from app import db, logger, socketio
from app.events import connected_sessions
from app.models import Corpus
from flask import current_app, request
from flask_login import current_user, login_required
from .CQiWrapper.CQiWrapper import CQiWrapper

'''
' A dictionary containing lists of, with corpus ids associated, Socket.IO
' session ids (sid). {<corpus_id>: [<sid>, ...], ...}
'''
corpus_analysis_sessions = {}
'''
' A dictionary containing Socket.IO session id - CQi client pairs.
' {<sid>: CQiClient, ...}
'''
corpus_analysis_clients = {}


@socketio.on('request_corpus_analysis')
@login_required
def request_corpus_analysis(corpus_id):
    corpus = Corpus.query.get(corpus_id)
    if corpus is None:
        socketio.emit('init_corpus_analysis', '[404]: Not Found',
                      room=request.sid)
    elif not (corpus.creator == current_user
              or current_user.is_administrator()):
        socketio.emit('init_corpus_analysis', '[403]: Forbidden',
                      room=request.sid)
    else:
        socketio.start_background_task(corpus_analysis_session_handler,
                                       current_app._get_current_object(),
                                       corpus_id, request.sid)


@socketio.on('corpus_analysis')
@login_required
def corpus_analysis(message):
    client = corpus_analysis_clients.get(request.sid)
    if client is None:
        socketio.emit('query', '[424]: Failed Dependency',
                      room=request.sid)
        return
    # Prepare and execute a query
    corpus_name = 'CORPUS'
    query = str(message['query'])
    result_len = int(message['hits_per_page'])
    context_len = int(message['context'])
    result_offset = 0
    client.select_corpus(corpus_name)
    try:
        client.query_subcorpus(query)
    except Exception as e:
        logger.warning(e)
        socketio.emit('corpus_analysis', str(e), room=request.sid)
    else:
        results = client.show_query_results(result_len=result_len,
                                            context_len=context_len,
                                            result_offset=result_offset)

        socketio.emit('corpus_analysis', results, room=request.sid)


@socketio.on('inspect_match')
@login_required
def inspect_match(message):
    client = corpus_analysis_clients.get(request.sid)
    if client is None:
        socketio.emit('query', '[424]: Failed Dependency',
                      room=request.sid)
        return
    # Get more context for given match CPOS
    match_context = client.get_sentences(message['cpos'],
                                         get_surrounding_s=True,
                                         l_r_s_context_additional_len=3)
    socketio.emit('match_context', match_context, room=request.sid)


def corpus_analysis_session_handler(app, corpus_id, session_id):
    with app.app_context():
        ''' Setup analysis session '''
        corpus = Corpus.query.get(corpus_id)
        while corpus.status != 'analysing':
            db.session.refresh(corpus)
            socketio.sleep(3)
        client = CQiWrapper(host='corpus_{}_analysis'.format(corpus_id))
        client.connect()
        corpus_analysis_clients[session_id] = client
        if corpus_id not in corpus_analysis_sessions:
            corpus_analysis_sessions[corpus_id] = [session_id]
        else:
            corpus_analysis_sessions[corpus_id].append(session_id)
        socketio.emit('request_corpus_analysis', '[201]: Created',
                      room=session_id)
        ''' Observe analysis session '''
        while session_id in connected_sessions:
            socketio.sleep(3)
        ''' Teardown analysis session '''
        client.disconnect()
        corpus_analysis_clients.pop(session_id, None)
        corpus_analysis_sessions[corpus_id].remove(session_id)
        if not corpus_analysis_sessions[corpus_id]:
            corpus_analysis_sessions.pop(corpus_id, None)
            corpus.status = 'stop analysis'
            db.session.commit()