#!/usr/bin/env python3
"""UI bridge files: status JSON, log jsonl, command file."""
from __future__ import annotations

import json
import logging
import time
from pathlib import Path
from typing import Any, Dict, List, Optional

from config import UI_LOG_LIMIT, cmd_path, status_path, ui_log_path

log = logging.getLogger("collector.ui")


def write_status(status: dict) -> None:
    path = status_path()
    tmp = Path(str(path) + ".tmp")
    try:
        tmp.write_text(json.dumps(status, ensure_ascii=False), encoding="utf-8")
        tmp.replace(path)
    except OSError as e:
        log.error("status write failed: %s", e)


def append_ui_log(level: str, message: str, **extra: Any) -> None:
    path = ui_log_path()
    entry = {
        "ts": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
        "level": level,
        "msg": message,
    }
    entry.update(extra)
    try:
        with path.open("a", encoding="utf-8") as f:
            f.write(json.dumps(entry, ensure_ascii=False) + "\n")
        _truncate_log(path, UI_LOG_LIMIT)
    except OSError as e:
        log.error("ui log write failed: %s", e)


def _truncate_log(path: Path, limit: int) -> None:
    try:
        lines = path.read_text(encoding="utf-8").splitlines()
    except OSError:
        return
    if len(lines) <= limit:
        return
    try:
        path.write_text("\n".join(lines[-limit:]) + "\n", encoding="utf-8")
    except OSError:
        pass


def read_cmd() -> Optional[Dict[str, Any]]:
    path = cmd_path()
    if not path.exists():
        return None
    try:
        raw = path.read_text(encoding="utf-8").strip()
        path.unlink(missing_ok=True)
    except OSError as e:
        log.error("cmd read failed: %s", e)
        return None
    if not raw:
        return {"op": "advertise"}
    try:
        return json.loads(raw)
    except ValueError:
        return {"op": "advertise"}


def write_advertise_cmd() -> None:
    """Helper for external callers (tests)."""
    try:
        cmd_path().write_text(json.dumps({"op": "advertise"}), encoding="utf-8")
    except OSError as e:
        log.error("cmd write failed: %s", e)