#!/usr/bin/env python3
"""AM-1 / M-D1-COV: every numbered GR-rule needs >=1 scenario.

Compares the rule IDs declared in specs/GroundRules.md against the
`covers:` lists in scenarios/ground/*.yaml. Exits non-zero when a
scenario claims a rule the spec does not define, so coverage can never
be inflated by a typo'd or invented rule ID.
"""
import glob
import re
import sys

spec = open("specs/GroundRules.md").read()
rules = sorted(set(re.findall(r"\*\*(GR-[A-Z]+\d+)", spec)))

covered = set()
for path in sorted(glob.glob("scenarios/ground/*.yaml")):
    match = re.search(r"covers: \[(.*?)\]", open(path).read(), re.S)
    if match:
        covered |= {c.strip() for c in match.group(1).split(",") if c.strip()}

known = set(rules)
hit = sorted(known & covered)
missing = [r for r in rules if r not in covered]
invented = sorted(covered - known)

pct = 100 * len(hit) // len(rules) if rules else 0
print(f"AM-1 rule coverage: {len(hit)}/{len(rules)} ({pct}%)")
if missing:
    print("  uncovered:", " ".join(missing))
if invented:
    print("  ERROR — claimed but not defined in the spec:", " ".join(invented))
    sys.exit(1)
sys.exit(0 if not missing else 2)