import os
from pathlib import Path

from apiflask import APIBlueprint
from flask import abort, current_app, send_from_directory

bp = APIBlueprint("front", __name__, tag="前端")


def _get_frontend_path():
    frontend_path = current_app.config.get("FRONTEND_PATH")
    if not frontend_path:
        abort(404)

    path = Path(frontend_path)
    if not path.is_absolute():
        base_dir = Path(current_app.config.get("BASE_DIR", os.getcwd()))
        path = base_dir / path
    return path.resolve()


@bp.get("/")
def index():
    """渲染前端 SPA 入口页面"""
    frontend_path = _get_frontend_path()
    index_path = frontend_path / "index.html"
    if not index_path.exists():
        abort(404)
    return send_from_directory(frontend_path, "index.html")


@bp.get("/<path:fallback>")
def fallback(fallback):
    """兜底: 避免history模式下的影响"""
    frontend_path = _get_frontend_path()
    target_path = frontend_path / fallback
    if target_path.exists() and target_path.is_file():
        return send_from_directory(frontend_path, fallback)

    index_path = frontend_path / "index.html"
    if not index_path.exists():
        abort(404)
    return send_from_directory(frontend_path, "index.html")