"""浏览器场景变量替换与 base URL 解析。"""

from __future__ import annotations

import re
from urllib.parse import urlparse

import env_config

_VAR_PATTERN = re.compile(r"\{\{([A-Z0-9_]+)\}\}")


def interpolate(value: str) -> str:
    def repl(match: re.Match[str]) -> str:
        key = match.group(1)
        resolved = env_config.env(key)
        if resolved is None:
            raise RuntimeError(f"场景变量未配置：{key}")
        return resolved

    return _VAR_PATTERN.sub(repl, value)


def default_base_url() -> str:
    explicit = (env_config.env("PREVIEW_BASE_URL") or "").strip()
    if explicit:
        return interpolate(explicit.rstrip("/"))

    preview = (env_config.env("PREVIEW_URL") or "").strip()
    if preview:
        parsed = urlparse(preview)
        scheme = parsed.scheme or "http"
        host = parsed.hostname or "127.0.0.1"
        port = parsed.port
        if port and port not in (80, 443):
            return f"{scheme}://{host}:{port}"
        return f"{scheme}://{host}"

    port = env_config.env("PREVIEW_PORT", "5173") or "5173"
    return f"http://127.0.0.1:{port}"


def resolve_url(base_url: str, target: str) -> str:
    target = interpolate(target.strip())
    if target.startswith("http://") or target.startswith("https://"):
        return target
    if not target.startswith("/"):
        target = "/" + target
    return base_url.rstrip("/") + target