#!/usr/bin/env python3
"""FeedOracle Treasury Audit - Response Verifier
Usage: python3 verify_response.py response.json
Deps:  pip install ecdsa
"""
import json, hashlib, base64, sys
from ecdsa import VerifyingKey, SECP256k1, BadSignatureError

JWKS_URL = "https://feedoracle.io/.well-known/jwks.json"
# Embedded public key (feedoracle-prod-2026)
PUB_X = "agNOLX9EhX3OyJ59GoeToUMY4NyFTo0CaXjq_NKzBWc"
PUB_Y = "TXHvNEUK1Ps22zbHVF1ZkRYnGwIJ-t3Xqp9TgR1WQRI"

def verify(path):
    d = json.load(open(path))
    ev = d.get("evidence")
    if not ev:
        print("ERROR: No evidence block found"); return False
    print(f"Request ID:  {d.get('request_id')}")
    print(f"Schema:      {d.get('schema_version')}")
    print(f"Timestamp:   {ev.get('timestamp')}")

    # Step 1: Remove /evidence, canonicalize, hash
    body = {k: v for k, v in d.items() if k not in ("evidence", "manifest_id")}
    canon = json.dumps(body, sort_keys=True, separators=(",", ":"))
    computed = hashlib.sha256(canon.encode()).hexdigest()
    claimed = ev["content_hash"]["hex"]
    print(f"\n[Hash Verification]")
    print(f"  Claimed:  {claimed}")
    print(f"  Computed: {computed}")
    if computed != claimed:
        print("  RESULT: HASH MISMATCH ❌"); return False
    print("  RESULT: HASH MATCH ✅")

    # Step 2: Load public key, verify signature
    sig_hex = ev["signature"]["value"]
    if not sig_hex:
        print("\n  RESULT: NO SIGNATURE ⚠️"); return False
    if sig_hex.startswith("0x"):
        sig_hex = sig_hex[2:]
    x = base64.urlsafe_b64decode(PUB_X + "==")
    y = base64.urlsafe_b64decode(PUB_Y + "==")
    vk = VerifyingKey.from_string(x + y, curve=SECP256k1)
    digest = bytes.fromhex(claimed)
    sig_bytes = bytes.fromhex(sig_hex)
    print(f"\n[Signature Verification]")
    print(f"  Algorithm: {ev['signature']['alg']}")
    print(f"  Key ID:    {ev.get('key_id')}")
    try:
        vk.verify_digest(sig_bytes, digest)
        print("  RESULT: SIGNATURE VALID ✅")
        return True
    except BadSignatureError:
        print("  RESULT: SIGNATURE INVALID ❌")
        return False

def verify_release(d="."):
    """Verify RELEASE.json: hash + signature + file checksums."""
    import os
    rpath = os.path.join(d, "RELEASE.json")
    spath = os.path.join(d, "RELEASE.json.sig")
    hpath = os.path.join(d, "RELEASE.json.sha256")
    m = json.load(open(rpath))
    print(f"Release: {m.get('release_id')}  Kit: {m.get('kit_version')}")
    print(f"Issued:  {m.get('generated_at')}  by {m.get('issuer')}")
    raw = open(rpath, "rb").read()
    h = hashlib.sha256(raw).hexdigest()
    claimed = open(hpath).read().strip()
    print(f"\n[Manifest Hash]")
    print(f"  Computed: {h}")
    print(f"  Claimed:  {claimed}")
    if h != claimed:
        print("  RESULT: HASH MISMATCH"); return False
    print("  RESULT: HASH MATCH")
    sig_obj = json.load(open(spath))
    sig_hex = sig_obj["signature"]
    if sig_hex.startswith("0x"): sig_hex = sig_hex[2:]
    x = base64.urlsafe_b64decode(PUB_X + "==")
    y = base64.urlsafe_b64decode(PUB_Y + "==")
    vk = VerifyingKey.from_string(x + y, curve=SECP256k1)
    print(f"\n[Manifest Signature]")
    try:
        vk.verify_digest(bytes.fromhex(sig_hex), bytes.fromhex(h))
        print("  RESULT: SIGNATURE VALID")
    except BadSignatureError:
        print("  RESULT: SIGNATURE INVALID"); return False
    print(f"\n[File Integrity] ({len(m['files'])} files)")
    all_ok = True
    for fi in m["files"]:
        p = os.path.join(d, os.path.basename(fi["path"]))
        if not os.path.exists(p):
            print(f"  MISSING {fi['path']}"); all_ok = False; continue
        fh = hashlib.sha256(open(p, "rb").read()).hexdigest()
        sz = os.stat(p).st_size
        ok = fh == fi["sha256"] and sz == fi["bytes"]
        tag = "OK" if ok else "FAIL"
        print(f"  {tag} {fi['path']} ({fi['bytes']}b)")
        if not ok: all_ok = False
    v = "ALL VERIFIED" if all_ok else "VERIFICATION FAILED"
    print(f"\n{v}")
    return all_ok

if __name__ == "__main__":
    if len(sys.argv) > 1 and sys.argv[1] == "--verify-release":
        d = sys.argv[2] if len(sys.argv) > 2 else "."
        ok = verify_release(d)
    else:
        f = sys.argv[1] if len(sys.argv) > 1 else "test_response.json"
        ok = verify(f)
    sys.exit(0 if ok else 1)