// Gupax - GUI Uniting P2Pool And XMRig
//
// Copyright (c) 2022 hinto-janaiyo
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

//---------------------------------------------------------------------------------------------------- Imports
use serde_derive::{Serialize,Deserialize};
use tokio::task::JoinHandle;
use std::time::Duration;
use std::sync::{Arc,Mutex};
use std::os::unix::fs::OpenOptionsExt;
use std::io::{Read,Write};
//use crate::{Name::*,State};
use rand::{thread_rng, Rng};
use rand::distributions::Alphanumeric;
use anyhow::Error;
use arti_hyper::*;
use arti_client::{TorClient,TorClientConfig};
use tokio::io::{AsyncReadExt,AsyncWriteExt};
use tls_api::{TlsConnector, TlsConnectorBuilder};
use hyper::header::HeaderValue;
use hyper::{Client,Body,Request};
use hyper_tls::HttpsConnector;
use arti_hyper::*;
use log::*;
use crate::update::Name::*;
use std::path::PathBuf;

// use tls_api_native_tls::{TlsConnector,TlsConnectorBuilder};

//---------------------------------------------------------------------------------------------------- Constants
// Package naming schemes:
// gupax  | gupax-vX.X.X-(windows|macos|linux)-x64.(zip|tar.gz)
// p2pool | p2pool-vX.X.X-(windows|macos|linux)-x64.(zip|tar.gz)
// xmrig  | xmrig-X.X.X-(msvc-win64|macos-x64|linux-static-x64).(zip|tar.gz)
//
// Download link = PREFIX + Version (found at runtime) + SUFFIX + Version + EXT
// Example: https://github.com/hinto-janaiyo/gupax/releases/download/v0.0.1/gupax-v0.0.1-linux-standalone-x64
//
// Exceptions (there are always exceptions...):
//   - XMRig doesn't have a [v], so it is [xmrig-6.18.0-...]
//   - XMRig separates the hash and signature
//   - P2Pool hashes are in UPPERCASE
//   - Gupax will be downloaded as a standalone binary (no decompression/extraction needed)

const GUPAX_METADATA: &'static str = "https://api.github.com/repos/hinto-janaiyo/gupax/releases/latest";
const P2POOL_METADATA: &'static str = "https://api.github.com/repos/SChernykh/p2pool/releases/latest";
const XMRIG_METADATA: &'static str = "https://api.github.com/repos/xmrig/xmrig/releases/latest";

const GUPAX_PREFIX: &'static str = "https://github.com/hinto-janaiyo/gupax/releases/download/";
const P2POOL_PREFIX: &'static str = "https://github.com/SChernykh/p2pool/releases/download/";
const XMRIG_PREFIX: &'static str = "https://github.com/xmrig/xmrig/releases/download/";

const GUPAX_SUFFIX: &'static str = "/gupax-";
const P2POOL_SUFFIX: &'static str = "/p2pool-";
const XMRIG_SUFFIX: &'static str = "/xmrig-";

const GUPAX_HASH: &'static str = "SHA256SUMS";
const P2POOL_HASH: &'static str = "sha256sums.txt.asc";
const XMRIG_HASH: &'static str = "SHA256SUMS";

#[cfg(target_os = "windows")]
const GUPAX_EXTENSION: &'static str = "-windows-standalone-x64.exe";
#[cfg(target_os = "windows")]
const P2POOL_EXTENSION: &'static str = "-windows-x64.zip";
#[cfg(target_os = "windows")]
const XMRIG_EXTENSION: &'static str = "-msvc-win64.zip";

#[cfg(target_os = "macos")]
const GUPAX_EXTENSION: &'static str = "-macos-standalone-x64";
#[cfg(target_os = "macos")]
const P2POOL_EXTENSION: &'static str = "-macos-x64.tar.gz";
#[cfg(target_os = "macos")]
const XMRIG_EXTENSION: &'static str = "-macos-x64.tar.gz";

#[cfg(target_os = "linux")]
const GUPAX_EXTENSION: &'static str = "-linux-standalone-x64";
#[cfg(target_os = "linux")]
const P2POOL_EXTENSION: &'static str = "-linux-x64.tar.gz";
#[cfg(target_os = "linux")]
const XMRIG_EXTENSION: &'static str = "-linux-static-x64.tar.gz";

// Some fake Curl/Wget user-agents because GitHub API requires one and a Tor browser
// user-agent might be fingerprintable without all the associated headers.
const FAKE_USER_AGENT: [&'static str; 50] = [
	"Wget/1.16.3",
	"Wget/1.17",
	"Wget/1.17.1",
	"Wget/1.18",
	"Wget/1.18",
	"Wget/1.19",
	"Wget/1.19.1",
	"Wget/1.19.2",
	"Wget/1.19.3",
	"Wget/1.19.4",
	"Wget/1.19.5",
	"Wget/1.20",
	"Wget/1.20.1",
	"Wget/1.20.2",
	"Wget/1.20.3",
	"Wget/1.21",
	"Wget/1.21.1",
	"Wget/1.21.2",
	"Wget/1.21.3",
	"curl/7.64.1",
	"curl/7.65.0",
	"curl/7.65.1",
	"curl/7.65.2",
	"curl/7.65.3",
	"curl/7.66.0",
	"curl/7.67.0",
	"curl/7.68.0",
	"curl/7.69.0",
	"curl/7.69.1",
	"curl/7.70.0",
	"curl/7.70.1",
	"curl/7.71.0",
	"curl/7.71.1",
	"curl/7.72.0",
	"curl/7.73.0",
	"curl/7.74.0",
	"curl/7.75.0",
	"curl/7.76.0",
	"curl/7.76.1",
	"curl/7.77.0",
	"curl/7.78.0",
	"curl/7.79.0",
	"curl/7.79.1",
	"curl/7.80.0",
	"curl/7.81.0",
	"curl/7.82.0",
	"curl/7.83.0",
	"curl/7.83.1",
	"curl/7.84.0",
	"curl/7.85.0",
];

const MSG_START: &'static str = "Starting update...";
const MSG_TMP: &'static str = "Creating temporary directory";
const MSG_PKG: &'static str = "Creating package list";
const MSG_TOR: &'static str = "Creating Tor+HTTPS client";
const MSG_HTTPS: &'static str = "Creating HTTPS client";
const MSG_METADATA: &'static str = "Fetching package metadata";
const MSG_ARCHIVE: &'static str = "Downloading packages";

// These two are sequential and not async so no need for a constant message.
// The package in question will be known at runtime, so that will be printed.
//const MSG_EXTRACT: &'static str = "Extracting packages";
//const MSG_UPGRADE: &'static str = "Upgrading packages";

//---------------------------------------------------------------------------------------------------- Update struct/impl
// Contains values needed during update
// Progress bar structure:
// 5%  | Create tmp directory
// 5%  | Create package list
// 10% | Create Tor/HTTPS client
// 20% | Download Metadata (x3)
// 30% | Download Archive (x3)
// 15% | Extract (x3)
// 15% | Upgrade (x3)

pub struct Update {
	path_gupax: String, // Full path to current gupax
	path_p2pool: String, // Full path to current p2pool
	path_xmrig: String, // Full path to current xmrig
	tmp_dir: String, // Full path to temporary directory
	updating: Arc<Mutex<bool>>, // Is an update in progress?
	prog: Arc<Mutex<u8>>, // Holds the 0-100% progress bar number
	msg: Arc<Mutex<String>>, // Message to display on [Gupax] tab while updating
	tor: bool, // Is Tor enabled or not?
}

impl Update {
	// Takes in current paths from [State]
	pub fn new(path_p2pool: &PathBuf, path_xmrig: &PathBuf, tor: bool) -> Self {
		Self {
			path_gupax: crate::get_exe().unwrap(),
			path_p2pool: path_p2pool.display().to_string(),
			path_xmrig: path_xmrig.display().to_string(),
			tmp_dir: "".to_string(),
			updating: Arc::new(Mutex::new(true)),
			prog: Arc::new(Mutex::new(0)),
			msg: Arc::new(Mutex::new("".to_string())),
			tor,
		}
	}

	// Get a temporary random folder
	// for package download contents
	// Will look like [/tmp/gupax_A1m98FN3fa/] on Unix
	pub fn get_tmp_dir() -> String {
		let rand_string: String = thread_rng()
			.sample_iter(&Alphanumeric)
			.take(10)
			.map(char::from)
			.collect();
		let tmp = std::env::temp_dir();
		let tmp = format!("{}{}{}{}", tmp.display(), "/gupax_", rand_string, "/");
		info!("Update | TMP directory ... {}", tmp);
		tmp
	}

	// The HTTPS client created when Tor is enabled:
	//     TLS implementation | tls-api -> native-tls
	//     Tor implementatoin | arti
	pub async fn get_tor_client() -> Result<ClientEnum, anyhow::Error> {
		info!("Update | Creating Tor+HTTPS client...");
		let tor = TorClient::create_bootstrapped(TorClientConfig::default()).await?;
		let tls = tls_api_native_tls::TlsConnector::builder()?.build()?;
	    let http = ArtiHttpConnector::new(tor, tls);
		let client = ClientEnum::Tor(Client::builder().build(http));
		info!("Update | Tor client ... OK");
		Ok(client)
	}

	// The HTTPS client created when Tor is disabled:
	//     TLS implementation | hyper-tls
	pub async fn get_client() -> Result<ClientEnum, anyhow::Error> {
		info!("Update | Creating HTTPS client...");
		let mut https = hyper_tls::HttpsConnector::new();
		https.https_only(true);
		let client = ClientEnum::Https(Client::builder().build(https));
		info!("Update | HTTPS client ... OK");
		Ok(client)
	}

	// Download process:
	// 0. setup tor, client, http, etc
	// 1. fill vector with all enums
	// 2. loop over vec, download metadata
	// 3. if current == version, remove from vec
	// 4. loop over vec, download links
	// 5. extract, upgrade

	#[tokio::main]
	pub async fn start(&mut self) -> Result<(), anyhow::Error> {
		// Set progress bar
		*self.msg.lock().unwrap() = MSG_START.to_string();
		*self.prog.lock().unwrap() = 0;

		// Get temporary directory
		*self.msg.lock().unwrap() = MSG_TMP.to_string();
		let tmp_dir = Self::get_tmp_dir();
		*self.prog.lock().unwrap() = 5;

		// Make Pkg vector
		*self.msg.lock().unwrap() = MSG_PKG.to_string();
		let vec = vec![
			Pkg::new(Gupax, &tmp_dir, self.prog.clone(), self.msg.clone()),
			Pkg::new(P2pool, &tmp_dir, self.prog.clone(), self.msg.clone()),
			Pkg::new(Xmrig, &tmp_dir, self.prog.clone(), self.msg.clone()),
		];
		let mut handles: Vec<JoinHandle<()>> = vec![];
		*self.prog.lock().unwrap() = 5;

		// Create Tor/HTTPS client
		let mut client: ClientEnum;
		if self.tor {
			*self.msg.lock().unwrap() = MSG_TOR.to_string();
			client = Self::get_tor_client().await?;
		} else {
			*self.msg.lock().unwrap() = MSG_HTTPS.to_string();
			client = Self::get_client().await?;
		}
		*self.prog.lock().unwrap() = 10;

		// loop for metadata
		for pkg in vec.iter() {
			info!("Update | Metadata | Starting ... {}", pkg.name);
			let name = pkg.name.clone();
			let version = Arc::clone(&pkg.version);
			let request = hyper::Request::builder()
				.method("GET")
				.uri(pkg.link_metadata)
				.header(hyper::header::USER_AGENT, hyper::header::HeaderValue::from_static("Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0"))
				.body(Body::empty())?;
			let client = client.clone();
			let handle: JoinHandle<()> = tokio::spawn(async move {
				Pkg::get_tor_response(name, version, client, request).await;
			});
			handles.push(handle);
		}
		for handle in handles {
			handle.await?;
		}
		info!("Update | Metadata ... OK\n");
		Ok(())

	//----------------------------------------------
	//
	//	// loop for download
	//	let mut handles: Vec<JoinHandle<()>> = vec![];
	//	for pkg in vec.iter() {
	//		let name = pkg.name.clone();
	//		let bytes = Arc::clone(&pkg.bytes);
	//		let version = pkg.version.lock().unwrap();
	//		let link;
	//		if pkg.name == Name::Xmrig {
	//			link = pkg.link_prefix.clone() + &version + &pkg.link_suffix_1 + &version[1..] + &pkg.link_suffix_2;
	//		} else {
	//			link = pkg.link_prefix.clone() + &version + &pkg.link_suffix_1 + &version + &pkg.link_suffix_2;
	//		}
	//		println!("download: {:#?} | {}", pkg.name, link);
	//		let request = Client::get(&client.clone(), &link);
	//		let handle: JoinHandle<()> = tokio::spawn(async move {
	//			get_bytes(request, bytes, name).await;
	//		});
	//		handles.push(handle);
	//	}
	//	for handle in handles {
	//		handle.await.unwrap();
	//	}
	//	println!("download ... OK\n");
	//
	//	// extract
	//	let TMP = num();
	//	std::fs::create_dir(&TMP).unwrap();
	//	for pkg in vec.iter() {
	//		let name = TMP.to_string() + &pkg.name.to_string();
	//		println!("extract: {:#?} | {}", pkg.name, name);
	//		if pkg.name == Name::Gupax {
	//			std::fs::OpenOptions::new().mode(0o700).create(true).write(true).open(&name);
	//			std::fs::write(name, pkg.bytes.lock().unwrap().as_ref()).unwrap();
	//		} else {
	//			std::fs::create_dir(&name).unwrap();
	//			tar::Archive::new(flate2::read::GzDecoder::new(pkg.bytes.lock().unwrap().as_ref())).unpack(name).unwrap();
	//		}
	//	}
	//	println!("extract ... OK");
	//
	//async fn get_bytes(request: RequestBuilder, bytes: Arc<Mutex<bytes::Bytes>>, name: Name) {
	//	*bytes.lock().unwrap() = request.send().await.unwrap().bytes().await.unwrap();
	//	println!("{} download ... OK", name);
	//}
	//
	//async fn func(request: RequestBuilder, version: Arc<Mutex<String>>, name: Name) {
	//	let response = request.send().await.unwrap().bytes().await.unwrap();
	//
	//	let mut bytes = flate2::read::GzDecoder::new(response.as_ref());
	//	let mut response = String::new();
	//	bytes.read_to_string(&mut response).unwrap();
	//
	//	let response: Version = serde_json::from_str(&response).unwrap();
	//	*version.lock().unwrap() = response.tag_name.clone();
	//	println!("{} {} ... OK", name, response.tag_name);
	//}
	}
}

// Wrapper type around Tor/HTTPS client
enum ClientEnum {
	Tor(Client<ArtiHttpConnector<tor_rtcompat::PreferredRuntime, tls_api_native_tls::TlsConnector>>),
	Https(Client<hyper_tls::HttpsConnector<hyper::client::HttpConnector>>),
}

//---------------------------------------------------------------------------------------------------- Pkg struct/impl
#[derive(Debug)]
pub struct Pkg {
	name: Name,
	link_metadata: &'static str,
	link_prefix: &'static str,
	link_suffix: &'static str,
	link_extension: &'static str,
	tmp_dir: String,
	update_prog: Arc<Mutex<u8>>,
	update_msg: Arc<Mutex<String>>,
	bytes: Arc<Mutex<bytes::Bytes>>,
	version: Arc<Mutex<String>>,
}

impl Pkg {
	pub fn new(name: Name, tmp_dir: &String, update_prog: Arc<Mutex<u8>>, update_msg: Arc<Mutex<String>>) -> Self {
		let link_metadata = match name {
			Gupax => GUPAX_METADATA,
			P2pool => P2POOL_METADATA,
			Xmrig => XMRIG_METADATA,
		};
		let link_prefix = match name {
			Gupax => GUPAX_PREFIX,
			P2pool => P2POOL_PREFIX,
			Xmrig => XMRIG_PREFIX,
		};
		let link_suffix = match name {
			Gupax => GUPAX_SUFFIX,
			P2pool => P2POOL_SUFFIX,
			Xmrig => XMRIG_SUFFIX,
		};
		let link_extension = match name {
			Gupax => GUPAX_EXTENSION,
			P2pool => P2POOL_EXTENSION,
			Xmrig => XMRIG_EXTENSION,
		};
		Self {
			name,
			link_metadata,
			link_prefix,
			link_suffix,
			link_extension,
			tmp_dir: tmp_dir.to_string(),
			update_prog,
			update_msg,
			bytes: Arc::new(Mutex::new(bytes::Bytes::new())),
			version: Arc::new(Mutex::new(String::new())),
		}
	}

	// Generate GET request based off input URI + fake user agent
	pub async fn get_request(self) -> Result<Request<Body>, anyhow::Error> {
		let user_agent = FAKE_USER_AGENT[thread_rng().gen_range(0..50)];
		let request = Request::builder()
			.method("GET")
			.uri(self.link_metadata)
			.header(hyper::header::USER_AGENT, HeaderValue::from_static(user_agent))
			.body(Body::empty())?;
		Ok(request)
	}

	// Get response using [Tor client] + [request]
	// and change the [version] under an Arc<Mutex>
	pub async fn get_tor_response(name: Name, version: Arc<Mutex<String>>, client: Client<ArtiHttpConnector<tor_rtcompat::PreferredRuntime, tls_api_native_tls::TlsConnector>>, request: Request<Body>) -> Result<(), Error> {
		let mut response = client.request(request).await?;
		let body = hyper::body::to_bytes(response.body_mut()).await?;
		let body: Version = serde_json::from_slice(&body)?;
		*version.lock().unwrap() = body.tag_name.clone();
		info!("Update | Metadata | {} {} ... OK", name, body.tag_name);
		Ok(())
	}

	// Same thing, but without Tor.
	pub async fn get_response(name: Name, version: Arc<Mutex<String>>, client: Client<hyper_tls::HttpsConnector<hyper::client::HttpConnector>>, request: Request<Body>) -> Result<(), Error> {
		let mut response = client.request(request).await?;
		let body = hyper::body::to_bytes(response.body_mut()).await?;
		let body: Version = serde_json::from_slice(&body)?;
		*version.lock().unwrap() = body.tag_name.clone();
		info!("Update | Metadata | {} {} ... OK", name, body.tag_name);
		Ok(())
	}
}

// This inherits the value of [tag_name] from GitHub's JSON API
#[derive(Debug, Serialize, Deserialize)]
struct Version {
	tag_name: String,
}

#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub enum Name {
	Gupax,
	P2pool,
	Xmrig,
}

impl std::fmt::Display for Name {
	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
		write!(f, "{:?}", self)
	}
}