"""Фейковое реле хаба для тестов агента: забирает req/<id>.json из папки и отвечает resp/<id>.json.
Режимы: forward — переслать в HTTP (FakeHub) и вернуть ответ; silent — забрать и не отвечать;
garbage — положить нечитаемый ответ; late — ответить через delay секунд."""
import json
import os
import threading
import time
import urllib.error
import urllib.request


def write_atomic(directory, name, payload):
    tmp = os.path.join(directory, "." + name + ".tmp")
    with open(tmp, "w", encoding="utf-8") as f:
        f.write(payload if isinstance(payload, str) else json.dumps(payload, ensure_ascii=False))
    os.replace(tmp, os.path.join(directory, name))


class FakeRelay:
    def __init__(self, root, target_base_url="", mode="forward", delay=0.0):
        self.root, self.base, self.mode, self.delay = root, target_base_url, mode, delay
        self.requests = []
        self._stop = threading.Event()
        self._thread = threading.Thread(target=self._loop, daemon=True)
        for sub in ("req", "resp"):
            os.makedirs(os.path.join(root, sub), exist_ok=True)

    def start(self):
        self._thread.start()
        return self

    def stop(self):
        self._stop.set()
        self._thread.join(5)

    def _loop(self):
        req_dir, resp_dir = os.path.join(self.root, "req"), os.path.join(self.root, "resp")
        while not self._stop.is_set():
            for name in sorted(os.listdir(req_dir)):
                if name.startswith(".") or not name.endswith(".json"):
                    continue
                path = os.path.join(req_dir, name)
                try:
                    with open(path, encoding="utf-8") as f:
                        req = json.load(f)
                    os.remove(path)
                except (OSError, ValueError):
                    continue
                self.requests.append(req)
                if self.mode == "silent":
                    continue
                if self.mode == "garbage":
                    write_atomic(resp_dir, name, "{не json")
                    continue
                if self.mode == "late":
                    time.sleep(self.delay)
                status, body = self._forward(req)
                write_atomic(resp_dir, name, {"id": req["id"], "status": status, "body": body})
            time.sleep(0.02)

    def _forward(self, req):
        data = json.dumps(req["body"]).encode("utf-8") if req.get("body") is not None else None
        r = urllib.request.Request(self.base + req["path"], data=data, method=req["method"])
        r.add_header("Authorization", req["authorization"])
        if data is not None:
            r.add_header("Content-Type", "application/json")
        try:
            with urllib.request.urlopen(r, timeout=10) as resp:
                return resp.status, resp.read().decode("utf-8")
        except urllib.error.HTTPError as e:
            try:
                return e.code, e.read().decode("utf-8")
            finally:
                e.close()