/* *
 *
 *  (c) 2009-2022 Øystein Moseng
 *
 *  Small MIDI file writer for sonification export.
 *
 *  License: www.highcharts.com/license
 *
 *  !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
 *
 * */
/* eslint-disable no-multi-spaces */
'use strict';
import SonificationInstrument from './SonificationInstrument.js';
import U from '../../Core/Utilities.js';
const { pick } = U;
const freqToNote = (f) => Math.round(12 * Math.log(f) / Math.LN2 - 48.37632), b = (byte, n) => n >>> 8 * byte & 0xFF, getHeader = (nTracks) => [
    0x4D, 0x54, 0x68, 0x64,
    0, 0, 0, 6,
    0, nTracks > 1 ? 1 : 0,
    b(1, nTracks), b(0, nTracks),
    // SMTPE: 0xE7 0x28
    // -25/40 time div gives us millisecond SMTPE, but not widely supported.
    1, 0xF4 // HD_TIMEDIV, 500 ticks per beat = millisecond at 120bpm
], timeInfo = [0, 0xFF, 0x51, 0x03, 0x07, 0xA1, 0x20], // META_TEMPO
varLenEnc = (n) => {
    let buf = n & 0x7F;
    const res = [];
    while (n >>= 7) { // eslint-disable-line no-cond-assign
        buf <<= 8;
        buf |= (n & 0x7F) | 0x80;
    }
    while (true) { // eslint-disable-line no-constant-condition
        res.push(buf & 0xFF);
        if (buf & 0x80) {
            buf >>= 8;
        }
        else {
            break;
        }
    }
    return res;
}, toMIDIEvents = (events) => {
    let cachedVel, cachedDur;
    const res = [], add = (el) => {
        let ix = res.length;
        while (ix-- && res[ix].timeMS > el.timeMS) { /* */ }
        res.splice(ix + 1, 0, el);
    };
    events.forEach((e) => {
        const o = e.instrumentEventOptions || {}, t = e.time, dur = cachedDur = pick(o.noteDuration, cachedDur), tNOF = dur && e.time + dur, ctrl = [{
                valMap: (n) => 64 + 63 * n & 0x7F,
                data: {
                    0x0A: o.pan,
                    0x5C: o.tremoloDepth,
                    0x5D: o.tremoloSpeed
                }
            }, {
                valMap: (n) => 127 * n / 20000 & 0x7F,
                data: {
                    0x4A: o.lowpassFreq,
                    0x4B: o.highpassFreq
                }
            }, {
                valMap: (n) => 63 * Math.min(18, Math.max(-18, n)) / 18 + 63 & 0x7F,
                data: {
                    0x47: o.lowpassResonance,
                    0x4C: o.highpassResonance
                }
            }], v = cachedVel = o.volume === void 0 ?
            pick(cachedVel, 127) : 127 * o.volume & 0x7F, freq = o.frequency, note = o.note || 0, noteVal = 12 + (freq ? freqToNote(freq) : // MIDI note #0 is C-1
            typeof note === 'string' ? SonificationInstrument
                .noteStringToC0Distance(note) : note) & 0x7F;
        // CTRL_CHANGE events
        ctrl.forEach((ctrlDef) => Object.keys(ctrlDef.data)
            .forEach((ctrlSignal) => {
            const val = ctrlDef.data[ctrlSignal];
            if (val !== void 0) {
                add({
                    timeMS: t,
                    type: 'CTRL_CHG',
                    data: [0xB0, parseInt(ctrlSignal, 10),
                        ctrlDef.valMap(val)]
                });
            }
        }));
        // NON/NOF
        if (tNOF) {
            add({ timeMS: t, type: 'NON', data: [0x90, noteVal, v] });
            add({ timeMS: tNOF, type: 'NOF', data: [0x80, noteVal, v] });
        }
    });
    return res;
}, getMetaEvents = (midiTrackName, midiInstrument) => {
    const events = [];
    if (midiInstrument) {
        // Program Change MIDI event
        events.push(0, 0xC0, midiInstrument & 0x7F);
    }
    if (midiTrackName) {
        // Track name meta event
        const textArr = [];
        for (let i = 0; i < midiTrackName.length; ++i) {
            const code = midiTrackName.charCodeAt(i);
            if (code < 128) { // Keep ASCII only
                textArr.push(code);
            }
        }
        return events.concat([0, 0xFF, 0x03], varLenEnc(textArr.length), textArr);
    }
    return events;
}, getTrackChunk = (events, addTimeInfo, midiTrackName, midiInstrument) => {
    let prevTime = 0;
    const metaEvents = getMetaEvents(midiTrackName, midiInstrument), trackEvents = toMIDIEvents(events).reduce((data, e) => {
        const t = varLenEnc(e.timeMS - prevTime);
        prevTime = e.timeMS;
        return data.concat(t, e.data);
    }, []);
    const trackEnd = [0, 0xFF, 0x2F, 0], size = (addTimeInfo ? timeInfo.length : 0) +
        metaEvents.length +
        trackEvents.length + trackEnd.length;
    return [
        0x4D, 0x54, 0x72, 0x6B,
        b(3, size), b(2, size),
        b(1, size), b(0, size)
    ].concat(addTimeInfo ? timeInfo : [], metaEvents, trackEvents, trackEnd // SYSEX_TRACK_END
    );
};
/**
 * Get MIDI data from a set of Timeline instrument channels.
 *
 * Outputs multi-track MIDI for Timelines with multiple channels.
 *
 * @private
 */
function toMIDI(channels) {
    const channelsToAdd = channels.filter((c) => !!c.events.length), numCh = channelsToAdd.length, multiCh = numCh > 1;
    return new Uint8Array(getHeader(multiCh ? numCh + 1 : numCh).concat(multiCh ? getTrackChunk([], true) : [], // Time info only
    channelsToAdd.reduce((chunks, channel) => {
        const engine = channel.engine;
        return chunks.concat(getTrackChunk(channel.events, !multiCh, engine.midiTrackName, engine.midiInstrument));
    }, [])));
}
export default toMIDI;
