# -*- coding: utf-8 -*-

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

class Invoice(models.Model):
    _inherit = "account.invoice"

    global_discount = fields.Boolean("Add Global Discount", readonly=True, states={'draft': [('readonly', False)]},)
    discount_type = fields.Selection([('fixed','Fixed'),('percentage','Percentage')], 
        "Discount Type", readonly=True, states={'draft': [('readonly', False)]}, default='fixed')
    discount_amount = fields.Float("Discount Amount", readonly=True, states={'draft': [('readonly', False)]},)
    discount_percentage = fields.Float("Discount Percentage", readonly=True, states={'draft': [('readonly', False)]},)

    @api.multi
    def _discount_unset(self):
        if self.env.user.company_id.invoice_discount_product_id:
            self.env['account.invoice.line'].search([('invoice_id', 'in', self.ids), ('product_id', '=', self.env.user.company_id.invoice_discount_product_id.id)]).unlink()

    @api.multi
    def create_discount(self):
        InvoiceLine = self.env['account.invoice.line']

        product_id = self.env.user.company_id.invoice_discount_product_id
        if not product_id:
            raise UserError(_('Please set Invoice Discount product in General Settings first.'))

        # Remove Discount line first
        self._discount_unset()

        account_id = product_id.property_account_income_id.id
        if not account_id:
            prop = self.env['ir.property'].get('property_account_income_categ_id', 'product.category')
            account_id = prop and prop.id or False

        for invoice in self:
            amount = 0
            if invoice.discount_type == 'fixed':
                amount = invoice.discount_amount
            if invoice.discount_type == 'percentage':
                amount = (invoice.amount_total * invoice.discount_percentage)/100

            # Apply fiscal position
            taxes = product_id.taxes_id.filtered(lambda t: t.company_id.id == invoice.company_id.id)
            taxes_ids = taxes.ids
            if invoice.partner_id and self.fiscal_position_id:
                taxes_ids = self.fiscal_position_id.map_tax(taxes, product_id, invoice.partner_id).ids

            # Create the Invoice line
            InvoiceLine.create({
                'name': product_id.name,
                'price_unit': -amount,
                'account_id': account_id,
                'quantity': 1.0,
                'discount': 0.0,
                'uom_id': product_id.uom_id.id,
                'product_id': product_id.id,
                'invoice_id': invoice.id,
                'invoice_line_tax_ids': [(6, 0, taxes_ids)],
                'sequence': 100,
            })
        return True