open.set_trigger (CallbackTrigger::Changed);
		but_open.emit (fltk_tx, Message::OpenPort (port_idx));
		but_close.set_trigger (CallbackTrigger::Changed);
		but_close.emit (fltk_tx, Message::ClosePort (port_idx));
		
		set_active (&mut but_open, true);
		set_active (&mut but_close, false);
		
		Self {
			input_client_port,
			input_server_id,
			input_server_port,
			but_open,
			but_close,
		}
	}
	
	fn get_params (&self) -> anyhow::Result <ForwardingParams>
	{
		let client_tcp_port = u16::from_str (&self.input_client_port.value ())?;
		let server_id = self.input_server_id.value ();
		let server_tcp_port = u16::from_str (&self.input_server_port.value ())?;
		
		Ok (ForwardingParams {
			client_tcp_port,
			server_id,
			server_tcp_port,
		})
	}
	
	fn set_forwarding (&mut self, x: bool) {
		set_active (&mut self.input_client_port, !x);
		set_active (&mut self.input_server_id, !x);
		set_active (&mut self.input_server_port, !x);
		set_active (&mut self.but_open, !x);
		set_active (&mut self.but_close, x);
		
		self.but_open.set (x);
		self.but_close.set (!x);
	}
}