from . import config, docker_client, Session
from .decorators import background
from .models import Corpus
import docker
import logging
import os
import shutil


@background
def check_corpora():
    session = Session()
    corpora = session.query(Corpus).all()
    for corpus in filter(lambda corpus: corpus.status == 'submitted', corpora):
        __create_build_corpus_service(corpus)
    for corpus in filter(lambda corpus: (corpus.status == 'queued'
                                         or corpus.status == 'running'),
                         corpora):
        __checkout_build_corpus_service(corpus)
    for corpus in filter(lambda corpus: corpus.status == 'start analysis',
                         corpora):
        __create_cqpserver_container(corpus)
    for corpus in filter(lambda corpus: corpus.status == 'stop analysis',
                         corpora):
        __remove_cqpserver_container(corpus)
    session.commit()
    Session.remove()


def __create_build_corpus_service(corpus):
    corpus_dir = os.path.join(config.DATA_DIR,
                              str(corpus.user_id),
                              'corpora',
                              str(corpus.id))
    corpus_data_dir = os.path.join(corpus_dir, 'data')
    corpus_file = os.path.join(corpus_dir, 'merged', 'corpus.vrt')
    corpus_registry_dir = os.path.join(corpus_dir, 'registry')
    if os.path.exists(corpus_data_dir):
        shutil.rmtree(corpus_data_dir)
    if os.path.exists(corpus_registry_dir):
        shutil.rmtree(corpus_registry_dir)
    os.mkdir(corpus_data_dir)
    os.mkdir(corpus_registry_dir)
    service_args = {'command': 'docker-entrypoint.sh build-corpus',
                    'constraints': ['node.role==worker'],
                    'labels': {'origin': 'nopaque',
                               'type': 'corpus.prepare',
                               'corpus_id': str(corpus.id)},
                    'mounts': [corpus_file + ':/root/files/corpus.vrt:ro',
                               corpus_data_dir + ':/corpora/data:rw',
                               corpus_registry_dir + ':/usr/local/share/cwb/registry:rw'],
                    'name': 'build-corpus_{}'.format(corpus.id),
                    'restart_policy': docker.types.RestartPolicy()}
    service_image = \
        'gitlab.ub.uni-bielefeld.de:4567/sfb1288inf/cqpserver:latest'
    try:
        service = docker_client.services.get(service_args['name'])
    except docker.errors.NotFound:
        pass
    except docker.errors.DockerException:
        return
    else:
        service.remove()
    try:
        docker_client.services.create(service_image, **service_args)
    except docker.errors.DockerException:
        corpus.status = 'failed'
    else:
        corpus.status = 'queued'


def __checkout_build_corpus_service(corpus):
    service_name = 'build-corpus_{}'.format(corpus.id)
    try:
        service = docker_client.services.get(service_name)
    except docker.errors.NotFound:
        logging.error('__checkout_build_corpus_service({}):'.format(corpus.id)
                      + ' The service does not exist.'
                      + ' (stauts: {} -> failed)'.format(corpus.status))
        corpus.status = 'failed'
        return
    except docker.errors.DockerException:
        return
    service_tasks = service.tasks()
    if not service_tasks:
        return
    task_state = service_tasks[0].get('Status').get('State')
    if corpus.status == 'queued' and task_state != 'pending':
        corpus.status = 'running'
    elif corpus.status == 'running' and task_state == 'complete':
        service.remove()
        corpus.status = 'prepared'
    elif corpus.status == 'running' and task_state == 'failed':
        service.remove()
        corpus.status = task_state


def __create_cqpserver_container(corpus):
    corpus_dir = os.path.join(config.DATA_DIR,
                              str(corpus.user_id),
                              'corpora',
                              str(corpus.id))
    corpus_data_dir = os.path.join(corpus_dir, 'data')
    corpus_registry_dir = os.path.join(corpus_dir, 'registry')
    container_args = {'command': 'cqpserver',
                      'detach': True,
                      'volumes': [corpus_data_dir + ':/corpora/data:rw',
                                  corpus_registry_dir + ':/usr/local/share/cwb/registry:rw'],
                      'name': 'cqpserver_{}'.format(corpus.id),
                      'network': 'nopaque_default'}
    container_image = \
        'gitlab.ub.uni-bielefeld.de:4567/sfb1288inf/cqpserver:latest'
    try:
        container = docker_client.containers.get(container_args['name'])
    except docker.errors.NotFound:
        pass
    except docker.errors.DockerException:
        return
    else:
        container.remove(force=True)
    try:
        docker_client.containers.run(container_image, **container_args)
    except docker.errors.DockerException:
        return
    else:
        corpus.status = 'analysing'


def __remove_cqpserver_container(corpus):
    container_name = 'cqpserver_{}'.format(corpus.id)
    try:
        container = docker_client.containers.get(container_name)
    except docker.errors.NotFound:
        pass
    except docker.errors.DockerException:
        return
    else:
        container.remove(force=True)
    corpus.status = 'prepared'