#![feature(try_blocks)]

mod blockchain;
mod indexer;
mod response;

use argp::FromArgs;
use log::error;
use serde::{Deserialize, Serialize};
use sp_core::{
	Pair as _,
	crypto::{Ss58AddressFormat, Ss58Codec, set_default_ss58_version},
};
use std::{
	collections::{HashMap, hash_map::Entry},
	io::{BufRead, Read},
	str::FromStr,
	sync::Arc,
};
use subxt::{ext::sp_core::ed25519::Pair, utils::AccountId32};
use tiny_http::{Response, ResponseBox, Server};
use tokio::sync::mpsc::{Sender, channel};
use typed_sled::Tree;

/// Game to Blockchain
const TREE_DEBT_G2B: &'static str = "debt_g2b";

/// Blob
#[derive(FromArgs)]
struct Opt {
	/// path to the database
	#[argp(option, short = 'd')]
	db: String,

	/// Duniter indexer URL
	#[argp(
		option,
		short = 'i',
		default = "String::from(\"https://gt-squid.axiom-team.fr/v1/graphql\")"
	)]
	indexer: String,

	/// secret key is legacy (two passwords on the two first lines)
	#[argp(switch, short = 'l')]
	legacy: bool,

	/// path to the file containing the secret key in Substrate format
	#[argp(option, short = 's')]
	secret_key: String,

	/// duniter node URL (default: ws://127.0.0.1:9944)
	#[argp(option, short = 'u', default = "String::from(\"ws://127.0.0.1:9944\")")]
	url: String,
}

#[derive(Deserialize, Serialize)]
struct DebtG2B {
	address: AccountId32,
	amount: u64,
}

#[tokio::main]
async fn main() {
	let opt: Opt = argp::parse_args_or_exit(argp::DEFAULT);

	let mut sk_file = std::fs::File::open(opt.secret_key).expect("Cannot open secret key file");
	let pair: Pair = if opt.legacy {
		let sk_reader = std::io::BufReader::new(sk_file);
		let mut sk_lines = sk_reader.lines();
		let psw1 = sk_lines
			.next()
			.expect("Secret key file should contain at least 2 lines for the 2 passwords")
			.unwrap();
		let psw2 = sk_lines
			.next()
			.expect("Secret key file should contain at least 2 lines for the 2 passwords")
			.unwrap();
		let params = scrypt::Params::new(12, 16, 1, 32).unwrap();
		let mut seed = [0u8; 32];
		scrypt::scrypt(
			psw2.trim().as_bytes(),
			psw1.trim().as_bytes(),
			&params,
			&mut seed,
		)
		.unwrap();
		Pair::from_seed(&seed)
	} else {
		let mut sk_content = String::new();
		sk_file
			.read_to_string(&mut sk_content)
			.expect("Cannot read secret key file");
		Pair::from_string(sk_content.trim(), None).expect("Cannot decode secret key")
	};

	set_default_ss58_version(Ss58AddressFormat::custom(4450));
	let pk: AccountId32 = pair.public().into();
	let pk: sp_core::crypto::AccountId32 = pk.0.into();
	let pk_str = dbg!(pk.to_ss58check_with_version(Ss58AddressFormat::custom(4450)));

	simplelog::SimpleLogger::init(log::LevelFilter::Debug, simplelog::Config::default()).unwrap();

	let db = typed_sled::open(opt.db).expect("Cannot open database");
	let tree_debt_g2b = Tree::<DebtG2B, ()>::open(&db, TREE_DEBT_G2B);

	let client = reqwest::Client::new();

	let (bc_send, bc_recv) = channel(128);

	tokio::spawn(blockchain::run(
		opt.url,
		pair,
		bc_recv,
		tree_debt_g2b.clone(),
	));

	let server = Server::http("127.0.0.1:30061").expect("Cannot start server");

	struct Locals {
		tree_debt_g2b: Tree<DebtG2B, ()>,
		bc_send: Sender<DebtG2B>,
		indexer: String,
		pk_str: String,
	}

	tokio::task_local! {
		static LOCALS: Arc<Locals>;
	};

	LOCALS.scope(
		Arc::new(Locals {
			tree_debt_g2b,
			bc_send,
			indexer: opt.indexer,
			pk_str: pk_str,
		}),
		async move {
			for request in server.incoming_requests() {
				let locals = LOCALS.get();
				let client = client.clone();
				tokio::spawn(async move {
					let url = request.url();

					let mut url_items = url.split('/').filter(|item| !item.is_empty());

					let resp: Option<ResponseBox> = try {
						match url_items.next() {
							Some("send") => {
								let address = AccountId32::from_str(url_items.next()?).ok()?;
								let amount = url_items.next()?.parse::<u64>().ok()?;

								let debt = DebtG2B { address, amount };
								locals.tree_debt_g2b.insert(&debt, &()).ok()?;
								locals.bc_send.send(debt).await.ok()?;

								Response::empty(200).boxed()
							}
							Some("recv") => {
								let block_number = url_items.next()?.parse::<u64>().ok()?;
								let req = client.post(&locals.indexer).body(dbg!(format!(
r#"[{{"query":"{{transfer(where:{{blockNumber:{{_gt:{}}},to:{{id:{{_eq:\"{}\"}}}}}}){{amount comment{{remark}}}}block(limit:1,orderBy:{{height:DESC}}){{height hash}}}}"}}]"#,
block_number, locals.pk_str))).build().unwrap();
								let Ok(res) = client.execute(req).await else {
									request.respond(Response::empty(500)).ok();
									error!("Error from indexer");
									return;
								};
								let Ok(res) = res.json::<indexer::Response>().await else {
									request.respond(Response::empty(500)).ok();
									error!("Bad JSON from indexer");
									return;
								};
								let Some(data) = res.first() else {
									request.respond(Response::empty(500)).ok();
									error!("No data from indexer");
									return;
								};
								let Some(block) = data.data.block.first() else {
									request.respond(Response::empty(500)).ok();
									error!("No block from indexer");
									return;
								};
								let mut debts = HashMap::<String, u64>::new();
								for transfer in data.data.transfer.iter() {
									if let Some(comment) = &transfer.comment {
										match debts.entry(comment.remark.clone()) {
											Entry::Occupied(mut debt) => {
												*debt.get_mut() = debt.get().saturating_add(transfer.amount);
											}
											Entry::Vacant(debt) => {
												debt.insert(transfer.amount);
											}
										}
									}
								}
								Response::from_string(serde_json::to_string(&response::Response {
									block: block.height,
									debts: debts.into_iter().map(|(name, amount)| response::Debt {
										name,
										amount,
									}).collect(),
								}).unwrap()).with_status_code(200).boxed()
							}
							_ => None?,
						}
					};
					if let Some(resp) = resp {
						request.respond(resp).ok();
					} else {
						request.respond(Response::empty(400)).ok();
					}
				});
			}
		},
	).await;
}