import argparse, csv, json
from pathlib import Path
try:
    import yaml
except Exception:
    yaml = None

def load_contract(path):
    text = Path(path).read_text(encoding="utf-8")
    if yaml:
        return yaml.safe_load(text)
    required = []
    for line in text.splitlines():
        if line.strip().startswith("- "):
            required.append(line.strip()[2:])
    return {"required_fields": required, "quality_thresholds": {"completeness": 0.0}}

def validate(contract_path, file_path):
    contract = load_contract(contract_path)
    required = contract.get("required_fields", [])
    with open(file_path, encoding="utf-8") as f:
        rows = list(csv.DictReader(f))
    fields = rows[0].keys() if rows else []
    missing_fields = [f for f in required if f not in fields]
    total_required = max(1, len(rows) * len(required))
    missing_values = sum(1 for row in rows for field in required if row.get(field, "") in ("", None))
    completeness = 1.0 - missing_values / total_required
    schema_validity = 1.0 if not missing_fields else 0.0
    threshold = contract.get("quality_thresholds", {}).get("completeness", 0.0)
    return {
        "valid": not missing_fields and completeness >= threshold,
        "row_count": len(rows),
        "missing_fields": missing_fields,
        "completeness": round(completeness, 4),
        "schema_validity": schema_validity,
        "quality_score": round(0.7 * completeness + 0.3 * schema_validity, 4),
    }

if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--contract", required=True)
    parser.add_argument("--file", required=True)
    args = parser.parse_args()
    print(json.dumps(validate(args.contract, args.file), indent=2))