import { useEffect, useRef, useState } from "react";
import type { FormEvent } from "react";
import { Eye, EyeOff, Info, LockKeyhole, UserRound } from "lucide-react";
import { api, getRemember, setRemember as persistRemember } from "../api";
import type { Team, User } from "../types";
import type { AuthMode } from "./route-config";

type LoginProgress = "checking" | "entering";

const LOGIN_PROGRESS_COPY: Record<LoginProgress, string> = {
  checking: "正在验证用户名和密码…",
  entering: "登录成功，正在进入 Airshelf"
};

type FieldErrors = {
  username?: string;
  password?: string;
};

export function AuthScreen({
  initialMode: _initialMode,
  onModeChange: _onModeChange,
  onAuthed
}: {
  initialMode: AuthMode;
  onModeChange: (mode: AuthMode) => void;
  onAuthed: (payload: { token: string; user: User; team: Team; remember?: boolean }) => void | Promise<void>;
}) {
  const remembered = getRemember();
  const [username, setUsername] = useState(remembered?.username || "");
  const [password, setPassword] = useState("");
  const [remember, setRemember] = useState(Boolean(remembered));
  const [showPwd, setShowPwd] = useState(false);
  const [fieldErrors, setFieldErrors] = useState<FieldErrors>({});
  const [error, setError] = useState("");
  const [busy, setBusy] = useState(false);
  const [toast, setToast] = useState<{ title: string; sub: string } | null>(null);
  const [loginProgress, setLoginProgress] = useState<LoginProgress | null>(null);
  const toastTimer = useRef<ReturnType<typeof setTimeout> | null>(null);

  useEffect(() => {
    const path = window.location.pathname.replace(/\/+$/, "").toLowerCase();
    if (path === "/register" || window.location.hash === "#register") {
      window.history.replaceState(null, "", "/login");
    }
  }, []);
  useEffect(() => () => { if (toastTimer.current) clearTimeout(toastTimer.current); }, []);

  function showToast(title: string, sub: string) {
    setToast({ title, sub });
    if (toastTimer.current) clearTimeout(toastTimer.current);
    toastTimer.current = setTimeout(() => setToast(null), 2800);
  }

  function setFieldValue(field: keyof FieldErrors, value: string) {
    if (field === "username") setUsername(value);
    if (field === "password") setPassword(value);
    setError("");
    setLoginProgress(null);
    setFieldErrors((current) => ({ ...current, [field]: undefined }));
  }

  function validateLogin() {
    const next: FieldErrors = {};
    if (!username.trim()) next.username = "请输入用户名";
    if (!password) next.password = "请输入密码";
    setFieldErrors(next);
    if (Object.keys(next).length > 0) {
      setError("请补全必填字段后再登录");
      return false;
    }
    return true;
  }

  async function submit(event?: FormEvent) {
    event?.preventDefault();
    if (busy) return;
    if (!validateLogin()) return;
    setBusy(true);
    setError("");
    setLoginProgress("checking");
    try {
      const payload = await api.login({ username: username.trim(), password });
      // 记住我:勾选则存用户名 + 7 天有效期,token 落 localStorage;否则只存当前会话
      persistRemember(username.trim(), remember);
      // 凭证验过即进:不再做任何人为延迟动画。"进入"态由真实的 onAuthed(身份+数据水合)驱动。
      setLoginProgress("entering");
      await onAuthed({ ...payload, remember });
    } catch (err) {
      setLoginProgress(null);
      const raw = err instanceof Error ? err.message : "";
      const friendly = /invalid credentials|unable to log in|non_field_errors/i.test(raw)
        ? "用户名或密码不正确"
        : raw || "登录失败,请稍后重试";
      setError(friendly);
    } finally {
      setBusy(false);
    }
  }

  return (
    <main className="auth-exact-page auth-login-page">
      <div className="auth-wrap">
        <span className="corner-tr" aria-hidden="true"></span><span className="corner-bl" aria-hidden="true"></span>
        <aside className="auth-brand">
          <div className="logo"><img className="logo-img" src="/assets/logo-dark.png" alt="Airshelf" /></div>
          <div className="tag">// SHORT-VIDEO COMMERCE PLATFORM</div>
          <div className="hero">
            <h1>AI 全流程<br /><span className="h">短剧化</span>带货生成</h1>
            <p>商品 → AI 脚本 → 故事板 → Seedance 视频片段 → 一键导出 9:16 ≤60s 成片。</p>
          </div>
          <div className="foot"><a href="#">关于</a><a href="#">定价</a><a href="#">联系</a><a href="#">隐私</a></div>
        </aside>
        <section className="auth-form" aria-label="登录">
          <div className="h-row"><h2>登录</h2><span className="sub">// LOGIN</span></div>
          <form id="login-form" autoComplete="off" onSubmit={submit} noValidate>
            <div className={`field${fieldErrors.username ? " has-error" : ""}`}>
              <label className="field-label" htmlFor="auth-username">用户名 <span className="req">*</span></label>
              <div className="field-input-wrap">
                <UserRound className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                <input
                  id="auth-username"
                  type="text"
                  placeholder="请输入用户名"
                  value={username}
                  autoComplete="username"
                  aria-invalid={Boolean(fieldErrors.username)}
                  onChange={(event) => setFieldValue("username", event.target.value)}
                />
              </div>
            </div>
            <div className={`field${fieldErrors.password ? " has-error" : ""}`}>
              <label className="field-label" htmlFor="auth-pwd">密码 <span className="req">*</span></label>
              <div className="field-input-wrap">
                <LockKeyhole className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                <input
                  id="auth-pwd"
                  type={showPwd ? "text" : "password"}
                  placeholder="请输入密码"
                  value={password}
                  autoComplete="current-password"
                  aria-invalid={Boolean(fieldErrors.password)}
                  onChange={(event) => setFieldValue("password", event.target.value)}
                />
                <button
                  type="button"
                  className={`toggle-pwd${showPwd ? " active" : ""}`}
                  aria-label={showPwd ? "隐藏密码" : "显示密码"}
                  aria-pressed={showPwd}
                  title={showPwd ? "隐藏密码" : "显示密码"}
                  onClick={() => setShowPwd((value) => !value)}
                >
                  {showPwd ? <EyeOff size={18} strokeWidth={1.5} aria-hidden="true" /> : <Eye size={18} strokeWidth={1.5} aria-hidden="true" />}
                </button>
              </div>
            </div>
            <div className="row-between">
              <label><input type="checkbox" checked={remember} onChange={(event) => setRemember(event.target.checked)} /> 记住我 7 天</label>
              <a href="#" onClick={(event) => { event.preventDefault(); showToast("重置密码", "请联系团队超管重置你的登录密码"); }}>忘记密码?</a>
            </div>
          </form>
        </section>
        <div className="auth-submit-zone">
          {loginProgress && !error && (
            <div className="login-progress" role="status" aria-live="polite">
              <span className="login-progress-spinner" aria-hidden="true"></span>
              <span>{LOGIN_PROGRESS_COPY[loginProgress]}</span>
            </div>
          )}
          {error && <div className="form-error" role="alert">{error}</div>}
          <button className="btn-cta" type="button" form="login-form" disabled={busy} onClick={() => { void submit(); }}>
            {busy ? "登录中" : "登录"}
          </button>
        </div>
      </div>
      {toast && (
        <div className="toast show" role="status" aria-live="polite">
          <div className="ic-t"><Info size={13} aria-hidden="true" /></div>
          <div className="txt">{toast.title}<span className="mono">// {toast.sub}</span></div>
        </div>
      )}
    </main>
  );
}