"""Blenderに依存しないSEライブラリの走査・設定処理。"""

from __future__ import annotations

import json
import os
from pathlib import Path


AUDIO_EXTENSIONS = {".mp3", ".wav", ".flac", ".ogg", ".m4a", ".aac"}
CONFIG_FILENAME = ".se_palette.json"


def scan_audio_files(folder: str) -> list[Path]:
    """フォルダ直下の対応音声ファイルを名前順で返す。"""
    root = Path(folder).expanduser()
    if not root.is_dir():
        return []
    return sorted(
        (
            path
            for path in root.iterdir()
            if path.is_file() and path.suffix.lower() in AUDIO_EXTENSIONS
        ),
        key=lambda path: path.name.casefold(),
    )


def default_label(path: Path) -> str:
    """拡張子と管理用の先頭番号を除いた表示名を作る。"""
    label = path.stem
    if len(label) > 3 and label[:2].isdigit() and label[2] in {"_", "-", " "}:
        label = label[3:]
    return label.replace("_", " ")


def load_config(folder: str) -> dict:
    config_path = Path(folder).expanduser() / CONFIG_FILENAME
    if not config_path.is_file():
        return {"items": {}}
    try:
        data = json.loads(config_path.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError):
        return {"items": {}}
    if not isinstance(data, dict) or not isinstance(data.get("items", {}), dict):
        return {"items": {}}
    return data


def save_config(folder: str, items: list[dict]) -> Path:
    root = Path(folder).expanduser()
    root.mkdir(parents=True, exist_ok=True)
    config_path = root / CONFIG_FILENAME
    payload = {
        "version": 1,
        "items": {
            item["filename"]: {
                "label": item.get("label", ""),
                "icon": item.get("icon", "PLAY_SOUND"),
                "icon_path": item.get("icon_path", ""),
            }
            for item in items
        },
    }
    temporary_path = config_path.with_suffix(config_path.suffix + ".tmp")
    temporary_path.write_text(
        json.dumps(payload, ensure_ascii=False, indent=2) + "\n",
        encoding="utf-8",
    )
    os.replace(temporary_path, config_path)
    return config_path