# -*- coding: utf-8 -*-
from __future__ import division, absolute_import, print_function, unicode_literals

#################################################################################################

import threading
import concurrent.futures
from datetime import date

from six.moves import range, queue as Queue

import requests
from helper import settings, stop, window
from jellyfin import Jellyfin
from jellyfin import api
from helper.exceptions import HTTPException
from helper import LazyLogger

#################################################################################################

LOG = LazyLogger(__name__)

#################################################################################################


def get_jellyfinserver_url(handler):

    if handler.startswith('/'):

        handler = handler[1:]
        LOG.info("handler starts with /: %s", handler)

    return "{server}/%s" % handler


def _http(action, url, request=None, server_id=None):

    if request is None:
        request = {}

    request.update({'url': url, 'type': action})
    return Jellyfin(server_id).http.request(request)


def _get(handler, params=None, server_id=None):
    return _http("GET", get_jellyfinserver_url(handler), {'params': params}, server_id)


def _post(handler, json=None, params=None, server_id=None):
    return _http("POST", get_jellyfinserver_url(handler), {'params': params, 'json': json}, server_id)


def _delete(handler, params=None, server_id=None):
    return _http("DELETE", get_jellyfinserver_url(handler), {'params': params}, server_id)


def validate_view(library_id, item_id):

    ''' This confirms a single item from the library matches the view it belongs to.
        Used to detect grouped libraries.
    '''
    try:
        result = _get("Users/{UserId}/Items", {
            'ParentId': library_id,
            'Recursive': True,
            'Ids': item_id
        })
    except Exception as error:
        LOG.exception(error)
        return False

    return True if len(result['Items']) else False


def get_single_item(parent_id, media):
    return _get("Users/{UserId}/Items", {
        'ParentId': parent_id,
        'Recursive': True,
        'Limit': 1,
        'IncludeItemTypes': media
    })


def get_movies_by_boxset(boxset_id):

    for items in get_items(boxset_id, "Movie"):
        yield items


def get_episode_by_show(show_id):

    query = {
        'url': "Shows/%s/Episodes" % show_id,
        'params': {
            'EnableUserData': True,
            'EnableImages': True,
            'UserId': "{UserId}",
            'Fields': api.info()
        }
    }
    for items in _get_items(query):
        yield items


def get_episode_by_season(show_id, season_id):

    query = {
        'url': "Shows/%s/Episodes" % show_id,
        'params': {
            'SeasonId': season_id,
            'EnableUserData': True,
            'EnableImages': True,
            'UserId': "{UserId}",
            'Fields': api.info()
        }
    }
    for items in _get_items(query):
        yield items


def get_item_count(parent_id, item_type=None, params=None):

    url = "Users/{UserId}/Items"

    query_params = {
        'ParentId': parent_id,
        'IncludeItemTypes': item_type,
        'EnableTotalRecordCount': True,
        'LocationTypes': "FileSystem,Remote,Offline",
        'Recursive': True,
        'Limit': 1
    }
    if params:
        query_params['params'].update(params)

    result = _get(url, query_params)

    return result.get('TotalRecordCount', 1)


def get_items(parent_id, item_type=None, basic=False, params=None):

    query = {
        'url': "Users/{UserId}/Items",
        'params': {
            'ParentId': parent_id,
            'IncludeItemTypes': item_type,
            'SortBy': "SortName",
            'SortOrder': "Ascending",
            'Fields': api.basic_info() if basic else api.info(),
            'CollapseBoxSetItems': False,
            'IsVirtualUnaired': False,
            'EnableTotalRecordCount': False,
            'LocationTypes': "FileSystem,Remote,Offline",
            'IsMissing': False,
            'Recursive': True
        }
    }
    if params:
        query['params'].update(params)

    for items in _get_items(query):
        yield items


def get_artists(parent_id=None):

    query = {
        'url': 'Artists',
        'params': {
            'UserId': "{UserId}",
            'ParentId': parent_id,
            'SortBy': "SortName",
            'SortOrder': "Ascending",
            'Fields': api.music_info(),
            'CollapseBoxSetItems': False,
            'IsVirtualUnaired': False,
            'EnableTotalRecordCount': False,
            'LocationTypes': "FileSystem,Remote,Offline",
            'IsMissing': False,
            'Recursive': True
        }
    }

    for items in _get_items(query):
        yield items


@stop
def _get_items(query, server_id=None):

    ''' query = {
            'url': string,
            'params': dict -- opt, include StartIndex to resume
        }
    '''
    items = {
        'Items': [],
        'TotalRecordCount': 0,
        'RestorePoint': {}
    }

    limit = min(int(settings('limitIndex') or 50), 50)
    dthreads = int(settings('limitThreads') or 3)

    url = query['url']
    query.setdefault('params', {})
    params = query['params']

    try:
        test_params = dict(params)
        test_params['Limit'] = 1
        test_params['EnableTotalRecordCount'] = True

        items['TotalRecordCount'] = _get(url, test_params, server_id=server_id)['TotalRecordCount']

    except Exception as error:
        LOG.exception("Failed to retrieve the server response %s: %s params:%s", url, error, params)

    else:
        params.setdefault('StartIndex', 0)

        def get_query_params(params, start, count):
            params_copy = dict(params)
            params_copy['StartIndex'] = start
            params_copy['Limit'] = count
            return params_copy

        query_params = [
            get_query_params(params, offset, limit)
            for offset
            in range(params['StartIndex'], items['TotalRecordCount'], limit)
        ]

        # multiprocessing.dummy.Pool completes all requests in multiple threads but has to
        # complete all tasks before allowing any results to be processed. ThreadPoolExecutor
        # allows for completed tasks to be processed while other tasks are completed on other
        # threads. Dont be a dummy.Pool, be a ThreadPoolExecutor
        with concurrent.futures.ThreadPoolExecutor(dthreads) as p:
            # dictionary for storing the jobs and their results
            jobs = {}

            # semaphore to avoid fetching complete library to memory
            thread_buffer = threading.Semaphore(dthreads)

            # wrapper function for _get that uses a semaphore
            def get_wrapper(params):
                thread_buffer.acquire()
                return _get(url, params, server_id=server_id)

            # create jobs
            for param in query_params:
                job = p.submit(get_wrapper, param)
                # the query params are later needed again
                jobs[job] = param

            # process complete jobs
            for job in concurrent.futures.as_completed(jobs):
                # get the result
                result = job.result() or {'Items': []}
                query['params'] = jobs[job]

                # free job memory
                del jobs[job]
                del job

                # Mitigates #216 till the server validates the date provided is valid
                if result['Items'][0].get('ProductionYear'):
                    try:
                        date(result['Items'][0]['ProductionYear'], 1, 1)
                    except ValueError:
                        LOG.info('#216 mitigation triggered. Setting ProductionYear to None')
                        result['Items'][0]['ProductionYear'] = None

                items['Items'].extend(result['Items'])
                # Using items to return data and communicate a restore point back to the callee is
                # a violation of the SRP. TODO: Seperate responsibilities.
                items['RestorePoint'] = query
                yield items
                del items['Items'][:]

                # release the semaphore again
                thread_buffer.release()


class GetItemWorker(threading.Thread):

    is_done = False

    def __init__(self, server, queue, output):

        self.server = server
        self.queue = queue
        self.output = output
        threading.Thread.__init__(self)

    def run(self):
        with requests.Session() as s:
            while True:
                try:
                    item_ids = self.queue.get(timeout=1)
                except Queue.Empty:

                    self.is_done = True
                    LOG.info("--<[ q:download/%s ]", id(self))

                    return

                request = {
                    'type': "GET",
                    'handler': "Users/{UserId}/Items",
                    'params': {
                        'Ids': ','.join(str(x) for x in item_ids),
                        'Fields': api.info()
                    }
                }

                try:
                    result = self.server.http.request(request, s)

                    for item in result['Items']:

                        if item['Type'] in self.output:
                            self.output[item['Type']].put(item)
                except HTTPException as error:
                    LOG.error("--[ http status: %s ]", error.status)

                    if error.status == 'ServerUnreachable':
                        self.is_done = True

                        break

                except Exception as error:
                    LOG.exception(error)

                self.queue.task_done()

                if window('jellyfin_should_stop.bool'):
                    break
