michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0: * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0: * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "experimental",
michael@0:   "engines": {
michael@0:     "Firefox": "> 28"
michael@0:   }
michael@0: };
michael@0: 
michael@0: const { Class } = require("../../core/heritage");
michael@0: const { EventTarget } = require("../../event/target");
michael@0: const { emit, off, setListeners } = require("../../event/core");
michael@0: const { Reactor, foldp, send, merges } = require("../../event/utils");
michael@0: const { Disposable } = require("../../core/disposable");
michael@0: const { OutputPort } = require("../../output/system");
michael@0: const { InputPort } = require("../../input/system");
michael@0: const { identify } = require("../id");
michael@0: const { pairs, object, map, each } = require("../../util/sequence");
michael@0: const { patch, diff } = require("diffpatcher/index");
michael@0: const { isLocalURL } = require("../../url");
michael@0: const { compose } = require("../../lang/functional");
michael@0: const { contract } = require("../../util/contract");
michael@0: const { id: addonID, data: { url: resolve }} = require("../../self");
michael@0: const { Frames } = require("../../input/frame");
michael@0: 
michael@0: 
michael@0: const output = new OutputPort({ id: "frame-change" });
michael@0: const mailbox = new OutputPort({ id: "frame-mailbox" });
michael@0: const input = Frames;
michael@0: 
michael@0: 
michael@0: const makeID = url =>
michael@0:   ("frame-" + addonID + "-" + url).
michael@0:     split("/").join("-").
michael@0:     split(".").join("-").
michael@0:     replace(/[^A-Za-z0-9_\-]/g, "");
michael@0: 
michael@0: const validate = contract({
michael@0:   name: {
michael@0:     is: ["string", "undefined"],
michael@0:     ok: x => /^[a-z][a-z0-9-_]+$/i.test(x),
michael@0:     msg: "The `option.name` must be a valid alphanumeric string (hyphens and " +
michael@0:          "underscores are allowed) starting with letter."
michael@0:   },
michael@0:   url: {
michael@0:     map: x => x.toString(),
michael@0:     is: ["string"],
michael@0:     ok: x => isLocalURL(x),
michael@0:     msg: "The `options.url` must be a valid local URI."
michael@0:   }
michael@0: });
michael@0: 
michael@0: const Source = function({id, ownerID}) {
michael@0:   this.id = id;
michael@0:   this.ownerID = ownerID;
michael@0: };
michael@0: Source.postMessage = ({id, ownerID}, data, origin) => {
michael@0:   send(mailbox, object([id, {
michael@0:     inbox: {
michael@0:       target: {id: id, ownerID: ownerID},
michael@0:       timeStamp: Date.now(),
michael@0:       data: data,
michael@0:       origin: origin
michael@0:     }
michael@0:   }]));
michael@0: };
michael@0: Source.prototype.postMessage = function(data, origin) {
michael@0:   Source.postMessage(this, data, origin);
michael@0: };
michael@0: 
michael@0: const Message = function({type, data, source, origin, timeStamp}) {
michael@0:   this.type = type;
michael@0:   this.data = data;
michael@0:   this.origin = origin;
michael@0:   this.timeStamp = timeStamp;
michael@0:   this.source = new Source(source);
michael@0: };
michael@0: 
michael@0: 
michael@0: const frames = new Map();
michael@0: const sources = new Map();
michael@0: 
michael@0: const Frame = Class({
michael@0:   extends: EventTarget,
michael@0:   implements: [Disposable, Source],
michael@0:   initialize: function(params={}) {
michael@0:     const options = validate(params);
michael@0:     const id = makeID(options.name || options.url);
michael@0: 
michael@0:     if (frames.has(id))
michael@0:       throw Error("Frame with this id already exists: " + id);
michael@0: 
michael@0:     const initial = { id: id, url: resolve(options.url) };
michael@0:     this.id = id;
michael@0: 
michael@0:     setListeners(this, params);
michael@0: 
michael@0:     frames.set(this.id, this);
michael@0: 
michael@0:     send(output, object([id, initial]));
michael@0:   },
michael@0:   get url() {
michael@0:     const state = reactor.value[this.id];
michael@0:     return state && state.url;
michael@0:   },
michael@0:   destroy: function() {
michael@0:     send(output, object([this.id, null]));
michael@0:     frames.delete(this.id);
michael@0:     off(this);
michael@0:   },
michael@0:   // `JSON.stringify` serializes objects based of the return
michael@0:   // value of this method. For convinienc we provide this method
michael@0:   // to serialize actual state data.
michael@0:   toJSON: function() {
michael@0:     return { id: this.id, url: this.url };
michael@0:   }
michael@0: });
michael@0: identify.define(Frame, frame => frame.id);
michael@0: 
michael@0: exports.Frame = Frame;
michael@0: 
michael@0: const reactor = new Reactor({
michael@0:   onStep: (present, past) => {
michael@0:     const delta = diff(past, present);
michael@0: 
michael@0:     each(([id, update]) => {
michael@0:       const frame = frames.get(id);
michael@0:       if (update) {
michael@0:         if (!past[id])
michael@0:           emit(frame, "register");
michael@0: 
michael@0:         if (update.outbox)
michael@0:           emit(frame, "message", new Message(present[id].outbox));
michael@0: 
michael@0:         each(([ownerID, state]) => {
michael@0:           const readyState = state ? state.readyState : "detach";
michael@0:           const type = readyState === "loading" ? "attach" :
michael@0:                        readyState === "interactive" ? "ready" :
michael@0:                        readyState === "complete" ? "load" :
michael@0:                        readyState;
michael@0: 
michael@0:           // TODO: Cache `Source` instances somewhere to preserve
michael@0:           // identity.
michael@0:           emit(frame, type, {type: type,
michael@0:                              source: new Source({id: id, ownerID: ownerID})});
michael@0:         }, pairs(update.owners));
michael@0:       }
michael@0:     }, pairs(delta));
michael@0:   }
michael@0: });
michael@0: reactor.run(input);