ltgcgo/octavia

// Middleware!
"use strict";
 
import {allocated} from "../state/index.mjs";
import MidiParser from "../../libs/midi-parser@colxi/main.min.js";
import {rawToPool} from "../basic/transform.js";
import {customInterpreter} from "../state/utils.js";
 
MidiParser.customInterpreter = customInterpreter;
 
// Use track 240 to 255 for middleware.
let toJson = function (data, track = 0) {
    let type = data[0] >> 4, part = data[0] & 15;
    let replyObj = {
        track: (track & 15) + 240,
        type,
        data: data.slice(1)
    };
    if (type < 15) {
        replyObj.part = part;
        return replyObj;
    } if (type == 12) {
        replyObj.data = data[1];
    } else {
        if (part == 0) {
            // SysEx
            return replyObj;
        } else {
            console.warn(`Unknown special event channel ${part}.`)
        };
    };
};
let fromJson = function (json) {
    let type = json.type, part = json.part;
    if (type == 255) {
        // Directly reject sending meta events
        return;
    };
    let binLength = 3;
    if (type == 12) {
        binLength = 2;
    } else if (type == 15) {
        binLength = json.data.length + 1;
    };
    let newInstr = new Uint8Array(binLength);
    if (type != 15) {
        newInstr[0] = json.type * 16 + json.part;
    } else {
        newInstr[0] = 240;
    };
    if (type == 12) {
        newInstr[1] = json.data;
    } else {
        if (json.data.forEach) {
            json.data.forEach((e, i) => {
                newInstr[i + 1] = e;
            });
        } else {
            console.debug(`Type ${type} value ${json.data.constructor.name} cannot be iterated.`);
        };
    };
    return newInstr;
};
 
let getBridge = function () {
    return new BroadcastChannel("cc.ltgc.octavia:MainInput");
};
let getBridgeOut = function () {
    return new BroadcastChannel("cc.ltgc.octavia:MainOutput");
};
 
export {
    toJson,
    fromJson,
    getBridge,
    getBridgeOut
};