import datetime
import uuid
from itertools import filterfalse

import marshmallow
from flask import g, current_app as app, render_template, request, Response
from flask.json import jsonify
from flask_sqlalchemy import Pagination
from sqlalchemy.util import OrderedSet
from marshmallow import fields, fields as f, validate as v, Schema as MarshmallowSchema
from teal import query
from teal.db import ResourceNotFound
from teal.cache import cache
from teal.resource import View
from teal.marshmallow import ValidationError

from ereuse_devicehub import auth
from ereuse_devicehub.db import db
from ereuse_devicehub.query import SearchQueryParser, things_response
from ereuse_devicehub.resources import search
from ereuse_devicehub.resources.action import models as actions
from ereuse_devicehub.resources.device import states
from ereuse_devicehub.resources.device.models import Device, Manufacturer, Computer
from ereuse_devicehub.resources.device.search import DeviceSearch
from ereuse_devicehub.resources.enums import SnapshotSoftware
from ereuse_devicehub.resources.lot.models import LotDeviceDescendants
from ereuse_devicehub.resources.action.models import Trade
from ereuse_devicehub.resources.tag.model import Tag


class OfType(f.Str):
    def __init__(self, column: db.Column, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.column = column

    def _deserialize(self, value, attr, data):
        v = super()._deserialize(value, attr, data)
        return self.column.in_(app.resources[v].subresources_types)


class RateQ(query.Query):
    rating = query.Between(actions.Rate._rating, f.Float())
    appearance = query.Between(actions.Rate._appearance, f.Float())
    functionality = query.Between(actions.Rate._functionality, f.Float())


class TagQ(query.Query):
    id = query.Or(query.ILike(Tag.id), required=True)
    org = query.ILike(Tag.org)


class LotQ(query.Query):
    id = query.Or(query.Equal(LotDeviceDescendants.ancestor_lot_id, fields.UUID()))


class Filters(query.Query):
    id = query.Or(query.Equal(Device.id, fields.Integer()))
    devicehub_id = query.Or(query.ILike(Device.devicehub_id))
    type = query.Or(OfType(Device.type))
    model = query.ILike(Device.model)
    manufacturer = query.ILike(Device.manufacturer)
    serialNumber = query.ILike(Device.serial_number)
    # todo test query for rating (and possibly other filters)
    rating = query.Join((Device.id == actions.ActionWithOneDevice.device_id)
                        & (actions.ActionWithOneDevice.id == actions.Rate.id),
                        RateQ)
    tag = query.Join(Device.id == Tag.device_id, TagQ)
    # todo This part of the query is really slow
    # And forces usage of distinct, as it returns many rows
    # due to having multiple paths to the same
    lot = query.Join((Device.id == LotDeviceDescendants.device_id),
                     LotQ)


class Sorting(query.Sort):
    id = query.SortField(Device.id)
    created = query.SortField(Device.created)
    updated = query.SortField(Device.updated)


class DeviceView(View):
    QUERY_PARSER = SearchQueryParser()

    class FindArgs(marshmallow.Schema):
        search = f.Str()
        filter = f.Nested(Filters, missing=[])
        sort = f.Nested(Sorting, missing=[Device.id.asc()])
        page = f.Integer(validate=v.Range(min=1), missing=1)
        unassign = f.Integer(validate=v.Range(min=0, max=1), missing=0)

    def get(self, id):
        """Devices view
        ---
        description: Gets a device or multiple devices.
        parameters:
          - name: id
            type: integer
            in: path}
            description: The identifier of the device.
        responses:
          200:
            description: The device or devices.
        """
        return super().get(id)

    def patch(self, id):
        dev = Device.query.filter_by(id=id, owner_id=g.user.id).one()
        if isinstance(dev, Computer):
            resource_def = app.resources['Computer']
            # TODO check how to handle the 'actions_one'
            patch_schema = resource_def.SCHEMA(
                only=['transfer_state', 'actions_one'], partial=True)
            json = request.get_json(schema=patch_schema)
            # TODO check how to handle the 'actions_one'
            json.pop('actions_one')
            if not dev:
                raise ValueError('Device non existent')
            for key, value in json.items():
                setattr(dev, key, value)
            db.session.commit()
            return Response(status=204)
        raise ValueError('Cannot patch a non computer')

    def one(self, id: str):
        """Gets one device."""
        if not request.authorization:
            return self.one_public(id)
        else:
            return self.one_private(id)

    def one_public(self, id: int):
        device = Device.query.filter_by(devicehub_id=id).one()
        return render_template('devices/layout.html', device=device, states=states)

    @auth.Auth.requires_auth
    def one_private(self, id: str):
        device = Device.query.filter_by(devicehub_id=id, owner_id=g.user.id).first()
        if not device:
            return self.one_public(id)
        return self.schema.jsonify(device)

    @auth.Auth.requires_auth
    # @cache(datetime.timedelta(minutes=1))
    def find(self, args: dict):
        """Gets many devices."""
        # Compute query
        query = self.query(args)
        devices = query.paginate(page=args['page'], per_page=30)  # type: Pagination
        return things_response(
            self.schema.dump(devices.items, many=True, nested=1),
            devices.page, devices.per_page, devices.total, devices.prev_num, devices.next_num
        )

    def query(self, args):
        trades = Trade.query.filter(
            (Trade.user_from == g.user) | (Trade.user_to == g.user)
        ).distinct()

        trades_dev_ids = {d.id for t in trades for d in t.devices}

        query = Device.query.filter(
            (Device.owner_id == g.user.id) | (Device.id.in_(trades_dev_ids))
        ).distinct()

        unassign = args.get('unassign', None)
        search_p = args.get('search', None)
        if search_p:
            properties = DeviceSearch.properties
            tags = DeviceSearch.tags
            devicehub_ids = DeviceSearch.devicehub_ids
            query = query.join(DeviceSearch).filter(
                search.Search.match(properties, search_p) |
                search.Search.match(tags, search_p) |
                search.Search.match(devicehub_ids, search_p)
            ).order_by(
                search.Search.rank(properties, search_p) +
                search.Search.rank(tags, search_p) +
                search.Search.rank(devicehub_ids, search_p)
            )
        if unassign:
            subquery = LotDeviceDescendants.query.with_entities(
                           LotDeviceDescendants.device_id
            )
            query = query.filter(Device.id.notin_(subquery))
        return query.filter(*args['filter']).order_by(*args['sort'])


class DeviceMergeView(View):
    """View for merging two devices
    Ex. ``device/<dev1_id>/merge/<dev2_id>``.
    """

    def post(self, dev1_id: int, dev2_id: int):
        device = self.merge_devices(dev1_id, dev2_id)

        ret = self.schema.jsonify(device)
        ret.status_code = 201

        db.session.commit()
        return ret

    @auth.Auth.requires_auth
    def merge_devices(self, dev1_id: int, dev2_id: int) -> Device:
        """Merge the current device with `with_device` (dev2_id) by
        adding all `with_device` actions under the current device, (dev1_id).

        This operation is highly costly as it forces refreshing
        many models in session.
        """
        # base_device = Device.query.filter_by(id=dev1_id, owner_id=g.user.id).one()
        self.base_device = Device.query.filter_by(id=dev1_id, owner_id=g.user.id).one()
        self.with_device = Device.query.filter_by(id=dev2_id, owner_id=g.user.id).one()

        if self.base_device.allocated or self.with_device.allocated:
            # Validation than any device is allocated
            msg = 'The device is allocated, please deallocated before merge.'
            raise ValidationError(msg)

        if not self.base_device.type == self.with_device.type:
            # Validation than we are speaking of the same kind of devices
            raise ValidationError('The devices is not the same type.')

        # Adding actions of self.with_device
        with_actions_one = [a for a in self.with_device.actions
                            if isinstance(a, actions.ActionWithOneDevice)]
        with_actions_multiple = [a for a in self.with_device.actions
                                 if isinstance(a, actions.ActionWithMultipleDevices)]

        # Moving the tags from `with_device` to `base_device`
        # Union of tags the device had plus the (potentially) new ones
        self.base_device.tags.update([x for x in self.with_device.tags])
        self.with_device.tags.clear()  # We don't want to add the transient dummy tags
        db.session.add(self.with_device)

        # Moving the actions from `with_device` to `base_device`
        for action in with_actions_one:
            if action.parent:
                action.parent = self.base_device
            else:
                self.base_device.actions_one.add(action)
        for action in with_actions_multiple:
            if action.parent:
                action.parent = self.base_device
            else:
                self.base_device.actions_multiple.add(action)

        # Keeping the components of with_device
        components = OrderedSet(c for c in self.with_device.components)
        self.base_device.components = components

        # Properties from with_device
        self.merge()

        db.session().add(self.base_device)
        db.session().final_flush()
        return self.base_device

    def merge(self):
        """Copies the physical properties of the base_device to the with_device.
        This method mutates base_device.
        """
        for field_name, value in self.with_device.physical_properties.items():
            if value is not None:
                setattr(self.base_device, field_name, value)

        self.base_device.hid = self.with_device.hid
        self.base_device.add_mac_to_hid()


class ManufacturerView(View):
    class FindArgs(marshmallow.Schema):
        search = marshmallow.fields.Str(required=True,
                                        # Disallow like operators
                                        validate=lambda x: '%' not in x and '_' not in x)

    @cache(datetime.timedelta(days=1))
    def find(self, args: dict):
        search = args['search']
        manufacturers = Manufacturer.query \
            .filter(Manufacturer.name.ilike(search + '%')) \
            .paginate(page=1, per_page=6)  # type: Pagination
        return jsonify(
            items=app.resources[Manufacturer.t].schema.dump(
                manufacturers.items,
                many=True,
                nested=1
            )
        )