"""启动前清空状态：默认仅重置客户端游标，保留 SQLite 历史快照。

由 start_fresh.sh 在 uvicorn 之前调用。
- 默认保留 SQLite 历史数据，仅重置 client_id 投递游标（fresh 语义）
- 设置 CLEAR_SQLITE_DATABASE=1 可强制清空 SQLite（主库 + wal/shm）
- 默认保留 measure_output 以复用中间步骤（点云等）
- 设置 CLEAR_MEASURE_OUTPUT=1 清空测量输出目录
- 设置 CLEAR_ACTION_OUTPUT=1 清空行为输出目录
"""

from __future__ import annotations

import os
from pathlib import Path

from app.db import _safe_rm_tree, remove_sqlite_database_files, reset_delivery_client_progress
from app.settings import get_settings


def _rm_legacy_json(path: Path | None) -> None:
    if path is None:
        return
    try:
        if path.is_file():
            path.unlink()
            print(f"[prestart-fresh] removed legacy JSON {path}", flush=True)
    except OSError as e:
        print(f"[prestart-fresh] skip {path}: {e}", flush=True)


def run_prestart_fresh() -> None:
    s = get_settings()

    clear_sqlite_database = os.environ.get("CLEAR_SQLITE_DATABASE", "").strip() in (
        "1",
        "true",
        "yes",
    )
    if clear_sqlite_database:
        remove_sqlite_database_files(s)
        print(
            f"[prestart-fresh] removed SQLite at {s.sqlite_path} (and -wal/-shm if present).",
            flush=True,
        )
    else:
        reset_delivery_client_progress(s)
        print(
            f"[prestart-fresh] kept SQLite history, reset delivery client progress in {s.sqlite_path}.",
            flush=True,
        )

    # 检查是否清空中间输出目录（默认保留以复用点云等中间步骤）
    clear_measure_output = os.environ.get("CLEAR_MEASURE_OUTPUT", "").strip() in ("1", "true", "yes")
    clear_action_output = os.environ.get("CLEAR_ACTION_OUTPUT", "").strip() in ("1", "true", "yes")

    if clear_measure_output:
        _safe_rm_tree(s.measure_output_root)
        print(f"[prestart-fresh] cleared measure_output: {s.measure_output_root}", flush=True)
    else:
        print(f"[prestart-fresh] kept measure_output for reuse: {s.measure_output_root}", flush=True)

    if clear_action_output:
        _safe_rm_tree(s.action_output_root)
        print(f"[prestart-fresh] cleared action_output: {s.action_output_root}", flush=True)
    else:
        print(f"[prestart-fresh] kept action_output: {s.action_output_root}", flush=True)

    # 始终清空媒体根目录和流临时目录（这些是可以重新生成的）
    _safe_rm_tree(s.media_root)
    _safe_rm_tree(s.stream_tmp_dir)
    print(
        f"[prestart-fresh] cleared media and stream_tmp: "
        f"media={s.media_root}, stream_tmp={s.stream_tmp_dir}",
        flush=True,
    )

    # 清理旧版 JSON 状态文件（数据已迁移到 SQLite）
    if s.measure_watch_use_state_file and s.measure_watch_dir is not None:
        _rm_legacy_json(s.measure_watch_dir / ".fishmeasure_watch_processed.json")

    if s.action_watch_use_state_file and s.action_watch_dir is not None:
        _rm_legacy_json(s.action_watch_dir / ".fishaction_watch_processed.json")

    print("[prestart-fresh] done.", flush=True)


def main() -> None:
    run_prestart_fresh()


if __name__ == "__main__":
    main()