import os
from urllib.parse import urlparse, urlsplit, urlunsplit


POS_ORIGIN = "https://pos.hengdianfilm.com"
POS_PROXY_URL_ENV = "POS_CASHIER_PROXY_URL"
POS_PROXY_TOKEN_ENV = "POS_CASHIER_PROXY_TOKEN"
POS_PROXY_AUTH_QUERY_ENV = "POS_CASHIER_PROXY_AUTH_QUERY"
POS_PROXY_TOKEN_HEADER = "X-POS-Proxy-Token"
TMS_PROXY_URL_ENV = "TMS_CF_WORKER_URL"
TMS_PROXY_TOKEN_ENV = "TMS_CF_WORKER_TOKEN"
POS_PROXY_USE_TMS_ENV = "POS_CASHIER_USE_TMS_PROXY"


def _env_flag(name, default=False):
    raw = str(os.getenv(name, "")).strip().lower()
    if not raw:
        return default
    return raw not in {"0", "false", "no", "off"}


def _normalize_url(raw):
    raw = str(raw or "").strip().strip('"').strip("'")
    if not raw:
        return ""
    if "://" not in raw:
        raw = f"https://{raw}"
    return raw.rstrip("/")


def _derive_pos_proxy_from_tms_proxy():
    tms_proxy_base_url = _normalize_url(os.getenv(TMS_PROXY_URL_ENV, ""))
    if not tms_proxy_base_url:
        return ""

    parts = urlsplit(tms_proxy_base_url)
    base_path = parts.path.rstrip("/")
    pos_path = f"{base_path}/pos-api" if base_path and base_path != "/" else "/pos-api"
    return urlunsplit((parts.scheme, parts.netloc, pos_path, parts.query, parts.fragment)).rstrip("/")


def get_pos_proxy_base_url(proxy_url=None):
    if proxy_url is not None:
        return _normalize_url(proxy_url)
    explicit_proxy_url = _normalize_url(os.getenv(POS_PROXY_URL_ENV, ""))
    if explicit_proxy_url:
        return explicit_proxy_url
    if _env_flag(POS_PROXY_USE_TMS_ENV, False):
        return _derive_pos_proxy_from_tms_proxy()
    return ""


def get_pos_origin(origin_url=None):
    return _normalize_url(origin_url if origin_url is not None else os.getenv("POS_CASHIER_BASE_URL", POS_ORIGIN)) or POS_ORIGIN


def build_pos_url(origin_url, proxy_url=None, origin_base_url=None):
    proxy_base_url = get_pos_proxy_base_url(proxy_url)
    if not proxy_base_url:
        return origin_url

    parsed = urlparse(origin_url)
    origin = f"{parsed.scheme}://{parsed.netloc}"
    if origin != get_pos_origin(origin_base_url):
        return origin_url

    base_parts = urlsplit(proxy_base_url)
    base_path = base_parts.path.rstrip("/")
    target_path = parsed.path
    final_path = f"{base_path}{target_path}" if base_path and base_path != "/" else target_path
    extra_query = os.getenv(POS_PROXY_AUTH_QUERY_ENV, "").strip().lstrip("?")
    query_parts = [q for q in (base_parts.query, extra_query, parsed.query) if q]
    return urlunsplit(
        (
            base_parts.scheme,
            base_parts.netloc,
            final_path,
            "&".join(query_parts),
            base_parts.fragment,
        )
    )


def with_pos_proxy_headers(headers=None, proxy_url=None):
    headers = dict(headers or {})
    if get_pos_proxy_base_url(proxy_url):
        pos_proxy_token = os.getenv(POS_PROXY_TOKEN_ENV, "").strip()
        tms_proxy_token = os.getenv(TMS_PROXY_TOKEN_ENV, "").strip()
        proxy_token = pos_proxy_token or tms_proxy_token or os.getenv("NEW_API_PROXY_TOKEN", "").strip()
        if proxy_token:
            headers[POS_PROXY_TOKEN_HEADER] = proxy_token
        if tms_proxy_token:
            headers["X-TMS-Proxy-Token"] = tms_proxy_token
    return headers


def mask_pos_proxy_url(proxy_url=None):
    proxy_base_url = get_pos_proxy_base_url(proxy_url)
    if not proxy_base_url:
        return ""
    return proxy_base_url.split("?", 1)[0] + ("?..." if "?" in proxy_base_url else "")