import base64
import subprocess
from pathlib import Path
from typing import Optional

from fastapi import FastAPI, HTTPException
from pydantic import BaseModel

app = FastAPI(title="CryptoPro Linux CSP Service", version="0.1.0")

CSPTEST = Path("/opt/cprocsp/bin/amd64/csptest")


def run_cmd(cmd: list[str], input_bytes: Optional[bytes] = None, allow_fail: bool = False) -> str:
    try:
        proc = subprocess.run(
            cmd,
            input=input_bytes,
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT,
            check=True,
        )
        return proc.stdout.decode("utf-8", errors="replace")
    except subprocess.CalledProcessError as exc:
        output = exc.stdout.decode("utf-8", errors="replace") if exc.stdout else ""
        if allow_fail:
            return output
        raise HTTPException(status_code=500, detail={"cmd": cmd, "output": output})


@app.get("/health")
def health():
    if not CSPTEST.exists():
        raise HTTPException(status_code=500, detail="csptest binary not found; ensure CryptoPro CSP is installed")
    return {"status": "ok", "csptest": str(CSPTEST)}


@app.get("/license")
def license_info():
    output = run_cmd([str(CSPTEST), "-keyset", "-info"], allow_fail=True)
    return {"output": output}


class HashRequest(BaseModel):
    data_b64: str


@app.post("/hash")
def hash_data(body: HashRequest):
    try:
        data = base64.b64decode(body.data_b64)
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid base64")

    cmd = [str(CSPTEST), "-hash", "-in", "-", "-hash_alg", "gost12_256"]
    output = run_cmd(cmd, input_bytes=data)
    return {"output": output}