"""Evidence reconstruction for historical KB conflicts.

The seed payload contains the current 90 observable conflicts but not the
identity/evidence rows for the remaining 73 historical conflict records. This
module makes that limitation explicit instead of fabricating identities.
"""

from collections import Counter

RESOLVED_EQUIVALENT_PRODUCT = "RESOLVED_EQUIVALENT_PRODUCT"
FALSE_MATCH = "FALSE_MATCH"
VALID_NCM_CONFLICT = "VALID_NCM_CONFLICT"
STALE_OBSERVATION = "STALE_OBSERVATION"
INSUFFICIENT_EVIDENCE = "INSUFFICIENT_EVIDENCE"


def reconstruct_historical_conflicts(payload: dict, historical_count: int = 73) -> dict:
    products = payload.get("products", [])
    gtin_count = sum(1 for product in products if product.get("gtin"))
    fingerprint_count = sum(1 for product in products if product.get("fingerprint"))
    evidence_summary = {
        "payload_products": len(products),
        "payload_gtin_products": gtin_count,
        "payload_fingerprint_products": fingerprint_count,
        "fields_available": ["gtin", "fingerprint", "normalized_description", "unit", "ncm", "observations"],
        "historical_identity_records_found": 0,
    }
    rows = []
    for index in range(1, historical_count + 1):
        rows.append({
            "historical_conflict_id": f"HISTORICAL-{index:03d}",
            "classification": INSUFFICIENT_EVIDENCE,
            "evidence_search": evidence_summary,
            "resolution": "PRESERVE_CONFLICT",
            "reason": "original conflict identity/evidence row is absent from available artifacts; no NCM selected",
        })
    return {
        "artifact": "KB_HISTORICAL_CONFLICT_AUDIT_V1",
        "historical_conflicts_before": historical_count,
        "historical_conflicts_resolved": 0,
        "historical_conflicts_remaining": historical_count,
        "classification_counts": dict(Counter(row["classification"] for row in rows)),
        "conflicts": rows,
        "current_observable_conflicts_preserved": 90,
        "current_conflict_policy": "NCM_CONFLICT rows remain blocked; no majority resolution",
        "evidence_complete": False,
    }