from __future__ import annotations

from typing import Any
from urllib.parse import parse_qsl, urlsplit

from app.discovery.enums import MappingStatus
from app.discovery.urlgen import decode_xf_roundtrip, generate_search_url


def verify_roundtrip(
    *,
    category_url: str,
    criterion: dict[str, Any],
    mapping: dict[str, Any],
) -> bool:
    """True when encoding a single mapping round-trips to the same source parameter."""
    probe = {**mapping, "status": MappingStatus.VERIFIED.value}
    url, internal = generate_search_url(
        category_url=category_url,
        criteria_items=[criterion],
        mappings=[probe],
    )
    if internal:
        return False
    encoding = mapping.get("encoding") or {}
    param = str(encoding.get("url_param") or "xf")
    if param == "xf":
        expected_key = str(mapping["external_filter_key"])
        expected_value = str(mapping.get("source_value") or "")
        decoded = decode_xf_roundtrip(url)
        return any(key == expected_key and value == expected_value.replace("+", " ") for key, value in decoded)
    expected = str(criterion.get("value"))
    query = parse_qsl(urlsplit(url).query, keep_blank_values=True)
    return any(name == param and value == expected for name, value in query)