var RPCConn = require("./rpcconn");

class StratumClient {
	constructor(ip, port, miner) {
		this.name = ip+":"+port;

		this.queue = [];
		this.working = false;
		this.nounceReady = false;
		this.difficultyReady = false;
		this.miner = miner;
		this.rpc = new RPCConn(ip, port);
	}

	log(...msgs) {
		process.stdout.write(this.name+": ");
		console.log.apply(console, msgs);
	}

	async startWork() {
		if (this.working)
			return;
		if (this.queue.length === 0)
			return;

		var work = this.queue.shift();

		this.log("Starting work", work.id);
		this.working = true;
		var res;
		try {
			res = await this.miner.startWork(work);
		} catch (err) {
			console.trace(err);
			return;
		} finally {
			this.working = false;
			this.startWork();
		}
		this.log("Work done,", res.toString("hex"));
	}

	async connect() {
		await this.rpc.wait();
		await this.miner.wait();

		this.rpc.on("mining.notify", async params => {
			var work = {
				id: params[0], prevHash: params[1],
				coinb1: params[2], coinb2: params[3],
				merkleBranch: params[4], version: params[5],
				nBits: params[6], nTime: params[7], cleanJobs: params[8],
			};
			this.log("Got work", work.id);

			this.queue.push(work);
			if (this.difficultyReady && this.nounceReady)
				this.startWork();
		});
		this.rpc.on("mining.set_difficulty", params => {
			this.log("Got difficulty", params[0]);
			this.miner.setDifficulty(params[0]);

			if (this.difficultyReady)
				return;

			this.difficultyReady = true;
			if (this.nounceReady)
				this.startWork();
		});

		var sub = await this.rpc.call("mining.subscribe");
		this.log("Got nounce", sub[1]);
		this.miner.setNounce(sub[1], sub[2]);
		this.nounceReady = true;
		if (this.difficultyReady)
			this.startWork();
	}

	async auth(user, pass) {
		var success = await this.rpc.call("mining.authorize", user, pass);
		if (!success)
			throw new Error("Incorrect username/password.");

		this.log("Authenticated "+user+".");
	}

	writePayload() {
		var rdlen = 95 - 63;
		var rdata = Buffer.alloc(rdlen);
		for (var i = 0; i < rdlen; ++i)
			rdata[i] = this._block[94 - i];

		var rmlen = 64;
		var rmid = Buffer.alloc(rmlen);
		for (var i = 0; i < rmlen; ++i)
			rmid[i] = this._midstate[rmlen - i - 1];

		var payload = Buffer.concat([rmid, rdata]);
		this.log("Writing '"+payload.toString("hex")+"'");
		this._port.write(payload);
	}
}

module.exports = StratumClient;