from pypofetch import PypoFetch
from telnetliquidsoap import TelnetLiquidsoap

from datetime import datetime
from datetime import timedelta

import eventtypes
import time

class PypoLiquidsoap():
    def __init__(self, logger, telnet_lock, host, port):
        self.logger = logger
        self.liq_queue_tracker = {
                "s0": None,
                "s1": None,
                "s2": None,
                "s3": None,
                }

        self.telnet_liquidsoap = TelnetLiquidsoap(telnet_lock, \
                logger,\
                host,\
                port,\
                self.liq_queue_tracker.keys())

    def get_telnet_dispatcher(self):
        return self.telnet_liquidsoap


    def play(self, media_item):
        if media_item["type"] == eventtypes.FILE:
            self.handle_file_type(media_item)
        elif media_item["type"] == eventtypes.EVENT:
            self.handle_event_type(media_item)
        elif media_item["type"] == eventtypes.STREAM_BUFFER_START:
            self.telnet_liquidsoap.start_web_stream_buffer(media_item)
        elif media_item["type"] == eventtypes.STREAM_OUTPUT_START:
            if media_item['row_id'] != self.telnet_liquidsoap.current_prebuffering_stream_id:
                #this is called if the stream wasn't scheduled sufficiently ahead of time
                #so that the prebuffering stage could take effect. Let's do the prebuffering now.
                self.telnet_liquidsoap.start_web_stream_buffer(media_item)
            self.telnet_liquidsoap.start_web_stream(media_item)
        elif media_item['type'] == eventtypes.STREAM_BUFFER_END:
            self.telnet_liquidsoap.stop_web_stream_buffer()
        elif media_item['type'] == eventtypes.STREAM_OUTPUT_END:
            self.telnet_liquidsoap.stop_web_stream_output()
        else: raise UnknownMediaItemType(str(media_item))

    def handle_file_type(self, media_item):
        """
        Wait maximum 5 seconds (50 iterations) for file to become ready, 
        otherwise give up on it.
        """
        iter_num = 0
        while not media_item['file_ready'] and iter_num < 50:
            time.sleep(0.1)
            iter_num += 1

        if media_item['file_ready']:
            available_queue = self.find_available_queue()

            try:
                self.telnet_liquidsoap.queue_push(available_queue, media_item)
                self.liq_queue_tracker[available_queue] = media_item
            except Exception as e:
                self.logger.error(e)
                raise
        else:
            self.logger.warn("File %s did not become ready in less than 5 seconds. Skipping...", media_item['dst'])

    def handle_event_type(self, media_item):
        if media_item['event_type'] == "kick_out":
            self.telnet_liquidsoap.disconnect_source("live_dj")
        elif media_item['event_type'] == "switch_off":
            self.telnet_liquidsoap.switch_source("live_dj", "off")


    def is_media_item_finished(self, media_item):
        if media_item is None:
            return True
        else:
            return datetime.utcnow() > media_item['end']

    def find_available_queue(self):
        available_queue = None
        for i in self.liq_queue_tracker:
            mi = self.liq_queue_tracker[i]
            if mi == None or self.is_media_item_finished(mi):
                #queue "i" is available. Push to this queue
                available_queue = i

        if available_queue == None:
            raise NoQueueAvailableException()

        return available_queue


    def verify_correct_present_media(self, scheduled_now):
        #verify whether Liquidsoap is currently playing the correct files.
        #if we find an item that Liquidsoap is not playing, then push it
        #into one of Liquidsoap's queues. If Liquidsoap is already playing
        #it do nothing. If Liquidsoap is playing a track that isn't in
        #currently_playing then stop it.

        #Check for Liquidsoap media we should source.skip
        #get liquidsoap items for each queue. Since each queue can only have one
        #item, we should have a max of 8 items.

        #2013-03-21-22-56-00_0: {
        #id: 1,
        #type: "stream_output_start",
        #row_id: 41,
        #uri: "http://stream2.radioblackout.org:80/blackout.ogg",
        #start: "2013-03-21-22-56-00",
        #end: "2013-03-21-23-26-00",
        #show_name: "Untitled Show",
        #independent_event: true
        #},


        scheduled_now_files = \
                filter(lambda x: x["type"] == eventtypes.FILE, scheduled_now)

        scheduled_now_webstream = \
                filter(lambda x: x["type"] == eventtypes.STREAM_OUTPUT_START, \
                        scheduled_now)

        schedule_ids = set(map(lambda x: x["row_id"], scheduled_now_files))

        row_id_map = {}
        liq_queue_ids = set()
        for i in self.liq_queue_tracker:
            mi = self.liq_queue_tracker[i]
            if not self.is_media_item_finished(mi):
                liq_queue_ids.add(mi["row_id"])
                row_id_map[mi["row_id"]] = mi

        to_be_removed = set()
        to_be_added = set()

        #Iterate over the new files, and compare them to currently scheduled
        #tracks. If already in liquidsoap queue still need to make sure they don't
        #have different attributes
        #if replay gain changes, it shouldn't change the amplification of the currently playing song
        for i in scheduled_now_files:
            if i["row_id"] in row_id_map:
                mi = row_id_map[i["row_id"]]
                correct = mi['start'] == i['start'] and \
                        mi['end'] == i['end'] and \
                        mi['row_id'] == i['row_id']

                if not correct:
                    #need to re-add
                    self.logger.info("Track %s found to have new attr." % i)
                    to_be_removed.add(i["row_id"])
                    to_be_added.add(i["row_id"])


        to_be_removed.update(liq_queue_ids - schedule_ids)
        to_be_added.update(schedule_ids - liq_queue_ids)

        if to_be_removed:
            self.logger.info("Need to remove items from Liquidsoap: %s" % \
                    to_be_removed)

            #remove files from Liquidsoap's queue
            for i in self.liq_queue_tracker:
                mi = self.liq_queue_tracker[i]
                if mi is not None and mi["row_id"] in to_be_removed:
                    self.stop(i)

        if to_be_added:
            self.logger.info("Need to add items to Liquidsoap *now*: %s" % \
                    to_be_added)

            for i in scheduled_now:
                if i["row_id"] in to_be_added:
                    self.modify_cue_point(i)
                    self.play(i)

        #handle webstreams
        current_stream_id = self.telnet_liquidsoap.get_current_stream_id()
        if scheduled_now_webstream:
            if int(current_stream_id) != int(scheduled_now_webstream[0]["row_id"]):
                self.play(scheduled_now_webstream[0])
        elif current_stream_id != "-1":
            #something is playing and it shouldn't be.
            self.telnet_liquidsoap.stop_web_stream_buffer()
            self.telnet_liquidsoap.stop_web_stream_output()

    def stop(self, queue):
        self.telnet_liquidsoap.queue_remove(queue)
        self.liq_queue_tracker[queue] = None

    def is_file(self, media_item):
        return media_item["type"] == eventtypes.FILE

    def clear_queue_tracker(self):
        for i in self.liq_queue_tracker.keys():
            self.liq_queue_tracker[i] = None

    def modify_cue_point(self, link):
        if not self.is_file(link):
            return

        tnow = datetime.utcnow()

        link_start = link['start']

        diff_td = tnow - link_start
        diff_sec = self.date_interval_to_seconds(diff_td)

        if diff_sec > 0:
            self.logger.debug("media item was supposed to start %s ago. Preparing to start..", diff_sec)
            original_cue_in_td = timedelta(seconds=float(link['cue_in']))
            link['cue_in'] = self.date_interval_to_seconds(original_cue_in_td) + diff_sec

    def date_interval_to_seconds(self, interval):
        """
        Convert timedelta object into int representing the number of seconds. If
        number of seconds is less than 0, then return 0.
        """
        seconds = (interval.microseconds + \
                   (interval.seconds + interval.days * 24 * 3600) * 10 ** 6) / float(10 ** 6)
        if seconds < 0: seconds = 0

        return seconds

    def clear_all_queues(self):
        self.telnet_liquidsoap.queue_clear_all()


class UnknownMediaItemType(Exception):
    pass

class NoQueueAvailableException(Exception):
    pass
