# Copyright 2018 Creu Blanca
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).

from odoo import api, fields, models, _
from odoo.exceptions import UserError
import logging

_logger = logging.getLogger(__name__)
try:
    import numpy
except (ImportError, IOError) as err:
    _logger.error(err)


class AccountLoanLine(models.Model):
    _name = 'account.loan.line'
    _description = 'Annuity'
    _order = 'sequence asc'

    name = fields.Char(compute='_compute_name')
    loan_id = fields.Many2one(
        'account.loan',
        required=True,
        readonly=True,
        ondelete='cascade',
    )
    is_leasing = fields.Boolean(related='loan_id.is_leasing', readonly=True, )
    loan_type = fields.Selection([
        ('fixed-annuity', 'Fixed Annuity'),
        ('fixed-principal', 'Fixed Principal'),
        ('interest', 'Only interest'),
    ], related='loan_id.loan_type', readonly=True,
    )
    loan_state = fields.Selection([
        ('draft', 'Draft'),
        ('posted', 'Posted'),
        ('cancelled', 'Cancelled'),
        ('closed', 'Closed'),
    ], related='loan_id.state', readonly=True, store=True)
    sequence = fields.Integer(required=True, readonly=True)
    date = fields.Date(
        required=True,
        readonly=True,
        help='Date when the payment will be accounted',
    )
    long_term_loan_account_id = fields.Many2one(
        'account.account',
        readony=True,
        related='loan_id.long_term_loan_account_id',
    )
    currency_id = fields.Many2one(
        'res.currency',
        related='loan_id.currency_id',
    )
    rate = fields.Float(
        required=True,
        readonly=True,
        digits=(8, 6),
    )
    pending_principal_amount = fields.Monetary(
        currency_field='currency_id',
        readonly=True,
        help='Pending amount of the loan before the payment',
    )
    long_term_pending_principal_amount = fields.Monetary(
        currency_field='currency_id',
        readonly=True,
        help='Pending amount of the loan before the payment that will not be '
             'payed in, at least, 12 months',
    )
    payment_amount = fields.Monetary(
        currency_field='currency_id',
        readonly=True,
        help='Total amount that will be payed (Annuity)',
    )
    interests_amount = fields.Monetary(
        currency_field='currency_id',
        readonly=True,
        help='Amount of the payment that will be assigned to interests',
    )
    principal_amount = fields.Monetary(
        currency_field='currency_id',
        compute='_compute_amounts',
        help='Amount of the payment that will reduce the pending loan amount',
    )
    long_term_principal_amount = fields.Monetary(
        currency_field='currency_id',
        readonly=True,
        help='Amount that will reduce the pending loan amount on long term',
    )
    final_pending_principal_amount = fields.Monetary(
        currency_field='currency_id',
        compute='_compute_amounts',
        help='Pending amount of the loan after the payment',
    )
    move_ids = fields.One2many(
        'account.move',
        inverse_name='loan_line_id',
    )
    has_moves = fields.Boolean(
        compute='_compute_has_moves'
    )
    invoice_ids = fields.One2many(
        'account.invoice',
        inverse_name='loan_line_id',
    )
    has_invoices = fields.Boolean(
        compute='_compute_has_invoices'
    )
    _sql_constraints = [
        ('sequence_loan',
         'unique(loan_id, sequence)',
         'Sequence must be unique in a loan')
    ]

    @api.depends('move_ids')
    def _compute_has_moves(self):
        for record in self:
            record.has_moves = bool(record.move_ids)

    @api.depends('invoice_ids')
    def _compute_has_invoices(self):
        for record in self:
            record.has_invoices = bool(record.invoice_ids)

    @api.depends('loan_id.name', 'sequence')
    def _compute_name(self):
        for record in self:
            record.name = '%s-%d' % (record.loan_id.name, record.sequence)

    @api.depends('payment_amount', 'interests_amount',
                 'pending_principal_amount')
    def _compute_amounts(self):
        for rec in self:
            rec.final_pending_principal_amount = (
                rec.pending_principal_amount - rec.payment_amount +
                rec.interests_amount
            )
            rec.principal_amount = rec.payment_amount - rec.interests_amount

    def compute_amount(self):
        """
        Computes the payment amount
        :return: Amount to be payed on the annuity
        """
        if self.sequence == self.loan_id.periods:
            return (self.pending_principal_amount + self.interests_amount -
                    self.loan_id.residual_amount)
        if self.loan_type == 'fixed-principal' and self.loan_id.round_on_end:
            return self.loan_id.fixed_amount + self.interests_amount
        if self.loan_type == 'fixed-principal':
            return (
                self.pending_principal_amount -
                self.loan_id.residual_amount
            ) / (
                self.loan_id.periods - self.sequence + 1
            ) + self.interests_amount
        if self.loan_type == 'interest':
            return self.interests_amount
        if self.loan_type == 'fixed-annuity' and self.loan_id.round_on_end:
            return self.loan_id.fixed_amount
        if self.loan_type == 'fixed-annuity':
            return self.currency_id.round(- numpy.pmt(
                self.rate / 100,
                self.loan_id.periods - self.sequence + 1,
                self.pending_principal_amount,
                -self.loan_id.residual_amount
            ))

    def check_amount(self):
        """Recompute amounts if the annuity has not been processed"""
        if self.move_ids or self.invoice_ids:
            raise UserError(_(
                'Amount cannot be recomputed if moves or invoices exists '
                'already'
            ))
        if not self.loan_id.round_on_end:
            self.interests_amount = self.currency_id.round(
                self.pending_principal_amount * self.rate / 100)
            self.payment_amount = self.currency_id.round(self.compute_amount())
        else:
            self.interests_amount = (
                self.pending_principal_amount * self.rate / 100)
            self.payment_amount = self.compute_amount()

    @api.multi
    def check_move_amount(self):
        """
        Changes the amounts of the annuity once the move is posted
        :return:
        """
        self.ensure_one()
        interests_moves = self.move_ids.mapped('line_ids').filtered(
            lambda r: r.account_id == self.loan_id.interest_expenses_account_id
        )
        short_term_moves = self.move_ids.mapped('line_ids').filtered(
            lambda r: r.account_id == self.loan_id.short_term_loan_account_id
        )
        long_term_moves = self.move_ids.mapped('line_ids').filtered(
            lambda r: r.account_id == self.loan_id.long_term_loan_account_id
        )
        self.interests_amount = (
            sum(interests_moves.mapped('debit')) -
            sum(interests_moves.mapped('credit'))
        )
        self.long_term_principal_amount = (
            sum(long_term_moves.mapped('debit')) -
            sum(long_term_moves.mapped('credit'))
        )
        self.payment_amount = (
            sum(short_term_moves.mapped('debit')) -
            sum(short_term_moves.mapped('credit')) +
            self.long_term_principal_amount +
            self.interests_amount
        )

    def move_vals(self):
        return {
            'loan_line_id': self.id,
            'loan_id': self.loan_id.id,
            'date': self.date,
            'ref': self.name,
            'journal_id': self.loan_id.journal_id.id,
            'line_ids': [(0, 0, vals) for vals in self.move_line_vals()]
        }

    def move_line_vals(self):
        vals = []
        partner = self.loan_id.partner_id.with_context(
            force_company=self.loan_id.company_id.id)
        vals.append({
            'account_id': partner.property_account_payable_id.id,
            'partner_id': partner.id,
            'credit': self.payment_amount,
            'debit': 0,
        })
        vals.append({
            'account_id': self.loan_id.interest_expenses_account_id.id,
            'credit': 0,
            'debit': self.interests_amount,
        })
        vals.append({
            'account_id': self.loan_id.short_term_loan_account_id.id,
            'credit': 0,
            'debit': self.payment_amount - self.interests_amount,
        })
        if self.long_term_loan_account_id and self.long_term_principal_amount:
            vals.append({
                'account_id': self.loan_id.short_term_loan_account_id.id,
                'credit': self.long_term_principal_amount,
                'debit': 0,
            })
            vals.append({
                'account_id': self.long_term_loan_account_id.id,
                'credit': 0,
                'debit': self.long_term_principal_amount,
            })
        return vals

    def invoice_vals(self):
        partner = self.loan_id.partner_id.with_context(
            force_company=self.loan_id.company_id.id)
        return {
            'loan_line_id': self.id,
            'loan_id': self.loan_id.id,
            'type': 'in_invoice',
            'partner_id': self.loan_id.partner_id.id,
            'date_invoice': self.date,
            'account_id': partner.property_account_payable_id.id,
            'journal_id': self.loan_id.journal_id.id,
            'company_id': self.loan_id.company_id.id,
            'invoice_line_ids': [(0, 0, vals) for vals in
                                 self.invoice_line_vals()]
        }

    def invoice_line_vals(self):
        vals = list()
        vals.append({
            'product_id': self.loan_id.product_id.id,
            'name': self.loan_id.product_id.name,
            'quantity': 1,
            'price_unit': self.principal_amount,
            'account_id': self.loan_id.short_term_loan_account_id.id,
        })
        vals.append({
            'product_id': self.loan_id.interests_product_id.id,
            'name': self.loan_id.interests_product_id.name,
            'quantity': 1,
            'price_unit': self.interests_amount,
            'account_id': self.loan_id.interest_expenses_account_id.id,
        })
        return vals

    @api.multi
    def generate_move(self):
        """
        Computes and post the moves of loans
        :return: list of account.move generated
        """
        res = []
        for record in self:
            if not record.move_ids:
                if record.loan_id.line_ids.filtered(
                        lambda r: r.date < record.date and not r.move_ids
                ):
                    raise UserError(_('Some moves must be created first'))
                move = self.env['account.move'].create(record.move_vals())
                move.post()
                res.append(move.id)
        return res

    @api.multi
    def generate_invoice(self):
        """
        Computes invoices of leases
        :return: list of account.invoice generated
        """
        res = []
        for record in self:
            if not record.invoice_ids:
                if record.loan_id.line_ids.filtered(
                        lambda r: r.date < record.date and not r.invoice_ids
                ):
                    raise UserError(_('Some invoices must be created first'))
                invoice = self.env['account.invoice'].create(
                    record.invoice_vals())
                res.append(invoice.id)
                for line in invoice.invoice_line_ids:
                    line._set_taxes()
                invoice.compute_taxes()
        return res

    @api.multi
    def view_account_values(self):
        """Shows the invoice if it is a leasing or the move if it is a loan"""
        self.ensure_one()
        if self.is_leasing:
            return self.view_account_invoices()
        return self.view_account_moves()

    @api.multi
    def view_process_values(self):
        """Computes the annuity and returns the result"""
        self.ensure_one()
        if self.is_leasing:
            self.generate_invoice()
        else:
            self.generate_move()
        return self.view_account_values()

    @api.multi
    def view_account_moves(self):
        self.ensure_one()
        action = self.env.ref('account.action_move_line_form')
        result = action.read()[0]
        result['context'] = {
            'default_loan_line_id': self.id,
            'default_loan_id': self.loan_id.id
        }
        result['domain'] = [('loan_line_id', '=', self.id)]
        if len(self.move_ids) == 1:
            res = self.env.ref('account.move.form', False)
            result['views'] = [(res and res.id or False, 'form')]
            result['res_id'] = self.move_ids.id
        return result

    @api.multi
    def view_account_invoices(self):
        self.ensure_one()
        action = self.env.ref('account.action_invoice_tree2')
        result = action.read()[0]
        result['context'] = {
            'default_loan_line_id': self.id,
            'default_loan_id': self.loan_id.id
        }
        result['domain'] = [
            ('loan_line_id', '=', self.id),
            ('type', '=', 'in_invoice')
        ]
        if len(self.invoice_ids) == 1:
            res = self.env.ref('account.invoice.supplier.form', False)
            result['views'] = [(res and res.id or False, 'form')]
            result['res_id'] = self.invoice_ids.id
        return result