"""Map Amazon marketplace domains to the reporting-region labels used by the workbook."""
from __future__ import annotations

DOMAIN_TO_REGION = {
    "amazon.com": "USA",
    "amazon.ca": "Canada",
    "amazon.co.uk": "UK",
    "amazon.de": "Germany",
    "amazon.fr": "France",
    "amazon.it": "Italy",
    "amazon.es": "Spain",
    "amazon.nl": "Netherlands",
    "amazon.se": "Sweden",
    "amazon.pl": "Poland",
    "amazon.com.be": "Belgium",
    "amazon.ie": "Ireland",
    "amazon.com.tr": "Turkey",
    "amazon.com.au": "Australia",
}

# Fallback: pick a region label from the source filename if the marketplace column is absent.
_FILENAME_HINTS = {
    "canada": "Canada", "uk": "UK", "germany": "Germany", "france": "France",
    "italy": "Italy", "spain": "Spain", "netherlands": "Netherlands", "sweden": "Sweden",
    "poland": "Poland", "belgium": "Belgium", "ireland": "Ireland", "turkey": "Turkey",
    "australia": "Australia", "usa": "USA", "us ": "USA",
}


def region_for(marketplace_value: str | None, filename: str | None = None,
               default: str = "USA") -> str:
    if marketplace_value:
        mv = str(marketplace_value).strip().lower()
        if mv in DOMAIN_TO_REGION:
            return DOMAIN_TO_REGION[mv]
        # tolerate values like "Amazon.com" or "amazon.com "
        for dom, region in DOMAIN_TO_REGION.items():
            if mv == dom or mv.endswith(dom):
                return region
    if filename:
        low = filename.lower()
        for hint, region in _FILENAME_HINTS.items():
            if hint in low:
                return region
    return default