odoo-membership-addons/membership_initial_discount/models/res_partner.py

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


class ResPartner(models.Model):
    _inherit = "res.partner"

    def initial_membership_check(self):
        self.ensure_one()
        partner = self.associate_member or self
        member_lines = self.env["membership.membership_line"].search(
            [
                ("partner", "=", partner.id),
                ("state", "not in", ["none", "canceled"]),
            ]
        )
        return not bool(member_lines)

    def prepare_membership_invoice_vals(self, product, amount):
        discount = 0.0
        if self.initial_membership_check():
            if product.initial_discount == "fixed" and product.fixed_discount:
                print("fixed discount")
                fixed_disc = product.fixed_discount
                amount -= fixed_disc
            elif product.initial_discount == "percent" and product.percent_discount:
                print("percent discount")
                discount = product.percent_discount
            else:
                pass
        vals = {
            "move_type": "out_invoice",
            "partner_id": self.id,
            "invoice_line_ids": [
                (
                    0,
                    None,
                    {
                        "product_id": product.id,
                        "quantity": 1,
                        "price_unit": amount,
                        "discount": discount,
                        "tax_ids": [(6, 0, product.taxes_id.ids)],
                    },
                )
            ],
        }
        return vals

    def create_membership_invoice(self, product, amount):
        """Create Customer Invoice of Membership for partners."""
        invoice_vals_list = []
        for partner in self:
            addr = partner.address_get(["invoice"])
            if partner.free_member:
                raise UserError(_("Partner is a free Member."))
            if not addr.get("invoice", False):
                raise UserError(
                    _("Partner doesn't have an address to make the invoice.")
                )
            invoice_vals_list.append(
                partner.prepare_membership_invoice_vals(product, amount)
            )

        return self.env["account.move"].create(invoice_vals_list)