from flask import current_app
from ..models import Corpus
import docker
import logging
import os
import shutil


class CheckCorporaMixin:
    def check_corpora(self):
        corpora = Corpus.query.all()
        queued_corpora = list(filter(lambda corpus: corpus.status == 'queued', corpora))  # noqa
        running_corpora = list(filter(lambda corpus: corpus.status == 'running', corpora))  # noqa
        start_analysis_corpora = list(filter(lambda corpus: corpus.status == 'start analysis', corpora))  # noqa
        analysing_corpora = list(filter(lambda corpus: corpus.status == 'analysing', corpora))  # noqa
        stop_analysis_corpora = list(filter(lambda corpus: corpus.status == 'stop analysis', corpora))  # noqa
        submitted_corpora = list(filter(lambda corpus: corpus.status == 'submitted', corpora))  # noqa
        for corpus in submitted_corpora:
            self.create_build_corpus_service(corpus)
        for corpus in queued_corpora + running_corpora:
            self.checkout_build_corpus_service(corpus)
        for corpus in start_analysis_corpora:
            self.create_cqpserver_container(corpus)
        for corpus in analysing_corpora:
            self.checkout_analysing_corpus_container(corpus)
        for corpus in stop_analysis_corpora:
            self.remove_cqpserver_container(corpus)

    def create_build_corpus_service(self, corpus):
        ''' # Docker service settings # '''
        ''' ## Command ## '''
        command = 'docker-entrypoint.sh build-corpus'
        ''' ## Constraints ## '''
        constraints = ['node.role==worker']
        ''' ## Image ## '''
        image = current_app.config['DOCKER_IMAGE_PREFIX'] + 'cqpserver:latest'
        ''' ## Labels ## '''
        labels = {
            'origin': current_app.config['SERVER_NAME'],
            'type': 'build-corpus',
            'corpus_id': str(corpus.id)
        }
        ''' ## Mounts ## '''
        ''' ### Corpus file mount ### '''
        corpus_file_source = os.path.join(corpus.path, 'merged', 'corpus.vrt')
        corpus_file_target = '/root/files/corpus.vrt'
        corpus_file_mount = \
            corpus_file_source + ':' + corpus_file_target + ':ro'
        ''' ### Corpus data mount ### '''
        corpus_data_source = os.path.join(corpus.path, 'data')
        corpus_data_target = '/corpora/data'
        corpus_data_mount = \
            corpus_data_source + ':' + corpus_data_target + ':rw'
        # Make sure that their is no data in the corpus data directory
        shutil.rmtree(corpus_data_source, ignore_errors=True)
        os.mkdir(corpus_data_source)
        ''' ### Corpus registry mount ### '''
        corpus_registry_source = os.path.join(corpus.path, 'registry')
        corpus_registry_target = '/usr/local/share/cwb/registry'
        corpus_registry_mount = \
            corpus_registry_source + ':' + corpus_registry_target + ':rw'
        # Make sure that their is no data in the corpus registry directory
        shutil.rmtree(corpus_registry_source, ignore_errors=True)
        os.mkdir(corpus_registry_source)
        mounts = [corpus_file_mount, corpus_data_mount, corpus_registry_mount]
        ''' ## Name ## '''
        name = 'build-corpus_{}'.format(corpus.id)
        ''' ## Restart policy ## '''
        restart_policy = docker.types.RestartPolicy()
        try:
            self.docker.services.create(
                image,
                command=command,
                constraints=constraints,
                labels=labels,
                mounts=mounts,
                name=name,
                restart_policy=restart_policy
            )
        except docker.errors.APIError as e:
            logging.error(
                'Create "{}" service raised '.format(name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
        else:
            corpus.status = 'queued'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)

    def checkout_build_corpus_service(self, corpus):
        service_name = 'build-corpus_{}'.format(corpus.id)
        try:
            service = self.docker.services.get(service_name)
        except docker.errors.NotFound:
            logging.error(
                'Get "{}" service raised '.format(service_name)
                + '"docker.errors.NotFound" The service does not exist. '
                + '(corpus.status: {} -> failed)'.format(corpus.status)
            )
            corpus.status = 'failed'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)
        except docker.errors.APIError as e:
            logging.error(
                'Get "{}" service raised '.format(service_name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
        except docker.errors.InvalidVersion:
            logging.error(
                'Get "{}" service raised '.format(service_name)
                + '"docker.errors.InvalidVersion" One of the arguments is '
                + 'not supported with the current API version.'
            )
        else:
            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'
                patch_operation = {
                    'op': 'replace',
                    'path': '/corpora/{}/status'.format(corpus.id),
                    'value': corpus.status
                }
                self.buffer_user_patch_operation(corpus, patch_operation)
            elif (corpus.status == 'running'
                  and task_state in ['complete', 'failed']):
                try:
                    service.remove()
                except docker.errors.APIError as e:
                    logging.error(
                        'Remove "{}" service raised '.format(service_name)
                        + '"docker.errors.APIError" The server returned an error. '  # noqa
                        + 'Details: {}'.format(e)
                    )
                    return
                else:
                    corpus.status = \
                        'prepared' if task_state == 'complete' else 'failed'
                    patch_operation = {
                        'op': 'replace',
                        'path': '/corpora/{}/status'.format(corpus.id),
                        'value': corpus.status
                    }
                    self.buffer_user_patch_operation(corpus, patch_operation)

    def create_cqpserver_container(self, corpus):
        ''' # Docker container settings # '''
        ''' ## Command ## '''
        command = 'cqpserver'
        ''' ## Detach ## '''
        detach = True
        ''' ## Image ## '''
        image = current_app.config['DOCKER_IMAGE_PREFIX'] + 'cqpserver:latest'
        ''' ## Name ## '''
        name = 'cqpserver_{}'.format(corpus.id),
        ''' ## Network ## '''
        network = 'nopaque_default'
        ''' ## Volumes ## '''
        ''' ### Corpus data volume ### '''
        corpus_data_source = os.path.join(corpus.path, 'data')
        corpus_data_target = '/corpora/data'
        corpus_data_volume = \
            corpus_data_source + ':' + corpus_data_target + ':rw'
        ''' ### Corpus registry volume ### '''
        corpus_registry_source = os.path.join(corpus.path, 'registry')
        corpus_registry_target = '/usr/local/share/cwb/registry'
        corpus_registry_volume = \
            corpus_registry_source + ':' + corpus_registry_target + ':rw'
        volumes = [corpus_data_volume, corpus_registry_volume]
        # Check if a cqpserver container already exists. If this is the case,
        # remove it and create a new one
        try:
            container = self.docker.containers.get(name)
        except docker.errors.NotFound:
            pass
        except docker.errors.APIError as e:
            logging.error(
                'Get "{}" container raised '.format(name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
            return
        else:
            try:
                container.remove(force=True)
            except docker.errors.APIError as e:
                logging.error(
                    'Remove "{}" container raised '.format(name)
                    + '"docker.errors.APIError" The server returned an error. '
                    + 'Details: {}'.format(e)
                )
                return
        try:
            self.docker.containers.run(image, command=command, detach=detach,
                                       volumes=volumes, name=name,
                                       network=network)
        except docker.errors.ContainerError:
            # This case should not occur, because detach is True.
            logging.error(
                'Run "{}" container raised '.format(name)
                + '"docker.errors.ContainerError" The container exits with a '
                + 'non-zero exit code and detach is False.'
            )
            corpus.status = 'failed'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)
        except docker.errors.ImageNotFound:
            logging.error(
                'Run "{}" container raised '.format(name)
                + '"docker.errors.ImageNotFound" The specified image does not '
                + 'exist.'
            )
            corpus.status = 'failed'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)
        except docker.errors.APIError as e:
            logging.error(
                'Run "{}" container raised '.format(name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
        else:
            corpus.status = 'analysing'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)

    def checkout_analysing_corpus_container(self, corpus):
        container_name = 'cqpserver_{}'.format(corpus.id)
        try:
            self.docker.containers.get(container_name)
        except docker.errors.NotFound:
            logging.error('Could not find "{}" but the corpus state is "analysing".')  # noqa
            corpus.status = 'prepared'
            patch_operation = {
                'op': 'replace',
                'path': '/corpora/{}/status'.format(corpus.id),
                'value': corpus.status
            }
            self.buffer_user_patch_operation(corpus, patch_operation)
        except docker.errors.APIError as e:
            logging.error(
                'Get "{}" container raised '.format(container_name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
            return

    def remove_cqpserver_container(self, corpus):
        container_name = 'cqpserver_{}'.format(corpus.id)
        try:
            container = self.docker.containers.get(container_name)
        except docker.errors.NotFound:
            pass
        except docker.errors.APIError as e:
            logging.error(
                'Get "{}" container raised '.format(container_name)
                + '"docker.errors.APIError" The server returned an error. '
                + 'Details: {}'.format(e)
            )
            return
        else:
            try:
                container.remove(force=True)
            except docker.errors.APIError as e:
                logging.error(
                    'Remove "{}" container raised '.format(container_name)
                    + '"docker.errors.APIError" The server returned an error. '
                    + 'Details: {}'.format(e)
                )
                return
        corpus.status = 'prepared'
        patch_operation = {
            'op': 'replace',
            'path': '/corpora/{}/status'.format(corpus.id),
            'value': corpus.status
        }
        self.buffer_user_patch_operation(corpus, patch_operation)