#!/usr/bin/env python3

import threading
import os
import os.path
import random
import time
import sys
import getopt

import blup.output
import blup.animation
import blup.frame


class AnimationLoaderThread(threading.Thread):
    """
    This class is used by the player to pre-load an animation while another one
    is being played.

    """

    def __init__(self, filename):
        threading.Thread.__init__(self)
        self.__filename = filename
        self.__anim = None
        self.__error = False

    def run(self):
        try:
            self.__anim = blup.animation.load(self.__filename)
        except Exception as e:
            print('%s: %s while loading %s' % (self.__class__.__name__,
                                               repr(e), self.__filename))
            self.__error = True
            self.__anim = None

    def getAnim(self):
        self.join()
        return self.__anim


class MiniPlayer(object):
    """
    Minimal animation player that does nothing but randomly selecting
    animations out of a directory and playing them.

    """

    def __init__(self, animDir, animExtensions, output):
        self.__animDir = animDir
        self.__animExtensions = animExtensions
        self.__output = output
        self.loopTime = 10000
        self.gap = 800
        self.maxPlayNext = 3
        self.__playNext = []
        self.__running = False
        self.__anims = {}
        self.__anims_remaining = {}

    def terminate(self):
        self.__running = False

    def playNext(self, filename):
        """ Add an animation to the queue. """

        if filename.find('/') >= 0:
            raise ValueError('filename must not contain slashes')

        if ( os.path.isfile(os.path.join(self.__animDir, filename)) and
             len(self.__playNext) < self.maxPlayNext ):
            self.__playNext.append(filename)
        else:
            return False

    def getNextFilename(self):
        """
        Return the next animation filename to be played, either from the queue,
        or randomly chosen.

        """

        if len(self.__playNext) > 0 and os.path.isfile(self.__playNext[0]):
            anim = self.__playNext.pop(0)
        else:
            anims = set()
            for dp, dns, fns in os.walk(self.__animDir, followlinks=True):
                for fn in fns:
                    root, ext = os.path.splitext(fn)
                    if ext[1:] in self.__animExtensions:
                        anims.add(os.path.join(dp, fn))

            if anims != self.__anims or len(self.__anims_remaining) == 0:
                self.__anims = anims
                self.__anims_remaining = set(anims)
            anim = random.sample(self.__anims_remaining, 1)[0]
            self.__anims_remaining.remove(anim)

        print(anim)
        return anim

    def run(self):
        """
        Runs the player until terminate() gets called (e.g. by another thread).

        """

        self.__running = True
        currentAnim = None
        player = blup.animation.AnimationPlayer()

        while self.__running:

            # begin to load the next animation
            loader = AnimationLoaderThread(self.getNextFilename())
            loader.start()

            # play the animation in case it had been successfully loaded before
            if currentAnim is not None:
                if currentAnim.duration < self.loopTime:
                    count = self.loopTime // currentAnim.duration
                else:
                    count = 1
                player.play(currentAnim, self.__output, count=count)

                # show a blank frame for some thime
                if self.gap > 0 and self.__running:
                    # TODO: use correct frame size
                    #dim = blup.frame.FrameDimension(18,8,8,3)
                    dim = blup.frame.FrameDimension(22, 16, 256, 3)
                    self.__output.sendFrame(blup.frame.Frame(dim))
                    time.sleep(self.gap / 1000.0)

            # get the next animation from the loader
            currentAnim = loader.getAnim()


def printUsage(errMsg=None):
    if errMsg is not None:
        print('error: %s\n' % (errMsg))
    print('usage: %s [OPTIONS] PATH' % (sys.argv[0]))
    print('where PATH is the directory containing the animations to play')
    print('supported options:')
    print('  -o OUTPUT         where to output the frames (default: shell)')
    print('  --output OUTPUT\n')
    print('  -h                print(this text')
    print('  --help')

def main():
    try:
        (opts, args) = getopt.gnu_getopt(sys.argv, 'ho:', ['help', 'output='])
        opts = dict(opts)
    except getopt.GetoptError as e:
        printUsage(e.msg)
        sys.exit(1)

    if '--help' in opts:
        printUsage()
        sys.exit(0)

    if '-o' in opts:
        output = opts['-o']
    elif '--output' in opts:
        output = opts['--output']
    else:
        output = 'shell'

    try:
        out = blup.output.getOutput(output)
    except blup.output.IllegalOutputSpecificationError:
        print('illegal output specification')
        print('available outputs:')
        print(blup.output.getOutputDescriptions())
        sys.exit(1)
    except Exception as e:
        print('could not initialize output: %s' % (str(e)))
        sys.exit(1)

    if len(args) != 2:
        printUsage()
        sys.exit(1)
    else:
        animDir = args[1]

    if not os.path.isdir(animDir):
        print('%s is not a directory' % (animDir))
        sys.exit(1)

    p = MiniPlayer(animDir, ['bml'], out)
    try:
        p.run()
    except KeyboardInterrupt:
        sys.exit(0)

if __name__ == '__main__':
    main()