# Copyright 2018 Markus Scheidgen
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an"AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
The repository API of the nomad@FAIRDI APIs. Currently allows to resolve repository
meta-data.
"""

from flask_restplus import Resource, abort, fields
from flask import request, g
from elasticsearch_dsl import Q
from elasticsearch.exceptions import NotFoundError
import datetime

from nomad import search

from .app import api, rfc3339DateTime
from .auth import login_if_available
from .common import pagination_model, pagination_request_parser, calc_route

ns = api.namespace('repo', description='Access repository metadata.')


@calc_route(ns)
class RepoCalcResource(Resource):
    @api.response(404, 'The upload or calculation does not exist')
    @api.response(401, 'Not authorized to access the calculation')
    @api.response(200, 'Metadata send', fields.Raw)
    @api.doc('get_repo_calc')
    @login_if_available
    def get(self, upload_id, calc_id):
        """
        Get calculation metadata in repository form.

        Repository metadata only entails the quantities shown in the repository.
        Calcs are references via *upload_id*, *calc_id* pairs.
        """
        try:
            calc = search.Entry.get(calc_id)
        except NotFoundError:
            abort(404, message='There is no calculation %s/%s' % (upload_id, calc_id))

        if calc.with_embargo or not calc.published:
            if g.user is None:
                abort(401, message='Not logged in to access %s/%s.' % (upload_id, calc_id))

            is_owner = g.user.user_id == 0
            if not is_owner:
                for owner in calc.owners:
                    # At somepoint ids will be emails (strings) anyways.
                    # Right now it is hard to make sure that both are either str or int.
                    if str(owner.user_id) == str(g.user.user_id):
                        is_owner = True
                        break
            if not is_owner:
                abort(401, message='Not authorized to access %s/%s.' % (upload_id, calc_id))

        return calc.to_dict(), 200


repo_calcs_model = api.model('RepoCalculations', {
    'pagination': fields.Nested(pagination_model),
    'results': fields.List(fields.Raw, description=(
        'A list of search results. Each result is a dict with quantitie names as key and '
        'values as values')),
    'scroll_id': fields.String(description='Id of the current scroll view in scroll based search.'),
    'aggregations': fields.Raw(description=(
        'A dict with all aggregations. Each aggregation is dictionary with a metrics dict as '
        'value and quantity value as key. The metrics are code runs(calcs), %s. ' %
        ', '.join(search.metrics_names))),
    'metrics': fields.Raw(description=(
        'A dict with the overall metrics. The metrics are code runs(calcs), %s.' %
        ', '.join(search.metrics_names)))
})

repo_request_parser = pagination_request_parser.copy()
repo_request_parser.add_argument(
    'owner', type=str,
    help='Specify which calcs to return: ``all``, ``public``, ``user``, ``staging``, default is ``all``')
repo_request_parser.add_argument(
    'from_time', type=lambda x: rfc3339DateTime.parse(x),
    help='A yyyy-MM-ddTHH:mm:ss (RFC3339) minimum entry time (e.g. upload time)')
repo_request_parser.add_argument(
    'until_time', type=lambda x: rfc3339DateTime.parse(x),
    help='A yyyy-MM-ddTHH:mm:ss (RFC3339) maximum entry time (e.g. upload time)')
repo_request_parser.add_argument(
    'scroll', type=bool, help='Enable scrolling')
repo_request_parser.add_argument(
    'scroll_id', type=str, help='The id of the current scrolling window to use.')
repo_request_parser.add_argument(
    'total_metrics', type=str, help=(
        'Metrics to aggregate all search results over.'
        'Possible values are %s.' % ', '.join(search.metrics_names)))
repo_request_parser.add_argument(
    'aggregation_metrics', type=str, help=(
        'Metrics to aggregate all aggregation buckets over as comma separated list. '
        'Possible values are %s.' % ', '.join(search.metrics_names)))

for search_quantity in search.search_quantities.keys():
    _, _, description = search.search_quantities[search_quantity]
    repo_request_parser.add_argument(search_quantity, type=str, help=description)


@ns.route('/')
class RepoCalcsResource(Resource):
    @api.doc('search')
    @api.response(400, 'Invalid requests, e.g. wrong owner type or bad quantities')
    @api.expect(repo_request_parser, validate=True)
    @api.marshal_with(repo_calcs_model, skip_none=True, code=200, description='Metadata send')
    @login_if_available
    def get(self):
        """
        Search for calculations in the repository from, paginated.

        The ``owner`` parameter determines the overall entries to search through.
        Possible values are: ``all`` (show all entries visible to the current user), ``public``
        (show all publically visible entries), ``user`` (show all user entries, requires login),
        ``staging`` (show all user entries in staging area, requires login).

        You can use the various quantities to search/filter for. For some of the
        indexed quantities this endpoint returns aggregation information. This means
        you will be given a list of all possible values and the number of entries
        that have the certain value. You can also use these aggregations on an empty
        search to determine the possible values.

        The pagination parameters allows determine which page to return via the
        ``page`` and ``per_page`` parameters. Pagination however, is limited to the first
        100k (depending on ES configuration) hits.

        An alternative to pagination is to use ``scroll`` and ``scroll_id``. With ``scroll``
        you will get a ``scroll_id`` on the first request. Each call with ``scroll`` and
        the respective ``scroll_id`` will return the next ``per_page`` (here the default is 1000)
        results. Scroll however, ignores ordering and does not return aggregations.
        The scroll view used in the background will stay alive for 1 minute between requests.
        If the given ``scroll_id`` is not available anymore, a HTTP 400 is raised.

        The search will return aggregations on a predefined set of quantities. Aggregations
        will tell you what quantity values exist and how many entries match those values.

        Ordering is determined by ``order_by`` and ``order`` parameters.
        """

        try:
            scroll = bool(request.args.get('scroll', False))
            scroll_id = request.args.get('scroll_id', None)
            page = int(request.args.get('page', 1))
            per_page = int(request.args.get('per_page', 10 if not scroll else 1000))
            order = int(request.args.get('order', -1))
            total_metrics_str = request.args.get('total_metrics', '')
            aggregation_metrics_str = request.args.get('aggregation_metrics', '')

            from_time = rfc3339DateTime.parse(request.args.get('from_time', '2000-01-01'))
            until_time_str = request.args.get('until_time', None)
            until_time = rfc3339DateTime.parse(until_time_str) if until_time_str is not None else datetime.datetime.now()
            time_range = (from_time, until_time)

            total_metrics = [
                metric for metric in total_metrics_str.split(',')
                if metric in search.metrics_names]
            aggregation_metrics = [
                metric for metric in aggregation_metrics_str.split(',')
                if metric in search.metrics_names]
        except Exception:
            abort(400, message='bad parameter types')

        owner = request.args.get('owner', 'all')
        order_by = request.args.get('order_by', 'formula')

        try:
            assert page >= 1
            assert per_page > 0
        except AssertionError:
            abort(400, message='invalid pagination')

        if order not in [-1, 1]:
            abort(400, message='invalid pagination')

        if owner == 'migrated':
            # TODO this should be removed after migration
            q = Q('term', published=True) & Q('term', with_embargo=False)
            if g.user is not None:
                q = q | Q('term', owners__user_id=g.user.user_id)
            q = q & ~Q('term', **{'uploader.user_id': 1})  # pylint: disable=invalid-unary-operand-type
        elif owner == 'all':
            q = Q('term', published=True) & Q('term', with_embargo=False)
            if g.user is not None:
                q = q | Q('term', owners__user_id=g.user.user_id)
        elif owner == 'public':
            q = Q('term', published=True) & Q('term', with_embargo=False)
        elif owner == 'user':
            if g.user is None:
                abort(401, message='Authentication required for owner value user.')

            q = Q('term', owners__user_id=g.user.user_id)
        elif owner == 'staging':
            if g.user is None:
                abort(401, message='Authentication required for owner value user.')
            q = Q('term', published=False) & Q('term', owners__user_id=g.user.user_id)
        elif owner == 'admin':
            if g.user is None or not g.user.is_admin:
                abort(401, message='This can only be used by the admin user.')
            q = None
        else:
            abort(400, message='Invalid owner value. Valid values are all|user|staging, default is all')

        # TODO this should be removed after migration
        without_currupted_mainfile = ~Q('term', code_name='currupted mainfile')  # pylint: disable=invalid-unary-operand-type
        q = q & without_currupted_mainfile if q is not None else without_currupted_mainfile

        data = dict(**request.args)
        data.pop('owner', None)
        data.pop('scroll', None)
        data.pop('scroll_id', None)
        data.pop('per_page', None)
        data.pop('page', None)
        data.pop('order', None)
        data.pop('order_by', None)
        data.pop('total_metrics', None)
        data.pop('aggregation_metrics', None)
        data.pop('from_time', None)
        data.pop('until_time', None)

        if scroll:
            data.update(scroll_id=scroll_id, size=per_page)
        else:
            data.update(
                per_page=per_page, page=page, order=order, order_by=order_by, time_range=time_range,
                total_metrics=total_metrics, aggregation_metrics=aggregation_metrics)

        try:
            if scroll:
                page = -1
                scroll_id, total, results = search.scroll_search(q=q, **data)
                aggregations = {}
                metrics = {}
            else:
                scroll_id = None
                total, results, aggregations, metrics = search.aggregate_search(q=q, **data)
        except search.ScrollIdNotFound:
            abort(400, 'The given scroll_id does not exist.')
        except KeyError as e:
            abort(400, str(e))

        # TODO just a workarround to make things prettier
        if 'code_name' in aggregations and 'currupted mainfile' in aggregations['code_name']:
            del(aggregations['code_name']['currupted mainfile'])

        return dict(
            pagination=dict(total=total, page=page, per_page=per_page),
            results=results,
            scroll_id=scroll_id,
            aggregations=aggregations,
            metrics=metrics), 200