# 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.


import datetime
from flask_keystone import current_user
from python_nemesis.db.models import FileLookupRequest
from python_nemesis.db.models import Files
from python_nemesis.extensions import db
from sqlalchemy import or_
from sqlalchemy.orm.exc import NoResultFound


def add_request(lookup_hash, result, file_id=None):
    now = datetime.datetime.now()
    nreq = FileLookupRequest(requested_at=now,
                             requestor=current_user.user_id,
                             file_id=file_id,
                             lookup_hash=lookup_hash,
                             result=result)
    db.session.add(nreq)
    db.session.commit()


def search_by_hash(lookup_hash):
    results = db.session.query(Files). \
        filter(or_(Files.sha512_hash == lookup_hash,
                   Files.sha256_hash == lookup_hash,
                   Files.sha1_hash == lookup_hash,
                   Files.md5_hash == lookup_hash))

    ret_results = []
    for file in results:
        ret_results.append(file.to_dict())

    return ret_results


def get_file_by_sha512_hash(lookup_hash):
    try:
        result = db.session.query(Files). \
            filter(Files.sha512_hash == lookup_hash).one()
    except NoResultFound:
        result = None

    return result


def create_new_file(md5_hash, sha1_hash, sha256_hash, sha512_hash,
                    size, file_type, submitter):
    now = datetime.datetime.now()
    file = Files(size=size,
                 mime_type=file_type,
                 md5_hash=md5_hash,
                 sha1_hash=sha1_hash,
                 sha256_hash=sha256_hash,
                 sha512_hash=sha512_hash,
                 submitted_by=submitter,
                 last_updated=now,
                 first_seen=now,
                 status='analysing')
    db.session.add(file)
    db.session.commit()
    return file


def create_or_renew_by_hash(hashes, file_size, file_type=None):
    current_file = get_file_by_sha512_hash(hashes['sha512'])

    if current_file:
        current_file.last_updated = datetime.datetime.now()
        current_file.status = 'analysing'
        db.session.commit()
        return current_file

    else:
        file = create_new_file(hashes['md5'],
                               hashes['sha1'],
                               hashes['sha256'],
                               hashes['sha512'],
                               file_size,
                               file_type,
                               current_user.user_id)
        return file


def get_file_by_id(file_id):
    try:
        result = db.session.query(Files). \
            filter(Files.file_id == file_id).one()
    except NoResultFound:
        result = None

    return result


def update_status_by_file_id(file_id, new_status):
    update_file = get_file_by_id(file_id)

    if update_file:
        update_file.status = new_status
        db.session.commit()
        return True
    else:
        return False