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

import { getDrawContext, getTheme } from '@strudel/draw';

import { analysers, getAnalyzerData } from 'superdough';

export function drawTimeScope(

  analyser,

  {

    align = true,

    color = 'white',

    thickness = 3,

    scale = 0.25,

    pos = 0.75,

    trigger = 0,

    ctx = getDrawContext(),

    id = 1,

  } = {},

) {

  ctx.lineWidth = thickness;

  ctx.strokeStyle = color;

  let canvas = ctx.canvas;

  if (!analyser) {

    // if analyser is undefined, draw straight line

    // it may be undefined when no sound has been played yet

    ctx.beginPath();

    let y = pos * canvas.height;

    ctx.moveTo(0, y);

    ctx.lineTo(canvas.width, y);

    ctx.stroke();

    return;

  }

  const dataArray = getAnalyzerData('time', id);

  ctx.beginPath();

  const bufferSize = analyser.frequencyBinCount;

  let triggerIndex = align

    ? Array.from(dataArray).findIndex((v, i, arr) => i && arr[i - 1] > -trigger && v <= -trigger)

    : 0;

  triggerIndex = Math.max(triggerIndex, 0); // fallback to 0 when no trigger is found

  const sliceWidth = (canvas.width * 1.0) / bufferSize;

  let x = 0;

  for (let i = triggerIndex; i < bufferSize; i++) {

    const v = dataArray[i] + 1;

    const y = (pos - scale * (v - 1)) * canvas.height;

    if (i === 0) {

      ctx.moveTo(x, y);

    } else {

      ctx.lineTo(x, y);

    }

    x += sliceWidth;

  }

  ctx.stroke();

}

export function drawFrequencyScope(

  analyser,

  { color = 'white', scale = 0.25, pos = 0.75, lean = 0.5, min = -150, max = 0, ctx = getDrawContext(), id = 1 } = {},

) {

  if (!analyser) {

    ctx.beginPath();

    let y = pos * canvas.height;

    ctx.moveTo(0, y);

    ctx.lineTo(canvas.width, y);

    ctx.stroke();

    return;

  }

  const dataArray = getAnalyzerData('frequency', id);

  const canvas = ctx.canvas;

  ctx.fillStyle = color;

  const bufferSize = analyser.frequencyBinCount;

  const sliceWidth = (canvas.width * 1.0) / bufferSize;

  let x = 0;

  for (let i = 0; i < bufferSize; i++) {

    const normalized = clamp((dataArray[i] - min) / (max - min), 0, 1);

    const v = normalized * scale;

    const h = v * canvas.height;

    const y = (pos - v * lean) * canvas.height;

    ctx.fillRect(x, y, Math.max(sliceWidth, 1), h);

    x += sliceWidth;

  }

}

function clearScreen(smear = 0, smearRGB = `0,0,0`, ctx = getDrawContext()) {

  if (!smear) {

    ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);

  } else {

    ctx.fillStyle = `rgba(${smearRGB},${1 - smear})`;

    ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);

  }

}

/**

 * Renders an oscilloscope for the frequency domain of the audio signal.

 * @name fscope

 * @param {string} color line color as hex or color name. defaults to white.

 * @param {number} scale scales the y-axis. Defaults to 0.25

 * @param {number} pos y-position relative to screen height. 0 = top, 1 = bottom of screen

 * @param {number} lean y-axis alignment where 0 = top and 1 = bottom

 * @param {number} min min value

 * @param {number} max max value

 * @example

 * s("sawtooth").fscope()

 */

Pattern.prototype.fscope = function (config = {}) {

  let id = config.id ?? 1;

  return this.analyze(id).draw(

    () => {

      clearScreen(config.smear, '0,0,0', config.ctx);

      analysers[id] && drawFrequencyScope(analysers[id], config);

    },

    { id },

  );

};

/**

 * Renders an oscilloscope for the time domain of the audio signal.

 * @name scope

 * @synonyms tscope

 * @param {object} config optional config with options:

 * @param {boolean} align if 1, the scope will be aligned to the first zero crossing. defaults to 1

 * @param {string} color line color as hex or color name. defaults to white.

 * @param {number} thickness line thickness. defaults to 3

 * @param {number} scale scales the y-axis. Defaults to 0.25

 * @param {number} pos y-position relative to screen height. 0 = top, 1 = bottom of screen

 * @param {number} trigger amplitude value that is used to align the scope. defaults to 0.

 * @example

 * s("sawtooth")._scope()

 */

let latestColor = {};

Pattern.prototype.tscope = function (config = {}) {

  let id = config.id ?? 1;

  return this.analyze(id).draw(

    (haps) => {

      config.color = haps[0]?.value?.color || getTheme().foreground;

      latestColor[id] = config.color;

      clearScreen(config.smear, '0,0,0', config.ctx);

      drawTimeScope(analysers[id], config);

    },

    { id },

  );

};

Pattern.prototype.scope = Pattern.prototype.tscope;