# 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 warnings

from sql import Cast, Literal, Query, Expression
from sql.functions import Substring, Position

from .field import (Field, search_order_validate, context_validate,
    with_inactive_records)
from .selection import SelectionMixin
from ...transaction import Transaction
from ...pool import Pool
from ...rpc import RPC


class Reference(Field, SelectionMixin):
    '''
    Define a reference field (``str``).
    '''
    _type = 'reference'
    _sql_type = 'VARCHAR'

    def __init__(self, string='', selection=None, selection_change_with=None,
            search_order=None, search_context=None, help='', required=False,
            readonly=False, domain=None, states=None, select=False,
            on_change=None, on_change_with=None, depends=None, context=None,
            loading='lazy', datetime_field=None):
        '''
        :param selection: A list or a function name that returns a list.
            The list must be a list of tuples. First member is an internal name
            of model and the second is the user name of model.
        :param datetime_field: The name of the field that contains the datetime
            value to read the target records.
        :param search_order: The order to use when searching for a record
        :param search_context: The context to use when searching for a record
        '''
        if datetime_field:
            if depends:
                depends.append(datetime_field)
            else:
                depends = [datetime_field]
        super(Reference, self).__init__(string=string, help=help,
            required=required, readonly=readonly, domain=domain, states=states,
            select=select, on_change=on_change, on_change_with=on_change_with,
            depends=depends, context=context, loading=loading)
        self.datetime_field = datetime_field
        self.selection = selection or None
        self.selection_change_with = set()
        if selection_change_with:
            warnings.warn('selection_change_with argument is deprecated, '
                'use the depends decorator',
                DeprecationWarning, stacklevel=2)
            self.selection_change_with |= set(selection_change_with)
        self.__search_order = None
        self.search_order = search_order
        self.__search_context = None
        self.search_context = search_context or {}

    __init__.__doc__ += Field.__init__.__doc__

    @property
    def search_order(self):
        return self.__search_order

    @search_order.setter
    def search_order(self, value):
        search_order_validate(value)
        self.__search_order = value

    @property
    def search_context(self):
        return self.__search_context

    @search_context.setter
    def search_context(self, value):
        context_validate(value)
        self.__search_context = value

    def set_rpc(self, model):
        super(Reference, self).set_rpc(model)
        if not isinstance(self.selection, (list, tuple)):
            assert hasattr(model, self.selection), \
                'Missing %s on model %s' % (self.selection, model.__name__)
            instantiate = 0 if self.selection_change_with else None
            model.__rpc__.setdefault(
                self.selection, RPC(instantiate=instantiate))

    def get(self, ids, model, name, values=None):
        '''
        Replace removed reference id by None.
        '''
        pool = Pool()
        if values is None:
            values = {}
        res = {}
        for i in values:
            res[i['id']] = i[name]
        ref_to_check = {}
        for i in ids:
            if not (i in res):
                res[i] = None
                continue
            if not res[i]:
                continue
            ref_model, ref_id = res[i].split(',', 1)
            if not ref_model:
                continue
            try:
                ref_id = int(ref_id)
            except Exception:
                continue
            if ref_id < 0:
                continue
            res[i] = ref_model + ',' + str(ref_id)
            ref_to_check.setdefault(ref_model, (set(), []))
            ref_to_check[ref_model][0].add(ref_id)
            ref_to_check[ref_model][1].append(i)

        # Check if reference ids still exist
        with Transaction().set_context(active_test=False), \
                Transaction().set_context(_check_access=False):
            for ref_model, (ref_ids, ids) in ref_to_check.items():
                try:
                    pool.get(ref_model)
                except KeyError:
                    res.update(dict((i, None) for i in ids))
                    continue
                Ref = pool.get(ref_model)
                refs = Ref.search([
                    ('id', 'in', list(ref_ids)),
                    ], order=[])
                refs = list(map(str, refs))
                for i in ids:
                    if res[i] not in refs:
                        res[i] = None
        return res

    def __set__(self, inst, value):
        from ..model import Model
        if not isinstance(value, (Model, type(None))):
            if isinstance(value, str):
                target, value = value.split(',')
            else:
                target, value = value
            Target = Pool().get(target)
            if isinstance(value, dict):
                value = Target(**value)
            else:
                value = Target(value)
        super(Reference, self).__set__(inst, value)

    def sql_format(self, value):
        if not isinstance(value, (str, Query, Expression)):
            try:
                value = '%s,%s' % tuple(value)
            except TypeError:
                pass
        return super(Reference, self).sql_format(value)

    @with_inactive_records
    def convert_domain(self, domain, tables, Model):
        if '.' not in domain[0]:
            return super(Reference, self).convert_domain(domain, tables, Model)
        pool = Pool()
        name, operator, value, target = domain[:4]
        Target = pool.get(target)
        table, _ = tables[None]
        name, target_name = name.split('.', 1)
        assert name == self.name
        column = self.sql_column(table)
        target_domain = [(target_name,) + tuple(domain[1:3])
            + tuple(domain[4:])]
        if 'active' in Target._fields:
            target_domain.append(('active', 'in', [True, False]))
        query = Target.search(target_domain, order=[], query=True)
        return (Cast(Substring(column,
                    Position(',', column) + Literal(1)),
                Model.id.sql_type().base).in_(query)
            & column.ilike(target + ',%'))
