"""手术室站点配置：单一 JSON 文件，严格结构，无历史格式分支。"""

from __future__ import annotations

import json
from dataclasses import dataclass
from pathlib import Path
from typing import Any

from loguru import logger

from app.services.voice_terminal_binding import VoiceTerminalBindingIndex

_ALLOWED_TOP_LEVEL = frozenset({"video_rtsp_urls", "voice_or_room_bindings"})


@dataclass(frozen=True)
class OrSiteConfig:
    """根对象须含 ``video_rtsp_urls`` 与 ``voice_or_room_bindings`` 两个键。"""

    video_rtsp_urls: dict[str, str]
    voice_bindings: VoiceTerminalBindingIndex


def parse_or_site_config_object(data: Any, *, source: str | Path = "") -> OrSiteConfig:
    label = str(source) if source else "JSON"
    if not isinstance(data, dict):
        raise ValueError(f"{label}: OR site config must be a JSON object")
    extra = set(data.keys()) - _ALLOWED_TOP_LEVEL
    if extra:
        raise ValueError(
            f"{label}: unknown top-level keys {sorted(extra)}; "
            f"allowed: {sorted(_ALLOWED_TOP_LEVEL)}"
        )
    if "video_rtsp_urls" not in data or "voice_or_room_bindings" not in data:
        raise ValueError(
            f"{label}: must include video_rtsp_urls and voice_or_room_bindings"
        )
    urls = data["video_rtsp_urls"]
    if not isinstance(urls, dict):
        raise ValueError(f"{label}: video_rtsp_urls must be a JSON object")
    raw_bindings = data["voice_or_room_bindings"]
    if not isinstance(raw_bindings, list):
        raise ValueError(f"{label}: voice_or_room_bindings must be a JSON array")
    for k, v in urls.items():
        if not isinstance(v, str):
            raise ValueError(
                f"{label}: video_rtsp_urls[{k!r}] must be a string (RTSP URL)"
            )
    idx = VoiceTerminalBindingIndex.from_binding_list(raw_bindings)
    if idx is None:
        raise ValueError(f"{label}: invalid voice_or_room_bindings content")
    return OrSiteConfig(
        video_rtsp_urls={str(k): str(v) for k, v in urls.items()},
        voice_bindings=idx,
    )


def load_or_site_config_from_path(path: Path) -> OrSiteConfig:
    p = path.expanduser()
    try:
        raw_text = p.read_text(encoding="utf-8")
    except OSError as exc:
        raise ValueError(f"Cannot read OR site config {p}: {exc}") from exc
    try:
        data: Any = json.loads(raw_text)
    except json.JSONDecodeError as exc:
        raise ValueError(f"Invalid JSON in OR site config {p}: {exc}") from exc
    return parse_or_site_config_object(data, source=p)


def merge_video_rtsp_urls_into_file(
    path: Path,
    url_map: dict[str, str],
    *,
    replace_host: str,
) -> None:
    """写入/更新站点配置中的 ``video_rtsp_urls``，保留 ``voice_or_room_bindings``。"""
    if replace_host in ("", "127.0.0.1"):
        out_urls = dict(url_map)
    else:
        out_urls = {
            k: v.replace("127.0.0.1", replace_host, 1)
            for k, v in url_map.items()
        }
    path = path.expanduser()
    path.parent.mkdir(parents=True, exist_ok=True)
    if path.is_file():
        raw_text = path.read_text(encoding="utf-8")
        data: Any = json.loads(raw_text)
        parse_or_site_config_object(data, source=path)
        bindings_list = data["voice_or_room_bindings"]
    else:
        bindings_list = []
    doc = {
        "video_rtsp_urls": out_urls,
        "voice_or_room_bindings": bindings_list,
    }
    text = json.dumps(doc, ensure_ascii=False, indent=2, sort_keys=True) + "\n"
    temp = path.with_name(path.name + ".tmp")
    temp.write_text(text, encoding="utf-8")
    temp.replace(path)
    logger.info("Updated video_rtsp_urls in OR site config {}", path)