#!/usr/bin/env python3
from pathlib import Path
import json, hashlib, sys

ROOT = Path(__file__).resolve().parents[1]

def sha256(p):
    h=hashlib.sha256()
    with open(p,"rb") as f:
        for c in iter(lambda:f.read(1024*1024),b""): h.update(c)
    return h.hexdigest()

errors=[]
# JSON/JSONL syntax
for p in ROOT.rglob("*.jsonl"):
    with open(p,encoding="utf-8") as f:
        for i,line in enumerate(f,1):
            if not line.strip(): continue
            try: json.loads(line)
            except Exception as e: errors.append(f"{p.relative_to(ROOT)}:{i}: {e}")
for p in ROOT.rglob("*.json"):
    try: json.loads(p.read_text(encoding="utf-8"))
    except Exception as e: errors.append(f"{p.relative_to(ROOT)}: {e}")

# raw checksums remain immutable
chk=ROOT/"00_raw/checksums.sha256"
for line in chk.read_text().splitlines():
    expected, rel=line.split("  ",1)
    p=ROOT/rel
    if not p.exists(): errors.append(f"missing {rel}")
    elif sha256(p)!=expected: errors.append(f"hash mismatch {rel}")

# expected cases
case_map=(ROOT/"01_canonical/case_map.csv").read_text(encoding="utf-8")
for i in range(1,5):
    cid=f"case_{i:04d}"
    if cid not in case_map: errors.append(f"missing case map entry {cid}")

# QA <-> evidence contract cross references
qas=[json.loads(x) for x in (ROOT/"03_semantics/qa_pairs.jsonl").read_text(encoding="utf-8").splitlines() if x.strip()]
contracts=[json.loads(x) for x in (ROOT/"12_evidence_contract/evidence_contracts.jsonl").read_text(encoding="utf-8").splitlines() if x.strip()]
contract_by_id={x['evidence_contract_id']:x for x in contracts}
qa_ids={x['qa_id'] for x in qas}
for q in qas:
    ec=q.get('evidence_contract_id')
    if not ec or ec not in contract_by_id: errors.append(f"QA {q['qa_id']} missing valid evidence contract")
for c in contracts:
    if c['qa_id'] not in qa_ids: errors.append(f"orphan evidence contract {c['evidence_contract_id']}")

# every QA gets exactly the five planned conditions
perts=[json.loads(x) for x in (ROOT/"13_perturbations/perturbation_manifest.jsonl").read_text(encoding="utf-8").splitlines() if x.strip()]
expected={'correct_image','question_only','same_modality_hard_mismatch','wrong_organ_or_modality','blank_or_target_occluded'}
for qid in qa_ids:
    got={x['condition'] for x in perts if x['qa_id']==qid}
    if got != expected: errors.append(f"{qid} perturbation conditions mismatch: {sorted(got)}")

# empirical fields must remain unset until a real run exists
for c in contracts:
    em=c['empirical_measurement']
    if em.get('status')=='not_run':
        leaked=[k for k,v in em.items() if k!='status' and v is not None]
        if leaked: errors.append(f"{c['qa_id']} has audit values despite status not_run: {leaked}")

if (ROOT/'VERSION').read_text().strip() != '0.2.0': errors.append('VERSION is not 0.2.0')

if errors:
    print("VALIDATION FAILED")
    print("\n".join(errors))
    sys.exit(1)
print("VALIDATION PASS")
print(f"{len(qas)} QA items linked to {len(contracts)} evidence contracts; five-condition perturbation plans verified; raw hashes unchanged.")