import os
from pathlib import Path

from fastapi import Request
from fastapi import HTTPException


PUBLIC_API_BASE_URL = os.getenv("PUBLIC_API_BASE_URL", "").strip().rstrip("/")
VALID_CLIENT_TOKEN = os.getenv("CLIENT_API_TOKEN")
RELEASE_MAIN_EXECUTABLE = os.getenv("RELEASE_MAIN_EXECUTABLE", "MainApp.exe").strip().replace(chr(92), "/").strip("/")
TARGET_PLATFORM = os.getenv("TARGET_PLATFORM", "windows")
TARGET_ARCH = os.getenv("TARGET_ARCH", "x64")
PUBLISH_MAX_REQUEST_BYTES = int(os.getenv("PUBLISH_MAX_REQUEST_MB", "4096")) * 1024 * 1024
PUBLISH_MAX_FILES = int(os.getenv("PUBLISH_MAX_FILES", "20000"))
PUBLISH_MAX_FIELDS = int(os.getenv("PUBLISH_MAX_FIELDS", str(PUBLISH_MAX_FILES + 100)))


def public_api_base_url(request: Request) -> str:
    if PUBLIC_API_BASE_URL:
        return PUBLIC_API_BASE_URL
    forwarded_proto = request.headers.get("x-forwarded-proto", "").split(",")[0].strip()
    forwarded_host = request.headers.get("x-forwarded-host", "").split(",")[0].strip()
    scheme = forwarded_proto or request.url.scheme
    host = forwarded_host or request.headers.get("host", "")
    if host:
        return f"{scheme}://{host}".rstrip("/")
    return str(request.base_url).rstrip("/")


def default_client_main_executable() -> str:
    path = RELEASE_MAIN_EXECUTABLE.strip().replace(chr(92), "/").strip("/")
    if path.casefold().startswith("bin/"):
        path = path[4:]
    return path or "SimCAE.exe"


def default_client_config_values(request: Request) -> dict:
    return {
        "api_base_url": public_api_base_url(request),
        "client_token": VALID_CLIENT_TOKEN or "",
        "launch_token": os.getenv("CLIENT_LAUNCH_TOKEN", "SimCAE_Launch_Token_2026_ChangeMe_32Bytes"),
        "request_timeout_ms": os.getenv("CLIENT_REQUEST_TIMEOUT_MS", "5000"),
        "temp_folder": os.getenv("CLIENT_TEMP_FOLDER", "update_temp"),
        "install_root": os.getenv("CLIENT_INSTALL_ROOT", ".."),
        "main_executable": os.getenv("CLIENT_MAIN_EXECUTABLE", default_client_main_executable()),
        "launcher_executable": os.getenv("CLIENT_LAUNCHER_EXECUTABLE", "Launcher.exe"),
        "updater_executable": os.getenv("CLIENT_UPDATER_EXECUTABLE", "Updater.exe"),
        "bootstrap_executable": os.getenv("CLIENT_BOOTSTRAP_EXECUTABLE", "Bootstrap.exe"),
        "health_check_timeout_ms": os.getenv("CLIENT_HEALTH_CHECK_TIMEOUT_MS", "15000"),
        "platform": TARGET_PLATFORM,
        "arch": TARGET_ARCH,
    }


def normalize_executable_name(value: str) -> str:
    normalized = str(value or "").strip().replace(chr(92), "/").strip("/")
    if not normalized:
        return ""
    if normalized.startswith("/") or ":" in normalized or any(part in ("", ".", "..") for part in Path(normalized).parts):
        raise HTTPException(status_code=400, detail="主程序文件名必须是安全的相对路径")
    if not normalized.casefold().endswith(".exe"):
        normalized += ".exe"
    return normalized