import asyncio
import shutil
from pathlib import Path

import yaml

from app.models.proxy import ProxyDocument


def script_path_for(work_dir: Path, proxy: ProxyDocument) -> Path:
    return work_dir / "addons" / f"{proxy.proxy_port}.py"


def conf_dir_for(work_dir: Path, proxy: ProxyDocument) -> Path:
    return work_dir / "conf" / str(proxy.proxy_port)


def config_path_for(work_dir: Path, proxy: ProxyDocument) -> Path:
    return conf_dir_for(work_dir, proxy) / "config.yaml"


def log_path_for(work_dir: Path, proxy: ProxyDocument) -> Path:
    return work_dir / "logs" / f"{proxy.proxy_port}.log"


async def write_script(work_dir: Path, proxy: ProxyDocument) -> Path:
    path = script_path_for(work_dir, proxy)
    await asyncio.to_thread(path.parent.mkdir, parents=True, exist_ok=True)
    await asyncio.to_thread(path.write_text, proxy.code, encoding="utf-8")
    return path


async def write_config(work_dir: Path, proxy: ProxyDocument) -> Path:
    path = config_path_for(work_dir, proxy)
    await asyncio.to_thread(path.parent.mkdir, parents=True, exist_ok=True)
    options = {"block_global": False, **proxy.mitm_options}
    config_text = yaml.safe_dump(options, sort_keys=True)
    await asyncio.to_thread(path.write_text, config_text, encoding="utf-8")
    return path


async def ensure_log_path(work_dir: Path, proxy: ProxyDocument) -> Path:
    path = log_path_for(work_dir, proxy)
    await asyncio.to_thread(path.parent.mkdir, parents=True, exist_ok=True)
    return path


async def read_log_tail(path: Path, limit: int = 4000) -> str:
    if not await asyncio.to_thread(path.exists):
        return ""
    content = await asyncio.to_thread(
        path.read_text,
        encoding="utf-8",
        errors="replace",
    )
    return content[-limit:].strip()


def remove_file(path: Path) -> None:
    try:
        path.unlink(missing_ok=True)
    except OSError:
        return


def remove_dir(path: Path) -> None:
    try:
        shutil.rmtree(path)
    except FileNotFoundError:
        return
    except OSError:
        return


def read_cmdline(pid: int) -> list[str]:
    path = Path(f"/proc/{pid}/cmdline")
    try:
        raw = path.read_bytes()
    except OSError:
        return []
    decoded = raw.decode("utf-8", errors="replace")
    return [part for part in decoded.split("\x00") if part]