const crypt = require("../crypt");

// methods
const isAuthed = require("./is-authed");
const logIn = require("./log-in");
const setupToken = require("./setup-token");

// authed sessions
global.authed = new WeakMap();
global.authed.tokens = new Object();

function parseRq (bytes) {
	try {
		return JSON.parse(bytes.toString());
	} catch (e) {
		return undefined;
	}
}

class APIMethods {
	constructor (parentObj) {
		this.parentObj = parentObj;
		this.info.cache = new Object();
		
		// Clear method cache on update config
		global.server.on("config.update", () => {
			this.info.cache = new Object();
		});
	}
	
	info (con, req, cb) {
		if (!req.fields) req.fields = "*";
		if (!req.fieldsExtSource) req.fieldsExtSource = "*";
		const cache = this.info.cache[
			JSON.stringify({
				f: req.fields, e: req.fieldsExtSource
			})
		];
		
		if (cache) {
			console.debug("CACHE!");
			return cb({ result: cache, trace_id: req.trace_id, ended: true });
		}
		
		const serverInfo = require("./server-info")();
		if (req.fields !== "*") {
			const fields = Object.fromEntries(req.fields.split(/\s*,\s*/g).map(x => [x.trim(), true]));
			Object.keys(serverInfo).forEach(k => {
				if (!fields[k]) serverInfo[k] = undefined;
			});
		}
		if (req.fieldsExtSource !== "*" && req.fields.extSource !== undefined) {
			const fields = Object.fromEntries(req.fieldsExtSource.split(/\s*,\s*/g).map(x => [x.trim(), true]));
			Object.keys(serverInfo).forEach(k => {
				if (!fields[k]) serverInfo.extSource[k] = undefined;
			});
		}
		this.info.cache[
			JSON.stringify({
				f: req.fields, e: req.fieldsExtSource
			})
		] = serverInfo;
		
		cb({ result: serverInfo, trace_id: req.trace_id, ended: true });
	}
	
	authed (con, req, cb) {
		isAuthed(con, req, cb);
	}
	
	async token (con, req, cb) {
		const authedMethod = this.authed;
		const isAuthed = await (new Promise((rs, rj) => {
			authedMethod(con, req, ({ result, ended }) => {
				if (ended) 
					return rs(result);
			});
		}));
		if (!isAuthed) {
			return setupToken(con, req, cb);
		}
		cb({
			error: "already logged-in",
			trace_id: req.trace_id,
			ended: true
		});
	}
	
	async login (con, req, cb) {
		const authedMethod = this.authed;
		const isAuthed = await (new Promise((rs, rj) => {
			authedMethod(con, req, ({ result, ended }) => {
				if (ended) 
					return rs(result);
			});
		}));
		if (!isAuthed) {
			return logIn(con, req, cb);
		}
		cb({
			error: "already logged-in",
			trace_id: req.trace_id,
			ended: true
		});
	}
	
	/*setSession (isEncrypted, address, { key, counter }, cb) {
		if (!global.config.server.secureMode)
			return cb({ error: "Encryption is off by configuration file into server" });
		if (!isEncrypted)
			return cb({ error: "Encryption required" });
		try {
			this.parent.sessions[address] = new crypt.AES(key, counter);
			return cb({ result: "Session key installed" });
		} catch (err) {
			return cb({ error: "Invalid params. Must be key and counter" });
		}
	}*/
}

class API {
    constructor () {
		this.methods = new APIMethods(this);
		this.sessions = global.authed;
    }
	
	decrypt (address, bytes) {
		throw new Error("Deprecated. Use TLS. If you see this error, please, create issue into: https://git.fullgream.tech/fullgream/ai-adventure-labs/issues");
	}
	
    async exec (connection, bytes, cb) {
		const request = parseRq(bytes);
		
		if (request === undefined)
			return cb({
				error: "required JSON object request"
			});
		
		if (typeof request === "object" && request !== null) {
			const {
				method,
				trace_id
			} = request;
			if (!method)
				return cb({
					error: "method missed",
					trace_id: trace_id ?? null,
					ended: true
				});
			if (!trace_id)
				return cb({
					error: "trace_id missed",
					trace_id: null,
					ended: true
				});
			if (this.methods[method] === undefined)
				return cb({
					error: "unknown method: " + method,
					trace_id,
					ended: true
				});
			return this.methods[method](connection, request, cb);
		} else {
			return cb({
				error: "required JSON-object based request",
				trace_id: null,
				ended: true
			});
		}
    }
}

module.exports = { API };