URL = "Gesaffelstein%20&%20Jesper%20Kyd%20-%20In%20Pursuit%20for%20Ezio%27s%20Family.ogg"

unless window.AudioContext
    alert "Nie znaleziono obsługi dla AudioContext!" unless window.webkitAudioContext
    window.AudioContext             = window.webkitAudioContext

context                             = new AudioContext()
ctx                                 = $("#music").get()[0].getContext("2d")
gradient                            = ctx.createLinearGradient(0, 0, 0, 325)
javascriptNode                      = 0
sourceNode                          = 0

gradient.addColorStop 1, "#FFFFFF"
gradient.addColorStop 0.75, "#00FFFF"
gradient.addColorStop 0.25, "#0000FF"
gradient.addColorStop 0, "#000000"

setupAudioNodes()

setupAudioNodes = ->
    javascriptNode                  = context.createScriptProcessor(2048, 1, 1)
    javascriptNode.connect(context.destination)
    analyser                        = context.createAnalyser()
    analyser.smoothingTimeConstant  = 0.75
    analyser.fftsize                = 512
    sourceNode                      = context.createBufferSource()
    sourceNode.connect(analyser)
    analyser.connect(javascriptNode)
    sourceNode.connect(context.destination)
    return

loadSound = (url) ->
    request                         = new XMLHttpRequest()
    request.open                    "GET", url, true
    request.responseType            = "arraybuffer"
    request.onload = () ->
        context.decodeAudioData request.response, (buffer) ->
            playSound buffer
            return
        , onError
        return
    request.send()
    return

playSound = (buffer) ->
    sourceNode.buffer = buffer
    sourceNode.start(0)
    return

onError = (e) ->
    console.log(e)
    return

javascriptNode.onaudioprocess = ->
    array = new Uint8Array(analyser.frequencyBinCount)
    analyser.getByteFrequencyData(array)
    ctx.clearRect 0, 0, 1024, 325
    ctx.fillStyle = gradient
    drawSpectrum array
    return

drawSpectrum = (array) ->
    i = 0
    while i < (array.length)
        val = array[i]
        ctx.fillRect(i * 5, 325 - val, 3, 325)
    return

$(document).ready ->
    $.ajax
        url: URL,
        success: ->
            $("#play_button").show()
            return
    return

loadSound(URL)