'''
Recommendation Engine Example
1 Nov 2017, 0x2620
'''

from collections import defaultdict
import json
import logging
import os
import random
import time

import ox

from utils import run_async

logger = logging.getLogger(__name__)
verbose = True


class Engine:
    _pandora = None

    def __init__(self, path, **kwargs):
        self.path = path
        self.pandora_args = dict(
            url=kwargs.get('pandora', 'http://pandora.dmp/api/'),
            username=kwargs.get('username', 'dd.re'),
            password=kwargs.get('password', 'dd.re')
        )
        filename = os.path.join(self.path, 'playlists.json')
        if os.path.exists(filename):
            with open(filename) as f:
                self.playlists = json.load(f)
        else:
            self.playlists = []

        filename = os.path.join(self.path, 'state.json')
        if os.path.exists(filename):
            with open(filename) as f:
                self.state = json.load(f)
        else:
            self.state = {
                'channels': {
                    'globalKeywords': {'locked': False, 'value': 7},
                    'userKeywords': {'locked': False, 'value': 7},
                    'screenings': {'locked': True, 'value': 2}
                },
                'globalKeywords': {},
            }
        if 'gridChange' not in self.state:
            self.state['gridChange'] = {
                'nextClip': {'locked': True, 'value': 4},
                'nextPlaylist': {'locked': False, 'value': 4},
                'staySame': {'locked': False, 'value': 8}
            }
        self.update_keywords()

    @property
    def pandora(self):
        while not self._pandora:
            try:
                self._pandora = Pandora(**self.pandora_args)
            except:
                logger.error('failed to connect to pandora, retry in 10 seconds')
                time.sleep(10)
        return self._pandora

    def _patch_clips(self, clips):
        inpoints = {}
        for index, clip in enumerate(clips):
            video_id = clip['id'].split('/')[0]
            inpoints[video_id] = inpoints.get(video_id, []) + [{
                'index': index,
                'position': clip['in']
            }]
        for video_id in inpoints:
            for i, inpoint in enumerate(sorted(
                inpoints[video_id], key=lambda inpoint: inpoint['position']
            )):
                if i < len(inpoints[video_id]) - 1:
                    clips[inpoint['index']]['out'] = inpoints[video_id][i + 1]['position']
                else:
                    clips[inpoint['index']]['out'] = self.pandora.get(video_id, ['duration'])['duration']
        return clips

    def get_videos(self, user):

        if user.get('events', [{}])[0].get("event")=="login": 
            return self.get_recommendations(user) 

        channels = {k: v.get('value', 0) for k, v in self.state['channels'].items()}
        sliders = {k: v.get('value', 0) for k, v in self.state['globalKeywords'].items()}
        grid_change = {k: v.get('value', 0) for k, v in self.state['gridChange'].items()}

        # check if there were grid events for all indexes.
        grid_events = {}
        (nc, np, ns) = (grid_change.get("nextClip"), grid_change.get("nextPlaylist"), grid_change.get("staySame"))
        # this assumes np + nc + ns = total number of videos in the grid view (16). 
        # Make sure sanity check exists in front-end (error if it does not add up to 16).
        video_num = nc + np + ns 

        # for event in user.get('events', []):
        #     if event.get('event') == "grid" and event.get('data').get('index') not in grid_events:
        #         grid_events[event.get('data').get('index')] = event.get('data')
        #     if len(grid_events) == video_num:
        #         break

        # # The version where the loop also extract play_index (requires "index" in play event data):
        play_index = None
        for event in user.get('events', []):
            if event.get('event') == "grid" and event.get('data').get('index') not in grid_events:
                grid_events[event.get('data').get('index')] = event.get('data')
            if event.get('event') == "play" and not play_index:
                play_index = event.get('data').get('index') 
            if len(grid_events) == video_num and play_index:
                break 

        prev_grid_list = sorted([v for v in grid_events.values()], key=lambda k:k['index'])

        # if there were no grid events for all, initialize all grids.
        if len(prev_grid_list) < video_num: 
            return self.get_recommendations(user)   

        else:
            if play_index is None:
                video_indx = list(range(video_num))
                random.shuffle(video_indx)
            else:
            # played index is excluded from the random shuffle and deterministically added to staySame pool.
                video_indx = [*range(play_index)]+[*range(play_index+1,video_num)]
                random.shuffle(video_indx)
                video_indx.append(play_index)

            next_clip_index = video_indx[:nc]
            next_playlist_index = video_indx[nc:nc+np]
            stay_same_index = video_indx[nc+np:]

            rec_list = []
            # select next clip for nextClip pool except when the playlist has only one clip. 
            for i in next_clip_index:
                if prev_grid_list[i].get('playlist') is None:
                # add this to deal with the absence of "playlist" data in old grid event.
                # If there's no playlist data recorded, add the nextClip pool to nextPlaylist pool.
                    next_playlist_index.append(next_clip_index)
                    break
                else:
                # if "playlist" and "playlistPostion" (if not, default to 0) exists in grid event
                    for playlist in self.playlists:
                        if playlist.get('name')== prev_grid_list[i].get('playlist'):
                            if len(playlist["clips"]) == 1:
                                next_playlist_index.append(i)
                                break
                            # Discuss how this behavour should be: should it switch to a new playlist if it is the end of the playlist clip sequence already?
                            elif prev_grid_list[i].get('playlistPosition', 0) + 1 == len(playlist['clips']):
                                playlist_pos = 0
                            else:
                                playlist_pos = prev_grid_list[i].get('playlistPosition', 0) + 1
                            
                            rec_list.append((i, {
                                'clips': playlist['clips'],
                                # 'position': random.randrange(len(playlist['clips'])),
                                'position': playlist_pos,
                                'name': playlist['name'],
                                'tags': playlist['tags'],
                            }))

            # randomly select playlists (excluding the playlists from the current grid once "playlist" is recorded for grid events)
            # for nextPlaylist pool.
            vids_exclude = [e.get("playlist") for e in prev_grid_list]
            while None in vids_exclude:
                vids_exclude.remove(None)
            video = self.get_recommendations(user, vids_exclude)
            rec_list += [(i, video[i]) for i in next_playlist_index]

            #staySame pool
            rec_list += [(i,{}) for i in stay_same_index]

            rec_list = sorted(rec_list, key=lambda k:k[0])
            return [e[1] for e in rec_list]


# NOTE for future improvement: vids_exclude element unit could be clip or in/out time pairs, rather than playlist. 
# The same playlist could be played in the grid view as long as these are differenct clips or separate times.
    def get_recommendations(self, user, vids_exclude = []):
        channels = {k: v.get('value', 0) for k, v in self.state['channels'].items()}
        sliders = {k: v.get('value', 0) for k, v in self.state['globalKeywords'].items()}
        gridChange = {k: v.get('value', 0) for k, v in self.state['gridChange'].items()}

        # Exclude playlists from the most recent grid 
        playlists = self.playlists
        if len(vids_exclude) > 0:
            for playlist in playlists:
                if playlist["name"] in vids_exclude:
                    playlists.remove(playlist)

        # For each playlist, compute user keyword score
        user_keywords = user.get('keywords', {})
        score = {}
        for playlist in playlists:
            score[playlist['name']] = random.random()
            for tag in [tag for tag in playlist['tags'] if tag in user_keywords]:
                score[playlist['name']] += user_keywords[tag]
        # Select highest scoring playlists
        playlists = sorted(
            playlists,
            key=lambda playlist: -score[playlist['name']]
        )
        videos = playlists[:channels['userKeywords']]
        playlists = playlists[channels['userKeywords']:]
        # For each playlist, compute global keyword score
        score = {}
        for playlist in playlists:
            score[playlist['name']] = random.random()
            for tag in [tag for tag in playlist['tags'] if tag in sliders]:
                score[playlist['name']] += sliders[tag]
        # Select highest scoring playlists
        playlists = sorted(
            playlists,
            key=lambda playlist: -score[playlist['name']]
        )
        videos += playlists[:channels['globalKeywords']]
        playlists = playlists[channels['globalKeywords']:]
        # Count products the user has seen
        count = defaultdict(lambda: 0)
        for event in user.get('events', []):
            if event.get('data', {}).get('product'):
                count[event['data']['product']] += 1
        # For each product in playlist tags, increment score by count
        for playlist in playlists:
            score[playlist['name']] = random.random()
            for tag in set(playlist['tags']) & set(count):
                score[playlist['name']] += count[tag]
        # Select highest scoring playlists
        videos += sorted(
            playlists,
            key=lambda playlist: -score[playlist['name']]
        )[:16 - channels['userKeywords'] - channels['globalKeywords']]
        # Shuffle playlists (randomize layout) and shift clips (randomize start)
        random.shuffle(videos)
        return [{
            'clips': video['clips'],
            'position': random.randrange(len(video['clips'])),
            'name': video['name'],
            'tags': video['tags'],
        } for video in videos]


    def get_next(self, user, position):
        grid_events = {}
        video_num = 16 

        for event in user.get('events', []):
            if event.get('event') == "grid" and event.get('data').get('index') not in grid_events:
                grid_events[event.get('data').get('index')] = event.get('data')
            if len(grid_events) == video_num:
                break
        prev_grid_list = sorted([v for v in grid_events.values()], key=lambda k:k['index'])
        vids_exclude = [e.get("playlist") for e in prev_grid_list]
        video = self.get_recommendations(user, vids_exclude)[position]
        return video

    def update_state(self, data):
        for key in data:
            if key in self.state:
                self.state[key].update(data[key])
            else:
                self.state[key] = data[key]
        self.save_state()
        return self.state

    def save_state(self):
        filename = os.path.join(self.path, 'state.json')
        with open(filename, 'w') as f:
            json.dump(self.state, f, indent=4, ensure_ascii=False, sort_keys=True)

    def update(self):
        # Get all storylines with tags
        storylines = [{
            'id': entity['id'],
            'name': entity['name'],
            'nodename': entity['nodename'],
            'tags': [t.strip() for t in entity['tags']]
        } for entity in self.pandora.find_entities({
            'conditions': [
                {'key': 'type', 'operator': '==', 'value': 'storylines'},
            ],
            'operator': '&'
        }, ['id', 'name', 'tags', 'nodename']) if entity.get('tags', []) and entity.get('nodename')]
        # Get list of storyline names
        names = list(set([storyline['name'] for storyline in storylines]))
        # Get list of items to use in DD
        items = [item['id'] for item in self.pandora.find({
            'conditions': [
                {'key': 'list', 'operator': '==', 'value': 'dau:DD'}
            ]
        }, ['id'])]
        # Get all clips annotated with storyline references
        clips = [clip for clip in self.pandora.find_annotations({
            'conditions': [
                {'key': 'layer', 'operator': '==', 'value': 'storylines'}
            ],
            'operator': '&'
        }, ['id', 'in', 'out', 'value']) if clip['value'] in names and clip['id'].split('/')[0] in items]
        # Get list of ids for videos with clips
        ids = list(set([clip['id'].split('/')[0] for clip in clips]))
        # Get and cache video data
        filename = os.path.join(self.path, 'videos.json')
        if os.path.exists(filename):
            with open(filename) as f:
                videos_ = json.loads(f.read())
                ids_ = [video['id'] for video in videos_]
        else:
            videos_, ids_ = [], []
        videos = sorted(videos_ + [
            self.pandora.get(id, ['code', 'id', 'order', 'title'])
            for id in ids if not id in ids_
        ], key=lambda video: int(video['order']))
        with open(filename, 'w') as f:
            f.write(json.dumps(videos, indent=4, sort_keys=True))
        # Get video order
        order = {video['id']: int(video['order']) for video in videos}
        # Sort clips
        clips = sorted(
            clips,
            key=lambda clip: (order[clip['id'].split('/')[0]], clip['in'])
        )
        # Get and cache playlists
        self.playlists = [playlist for playlist in [{
            'id': storyline['id'],
            'name': storyline['nodename'].strip(),
            'tags': storyline['tags'],
            'clips': [{
                'item': clip['id'].split('/')[0],
                'id': clip['id'],
                'in': clip['in'],
                'out': clip['out']
            } for clip in clips if clip['value'] == storyline['name']]
        } for storyline in storylines] if playlist['clips']]
        with open(os.path.join(self.path, 'playlists.json'), 'w') as f:
            f.write(json.dumps(self.playlists, indent=4, sort_keys=True))
        self.update_keywords()

    def update_keywords(self):
        changed = False
        if 'globalKeywords' not in self.state:
            self.state['globalKeywords'] = {}
            changed = True
        existing_tags = set()
        for playlist in self.playlists:
            for tag in playlist.get('tags', []):
                if not tag.isupper() and tag:
                    existing_tags.add(tag)
                if not tag.isupper() and tag not in self.state['globalKeywords']:
                    self.state['globalKeywords'][tag] = {'value': 0}
                    changed = True
        for tag in set(self.state['globalKeywords']) - existing_tags:
            del self.state['globalKeywords'][tag]
            changed = True
        if changed:
            self.save_state()

    @run_async
    def update_async(self):
        self.update()


class Pandora:

    # pan.do/ra API wrapper

    def __init__(self, url, username, password):
        self.api = ox.API(url)
        self.api.signin(username=username, password=password)

    def find(self, query, keys):
        # print('FIND', query, keys)
        return self.api.find({
            'keys': keys,
            'query': query,
            'range': [0, 1000000]
        })['data']['items']

    def find_annotations(self, query, keys):
        # print('FIND ANNOTATIONS', query, keys)
        return self.api.findAnnotations({
            'keys': keys,
            'query': query,
            'range': [0, 1000000]
        })['data']['items']

    def find_entities(self, query, keys):
        # print('FIND ENTITIES', query, keys)
        return self.api.findEntities({
            'keys': keys,
            'query': query,
            'range': [0, 1000000]
        })['data']['items']

    def get(self, id, keys):
        # print('GET', id, keys)
        return self.api.get({
            'id': id,
            'keys': keys
        })['data']


if __name__ == '__main__':
    engine = Engine('json')
    engine.update()