Price List Converter and Validator

We run a wholesale catalog that pulls price lists from dozens of suppliers, and every one of them sends data in a different shape. Some deliver spreadsheets with merged cells and inconsistent headers, others push XML feeds, and a few still email plain CSV exports with their own separators and encodings. Right now our team copies columns by hand, and mistakes slip through into the storefront: wrong prices, missing stock counts, duplicated article numbers.

We need a converter and validator that reads any of these source formats and maps their fields onto our single internal schema. Field mapping should be configurable, so that a supplier column named 'Art', 'SKU' or 'Product code' can all point to the same target field without touching the code each time. After mapping, the tool must validate every row: numeric prices, non-empty article numbers, allowed currency codes, sane quantity ranges, and no duplicate keys within a file.

Anything that fails validation should not silently disappear. We want a clear error log that names the file, the row and the exact reason, so an operator can fix the source or override the rule. Clean rows go into a normalized export ready for import. Please describe how you would store the mapping profiles, how you handle broken encodings, and how the log is presented to the operator.