"""Plan validation and independent evidence check. Author: Sandeep Belgavi."""
from dataclasses import dataclass

@dataclass(frozen=True)
class Step:
    key: str
    evidence_ref: str

def execute(planner, records, max_steps=3):
    if type(max_steps) is not int or not 1 <= max_steps <= 10:
        raise ValueError("invalid limit")
    plan = planner()
    if not isinstance(plan, (list, tuple)) or not 1 <= len(plan) <= max_steps:
        raise ValueError("invalid plan size")
    if any(not isinstance(s, Step) or not isinstance(s.key, str)
           or not isinstance(s.evidence_ref, str)
           or not s.key or not s.evidence_ref for s in plan):
        raise ValueError("invalid step")
    if len({s.key for s in plan}) != len(plan):
        raise ValueError("duplicate step")
    report = []
    for step in plan:
        row = records.get(step.evidence_ref)
        report.append({"step": step.key, "ref": step.evidence_ref,
                       "claim": "degraded" if row == "high" else "unknown"})
    return report

def verify(report, independent_records):
    """Separate evidence input, not a second approval from the planner."""
    if not report:
        return False
    for item in report:
        if not isinstance(item, dict): return False
        if item.get("claim") != "degraded": return False
        if not isinstance(item.get("ref"), str): return False
        if independent_records.get(item.get("ref")) != "high": return False
    return True

if __name__ == "__main__":
    report = execute(lambda: [Step("inspect", "L1")], {"L1": "high"})
    print(f"steps={len(report)} verified={str(verify(report, {'L1': 'high'})).lower()} remediation=none")