import wavefile from 'wavefile';
let WaveFile = wavefile.WaveFile;

import {default as dct} from 'dct';

const sampleRate = 15000;
let frameRate = 60;
let samplesPerFrame = sampleRate / frameRate;

import {
    readFileSync,
    writeFileSync
} from 'fs';

function audio2voices(samples) {
    let voices = [];

    let floatSamples = samples.map((byte) => ((byte / 256) - 0.5) * 2);
    let transformed = dct(floatSamples);
    console.log('audio2voices');
    console.log(floatSamples);
    console.log(transformed);
    //throw new Error('xxxxx');

    let freqs = transformed.map((_f, i) => i * frameRate);

    let bands = new Float64Array(256);
    for (let i = 0; i < transformed.length; i++) {
        let amplitude = transformed[i];
        let freq = freqs[i];
        if (freq == 0) {
            continue;
        }
        let divisor = Math.floor(sampleRate / freq) - 1;
        if (divisor > 255) {
            continue;
        }
        bands[divisor] += amplitude;
    }
    console.log(bands);

    for (let i = 0; i < 4; i++) {
        let divisor = 0;
        let max = 0;
        for (let j = 0; j < bands.length; j++) {
            if (bands[j] > max) {
                divisor = j;
                max = bands[j];
            }
        }
        let amplitude16 = Math.floor(max * 7) + 8;
        voices.push(divisor, amplitude16);
    }
    return voices;
}

function byte2byte(arr) {
    let lines = [];
    for (let i=0; i < arr.length; i++) {
        lines.push(`.byte ${arr[i]}`);
    }
    return lines.join('\n');
}

function output2assembly(output) {
    return `
.segment "AUDIO"

    .export audio_samples
    .export audio_samples_end

audio_samples:
    ${byte2byte(output)}
audio_samples_end:
    .byte 24

`;
}

function wav2assembly(buffer) {
    let wav = new WaveFile(buffer);
    let samples = wav.getSamples();
    let seconds = samples.length / sampleRate;
    let frames = Math.floor(seconds * frameRate);

    let output = [];
    for (let i = 0; i < frames * samplesPerFrame; i += samplesPerFrame) {
        let voices = audio2voices(samples.slice(i, i + samplesPerFrame));
        output.push(...voices);
    }

    console.log(output);
    return output2assembly(output);
}

let infile = process.argv[2];
let outfile = process.argv[3];

let buffer = readFileSync(infile);
let asm = wav2assembly(buffer);
writeFileSync(outfile, asm, 'utf-8');