# -*- coding: utf-8 -*-
# Copyright 2026 Nexa Systems Inc.
# License OPL-1
from odoo import api, fields, models


class SaleOrder(models.Model):
    _inherit = "sale.order"

    def _fc_rate_usage(self, charge, period_start, period_end):
        """Aggregate this subscription's usage for `charge`'s metric in the period,
        compute the overage amount, and upsert a matching overage order line.
        Returns the amount.

        A zero amount never *creates* a new line (no $0.00 overage clutter); if a
        line already exists it is still updated so a dropped-to-zero overage clears.
        """
        self.ensure_one()
        Usage = self.env['fusion.billing.usage']
        total = Usage._aggregate(self, charge.metric_id, period_start, period_end)
        _overage, amount = charge._compute_billable(total)
        if charge.product_id:
            line = self.order_line.filtered(lambda l: l.product_id == charge.product_id)
            if not line and amount == 0:
                return amount
            vals = {'product_uom_qty': 1, 'price_unit': amount}
            if line:
                line.write(vals)
            else:
                self.env['sale.order.line'].create(
                    {'order_id': self.id, 'product_id': charge.product_id.id, **vals})
        return amount