# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import datetime
from decimal import Decimal

from trytond.model import ModelView, ModelSQL, MatchMixin, fields, \
    sequence_ordered
from trytond import backend
from trytond.pyson import Eval, If
from trytond.transaction import Transaction
from trytond.pool import Pool, PoolMeta
from trytond.tools import grouped_slice

__all__ = ['Location', 'Party', 'ProductsByLocationsContext',
    'LocationLeadTime']

STATES = {
    'readonly': ~Eval('active'),
}
DEPENDS = ['active']


class Location(ModelSQL, ModelView):
    "Stock Location"
    __name__ = 'stock.location'
    name = fields.Char("Name", size=None, required=True, states=STATES,
        depends=DEPENDS, translate=True)
    code = fields.Char("Code", size=None, states=STATES, depends=DEPENDS,
        select=True)
    active = fields.Boolean('Active', select=True)
    address = fields.Many2One("party.address", "Address",
        states={
            'invisible': Eval('type') != 'warehouse',
            'readonly': ~Eval('active'),
            },
        depends=['type', 'active'])
    type = fields.Selection([
        ('supplier', 'Supplier'),
        ('customer', 'Customer'),
        ('lost_found', 'Lost and Found'),
        ('warehouse', 'Warehouse'),
        ('storage', 'Storage'),
        ('production', 'Production'),
        ('drop', 'Drop'),
        ('view', 'View'),
        ], 'Location type', states=STATES, depends=DEPENDS)
    parent = fields.Many2One("stock.location", "Parent", select=True,
        left="left", right="right",
        states={
            'invisible': Eval('type') == 'warehouse',
            },
        depends=['type'])
    left = fields.Integer('Left', required=True, select=True)
    right = fields.Integer('Right', required=True, select=True)
    childs = fields.One2Many("stock.location", "parent", "Children")
    warehouse = fields.Function(fields.Many2One('stock.location', 'Warehouse'),
        'get_warehouse')
    input_location = fields.Many2One(
        "stock.location", "Input", states={
            'invisible': Eval('type') != 'warehouse',
            'readonly': ~Eval('active'),
            'required': Eval('type') == 'warehouse',
            },
        domain=[
            ('type', '=', 'storage'),
            ['OR',
                ('parent', 'child_of', [Eval('id')]),
                ('parent', '=', None),
                ],
            ],
        depends=['type', 'active', 'id'])
    output_location = fields.Many2One(
        "stock.location", "Output", states={
            'invisible': Eval('type') != 'warehouse',
            'readonly': ~Eval('active'),
            'required': Eval('type') == 'warehouse',
        },
        domain=[
            ('type', '=', 'storage'),
            ['OR',
                ('parent', 'child_of', [Eval('id')]),
                ('parent', '=', None)]],
        depends=['type', 'active', 'id'])
    storage_location = fields.Many2One(
        "stock.location", "Storage", states={
            'invisible': Eval('type') != 'warehouse',
            'readonly': ~Eval('active'),
            'required': Eval('type') == 'warehouse',
        },
        domain=[
            ('type', 'in', ['storage', 'view']),
            ['OR',
                ('parent', 'child_of', [Eval('id')]),
                ('parent', '=', None)]],
        depends=['type', 'active', 'id'])
    picking_location = fields.Many2One(
        'stock.location', 'Picking', states={
            'invisible': Eval('type') != 'warehouse',
            'readonly': ~Eval('active'),
            },
        domain=[
            ('type', '=', 'storage'),
            ('parent', 'child_of', [Eval('storage_location', -1)]),
            ],
        depends=['type', 'active', 'storage_location'],
        help='If empty the Storage is used')
    quantity = fields.Function(fields.Float('Quantity'), 'get_quantity')
    forecast_quantity = fields.Function(fields.Float('Forecast Quantity'),
            'get_quantity')
    cost_value = fields.Function(fields.Numeric('Cost Value'),
        'get_cost_value')

    @classmethod
    def __setup__(cls):
        super(Location, cls).__setup__()
        cls._order.insert(0, ('name', 'ASC'))
        cls._error_messages.update({
                'invalid_type_for_moves': ('Location "%s" with existing moves '
                    'cannot be changed to a type that does not support moves.'
                    ),
                'child_of_warehouse': ('Location "%(location)s" must be a '
                    'child of warehouse "%(warehouse)s".'),
                })

        parent_domain = []
        childs_domain = []
        childs_mapping = cls._childs_domain()
        for type_, allowed_parents in cls._parent_domain().iteritems():
            parent_domain.append(If(Eval('type') == type_,
                    ('type', 'in', allowed_parents), ()))
            childs_domain.append(If(Eval('type') == type_,
                    ('type', 'in', childs_mapping[type_]), ()))
        cls.parent.domain = parent_domain
        cls.childs.domain = childs_domain
        cls.childs.depends.append('type')

    @classmethod
    def _parent_domain(cls):
        '''Returns a dict with location types as keys and a list of allowed
        parent location types as values'''
        return {
            'customer': ['customer'],
            'supplier': ['supplier'],
            'production': ['production'],
            'lost_found': ['lost_found'],
            'view': ['warehouse', 'view', 'storage'],
            'storage': ['warehouse', 'view', 'storage'],
            'warehouse': [''],
            }

    @classmethod
    def _childs_domain(cls):
        childs_domain = {}
        for type_, allowed_parents in cls._parent_domain().iteritems():
            for parent in allowed_parents:
                childs_domain.setdefault(parent, [])
                childs_domain[parent].append(type_)
        return childs_domain

    @classmethod
    def __register__(cls, module_name):
        TableHandler = backend.get('TableHandler')
        super(Location, cls).__register__(module_name)

        table = TableHandler(cls, module_name)
        table.index_action(['left', 'right'], 'add')

    @classmethod
    def validate(cls, locations):
        super(Location, cls).validate(locations)
        cls.check_recursion(locations)
        for location in locations:
            location.check_type_for_moves()

    def check_type_for_moves(self):
        """ Check locations with moves have types compatible with moves. """
        invalid_move_types = ['warehouse', 'view']
        Move = Pool().get('stock.move')
        if (self.type in invalid_move_types
                and Move.search([
                        ['OR',
                            ('to_location', '=', self.id),
                            ('from_location', '=', self.id),
                            ],
                        ('state', 'not in', ['staging', 'draft']),
                        ])):
            self.raise_user_error('invalid_type_for_moves', (self.rec_name,))

    @staticmethod
    def default_active():
        return True

    @staticmethod
    def default_left():
        return 0

    @staticmethod
    def default_right():
        return 0

    @staticmethod
    def default_type():
        return 'storage'

    @classmethod
    def check_xml_record(self, records, values):
        return True

    def get_warehouse(self, name):
        # Order by descending left to get the first one in the tree
        with Transaction().set_context(active_test=False):
            locations = self.search([
                    ('parent', 'parent_of', [self.id]),
                    ('type', '=', 'warehouse'),
                    ], order=[('left', 'DESC')])
        if locations:
            return locations[0].id

    @classmethod
    def search_rec_name(cls, name, clause):
        locations = cls.search([
                ('code', '=', clause[2]),
                ], order=[])
        if locations:
            return [('id', 'in', [l.id for l in locations])]
        return [(cls._rec_name,) + tuple(clause[1:])]

    @classmethod
    def get_quantity(cls, locations, name):
        pool = Pool()
        Product = pool.get('product.product')
        Date_ = pool.get('ir.date')

        if (not Transaction().context.get('product')) \
                or not (isinstance(Transaction().context['product'],
                    (int, long))):
            return dict([(l.id, 0) for l in locations])

        with Transaction().set_context(active_test=False):
            if not Product.search([
                        ('id', '=', Transaction().context['product']),
                        ]):
                return dict([(l.id, 0) for l in locations])

        context = {}
        if (name == 'quantity'
                and Transaction().context.get('stock_date_end') >
                Date_.today()):
            context['stock_date_end'] = Date_.today()

        if name == 'forecast_quantity':
            context['forecast'] = True
            if not Transaction().context.get('stock_date_end'):
                context['stock_date_end'] = datetime.date.max

        product_id = Transaction().context['product']
        pbl = {}
        for sub_locations in grouped_slice(locations):
            location_ids = [l.id for l in sub_locations]
            with Transaction().set_context(context):
                pbl.update(Product.products_by_location(
                        location_ids=location_ids, product_ids=[product_id],
                        with_childs=True))

        return dict((loc.id, pbl.get((loc.id, product_id), 0))
            for loc in locations)

    @classmethod
    def get_cost_value(cls, locations, name):
        Product = Pool().get('product.product')
        trans_context = Transaction().context
        product_id = trans_context.get('product')
        if not product_id:
            return dict((l.id, None) for l in locations)
        cost_values, context = {}, {}
        if 'stock_date_end' in trans_context:
            # Use the last cost_price of the day
            context['_datetime'] = datetime.datetime.combine(
                trans_context['stock_date_end'], datetime.time.max)
        with Transaction().set_context(context):
            product = Product(product_id)
            for location in locations:
                # The date could be before the product creation
                if not isinstance(product.cost_price, Decimal):
                    cost_values[location.id] = None
                else:
                    cost_values[location.id] = (Decimal(str(location.quantity))
                        * product.cost_price)
        return cost_values

    @classmethod
    def _set_warehouse_parent(cls, locations):
        '''
        Set the parent of child location of warehouse if not set
        '''
        to_update = set()
        to_save = []
        for location in locations:
            if location.type == 'warehouse':
                if not location.input_location.parent:
                    to_update.add(location.input_location)
                if not location.output_location.parent:
                    to_update.add(location.output_location)
                if not location.storage_location.parent:
                    to_update.add(location.storage_location)
                if to_update:
                    for child_location in to_update:
                        child_location.parent = location
                        to_save.append(child_location)
                    to_update.clear()
        cls.save(to_save)

    @classmethod
    def create(cls, vlist):
        locations = super(Location, cls).create(vlist)
        cls._set_warehouse_parent(locations)
        return locations

    @classmethod
    def write(cls, *args):
        super(Location, cls).write(*args)
        locations = sum(args[::2], [])
        cls._set_warehouse_parent(locations)

        ids = [l.id for l in locations]
        warehouses = cls.search([
                ('type', '=', 'warehouse'),
                ['OR',
                    ('storage_location', 'in', ids),
                    ('input_location', 'in', ids),
                    ('output_location', 'in', ids),
                    ]])

        fields = ('storage_location', 'input_location', 'output_location')
        wh2childs = {}
        for warehouse in warehouses:
            in_out_sto = (getattr(warehouse, f).id for f in fields)
            for location in locations:
                if location.id not in in_out_sto:
                    continue
                childs = wh2childs.setdefault(warehouse.id, cls.search([
                            ('parent', 'child_of', warehouse.id),
                            ]))
                if location not in childs:
                    cls.raise_user_error('child_of_warehouse', {
                            'location': location.rec_name,
                            'warehouse': warehouse.rec_name,
                            })

    @classmethod
    def copy(cls, locations, default=None):
        if default is None:
            default = {}

        res = []
        for location in locations:
            if location.type == 'warehouse':

                wh_default = default.copy()
                wh_default['type'] = 'view'
                wh_default['input_location'] = None
                wh_default['output_location'] = None
                wh_default['storage_location'] = None
                wh_default['childs'] = None

                new_location, = super(Location, cls).copy([location],
                    default=wh_default)

                with Transaction().set_context(
                        cp_warehouse_locations={
                            'input_location': location.input_location.id,
                            'output_location': location.output_location.id,
                            'storage_location': location.storage_location.id,
                            },
                        cp_warehouse_id=new_location.id):
                    cls.copy(location.childs,
                        default={'parent': new_location.id})
                cls.write([new_location], {
                        'type': 'warehouse',
                        })
            else:
                new_location, = super(Location, cls).copy([location],
                    default=default)
                warehouse_locations = Transaction().context.get(
                    'cp_warehouse_locations') or {}
                if location.id in warehouse_locations.values():
                    cp_warehouse = cls(
                        Transaction().context['cp_warehouse_id'])
                    for field, loc_id in warehouse_locations.iteritems():
                        if loc_id == location.id:
                            cls.write([cp_warehouse], {
                                    field: new_location.id,
                                    })

            res.append(new_location)
        return res


class Party:
    __metaclass__ = PoolMeta
    __name__ = 'party.party'
    supplier_location = fields.Property(fields.Many2One('stock.location',
        'Supplier Location', domain=[('type', '=', 'supplier')],
        help='The default source location when receiving products from the '
        'party.'))
    customer_location = fields.Property(fields.Many2One('stock.location',
        'Customer Location', domain=[('type', '=', 'customer')],
        help='The default destination location when sending products to the '
        'party.'))


class ProductsByLocationsContext(ModelView):
    'Products by Locations'
    __name__ = 'stock.products_by_locations.context'
    forecast_date = fields.Date(
        'At Date', help=('Allow to compute expected '
            'stock quantities for this date.\n'
            '* An empty value is an infinite date in the future.\n'
            '* A date in the past will provide historical values.'))
    stock_date_end = fields.Function(fields.Date('At Date'),
        'on_change_with_stock_date_end')

    @staticmethod
    def default_forecast_date():
        Date_ = Pool().get('ir.date')
        return Date_.today()

    @fields.depends('forecast_date')
    def on_change_with_stock_date_end(self, name=None):
        if self.forecast_date is None:
            return datetime.date.max
        return self.forecast_date


class LocationLeadTime(sequence_ordered(), ModelSQL, ModelView, MatchMixin):
    'Location Lead Time'
    __name__ = 'stock.location.lead_time'

    warehouse_from = fields.Many2One('stock.location', 'Warehouse From',
        ondelete='CASCADE',
        domain=[
            ('type', '=', 'warehouse'),
            ])
    warehouse_to = fields.Many2One('stock.location', 'Warehouse To',
        ondelete='CASCADE',
        domain=[
            ('type', '=', 'warehouse'),
            ])
    lead_time = fields.TimeDelta('Lead Time')

    @classmethod
    def get_lead_time(cls, pattern):
        for record in cls.search([]):
            if record.match(pattern):
                return record.lead_time
