Chargeback Validation Summary

You receive a raw export of dispute records, one string per row, in the format:

dispute_id,merchant_id,amount_cents,status

Split each row on commas and trim surrounding whitespace from every field. A row is valid when all of these hold:

• it has exactly 4 fields;
• dispute_id and merchant_id are non-empty;
• amount_cents is a non-negative integer written with digits only: no sign, no decimal point, and no leading zeros ("0" itself is fine, "007" is not);
• status is exactly one of open, lost, won, withdrawn (case-sensitive);
• no earlier valid row used the same dispute_id. An invalid row does not reserve its id, so a later valid row with that id is still accepted.

Invalid rows are skipped. Return [valid_count, lost_amount_cents, withdrawn_ids] where lost_amount_cents is the sum of amount_cents over valid lost rows and withdrawn_ids is the list of dispute_ids of valid withdrawn rows, sorted lexicographically.