from datetime import datetime, timedelta, timezone
from distutils.version import StrictVersion
from typing import List, Tuple
from uuid import uuid4

import pytest
from teal.db import UniqueViolation
from teal.marshmallow import ValidationError

from ereuse_devicehub.client import UserClient
from ereuse_devicehub.db import db
from ereuse_devicehub.devicehub import Devicehub
from ereuse_devicehub.resources.device import models as m
from ereuse_devicehub.resources.device.exceptions import NeedsId
from ereuse_devicehub.resources.device.sync import MismatchBetweenTagsAndHid
from ereuse_devicehub.resources.enums import Bios, ComputerChassis, RatingSoftware, \
    SnapshotSoftware
from ereuse_devicehub.resources.event.models import AggregateRate, BenchmarkProcessor, \
    EraseSectors, Event, Snapshot, SnapshotRequest, WorkbenchRate
from ereuse_devicehub.resources.tag import Tag
from ereuse_devicehub.resources.user.models import User
from tests.conftest import file


@pytest.mark.usefixtures('auth_app_context')
def test_snapshot_model():
    """
    Tests creating a Snapshot with its relationships ensuring correct
    DB mapping.
    """
    device = m.Desktop(serial_number='a1', chassis=ComputerChassis.Tower)
    # noinspection PyArgumentList
    snapshot = Snapshot(uuid=uuid4(),
                        end_time=datetime.now(timezone.utc),
                        version='1.0',
                        software=SnapshotSoftware.DesktopApp,
                        elapsed=timedelta(seconds=25))
    snapshot.device = device
    snapshot.request = SnapshotRequest(request={'foo': 'bar'})
    snapshot.events.add(WorkbenchRate(processor=0.1,
                                      ram=1.0,
                                      bios=Bios.A,
                                      labelling=False,
                                      graphic_card=0.1,
                                      data_storage=4.1,
                                      software=RatingSoftware.ECost,
                                      version=StrictVersion('1.0'),
                                      device=device))
    db.session.add(snapshot)
    db.session.commit()
    device = m.Desktop.query.one()  # type: m.Desktop
    e1, e2 = device.events
    assert isinstance(e1, Snapshot), 'Creation order must be preserved: 1. snapshot, 2. WR'
    assert isinstance(e2, WorkbenchRate)
    db.session.delete(device)
    db.session.commit()
    assert Snapshot.query.one_or_none() is None
    assert SnapshotRequest.query.one_or_none() is None
    assert User.query.one() is not None
    assert m.Desktop.query.one_or_none() is None
    assert m.Device.query.one_or_none() is None


def test_snapshot_schema(app: Devicehub):
    with app.app_context():
        s = file('basic.snapshot')
        app.resources['Snapshot'].schema.load(s)


def test_snapshot_post(user: UserClient):
    """
    Tests the post snapshot endpoint (validation, etc), data correctness,
    and relationship correctness.
    """
    snapshot = snapshot_and_check(user, file('basic.snapshot'),
                                  event_types=(
                                      WorkbenchRate.t,
                                      AggregateRate.t,
                                      BenchmarkProcessor.t
                                  ),
                                  perform_second_snapshot=False)
    assert snapshot['software'] == 'Workbench'
    assert snapshot['version'] == '11.0'
    assert snapshot['uuid'] == 'f5efd26e-8754-46bc-87bf-fbccc39d60d9'
    assert snapshot['elapsed'] == 4
    assert snapshot['author']['id'] == user.user['id']
    assert 'events' not in snapshot['device']
    assert 'author' not in snapshot['device']
    device, _ = user.get(res=m.Device, item=snapshot['device']['id'])
    assert snapshot['components'] == device['components']

    assert tuple(c['type'] for c in snapshot['components']) == (m.GraphicCard.t, m.RamModule.t,
                                                                m.Processor.t)
    rate = next(e for e in snapshot['events'] if e['type'] == WorkbenchRate.t)
    rate, _ = user.get(res=Event, item=rate['id'])
    assert rate['device']['id'] == snapshot['device']['id']
    assert rate['components'] == snapshot['components']
    assert rate['snapshot']['id'] == snapshot['id']


def test_snapshot_component_add_remove(user: UserClient):
    """
    Tests adding and removing components and some don't generate HID.
    All computers generate HID.
    """

    def get_events_info(events: List[dict]) -> tuple:
        return tuple(
            (
                e['type'],
                [c['serialNumber'] for c in e['components']]
            )
            for e in user.get_many(res=Event, resources=events, key='id')
        )

    # We add the first device (2 times). The distribution of components
    # (represented with their S/N) should be:
    # PC 1: p1c1s, p1c2s, p1c3s. PC 2: ø
    s1 = file('1-device-with-components.snapshot')
    snapshot1 = snapshot_and_check(user, s1, perform_second_snapshot=False)
    pc1_id = snapshot1['device']['id']
    pc1, _ = user.get(res=m.Device, item=pc1_id)
    # Parent contains components
    assert tuple(c['serialNumber'] for c in pc1['components']) == ('p1c1s', 'p1c2s', 'p1c3s')
    # Components contain parent
    assert all(c['parent'] == pc1_id for c in pc1['components'])
    # pc has Snapshot as event
    assert len(pc1['events']) == 1
    assert pc1['events'][0]['type'] == Snapshot.t
    # p1c1s has Snapshot
    p1c1s, _ = user.get(res=m.Device, item=pc1['components'][0]['id'])
    assert tuple(e['type'] for e in p1c1s['events']) == ('Snapshot',)

    # We register a new device
    # It has the processor of the first one (p1c2s)
    # PC 1: p1c1s, p1c3s. PC 2: p2c1s, p1c2s
    # Events PC1: Snapshot, Remove. PC2: Snapshot
    s2 = file('2-second-device-with-components-of-first.snapshot')
    # num_events = 2 = Remove, Add
    snapshot2 = snapshot_and_check(user, s2, event_types=('Remove',),
                                   perform_second_snapshot=False)
    pc2_id = snapshot2['device']['id']
    pc1, _ = user.get(res=m.Device, item=pc1_id)
    pc2, _ = user.get(res=m.Device, item=pc2_id)
    # PC1
    assert tuple(c['serialNumber'] for c in pc1['components']) == ('p1c1s', 'p1c3s')
    assert all(c['parent'] == pc1_id for c in pc1['components'])
    assert tuple(e['type'] for e in pc1['events']) == ('Snapshot', 'Remove')
    # PC2
    assert tuple(c['serialNumber'] for c in pc2['components']) == ('p1c2s', 'p2c1s')
    assert all(c['parent'] == pc2_id for c in pc2['components'])
    assert tuple(e['type'] for e in pc2['events']) == ('Snapshot',)
    # p1c2s has two Snapshots, a Remove and an Add
    p1c2s, _ = user.get(res=m.Device, item=pc2['components'][0]['id'])
    assert tuple(e['type'] for e in p1c2s['events']) == ('Snapshot', 'Snapshot', 'Remove')

    # We register the first device again, but removing motherboard
    # and moving processor from the second device to the first.
    # We have created 1 Remove (from PC2's processor back to PC1)
    # PC 0: p1c2s, p1c3s. PC 1: p2c1s
    s3 = file('3-first-device-but-removing-motherboard-and-adding-processor-from-2.snapshot')
    snapshot_and_check(user, s3, ('Remove',), perform_second_snapshot=False)
    pc1, _ = user.get(res=m.Device, item=pc1_id)
    pc2, _ = user.get(res=m.Device, item=pc2_id)
    # PC1
    assert {c['serialNumber'] for c in pc1['components']} == {'p1c2s', 'p1c3s'}
    assert all(c['parent'] == pc1_id for c in pc1['components'])
    assert tuple(get_events_info(pc1['events'])) == (
        # id, type, components, snapshot
        ('Snapshot', ['p1c1s', 'p1c2s', 'p1c3s']),  # first Snapshot1
        ('Remove', ['p1c2s']),  # Remove Processor in Snapshot2
        ('Snapshot', ['p1c2s', 'p1c3s'])  # This Snapshot3
    )
    # PC2
    assert tuple(c['serialNumber'] for c in pc2['components']) == ('p2c1s',)
    assert all(c['parent'] == pc2_id for c in pc2['components'])
    assert tuple(e['type'] for e in pc2['events']) == (
        'Snapshot',  # Second Snapshot
        'Remove'  # the processor we added in 2.
    )
    # p1c2s has Snapshot, Remove and Add
    p1c2s, _ = user.get(res=m.Device, item=pc1['components'][0]['id'])
    assert tuple(get_events_info(p1c2s['events'])) == (
        ('Snapshot', ['p1c1s', 'p1c2s', 'p1c3s']),  # First Snapshot to PC1
        ('Snapshot', ['p1c2s', 'p2c1s']),  # Second Snapshot to PC2
        ('Remove', ['p1c2s']),  # ...which caused p1c2s to be removed form PC1
        ('Snapshot', ['p1c2s', 'p1c3s']),  # The third Snapshot to PC1
        ('Remove', ['p1c2s'])  # ...which caused p1c2 to be removed from PC2
    )

    # We register the first device but without the processor,
    # adding a graphic card and adding a new component
    s4 = file('4-first-device-but-removing-processor.snapshot-and-adding-graphic-card')
    snapshot_and_check(user, s4, perform_second_snapshot=False)
    pc1, _ = user.get(res=m.Device, item=pc1_id)
    pc2, _ = user.get(res=m.Device, item=pc2_id)
    # PC 0: p1c3s, p1c4s. PC1: p2c1s
    assert {c['serialNumber'] for c in pc1['components']} == {'p1c3s', 'p1c4s'}
    assert all(c['parent'] == pc1_id for c in pc1['components'])
    # This last Snapshot only
    assert get_events_info(pc1['events'])[-1] == ('Snapshot', ['p1c3s', 'p1c4s'])
    # PC2
    # We haven't changed PC2
    assert tuple(c['serialNumber'] for c in pc2['components']) == ('p2c1s',)
    assert all(c['parent'] == pc2_id for c in pc2['components'])


def _test_snapshot_computer_no_hid(user: UserClient):
    """
    Tests inserting a computer that doesn't generate a HID, neither
    some of its components.
    """
    # PC with 2 components. PC doesn't have HID and neither 1st component
    s = file('basic.snapshot')
    del s['device']['model']
    del s['components'][0]['model']
    user.post(s, res=Snapshot, status=NeedsId)
    # The system tells us that it could not register the device because
    # the device (computer) cannot generate a HID.
    # In such case we need to specify an ``id`` so the system can
    # recognize the device. The ``id`` can reference to the same
    # device, it already existed in the DB, or to a placeholder,
    # if the device is new in the DB.
    user.post(s, res=m.Device)
    s['device']['id'] = 1  # Assign the ID of the placeholder
    user.post(s, res=Snapshot)


def test_snapshot_mismatch_id():
    """Tests uploading a device with an ID from another device."""
    # Note that this won't happen as in this new version
    # the ID is not used in the Snapshot process
    pass


def test_snapshot_tag_inner_tag(tag_id: str, user: UserClient, app: Devicehub):
    """Tests a posting Snapshot with a local tag."""
    b = file('basic.snapshot')
    b['device']['tags'] = [{'type': 'Tag', 'id': tag_id}]
    snapshot_and_check(user, b,
                       event_types=(WorkbenchRate.t, AggregateRate.t, BenchmarkProcessor.t))
    with app.app_context():
        tag = Tag.query.one()  # type: Tag
        assert tag.device_id == 1, 'Tag should be linked to the first device'


def test_snapshot_tag_inner_tag_mismatch_between_tags_and_hid(user: UserClient, tag_id: str):
    """Ensures one device cannot 'steal' the tag from another one."""
    pc1 = file('basic.snapshot')
    pc1['device']['tags'] = [{'type': 'Tag', 'id': tag_id}]
    user.post(pc1, res=Snapshot)
    pc2 = file('1-device-with-components.snapshot')
    user.post(pc2, res=Snapshot)  # PC2 uploads well
    pc2['device']['tags'] = [{'type': 'Tag', 'id': tag_id}]  # Set tag from pc1 to pc2
    user.post(pc2, res=Snapshot, status=MismatchBetweenTagsAndHid)


@pytest.mark.xfail(reason='There is no attribute checking for tag-matching devices')
def test_snapshot_different_properties_same_tags(user: UserClient, tag_id: str):
    """
    Tests a snapshot performed to device 1 with tag A and then to
    device 2 with tag B. Both don't have HID but are different type.
    Devicehub must fail the Snapshot.
    """
    # 1. Upload PC1 without hid but with tag
    pc1 = file('basic.snapshot')
    pc1['device']['tags'] = [{'type': 'Tag', 'id': tag_id}]
    del pc1['device']['serialNumber']
    user.post(pc1, res=Snapshot)
    # 2. Upload PC2 without hid, a different characteristic than PC1, but with same tag
    pc2 = file('basic.snapshot')
    pc2['uuid'] = uuid4()
    pc2['device']['tags'] = pc1['device']['tags']
    del pc2['device'][
        'model']  # pc2 model is unknown but pc1 model is set = different characteristic
    user.post(pc2, res=Snapshot, status=422)


def test_snapshot_upload_twice_uuid_error(user: UserClient):
    pc1 = file('basic.snapshot')
    user.post(pc1, res=Snapshot)
    user.post(pc1, res=Snapshot, status=UniqueViolation)


def test_snapshot_component_containing_components(user: UserClient):
    """There is no reason for components to have components and when
    this happens it is always an error.

    This test avoids this until an appropriate use-case is presented.
    """
    s = file('basic.snapshot')
    s['device'] = {
        'type': 'Processor',
        'serialNumber': 'foo',
        'manufacturer': 'bar',
        'model': 'baz'
    }
    user.post(s, res=Snapshot, status=ValidationError)


def test_erase(user: UserClient):
    """Tests a Snapshot with EraseSectors."""
    s = file('erase-sectors.snapshot')
    snapshot = snapshot_and_check(user, s, (EraseSectors.t,), perform_second_snapshot=True)
    storage, *_ = snapshot['components']
    assert storage['type'] == 'SolidStateDrive', 'Components must be ordered by input order'
    storage, _ = user.get(res=m.Device, item=storage['id'])  # Let's get storage events too
    # order: creation time descending
    erasure1, _snapshot1, erasure2, _snapshot2 = storage['events']
    assert erasure1['type'] == erasure2['type'] == 'EraseSectors'
    assert _snapshot1['type'] == _snapshot2['type'] == 'Snapshot'
    assert snapshot == user.get(res=Event, item=_snapshot2['id'])[0]
    erasure, _ = user.get(res=Event, item=erasure1['id'])
    assert len(erasure['steps']) == 2
    assert erasure['steps'][0]['startTime'] == '2018-06-01T08:15:00+00:00'
    assert erasure['steps'][0]['endTime'] == '2018-06-01T09:16:00+00:00'
    assert erasure['steps'][1]['startTime'] == '2018-06-01T08:16:00+00:00'
    assert erasure['steps'][1]['endTime'] == '2018-06-01T09:17:00+00:00'
    assert erasure['device']['id'] == storage['id']
    for step in erasure['steps']:
        assert step['type'] == 'StepZero'
        assert step['error'] is False
        assert 'num' not in step


def test_snapshot_computer_monitor(user: UserClient):
    s = file('computer-monitor.snapshot')
    snapshot_and_check(user, s, event_types=('AppRate',))


def test_snapshot_components_none():
    """
    Tests that a snapshot without components does not
    remove them from the computer.
    """
    # todo test
    pass


def test_snapshot_components_empty():
    """
    Tests that a snapshot whose components are an empty list remove
    all its components.
    """


def assert_similar_device(device1: dict, device2: dict):
    """
    Like :class:`ereuse_devicehub.resources.device.models.Device.
    is_similar()` but adapted for testing.
    """
    assert isinstance(device1, dict) and device1
    assert isinstance(device2, dict) and device2
    for key in 'serialNumber', 'model', 'manufacturer', 'type':
        assert device1.get(key, '').lower() == device2.get(key, '').lower()


def assert_similar_components(components1: List[dict], components2: List[dict]):
    """
    Asserts that the components in components1 are
    similar than the components in components2.
    """
    assert len(components1) == len(components2)
    for c1, c2 in zip(components1, components2):
        assert_similar_device(c1, c2)


def snapshot_and_check(user: UserClient,
                       input_snapshot: dict,
                       event_types: Tuple[str] = tuple(),
                       perform_second_snapshot=True) -> dict:
    """
        Performs a Snapshot and then checks if the result is ok:

        - There have been performed the types of events and in the same
          order as described in the passed-in ``event_types``.
        - The inputted devices are similar to the resulted ones.
        - There is no Remove event after the first Add.
        - All input components are now inside the parent device.

        Optionally, it can perform a second Snapshot which should
        perform an exact result, except for the events.

        :return: The last resulting snapshot.
    """
    snapshot, _ = user.post(res=Snapshot, data=input_snapshot)
    assert all(e['type'] in event_types for e in snapshot['events'])
    assert len(snapshot['events']) == len(event_types)
    # Ensure there is no Remove event after the first Add
    found_add = False
    for event in snapshot['events']:
        if event['type'] == 'Add':
            found_add = True
        if found_add:
            assert event['type'] != 'Receive', 'All Remove events must be before the Add ones'
    assert input_snapshot['device']
    assert_similar_device(input_snapshot['device'], snapshot['device'])
    if input_snapshot.get('components', None):
        assert_similar_components(input_snapshot['components'], snapshot['components'])
    assert all(c['parent'] == snapshot['device']['id'] for c in snapshot['components']), \
        'Components must be in their parent'
    if perform_second_snapshot:
        if 'uuid' in input_snapshot:
            input_snapshot['uuid'] = uuid4()
        return snapshot_and_check(user, input_snapshot, event_types, perform_second_snapshot=False)
    else:
        return snapshot