import { Invoke } from './utils.mjs';

import { Pattern, getEventOffsetMs, noteToMidi } from '@strudel/core';

const ON_MESSAGE = 0x90;

const OFF_MESSAGE = 0x80;

const CC_MESSAGE = 0xb0;

Pattern.prototype.midi = function (output) {

  return this.onTrigger((hap, currentTime, cps, targetTime) => {

    let { note, nrpnn, nrpv, ccn, ccv, velocity = 0.9, gain = 1 } = hap.value;

    //magic number to get audio engine to line up, can probably be calculated somehow

    const latencyMs = 34;

    const offset = getEventOffsetMs(targetTime, currentTime) + latencyMs;

    velocity = Math.floor(gain * velocity * 100);

    const duration = Math.floor((hap.duration.valueOf() / cps) * 1000 - 10);

    const roundedOffset = Math.round(offset);

    const midichan = (hap.value.midichan ?? 1) - 1;

    const requestedport = output ?? 'IAC';

    const messagesfromjs = [];

    if (note != null) {

      const midiNumber = typeof note === 'number' ? note : noteToMidi(note);

      messagesfromjs.push({

        requestedport,

        message: [ON_MESSAGE + midichan, midiNumber, velocity],

        offset: roundedOffset,

      });

      messagesfromjs.push({

        requestedport,

        message: [OFF_MESSAGE + midichan, midiNumber, velocity],

        offset: roundedOffset + duration,

      });

    }

    if (ccv && ccn) {

      if (typeof ccv !== 'number' || ccv < 0 || ccv > 1) {

        throw new Error('expected ccv to be a number between 0 and 1');

      }

      if (!['string', 'number'].includes(typeof ccn)) {

        throw new Error('expected ccn to be a number or a string');

      }

      const scaled = Math.round(ccv * 127);

      messagesfromjs.push({

        requestedport,

        message: [CC_MESSAGE + midichan, ccn, scaled],

        offset: roundedOffset,

      });

    }

    // invoke is temporarily blocking, run in an async process

    if (messagesfromjs.length) {

      setTimeout(() => {

        Invoke('sendmidi', { messagesfromjs });

      });

    }

  });

};