import { marked } from "marked";

const DEFAULT_DEV_API_BASE = "http://localhost:8080";
const DEFAULT_PROD_API_BASE = "https://auth.api.shumengya.top";

export const API_BASE = (() => {
  const configuredBase = import.meta.env.VITE_API_BASE?.trim();
  const fallbackBase = import.meta.env.DEV ? DEFAULT_DEV_API_BASE : DEFAULT_PROD_API_BASE;
  return (configuredBase || fallbackBase).replace(/\/+$/, "");
})();

/** OAuth 成功回跳：当前页（不含 # fragment），与后端 `allowedReturnPrefixes` 白名单配合 */
export function getOAuthReturnTo() {
  if (typeof window === "undefined") return "";
  return `${window.location.origin}${window.location.pathname}${window.location.search}`;
}

/** `public/logo192.png`，含 Vite `base` 前缀，避免子路径部署时顶栏/开屏裂图 */
export const LOGO_192_SRC = `${import.meta.env.BASE_URL}logo192.png`;

/** 全站随机背景（`GET /api/random?format=json`，见 https://randbg.api.smyhub.com） */
export const RAND_BG_API_ORIGIN = "https://randbg.api.smyhub.com";

const SELF_SERVICE_ACCOUNT_ALPHABET = "abcdefghijklmnopqrstuvwxyz0123456789";

/** 与自助注册规则一致：随机小写字母与数字（默认长度 10） */
export function randomSelfServiceAccount(length = 10) {
  const n = Math.max(3, Math.min(32, Number(length) || 10));
  const buf = new Uint8Array(n);
  crypto.getRandomValues(buf);
  let s = "";
  for (let i = 0; i < n; i++) {
    s += SELF_SERVICE_ACCOUNT_ALPHABET[buf[i] % SELF_SERVICE_ACCOUNT_ALPHABET.length];
  }
  return s;
}

/** 输入时规范为自助注册允许的字符（小写、数字），超长截断 */
export function normalizeSelfServiceAccountInput(raw, maxLen = 32) {
  const m = Math.max(3, Math.min(32, maxLen));
  return String(raw || "")
    .toLowerCase()
    .replace(/[^a-z0-9]/g, "")
    .slice(0, m);
}

/** 浏览器侧 IP/地理（与后端写入「最后访问」字段配合使用） */
export const CLIENT_GEO_LOOKUP_URL = "https://cf-ip-geo.smyhub.com/api";

export function formatVisitDisplayLocation(payload) {
  const g = payload?.geo;
  if (!g || typeof g !== "object") return "";
  const parts = [g.countryName, g.regionName, g.cityName].filter(
    (x) => typeof x === "string" && x.trim()
  );
  return parts.join(" ");
}

export async function fetchClientVisitMeta(timeoutMs = 2800) {
  const ctrl = new AbortController();
  const id = setTimeout(() => ctrl.abort(), timeoutMs);
  try {
    const res = await fetch(CLIENT_GEO_LOOKUP_URL, {
      credentials: "omit",
      signal: ctrl.signal
    });
    clearTimeout(id);
    if (!res.ok) return { ip: "", displayLocation: "" };
    const data = await res.json();
    const ip = typeof data.ip === "string" ? data.ip.trim() : "";
    const displayLocation = formatVisitDisplayLocation(data);
    return { ip, displayLocation };
  } catch {
    clearTimeout(id);
    return { ip: "", displayLocation: "" };
  }
}

marked.setOptions({ breaks: true });
export { marked };

export const emptyForm = {
  account: "",
  password: "",
  username: "",
  email: "",
  level: 0,
  sproutCoins: 0,
  secondaryEmails: "",
  phone: "",
  avatarUrl: "",
  websiteUrl: "",
  bio: "",
  banned: false,
  banReason: ""
};

/** 后端封禁响应：`error` + 可选 `banReason`（登录/me 等 403） */
export function formatAuthBanMessage(data) {
  const base = (data && data.error && String(data.error).trim()) || "account is banned";
  const reason = data && data.banReason != null && String(data.banReason).trim();
  return reason ? `${base}：${reason}` : base;
}

/** 展示用：从完整 URL 得到「主机 + 路径」短文案 */
export function formatWebsiteLabel(url) {
  if (!url || typeof url !== "string") return "";
  try {
    const u = new URL(url);
    const path = u.pathname === "/" ? "" : u.pathname;
    return u.host + path;
  } catch {
    return url;
  }
}

/** 用户 `createdAt`（RFC3339）→ 本地可读注册时间 */
export function formatUserRegisteredAt(iso) {
  if (!iso || typeof iso !== "string") return "未知";
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return iso;
  return new Intl.DateTimeFormat("zh-CN", {
    dateStyle: "long",
    timeStyle: "short"
  }).format(d);
}

/** RFC3339 / 后端存储时间 → 本地可读（用于应用接入记录等） */
export function formatIsoDateTimeReadable(iso) {
  if (!iso || typeof iso !== "string") return "—";
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return iso;
  return new Intl.DateTimeFormat("zh-CN", {
    dateStyle: "medium",
    timeStyle: "medium"
  }).format(d);
}

export const parseEmailList = (value) =>
  value.split(",").map((item) => item.trim()).filter(Boolean);

/** 可点击发信：`mailto:`，排除明显非法地址 */
export function mailtoHref(address) {
  const a = typeof address === "string" ? address.trim() : "";
  if (!a || /\s/.test(a) || a.includes("<") || a.includes(">")) return null;
  const at = a.indexOf("@");
  if (at < 1 || at === a.length - 1) return null;
  return `mailto:${a}`;
}

export function getPublicAccountFromPathname(pathname) {
  if (pathname !== "/user" && !pathname.startsWith("/user/")) return "";
  const raw = pathname === "/user" ? "" : pathname.slice("/user/".length).split("/")[0];
  if (!raw) return "";
  try {
    return decodeURIComponent(raw).trim();
  } catch {
    return raw.trim();
  }
}

export function getAuthFlowFromSearch(search) {
  const params = new URLSearchParams(search);
  const redirectUri = (params.get("redirect_uri") || params.get("return_url") || "").trim();
  const scopeRaw = (params.get("scope") || "").trim();
  const scopes = scopeRaw
    ? scopeRaw.split(/[\s+]+/).map((s) => s.trim()).filter(Boolean)
    : [];
  return {
    redirectUri,
    state: (params.get("state") || "").trim(),
    prompt: (params.get("prompt") || "").trim(),
    clientId: (params.get("client_id") || "").trim(),
    clientName: (params.get("client_name") || "").trim(),
    scopes,
    scopeRaw
  };
}

/** 授权页展示用：回跳地址可读标签（主机 + 路径） */
export function formatOAuthRedirectLabel(redirectUri) {
  if (!redirectUri || typeof redirectUri !== "string") return "—";
  const t = redirectUri.trim();
  if (!t) return "—";
  try {
    const u = new URL(t, typeof window !== "undefined" ? window.location.href : "https://example.com");
    const path = u.pathname === "/" ? "" : u.pathname;
    return `${u.host}${path}` || u.host;
  } catch {
    return t.length > 64 ? `${t.slice(0, 61)}…` : t;
  }
}

const AUTH_CLIENT_ID_KEY = "sproutgate_auth_client_id";
const AUTH_CLIENT_NAME_KEY = "sproutgate_auth_client_name";

/** 从统一登录 URL 上的 `client_id` / `client_name` 写入 session，后续请求带 `X-Auth-Client` 头以便记录接入应用 */
export function persistAuthClientFromFlow(authFlow) {
  if (!authFlow?.clientId) return;
  try {
    sessionStorage.setItem(AUTH_CLIENT_ID_KEY, authFlow.clientId);
    if (authFlow.clientName) sessionStorage.setItem(AUTH_CLIENT_NAME_KEY, authFlow.clientName);
  } catch {
    /* ignore */
  }
}

export function authClientFetchHeaders() {
  try {
    const id = (sessionStorage.getItem(AUTH_CLIENT_ID_KEY) || "").trim();
    const name = (sessionStorage.getItem(AUTH_CLIENT_NAME_KEY) || "").trim();
    const h = {};
    if (id) h["X-Auth-Client"] = id;
    if (name) h["X-Auth-Client-Name"] = name;
    return h;
  } catch {
    return {};
  }
}

export function clearAuthClientContext() {
  try {
    sessionStorage.removeItem(AUTH_CLIENT_ID_KEY);
    sessionStorage.removeItem(AUTH_CLIENT_NAME_KEY);
  } catch {
    /* ignore */
  }
}

export function buildAuthCallbackUrl(redirectUri, payload) {
  const url = new URL(redirectUri, window.location.href);
  const hashParams = new URLSearchParams(url.hash ? url.hash.slice(1) : "");
  Object.entries(payload).forEach(([key, value]) => {
    if (value === undefined || value === null || value === "") return;
    hashParams.set(key, String(value));
  });
  url.hash = hashParams.toString();
  return url.toString();
}

/** 用户拒绝授权：回跳到应用地址，在 URL hash 中携带 OAuth 风格 error（与成功回跳一致使用 fragment） */
export function buildAuthDenyCallbackUrl(redirectUri, state = "") {
  if (!redirectUri || typeof redirectUri !== "string") return "";
  const url = new URL(redirectUri, window.location.href);
  const hashParams = new URLSearchParams();
  hashParams.set("error", "access_denied");
  hashParams.set("error_description", "resource_owner_denied");
  if (state) hashParams.set("state", String(state));
  url.hash = hashParams.toString();
  return url.toString();
}