from __future__ import annotations

import hashlib
import json
import os
import socket
import time
import sys

ROOT = os.environ.get("TORRENT_PEER_ROOT", "/work")
sys.path.insert(0, os.path.join(ROOT, "harness"))

from torrent_meta import Metadata, load_metadata  # noqa: E402


def parse_size(text: str) -> int:
    s = text.strip().upper()
    mult = 1
    if s[-1:] in ("K", "M", "G"):
        mult = {"K": 1024, "M": 1024**2, "G": 1024**3}[s[-1]]
        s = s[:-1]
    return int(s) * mult


def file_sha1(path: str) -> str:
    h = hashlib.sha1()
    with open(path, "rb") as f:
        for chunk in iter(lambda: f.read(1024 * 1024), b""):
            h.update(chunk)
    return h.hexdigest()


def write_manifest(path: str, **items) -> None:
    tmp = path + ".tmp"
    with open(tmp, "w", encoding="utf-8") as f:
        json.dump(items, f, indent=2, sort_keys=True)
        f.write("\n")
    os.replace(tmp, path)


def wait_for_tcp(host: str, port: int, timeout: float = 30.0) -> None:
    deadline = time.time() + timeout
    last_error = None
    while time.time() < deadline:
        try:
            with socket.create_connection((host, port), timeout=1.0):
                return
        except OSError as exc:
            last_error = exc
            time.sleep(0.25)
    raise TimeoutError(f"timed out waiting for {host}:{port}: {last_error}")


def resolve_ipv4(host: str) -> str:
    infos = socket.getaddrinfo(host, None, socket.AF_INET, socket.SOCK_STREAM)
    if not infos:
        raise OSError(f"no IPv4 address for {host}")
    return infos[0][4][0]


def touch_ready(path: str = "/tmp/seed-ready") -> None:
    with open(path, "w", encoding="utf-8") as f:
        f.write("ready\n")