import types from '../types'

import Tone from 'tone'
import JSZip from 'jszip'
import FileSaver from 'file-saver'
import { sprintf } from 'sprintf-js'

import * as draw from './lib/draw'
import output from './lib/output'
import spectrum from './lib/spectrum'

import { requestAudioContext } from './lib'

const FRAME_LENGTH = 126 * 255
const FRAME_OFFSET = FRAME_LENGTH / 4

const _r = 8
const _i = 8

// requestAudioContext(() => {})

export const loadBuffer = file => {
  return new Promise((resolve, reject) => {
    const url = URL.createObjectURL(file)
    let buffer = new Tone.Buffer(
      url,
      loadBuffer,
      err => {
        console.error('err', err)
        reject(err)
      }
    )
    function loadBuffer() {
      URL.revokeObjectURL(url)
      resolve(buffer)
    }
  })
}

export const loadPCM = (file) => {
  return new Promise((resolve, reject) => {
    loadBuffer(file).then(buffer => {
      const pcm = buffer._buffer.getChannelData(0)
      const sr = buffer._buffer.sampleRate
      if (! pcm) return reject()
      console.log(buffer, pcm, sr)
      resolve({ buffer, pcm, sr })
    })
  })
}

export const renderFrames = (file, { frame_offset=FRAME_OFFSET, max=10 }) => dispatch => {
  return new Promise((resolve, reject) => {
    loadPCM(file).then(({ buffer, pcm, sr }) => {
      dispatch({ type: types.wav2pix.loaded_buffer })
      let canvases = []
      for (let offset = 0, count = 0, _len = pcm.length - FRAME_LENGTH;
            offset < _len && count < max;
            offset += frame_offset, count += 1
          ) {
        canvases.push(render(pcm.slice(offset, offset+FRAME_LENGTH), sr, count))
      }
      dispatch({ type: types.wav2pix.draw_finish })
      resolve(canvases)
    })
  })
}

export const buildZip = (name, file, { frame_offset=FRAME_OFFSET, max=10000 }) => dispatch => {
  return new Promise((resolve, reject) => {
    loadPCM(file).then(({ buffer, pcm, sr }) => {
      dispatch({ type: types.wav2pix.loaded_buffer })

      const zip = new JSZip()
      const zip_folder = zip.folder("wav2pix_" + name);

      let offset = 0, count = 0, _len = pcm.length - FRAME_LENGTH
      for (;
            offset < _len && count < max;
            offset += frame_offset, count += 1
          ) {
        if ((count % 10) === 0) {
          dispatch({ type: types.wav2pix.draw_progress, count })
        }
        render(pcm.slice(offset, offset+FRAME_LENGTH), sr, count, zip_folder)
      }

      // dispatch event
      dispatch({ type: types.wav2pix.draw_finish })
      zip.generateAsync({ type: "blob" }).then(content => {
        dispatch({ type: types.wav2pix.load_zip })
        // FileSaver.saveAs(content, "wav2pix_" + name + ".zip")
        resolve({
          zip: content,
          name: "wav2pix_" + name + ".zip",
          count
        })
      })
    })
  })
}

function render(pcm, sr, count, zip){
  const fft = spectrum.toSpectrum(pcm, sr)
  // console.log('render', fft)
  // const pcm_rev = pcm.slice().reverse()
  // const spec_rev = spectrum.toSpectrum(pcm_rev, spec.sr)
  const { canvas, imageData } = draw.raw_spectrum(fft, 0, 256, 0, 256, _r, _i)
  if (zip) {
    const name = sprintf('frame_%05d.png', count)
    const dataURL = canvas.toDataURL("image/png")
    zip.file(name, dataURL.split(',')[1], {base64: true})
  }
  return { fft, canvas, imageData }
}