Implemented a basic extraction loop

lib/agent.js

@@ -0,0 +1,72 @@
+import { registerAgent } from '../database/config.js';
+import * as api from './api.js';
+import * as ships from './ships.js';
+
+// This starts an extraction loop with a ship which ends when the ship's cargo is at least 90% full with only one desired good
+// ctx must must have two attributes: `ship` and `good`
+export function extract(ctx, response) {
+	if (response !== undefined) {
+		if (response.error !== undefined) {
+			switch(response.error.code) {
+			case 4000: // ship is on cooldown
+				setTimeout(extract, response.error.data.cooldown.remainingSeconds  * 1000, ctx);
+				return;
+			case 4228: // ship is full. Running the ship inventory function to list the cargo so that know if we need to sell
+				ships.ship({ship: ctx.ship, next:{action: extract, ship: ctx.ship, good: ctx.good}});
+				return;
+			default:
+				throw response;
+			}
+		}
+		if (response.data.extraction !== undefined && response.data.extraction.yield !== undefined) { // yield won't be defined if we reached this point from an inventory request
+			console.log(`${ctx.ship}: extracted ${response.data.extraction.yield.units} of ${response.data.extraction.yield.symbol}`);
+		}
+		if (response.data.cargo !== undefined && response.data.cargo.capacity * 0.9 <= response.data.cargo.units) { // > 90% full
+			const good = response.data.cargo.inventory.filter(i => i.symbol === ctx.good)[0];
+			const inventory = response.data.cargo.inventory.filter(i => i.symbol !== ctx.good);
+			if (good?.units >= response.data.cargo.capacity * 0.9) { // > 90% full
+				console.log(`ship's cargo is full with ${response.data.cargo.units} of ${ctx.good}!`);
+				return;
+			}
+			let actions = [{ action: ships.dock, ship: ctx.ship }];
+			inventory.forEach(i => actions.push({action: ships.sell, ship: ctx.ship, good: i.symbol, units: i.units}));
+			actions.push({action: ships.orbit, ship: ctx.ship});
+			actions.push({action: extract, ship: ctx.ship, good: ctx.good});
+			api.chain(actions);
+			return;
+		} else { // we need to mine more
+			if (response.data.cooldown) { // we are on cooldown, call ourselves again in a moment
+				setTimeout(extract, response.data.cooldown.remainingSeconds  * 1000, ctx);
+				return;
+			}
+		}
+	}
+	ships.extract({ship: ctx.ship, good: ctx.good, next: { action: extract, ship: ctx.ship, good: ctx.good }});
+}
+
+// This function inits the database in case we have an already registered game
+export function init(symbol, faction, token) {
+	registerAgent(symbol, faction, token);
+}
+
+// This function registers then inits the database
+export function register(symbol, faction) {
+	fetch(
+		'https://api.spacetraders.io/v2/register',
+		{
+			method: 'POST',
+			headers: {
+				'Content-Type': 'application/json',
+			},
+			body: JSON.stringify({
+				symbol: symbol,
+				faction: faction,
+			}),
+		})
+		.then(response => response.json())
+		.then(response => {
+			console.log(JSON.stringify(response, null, 2));
+			init(symbol, faction, response.data.token);
+		})
+		.catch(err => console.error(err));
+}

lib/api.js

@@ -0,0 +1,76 @@
+import { getToken } from '../database/config.js';
+import { PriorityQueue } from './priority_queue.js';
+
+let busy = false; // lets us know if we are already sending api requests or not.
+let headers = undefined; // a file scope variable so that we only evaluate these once.
+let queue = new PriorityQueue(); // a priority queue to hold api calls we want to send, allows for throttling.
+
+// chain takes an array of actions as argument. For each one it sets the `next` property.
+// example action: {
+//    action: function to call,
+//    next: optional nested action object, would get overriden by this function, except for the last action,
+//    ... other attributes as required by the action function (for example ship or waypoing symbol...)
+// }
+export function chain(actions) {
+	for(let i=actions.length-1;i>0;--i) {
+		actions[i-1].next = actions[i];
+	}
+	actions[0].action(actions[0]);
+}
+
+// send takes a data object as argument
+// example data: {
+//    endpoint: the url endpoint to call,
+//    method: HTTP method for `fetch` call, defaults to 'GET',
+//    next: optional nested action object, as specified above with the chain function,
+//    payload: optional json object that will be send along with the request,
+// }
+export function send(data) {
+	if (!busy) {
+		send_this(data);
+	} else {
+		queue.enqueue(data, data.priority ? data.priority : 10);
+	}
+}
+
+function send_next() {
+	if (queue.isEmpty()) {
+		busy = false;
+	} else {
+		send_this(queue.dequeue().element);
+	}
+}
+
+function send_this(data) {
+	if (headers === undefined) {
+		const token = getToken();
+		if (token === null) {
+			throw 'Could not get token from the database. Did you init or register yet?';
+		}
+		headers = {
+			'Content-Type': 'application/json',
+			'Authorization': `Bearer ${token}`
+		};
+	}
+	let options = {
+		headers: headers,
+	};
+	if (data.method !== undefined) {
+		options['method'] = data.method;
+	}
+	if (data.payload !== undefined) {
+		options['body'] = JSON.stringify(data.payload);
+	}
+	busy = true;
+	fetch(`https://api.spacetraders.io/v2${data.endpoint}`, options)
+		.then(response => response.json())
+		.then(response => {
+			if (data.next !== undefined) { // if we have a next action, call it now
+				data.next.action(data.next, response);
+			} else { // otherwise use this debug action
+				console.log(JSON.stringify(response, null, 2));
+			}
+		})
+		.catch(err => console.error(err));
+	setTimeout(send_next, 500);
+}

lib/priority_queue.js

@@ -0,0 +1,39 @@
+export class QElement {
+	constructor(element, priority) {
+		this.element = element;
+		this.priority = priority;
+	}
+}
+
+export class PriorityQueue {
+	constructor(elt) {
+		this.items = [];
+		if (elt !== undefined) {
+			this.enqueue(elt, 0);
+		}
+	}
+
+	enqueue(element, priority) {
+		let qElement = new QElement(element, priority);
+
+		for (let i = 0; i < this.items.length; ++i) {
+			if (this.items[i].priority > qElement.priority) {
+				this.items.splice(i, 0, qElement);
+				return;
+			}
+		}
+		this.items.push(qElement);
+	}
+	dequeue() {
+		return this.items.shift(); // we would use pop to get the highest priority, shift() gives us the lowest priority
+	}
+	front() {
+		return this.items[0];
+	}
+	rear() {
+		return this.items[this.items.length - 1];
+	}
+	isEmpty() {
+		return this.items.length === 0;
+	}
+}

lib/ships.js

@@ -0,0 +1,35 @@
+import * as api from './api.js';
+
+export function extract(ctx) {
+	console.log(`${ctx.ship}: extracting`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/extract`, method: 'POST', next: ctx.next});
+}
+
+export function dock(ctx) {
+	console.log(`${ctx.ship}: docking`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/dock`, method: 'POST', next: ctx.next});
+}
+
+export function navigate(ctx) {
+	console.log(`${ctx.ship}: navigating to ${ctx.waypoint}`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/navigate`, method: 'POST', payload: { waypointSymbol: ctx.waypoint }, next: ctx.next});
+}
+
+export function orbit(ctx) {
+	console.log(`${ctx.ship}: orbiting`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/orbit`, method: 'POST', next: ctx.next});
+}
+
+export function refuel(ctx) {
+	console.log(`${ctx.ship}: refueling`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/refuel`, method: 'POST', next: ctx.next});
+}
+
+export function sell(ctx) {
+	console.log(`${ctx.ship}: selling ${ctx.units} of ${ctx.good}`);
+	api.send({endpoint: `/my/ships/${ctx.ship}/sell`, method: 'POST', payload: { symbol: ctx.good, units: ctx.units }, next: ctx.next});
+}
+
+export function ship(ctx) {
+	api.send({endpoint: `/my/ships/${ctx.ship}`, next: ctx.next});
+}