#!/usr/bin/env python3
# Derive AereFalcon512VerifierHTP.sol from AereFalcon512Verifier.sol by replacing
# ONLY the in-EVM hashToPoint with a call to the native 0x0AE7 precompile. Every
# other step (SHAKE helpers, decode, ring mul, norm check) is byte-identical, so a
# WITH-vs-WITHOUT gas comparison isolates exactly the HashToPoint cost.
import re
import sys

src_path = sys.argv[1]
out_path = sys.argv[2]
s = open(src_path).read()

# 1. rename the contract
s = s.replace("contract AereFalcon512Verifier {", "contract AereFalcon512VerifierHTP {")

# 2. relax `pure` -> `view` on function declarations (the precompile call is a staticcall = view)
s = re.sub(r"\)(\s*)(public|internal|external|private)(\s+)pure", r")\1\2\3view", s)

# 3. replace the whole hashToPoint function body with a precompile-backed one (brace-matched)
start = s.index("function hashToPoint(")
# walk to the opening brace of the body
brace = s.index("{", start)
depth = 0
i = brace
while i < len(s):
    if s[i] == "{":
        depth += 1
    elif s[i] == "}":
        depth -= 1
        if depth == 0:
            break
    i += 1
end = i + 1  # inclusive of closing brace

replacement = (
    "function hashToPoint(bytes memory nonce, bytes memory message) public view returns (uint256[512] memory cc) {\n"
    "        // Native AERE Falcon HashToPoint precompile @ 0x0AE7: logn(1)=9 || nonce(40) || message\n"
    "        bytes memory input = bytes.concat(bytes1(uint8(9)), nonce, message);\n"
    "        (bool okp, bytes memory outp) = address(0x0AE7).staticcall(input);\n"
    "        require(okp && outp.length == 1024, \"htp precompile failed\");\n"
    "        for (uint256 i = 0; i < 512; i++) {\n"
    "            cc[i] = (uint256(uint8(outp[2 * i])) << 8) | uint256(uint8(outp[2 * i + 1]));\n"
    "        }\n"
    "    }"
)
s = s[:start] + replacement + s[end:]

open(out_path, "w").write(s)
print("wrote", out_path)