from odoo import api, fields, models


class AccountMove(models.Model):
    _inherit = "account.move"

    last_payment_date = fields.Date(
        compute="_compute_last_payment_info",
        store=True,
        copy=False,
        help="Date of the most recent payment reconciled with this "
        "invoice, whatever the reconciliation path (explicit payment "
        "or direct bank statement line reconciliation).",
    )
    last_payment_method = fields.Char(
        compute="_compute_last_payment_info",
        store=True,
        copy=False,
        help="Payment method of the most recent payment reconciled with this invoice.",
    )

    @api.depends(
        "line_ids.matched_debit_ids.debit_move_id.date",
        "line_ids.matched_debit_ids.debit_move_id.move_id.origin_payment_id.payment_method_line_id.name",
        "line_ids.matched_debit_ids.debit_move_id.move_id.statement_line_id",
        "line_ids.matched_credit_ids.credit_move_id.date",
        "line_ids.matched_credit_ids.credit_move_id.move_id.origin_payment_id.payment_method_line_id.name",
        "line_ids.matched_credit_ids.credit_move_id.move_id.statement_line_id",
    )
    def _compute_last_payment_info(self):
        """Compute the last real payment date and method.

        Only customer and vendor invoices carry the information; every
        other move type gets both fields cleared. Candidates are the
        reconciliation counterpart lines of the receivable/payable
        lines (exchange difference moves excluded). The most recent
        candidate wins; on equal dates the first candidate found wins.
        """
        for move in self:
            if move.move_type not in ("in_invoice", "out_invoice"):
                move.last_payment_date = False
                move.last_payment_method = False
                continue
            candidates = move._get_last_payment_candidates()
            if not candidates:
                move.last_payment_date = False
                move.last_payment_method = False
            else:
                latest_date, latest_method = max(
                    candidates, key=lambda candidate: candidate[0]
                )
                move.last_payment_date = latest_date
                move.last_payment_method = latest_method

    def _get_last_payment_candidates(self):
        """Collect the candidate real payments for this invoice.

        A candidate is a ``(date, method)`` tuple built from each
        reconciliation counterpart line:

        - counterpart move with ``origin_payment_id``: explicit
          payment, dated with the payment date, method from the
          payment method line;
        - counterpart move with ``statement_line_id``: direct bank
          statement reconciliation, dated with the counterpart move
          date, method fixed to the bank transfer label;
        - any other manual reconciliation is ignored.

        :return: list of ``(date, method)`` tuples, possibly empty.
        """
        self.ensure_one()
        invoice_partials, exchange_diff_moves = self._get_reconciled_invoices_partials()
        candidates = []
        for _partial, _amount, counterpart_line in invoice_partials:
            if counterpart_line.move_id.id in exchange_diff_moves:
                continue
            payment = counterpart_line.move_id.origin_payment_id
            if payment:
                candidates.append((payment.date, payment.payment_method_line_id.name))
            elif counterpart_line.move_id.statement_line_id:
                candidates.append(
                    (counterpart_line.move_id.date, self.env._("Bank Transfer"))
                )
        return candidates