# This file is part of account_bank module for Tryton.
# The COPYRIGHT file at the top level of this repository contains
# the full copyright notices and license terms.
from sql import Null
from sql.aggregate import BoolOr
from sql.operators import In
from decimal import Decimal

from trytond.model import ModelView, fields
from trytond.pool import Pool, PoolMeta
from trytond.pyson import Eval, Bool, If
from trytond.transaction import Transaction
from trytond.wizard import Wizard, StateTransition, StateView, Button

__all__ = ['PaymentType', 'BankAccount', 'Party', 'Invoice', 'Reconciliation',
    'Line', 'CompensationMoveStart', 'CompensationMove']

ACCOUNT_BANK_KIND = [
    ('none', 'None'),
    ('party', 'Party'),
    ('company', 'Company'),
    ('other', 'Other'),
    ]


class PaymentType(metaclass=PoolMeta):
    __name__ = 'account.payment.type'
    account_bank = fields.Selection(ACCOUNT_BANK_KIND, 'Account Bank Kind',
        select=True, required=True)
    party = fields.Many2One('party.party', 'Party',
        states={
            'required': Eval('account_bank') == 'other',
            'invisible': Eval('account_bank') != 'other',
            },
        depends=['account_bank'])
    bank_account = fields.Many2One('bank.account', 'Bank Account',
        domain=[
            If(Eval('party', None) == None,
                ('id', '=', -1),
                ('owners.id', '=', Eval('party')),
                ),
            ],
        states={
            'required': Eval('account_bank') == 'other',
            'invisible': Eval('account_bank') != 'other',
            },
        depends=['party', 'account_bank'])

    @classmethod
    def __setup__(cls):
        super(PaymentType, cls).__setup__()
        cls._check_modify_fields |= set(['account_bank', 'party',
                'bank_account'])

    @staticmethod
    def default_account_bank():
        return 'none'


class BankAccount(metaclass=PoolMeta):
    __name__ = 'bank.account'

    @classmethod
    def __setup__(cls):
        super(BankAccount, cls).__setup__()
        cls._check_owners_fields = set(['owners'])
        cls._check_owners_related_models = set([
                ('account.invoice', 'bank_account'),
                ])
        cls._error_messages.update({
                'modify_with_related_model': ('It is not possible to modify '
                    'the owner of bank account "%(account)s" as it is used on '
                    'the %(field)s of %(model)s "%(name)s"'),
                })

    @classmethod
    def write(cls, *args):
        actions = iter(args)
        all_accounts = []
        for accounts, values in zip(actions, actions):
            if set(values.keys()) & cls._check_owners_fields:
                all_accounts += accounts
        super(BankAccount, cls).write(*args)
        cls.check_owners(all_accounts)

    @classmethod
    def check_owners(cls, accounts):
        pool = Pool()
        IrModel = pool.get('ir.model')
        Field = pool.get('ir.model.field')
        account_ids = [a.id for a in accounts]
        for value in cls._check_owners_related_models:
            model_name, field_name = value
            Model = pool.get(model_name)
            records = Model.search([(field_name, 'in', account_ids)])
            model, = IrModel.search([('model', '=', model_name)])
            field, = Field.search([
                    ('model.model', '=', model_name),
                    ('name', '=', field_name),
                    ], limit=1)
            for record in records:
                target = record.account_bank_from
                account = getattr(record, field_name)
                if target not in account.owners:
                    error_args = {
                        'account': account.rec_name,
                        'model': model.name,
                        'field': field.field_description,
                        'name': record.rec_name,
                        }
                    cls.raise_user_error('modify_with_related_model',
                        error_args)


class Party(metaclass=PoolMeta):
    __name__ = 'party.party'

    @classmethod
    def write(cls, *args):
        pool = Pool()
        BankAccount = pool.get('bank.account')
        actions = iter(args)
        all_accounts = []
        for parties, values in zip(actions, actions):
            if set(values.keys()) & set(['bank_accounts']):
                all_accounts += list(set(
                        [a for p in parties for a in p.bank_accounts]))
        super(Party, cls).write(*args)
        BankAccount.check_owners(all_accounts)


class BankMixin(object):
    account_bank = fields.Function(fields.Selection(ACCOUNT_BANK_KIND,
            'Account Bank'),
        'on_change_with_account_bank')
    account_bank_from = fields.Function(fields.Many2One('party.party',
            'Account Bank From'),
        'on_change_with_account_bank_from')
    bank_account = fields.Many2One('bank.account', 'Bank Account',
        domain=[
            If(Eval('account_bank_from', None) == None,
                ('id', '=', -1),
                ('owners.id', '=', Eval('account_bank_from')),
                ),
            ],
        states={
                'readonly': Eval('account_bank') == 'other',
                'invisible': ~Bool(Eval('account_bank_from')),
        },
        depends=['party', 'payment_type', 'account_bank_from', 'account_bank'],
        ondelete='RESTRICT')

    @fields.depends('payment_type')
    def on_change_with_account_bank(self, name=None):
        if self.payment_type:
            return self.payment_type.account_bank

    def _get_bank_account(self):
        pool = Pool()
        Party = pool.get('party.party')

        self.bank_account = None
        if self.party and self.payment_type:
            if self.payment_type.account_bank == 'other':
                self.bank_account = self.payment_type.bank_account
            else:
                party_fname = '%s_bank_account' % self.payment_type.kind
                if hasattr(Party, party_fname):
                    account_bank = self.payment_type.account_bank
                    if account_bank == 'company':
                        party_company_fname = ('%s_company_bank_account' %
                            self.payment_type.kind)
                        company_bank = getattr(self.party, party_company_fname,
                            None)
                        if company_bank:
                            self.bank_account = company_bank
                        elif hasattr(self, 'company') and self.company:
                            default_bank = getattr(
                                self.company.party, party_fname)
                            self.bank_account = default_bank
                        return
                    elif account_bank == 'party' and self.party:
                        default_bank = getattr(self.party, party_fname)
                        self.bank_account = default_bank
                        return

    @fields.depends('party', 'payment_type',
        methods=['on_change_with_payment_type'])
    def on_change_with_bank_account(self):
        '''
        Add account bank when changes payment_type or party.
        '''
        self._get_bank_account()
        return self.bank_account.id if self.bank_account else None

    @fields.depends('payment_type', 'party',
        methods=['on_change_with_payment_type'])
    def on_change_with_account_bank_from(self, name=None):
        '''
        Sets the party where get bank account for this move line.
        '''
        Company = Pool().get('company.company')

        if self.payment_type and self.party:
            payment_type = self.payment_type
            party = self.party
            if payment_type.account_bank == 'party':
                return party.id
            elif payment_type.account_bank == 'company':
                company = Transaction().context.get('company')
                if company:
                    return Company(company).party.id
            elif payment_type.account_bank == 'other':
                return payment_type.party.id


class Invoice(BankMixin, metaclass=PoolMeta):
    __name__ = 'account.invoice'

    @classmethod
    def __setup__(cls):
        super(Invoice, cls).__setup__()
        readonly = ~Eval('state').in_(['draft', 'validated'])
        previous_readonly = cls.bank_account.states.get('readonly')
        if previous_readonly:
            readonly = readonly | previous_readonly
        cls.bank_account.states.update({
                'readonly': readonly,
                })
        cls._error_messages.update({
                'invoice_without_bank_account': ('Invoice "%(invoice)s" has '
                    'no bank account associated but payment type '
                    '"%(payment_type)s" requires it.'),
                })

    @fields.depends('payment_type', 'party', 'company')
    def on_change_party(self):
        '''
        Add account bank to invoice line when changes party.
        '''
        super(Invoice, self).on_change_party()
        self.bank_account = None
        if self.payment_type:
            self._get_bank_account()

    @classmethod
    def post(cls, invoices):
        '''
        Check up invoices that requires bank account because its payment type,
        has one
        '''
        to_save = []
        for invoice in invoices:
            account_bank = (invoice.payment_type and
                invoice.payment_type.account_bank or 'none')
            if (invoice.payment_type and account_bank != 'none'
                    and not invoice.bank_account):
                invoice._get_bank_account()
                if not invoice.bank_account:
                    cls.raise_user_error('invoice_without_bank_account', {
                            'invoice': invoice.rec_name,
                            'payment_type': invoice.payment_type.rec_name,
                            })
                to_save.append(invoice)
        if to_save:
            cls.save(to_save)
        super(Invoice, cls).post(invoices)


class Reconciliation(metaclass=PoolMeta):
    __name__ = 'account.move.reconciliation'

    @classmethod
    def create(cls, vlist):
        Invoice = Pool().get('account.invoice')
        reconciliations = super(Reconciliation, cls).create(vlist)
        moves = set()
        for reconciliation in reconciliations:
            moves |= set(l.move for l in reconciliation.lines)
        invoices = []
        for move in moves:
            if (move.origin and isinstance(move.origin, Invoice)
                    and move.origin.state == 'posted'):
                invoices.append(move.origin)
        if invoices:
            Invoice.process(invoices)
        return reconciliations

    @classmethod
    def delete(cls, reconciliations):
        Invoice = Pool().get('account.invoice')

        moves = set()
        for reconciliation in reconciliations:
            moves |= set(l.move for l in reconciliation.lines)
        invoices = []
        for move in moves:
            if move.origin and isinstance(move.origin, Invoice):
                invoices.append(move.origin)
        super(Reconciliation, cls).delete(reconciliations)
        if invoices:
            Invoice.process(invoices)


class Line(metaclass=PoolMeta):
    __name__ = 'account.move.line'

    reverse_moves = fields.Function(fields.Boolean('With Reverse Moves'),
        'get_reverse_moves', searcher='search_reverse_moves')
    netting_moves = fields.Function(fields.Boolean('With Netting Moves'),
        'get_netting_moves', searcher='search_netting_moves')

    def get_reverse_moves(self, name):
        if (not self.account
                or self.account.kind not in ['receivable', 'payable']):
            return False
        domain = [
            ('account', '=', self.account.id),
            ('reconciliation', '=', None),
            ]
        if self.party:
            domain.append(('party', '=', self.party.id))
        if self.credit > Decimal('0.0'):
            domain.append(('debit', '>', 0))
        if self.debit > Decimal('0.0'):
            domain.append(('credit', '>', 0))
        moves = self.search(domain, limit=1)
        return len(moves) > 0

    @classmethod
    def search_reverse_moves(cls, name, clause):
        pool = Pool()
        Account = pool.get('account.account')
        MoveLine = pool.get('account.move.line')
        operator = 'in' if clause[2] else 'not in'
        lines = MoveLine.__table__()
        move_line = MoveLine.__table__()
        account = Account.__table__()
        cursor = Transaction().connection.cursor()

        reverse = move_line.join(account, condition=(
                account.id == move_line.account)).select(
                    move_line.account, move_line.party,
                    where=(account.reconcile
                        & (move_line.reconciliation == Null)),
                    group_by=(move_line.account, move_line.party),
                    having=((BoolOr((move_line.debit) != Decimal(0)))
                        & (BoolOr((move_line.credit) != Decimal(0))))
                    )
        query = lines.select(lines.id, where=(
                In((lines.account, lines.party), reverse)))
        # Fetch the data otherwise its too slow
        cursor.execute(*query)

        return [('id', operator, [x[0] for x in cursor.fetchall()])]

    def get_netting_moves(self, name):
        if (not self.account
                or self.account.kind not in ['receivable', 'payable']):
            return False
        if not self.account.party_required:
            return False
        domain = [
            ('party', '=', self.party.id),
            ('reconciliation', '=', None),
            ]
        if self.credit > Decimal('0.0'):
            domain.append(('debit', '>', 0))
        if self.debit > Decimal('0.0'):
            domain.append(('credit', '>', 0))
        moves = self.search(domain, limit=1)
        return len(moves) > 0

    @classmethod
    def search_netting_moves(cls, name, clause):
        pool = Pool()
        Account = pool.get('account.account')
        MoveLine = pool.get('account.move.line')
        operator = 'in' if clause[2] else 'not in'

        move_line = MoveLine.__table__()
        account = Account.__table__()
        query = move_line.join(account, condition=(
                account.id == move_line.account)).select(
                    move_line.party,
                    where=(account.reconcile
                        & (move_line.reconciliation == Null)),
                    group_by=(move_line.party,),
                    having=((BoolOr((move_line.debit) != Decimal(0)))
                        & (BoolOr((move_line.credit) != Decimal(0))))
                    )
        return [('party', operator, query)]


class CompensationMoveStart(ModelView):
    'Create Compensation Move Start'
    __name__ = 'account.move.compensation_move.start'
    party = fields.Many2One('party.party', 'Party', readonly=True)
    account = fields.Many2One('account.account', 'Account', required=True)
    date = fields.Date('Date')
    maturity_date = fields.Date('Maturity Date')

    @classmethod
    def __setup__(cls):
        super(CompensationMoveStart, cls).__setup__()
        cls._error_messages.update({
                'normal_reconcile': ('Selected moves are balanced. Use '
                    'concile wizard instead of creating a compensation move.'),
                'different_parties': ('Parties can not be mixed to create a '
                    'compensation move. Party "%s" in line "%s" is different '
                    'from previous party "%s"'),
                })

    @staticmethod
    def default_date():
        pool = Pool()
        return pool.get('ir.date').today()

    @staticmethod
    def default_maturity_date():
        pool = Pool()
        return pool.get('ir.date').today()

    @classmethod
    def default_get(cls, fields, with_rec_name=True):
        pool = Pool()
        Line = pool.get('account.move.line')

        defaults = super(CompensationMoveStart, cls).default_get(fields,
            with_rec_name)

        party = None
        company = None
        amount = Decimal('0.0')

        lines = Line.browse(Transaction().context.get('active_ids', []))
        for line in lines:
            amount += line.debit - line.credit
            if not party:
                party = line.party
            elif party != line.party:
                cls.raise_user_error('different_parties', (line.party.rec_name,
                        line.rec_name, party.rec_name))
            if not company:
                company = line.account.company
        if (company and company.currency.is_zero(amount)
                and len(set([x.account for x in lines])) == 1):
            cls.raise_user_error('normal_reconcile')
        if party:
            defaults['party'] = party.id
            if amount > 0:
                defaults['account'] = (party.account_receivable.id
                    if party.account_receivable else None)
            else:
                defaults['account'] = (party.account_payable.id
                    if party.account_payable else None)
        return defaults


class CompensationMove(Wizard):
    'Create Compensation Move'
    __name__ = 'account.move.compensation_move'
    start = StateView('account.move.compensation_move.start',
        'account_bank.compensation_move_lines_start_view_form', [
            Button('Cancel', 'end', 'tryton-cancel'),
            Button('Create', 'create_move', 'tryton-ok', default=True),
            ])
    create_move = StateTransition()

    def transition_create_move(self):
        pool = Pool()
        Move = pool.get('account.move')
        Line = pool.get('account.move.line')

        move_lines = []
        lines = Line.browse(Transaction().context.get('active_ids'))

        for line in lines:
            if (line.account.kind not in ('payable', 'receivable')
                    or line.reconciliation):
                continue
            move_lines.append(self.get_counterpart_line(line))

        if not lines or not move_lines:
            return 'end'

        move = self.get_move(lines)
        extra_lines, origin = self.get_extra_lines(lines, self.start.account,
            self.start.party)

        if origin:
            move.origin = origin
        move.lines = move_lines + extra_lines
        move.save()
        Move.post([move])
        to_reconcile = {}
        for line in lines:
            to_reconcile.setdefault(line.account.id, []).append(line)
        for line in move.lines:
            append = True
            for extra_line in extra_lines:
                if self.is_extra_line(line, extra_line):
                    append = False
                    break
            if append:
                to_reconcile.setdefault(line.account.id, []).append(line)
        for lines_to_reconcile in to_reconcile.values():
            Line.reconcile(lines_to_reconcile)
        return 'end'

    def is_extra_line(self, line, extra_line):
        " Returns true if both lines are equal"
        return (line.debit == extra_line.debit and
            line.credit == extra_line.credit and
            line.maturity_date == extra_line.maturity_date)

    def get_counterpart_line(self, line):
        'Returns the counterpart line to create from line'
        pool = Pool()
        Line = pool.get('account.move.line')

        new_line = Line()
        new_line.account = line.account
        new_line.debit = line.credit
        new_line.credit = line.debit
        new_line.description = line.description
        new_line.second_curency = line.second_currency
        new_line.amount_second_currency = line.amount_second_currency
        new_line.party = line.party

        return new_line

    def get_move(self, lines):
        'Returns the new move to create from lines'
        pool = Pool()
        Move = pool.get('account.move')
        Period = pool.get('account.period')
        Date = pool.get('ir.date')

        period_id = Period.find(lines[0].account.company.id)
        move = Move()
        move.period = Period(period_id)
        move.journal = lines[0].move.journal
        move.date = Date.today()

        return move

    def get_extra_lines(self, lines, account, party):
        'Returns extra lines to balance move and move origin'
        pool = Pool()
        Line = pool.get('account.move.line')

        amount = Decimal('0.0')
        origins = {}
        for line in lines:
            line_amount = line.debit - line.credit
            amount += line_amount
            if line.origin:
                if line.origin not in origins:
                    origins[line.origin] = Decimal('0.0')
                origins[line.origin] += abs(line_amount)

        if not account or not party:
            return ([], None)

        extra_line = Line()
        extra_line.account = account
        extra_line.party = party
        extra_line.maturity_date = self.start.maturity_date
        extra_line.credit = extra_line.debit = Decimal('0.0')
        if amount > 0:
            extra_line.debit = amount
        else:
            extra_line.credit = abs(amount)

        origin = None
        for line_origin, line_amount in sorted(origins.items(),
                key=lambda x: x[1]):
            if abs(amount) < line_amount:
                origin = line_origin
                break
        return [extra_line], origin