from PIL import Image, ImageDraw
from PyQt4 import uic, QtGui, QtCore
import os
import subprocess
import threading
from queue import PriorityQueue
from . import __base__


class Video:
    '''Video Component Frame-Fetcher'''
    def __init__(self, **kwargs):
        mandatoryArgs = ['ffmpeg', 'videoPath', 'width', 'height',
            'frameRate', 'chunkSize', 'parent']
        for arg in mandatoryArgs:
            try:
                exec('self.%s = kwargs[arg]' % arg)
            except KeyError:
                raise __base__.BadComponentInit(arg, self.__doc__)

        self.frameNo = -1
        self.currentFrame = 'None'
        if 'loopVideo' in kwargs and kwargs['loopVideo']:
            self.loopValue = '-1'
        else:
            self.loopValue = '0'
        self.command = [
            self.ffmpeg,
            '-thread_queue_size', '512',
            '-r', str(self.frameRate),
            '-stream_loop', self.loopValue,
            '-i', self.videoPath,
            '-f', 'image2pipe',
            '-pix_fmt', 'rgba',
            '-filter:v', 'scale='+str(self.width)+':'+str(self.height),
            '-vcodec', 'rawvideo', '-',
        ]

        self.frameBuffer = PriorityQueue()
        self.frameBuffer.maxsize = self.frameRate
        self.finishedFrames = {}

        self.thread = threading.Thread(
            target=self.fillBuffer,
            name=self.__doc__
        )
        self.thread.daemon = True
        self.thread.start()

    def frame(self, num):
        while True:
            if num in self.finishedFrames:
                image = self.finishedFrames.pop(num)
                return Image.frombytes('RGBA', (self.width, self.height), image)
            i, image = self.frameBuffer.get()
            self.finishedFrames[i] = image
            self.frameBuffer.task_done()

    def fillBuffer(self):
        pipe = subprocess.Popen(
            self.command, stdout=subprocess.PIPE,
            stderr=subprocess.DEVNULL, bufsize=10**8
        )
        while True:
            if self.parent.canceled:
                break
            self.frameNo += 1

            # If we run out of frames, use the last good frame and loop.
            if len(self.currentFrame) == 0:
                self.frameBuffer.put((self.frameNo-1, self.lastFrame))
                continue

            self.currentFrame = pipe.stdout.read(self.chunkSize)
            if len(self.currentFrame) != 0:
                self.frameBuffer.put((self.frameNo, self.currentFrame))
                self.lastFrame = self.currentFrame


class Component(__base__.Component):
    '''Video'''
    def widget(self, parent):
        self.parent = parent
        self.settings = parent.settings
        page = uic.loadUi(os.path.join(
            os.path.dirname(os.path.realpath(__file__)),
            'video.ui'
        ))
        self.videoPath = ''
        self.x = 0
        self.y = 0
        self.loopVideo = False

        page.lineEdit_video.textChanged.connect(self.update)
        page.pushButton_video.clicked.connect(self.pickVideo)
        page.checkBox_loop.stateChanged.connect(self.update)

        self.page = page
        return page

    def update(self):
        self.videoPath = self.page.lineEdit_video.text()
        self.loopVideo = self.page.checkBox_loop.isChecked()
        self.parent.drawPreview()

    def previewRender(self, previewWorker):
        width = int(previewWorker.core.settings.value('outputWidth'))
        height = int(previewWorker.core.settings.value('outputHeight'))
        self.chunkSize = 4*width*height
        frame = self.getPreviewFrame(width, height)
        if not frame:
            return Image.new("RGBA", (width, height), (0, 0, 0, 0))
        else:
            return frame

    def preFrameRender(self, **kwargs):
        super().preFrameRender(**kwargs)
        width = int(self.worker.core.settings.value('outputWidth'))
        height = int(self.worker.core.settings.value('outputHeight'))
        self.chunkSize = 4*width*height
        self.video = Video(
            ffmpeg=self.parent.core.FFMPEG_BIN, videoPath=self.videoPath,
            width=width, height=height, chunkSize=self.chunkSize,
            frameRate=int(self.settings.value("outputFrameRate")),
            parent=self.parent, loopVideo=self.loopVideo
        )

    def frameRender(self, moduleNo, arrayNo, frameNo):
        return self.video.frame(frameNo)

    def loadPreset(self, pr):
        self.page.lineEdit_video.setText(pr['video'])
        self.page.checkBox_loop.setChecked(pr['loop'])

    def savePreset(self):
        return {
            'video': self.videoPath,
            'loop': self.loopVideo,
        }

    def pickVideo(self):
        imgDir = self.settings.value("backgroundDir", os.path.expanduser("~"))
        filename = QtGui.QFileDialog.getOpenFileName(
            self.page, "Choose Video",
            imgDir, "Video Files (*.mp4 *.mov)"
        )
        if filename: 
            self.settings.setValue("backgroundDir", os.path.dirname(filename))
            self.page.lineEdit_video.setText(filename)
            self.update()

    def getPreviewFrame(self, width, height):
        if not self.videoPath or not os.path.exists(self.videoPath):
            return
        command = [
            self.parent.core.FFMPEG_BIN,
            '-thread_queue_size', '512',
            '-i', self.videoPath,
            '-f', 'image2pipe',
            '-pix_fmt', 'rgba',
            '-filter:v', 'scale='+str(width)+':'+str(height),
            '-vcodec', 'rawvideo', '-',
            '-ss', '90',
            '-vframes', '1',
        ]
        pipe = subprocess.Popen(
            command, stdout=subprocess.PIPE,
            stderr=subprocess.DEVNULL, bufsize=10**8
        )
        byteFrame = pipe.stdout.read(self.chunkSize)
        image = Image.frombytes('RGBA', (width, height), byteFrame)
        pipe.stdout.close()
        pipe.kill()
        return image