import { useEffect, useRef, useState } from "react";
import type { FormEvent } from "react";
import {
  ArrowRight,
  Eye,
  EyeOff,
  Info,
  LockKeyhole,
  ScanLine,
  ShieldCheck,
  Ticket,
  UserRound,
  Users
} 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，正在进入工作台…"
};

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

type RegisterErrors = {
  team?: string;
  username?: string;
  password?: string;
  password2?: string;
  agree?: string;
};

// 注册码优先:先验码,验过才展开对应表单(create_team 开团队 / join_team 加入已有团队)。
type InviteState =
  | { status: "idle" }
  | { status: "checking" }
  | { status: "valid"; kind: "join_team" | "create_team"; teamName: string | null; role?: string }
  | { status: "invalid"; detail: string };

export function AuthScreen({
  initialMode,
  onModeChange,
  onAuthed
}: {
  initialMode: AuthMode;
  onModeChange: (mode: AuthMode) => void;
  onAuthed: (payload: { token: string; user: User; team: Team; role?: string; remember?: boolean }) => void | Promise<void>;
}) {
  const remembered = getRemember();
  const [mode, setMode] = useState<AuthMode>(initialMode);

  // ── 登录态 ──
  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>({});

  // ── 注册态 ──
  const [regTeam, setRegTeam] = useState("");
  const [regUsername, setRegUsername] = useState("");
  const [regPassword, setRegPassword] = useState("");
  const [regPassword2, setRegPassword2] = useState("");
  const [regInvite, setRegInvite] = useState("");
  const [inviteState, setInviteState] = useState<InviteState>({ status: "idle" });
  const [regAgree, setRegAgree] = useState(true);
  const [regShowPwd, setRegShowPwd] = useState(false);
  const [regShowPwd2, setRegShowPwd2] = useState(false);
  const [regErrors, setRegErrors] = useState<RegisterErrors>({});

  // ── 共用 ──
  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);

  // initialMode 由路由驱动(/login ↔ /register),外部回退/前进时跟随
  useEffect(() => {
    setMode(initialMode);
  }, [initialMode]);
  useEffect(() => () => { if (toastTimer.current) clearTimeout(toastTimer.current); }, []);

  // 邀请链接 ?invite=CODE:进注册页自动回填 + 验码(团管/超管发的链接点开即识别团队)
  useEffect(() => {
    if (mode !== "register") return;
    const code = new URLSearchParams(window.location.search).get("invite");
    if (code && !regInvite) {
      setRegInvite(code);
      void checkInvite(code);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [mode]);

  // 验码:验过才展开对应表单;未验/无效不暴露团队信息
  async function checkInvite(rawCode?: string) {
    const code = (rawCode ?? regInvite).trim().toUpperCase();
    setError("");
    if (!code) { setInviteState({ status: "invalid", detail: "请填写邀请码" }); return; }
    setInviteState({ status: "checking" });
    try {
      const res = await api.validateInvite(code);
      if (res.valid && res.kind) {
        setInviteState({ status: "valid", kind: res.kind, teamName: res.team_name ?? null, role: res.role });
        if (res.kind === "join_team") setRegTeam(res.team_name || "");
      } else {
        setInviteState({ status: "invalid", detail: res.detail || "邀请码无效或已过期" });
      }
    } catch {
      setInviteState({ status: "invalid", detail: "邀请码校验失败,请重试" });
    }
  }

  // 改码即重置验证态:必须重新验证(避免拿旧验证结果提交)
  function onInviteChange(value: string) {
    setRegInvite(value);
    setError("");
    if (inviteState.status !== "idle") setInviteState({ status: "idle" });
  }

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

  function switchMode(next: AuthMode) {
    if (next === mode) return;
    setMode(next);
    setError("");
    setLoginProgress(null);
    setFieldErrors({});
    setRegErrors({});
    onModeChange(next);
  }

  // ── 登录 ──
  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 submitLogin(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);
    }
  }

  // ── 注册 ──
  function setRegValue(field: keyof RegisterErrors, value: string) {
    if (field === "team") setRegTeam(value);
    if (field === "username") setRegUsername(value);
    if (field === "password") setRegPassword(value);
    if (field === "password2") setRegPassword2(value);
    setError("");
    setRegErrors((current) => ({ ...current, [field]: undefined }));
  }

  function validateRegister() {
    if (inviteState.status !== "valid") {
      setError("请先验证邀请码");
      return false;
    }
    const next: RegisterErrors = {};
    // 仅开团队码需要填团队名;加入码用只读团队名
    if (inviteState.kind === "create_team" && !regTeam.trim()) next.team = "请输入团队名";
    if (!regUsername.trim()) next.username = "请输入用户名";
    if (!regPassword) next.password = "请输入密码";
    else if (regPassword.length < 8) next.password = "密码至少 8 位";
    if (!regPassword2) next.password2 = "请再次输入密码";
    else if (regPassword && regPassword2 !== regPassword) next.password2 = "两次密码不一致";
    if (!regAgree) next.agree = "请阅读并同意用户协议";
    setRegErrors(next);
    if (Object.keys(next).length > 0) {
      setError("请补全必填字段后再继续");
      return false;
    }
    return true;
  }

  async function submitRegister(event?: FormEvent) {
    event?.preventDefault();
    if (busy) return;
    if (!validateRegister() || inviteState.status !== "valid") return;
    setBusy(true);
    setError("");
    setLoginProgress("entering");
    try {
      const payload = await api.register({
        username: regUsername.trim(),
        password: regPassword,
        invite_code: regInvite.trim().toUpperCase(),
        // 开团队码才带团队名;加入码服务端按邀请所属团队入伙
        ...(inviteState.kind === "create_team" ? { team_name: regTeam.trim() } : {})
      });
      // 注册即登录:记住新账号用户名,与登录一致地交给 onAuthed 完成身份+数据水合
      persistRemember(regUsername.trim(), true);
      await onAuthed({ ...payload, remember: true });
    } catch (err) {
      setLoginProgress(null);
      const raw = err instanceof Error ? err.message : "";
      const friendly = /already exists|unique|taken/i.test(raw)
        ? "该用户名已被占用,换一个试试"
        : /invite|invitation|邀请码/i.test(raw)
          ? "邀请码无效或已过期,请重新验证"
          : raw || "提交失败,请稍后重试";
      setError(friendly);
    } finally {
      setBusy(false);
    }
  }

  const brand = (
    <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">
        {mode === "register" ? (
          <>
            <h1>开通团队，<br />拍出第一条 <span className="h">带货短剧</span></h1>
            <p>1-2 小时，从一张商品图，到一条能卖货的短剧。</p>
          </>
        ) : (
          <>
            <h1>让每件商品<br />都有自己的<span className="h">带货短剧</span></h1>
            <p>商品图进，带货短剧出 —— 你只管挑成片。</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>
  );

  if (mode === "register") {
    return (
      <main className="auth-exact-page auth-register-page">
        <div className="auth-wrap">
          <span className="corner-tr" aria-hidden="true"></span><span className="corner-bl" aria-hidden="true"></span>
          {brand}
          <section className="auth-form" aria-label="注册">
            <div className="h-row"><h2>注册</h2><span className="sub">// /auth/register</span></div>
            <p className="lead">
              {inviteState.status === "valid"
                ? inviteState.kind === "create_team"
                  ? "邀请码有效 · 开新团队，你将成为团队超管。"
                  : `邀请码有效 · 加入「${inviteState.teamName || "团队"}」。`
                : "输入邀请码开通账户 —— 没有码请联系团队管理员或平台。"}
            </p>
            <form id="register-form" autoComplete="off" onSubmit={submitRegister} noValidate>
              {/* 第一步:邀请码(必填)· 验过才展开后续表单 */}
              <div className={`field${inviteState.status === "invalid" ? " has-error" : ""}`}>
                <label className="field-label" htmlFor="reg-invite">邀请码 <span className="req">*</span></label>
                <div className="invite-verify-row">
                  <div className="field-input-wrap">
                    <Ticket className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                    <input
                      id="reg-invite"
                      type="text"
                      placeholder="例: TEAM-XXXX-XXXX"
                      value={regInvite}
                      autoComplete="off"
                      aria-invalid={inviteState.status === "invalid"}
                      onChange={(event) => onInviteChange(event.target.value)}
                      onKeyDown={(event) => { if (event.key === "Enter") { event.preventDefault(); void checkInvite(); } }}
                    />
                  </div>
                  <button
                    type="button"
                    className="btn invite-verify-btn"
                    disabled={inviteState.status === "checking" || !regInvite.trim()}
                    onClick={() => void checkInvite()}
                  >
                    {inviteState.status === "checking" ? "验证中…" : inviteState.status === "valid" ? "重新验证" : "验证"}
                  </button>
                </div>
                {inviteState.status === "invalid" && <p className="field-note err">{inviteState.detail}</p>}
                {inviteState.status === "valid" && (
                  <p className="field-note ok">
                    <ShieldCheck size={13} strokeWidth={1.8} aria-hidden="true" />
                    {inviteState.kind === "create_team" ? "可开新团队" : `将加入「${inviteState.teamName || "团队"}」`}
                  </p>
                )}
              </div>

              {/* 第二步:验过码后展开 —— 不暴露任何团队列表 */}
              {inviteState.status === "valid" && (
                <>
                  {inviteState.kind === "create_team" ? (
                    <div className={`field${regErrors.team ? " has-error" : ""}`}>
                      <label className="field-label" htmlFor="reg-team">团队名 <span className="req">*</span></label>
                      <div className="field-input-wrap">
                        <Users className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                        <input
                          id="reg-team"
                          type="text"
                          placeholder="例: 小李的店 / XX 文化传媒"
                          value={regTeam}
                          aria-invalid={Boolean(regErrors.team)}
                          onChange={(event) => setRegValue("team", event.target.value)}
                        />
                      </div>
                    </div>
                  ) : (
                    <div className="field">
                      <label className="field-label">团队</label>
                      <div className="field-input-wrap is-readonly">
                        <Users className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                        <input type="text" value={inviteState.teamName || "已绑定团队"} readOnly disabled />
                      </div>
                      <p className="field-note">邀请码已绑定该团队，你将作为成员加入。</p>
                    </div>
                  )}

                  <div className={`field${regErrors.username ? " has-error" : ""}`}>
                    <label className="field-label" htmlFor="reg-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="reg-username"
                        type="text"
                        placeholder="登录用，建议字母 / 数字"
                        value={regUsername}
                        autoComplete="username"
                        aria-invalid={Boolean(regErrors.username)}
                        onChange={(event) => setRegValue("username", event.target.value)}
                      />
                    </div>
                  </div>

                  <div className="field-row">
                    <div className={`field${regErrors.password ? " has-error" : ""}`}>
                      <label className="field-label" htmlFor="reg-pwd">密码 <span className="req">*</span></label>
                      <div className="field-input-wrap">
                        <LockKeyhole className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                        <input
                          id="reg-pwd"
                          type={regShowPwd ? "text" : "password"}
                          placeholder="至少 8 位"
                          value={regPassword}
                          autoComplete="new-password"
                          aria-invalid={Boolean(regErrors.password)}
                          onChange={(event) => setRegValue("password", event.target.value)}
                        />
                        <button
                          type="button"
                          className={`toggle-pwd${regShowPwd ? " active" : ""}`}
                          aria-label={regShowPwd ? "隐藏密码" : "显示密码"}
                          aria-pressed={regShowPwd}
                          title={regShowPwd ? "隐藏密码" : "显示密码"}
                          onClick={() => setRegShowPwd((value) => !value)}
                        >
                          {regShowPwd ? <EyeOff size={18} strokeWidth={1.5} aria-hidden="true" /> : <Eye size={18} strokeWidth={1.5} aria-hidden="true" />}
                        </button>
                      </div>
                    </div>
                    <div className={`field${regErrors.password2 ? " has-error" : ""}`}>
                      <label className="field-label" htmlFor="reg-pwd2">确认密码 <span className="req">*</span></label>
                      <div className="field-input-wrap">
                        <LockKeyhole className="ic-l" size={16} strokeWidth={1.5} aria-hidden="true" />
                        <input
                          id="reg-pwd2"
                          type={regShowPwd2 ? "text" : "password"}
                          placeholder="再输一次"
                          value={regPassword2}
                          autoComplete="new-password"
                          aria-invalid={Boolean(regErrors.password2)}
                          onChange={(event) => setRegValue("password2", event.target.value)}
                        />
                        <button
                          type="button"
                          className={`toggle-pwd${regShowPwd2 ? " active" : ""}`}
                          aria-label={regShowPwd2 ? "隐藏密码" : "显示密码"}
                          aria-pressed={regShowPwd2}
                          title={regShowPwd2 ? "隐藏密码" : "显示密码"}
                          onClick={() => setRegShowPwd2((value) => !value)}
                        >
                          {regShowPwd2 ? <EyeOff size={18} strokeWidth={1.5} aria-hidden="true" /> : <Eye size={18} strokeWidth={1.5} aria-hidden="true" />}
                        </button>
                      </div>
                    </div>
                  </div>

                  <label className={`agree${regErrors.agree ? " has-error" : ""}`}>
                    <input
                      type="checkbox"
                      checked={regAgree}
                      onChange={(event) => { setRegAgree(event.target.checked); setRegErrors((c) => ({ ...c, agree: undefined })); setError(""); }}
                    />
                    <span>
                      我已阅读并同意{" "}
                      <a href="#" onClick={(event) => { event.preventDefault(); showToast("用户协议", "含数据处理 / 内容生成版权 / 计费规则三章 · 完整文本将在正式版接入"); }}>用户协议</a>{" "}
                      与{" "}
                      <a href="#" onClick={(event) => { event.preventDefault(); showToast("隐私政策", "遵循《个人信息保护法》· 团队数据存中国境内 · 默认不用于模型训练"); }}>隐私政策</a>。
                    </span>
                  </label>

                  {loginProgress && !error && (
                    <div className="login-progress" role="status" aria-live="polite">
                      <span className="login-progress-spinner" aria-hidden="true"></span>
                      <span>{inviteState.kind === "create_team" ? "正在创建团队，进入工作台…" : "正在加入团队，进入工作台…"}</span>
                    </div>
                  )}
                  {error && <div className="form-error" role="alert">{error}</div>}

                  <button className="btn-cta" type="submit" disabled={busy}>
                    {busy
                      ? "提交中"
                      : inviteState.kind === "create_team"
                        ? <>创建团队 · 开始使用 <ArrowRight size={15} strokeWidth={2} aria-hidden="true" /></>
                        : <>加入团队 · 开始使用 <ArrowRight size={15} strokeWidth={2} aria-hidden="true" /></>}
                  </button>
                </>
              )}

              {inviteState.status !== "valid" && error && <div className="form-error" role="alert">{error}</div>}

              <div className="switch-row">
                已有账号? <a href="/login" onClick={(event) => { event.preventDefault(); switchMode("login"); }}>去登录 →</a>
              </div>
            </form>
          </section>
        </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>
    );
  }

  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>
        {brand}
        <section className="auth-form" aria-label="登录">
          <div className="h-row"><h2>登录</h2><span className="sub">// /auth/login</span></div>
          <form id="login-form" autoComplete="off" onSubmit={submitLogin} noValidate>
            <p className="lead">用团队账号登录，进入你的工作台与生产管线。</p>
            <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>
            <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="submit" disabled={busy}>
            {busy ? "登录中" : "登录"}
          </button>
          <div className="divider"><span className="line"></span><span className="txt">OR</span><span className="line"></span></div>
          <div className="sso-row">
            <button type="button" className="sso-btn" onClick={() => showToast("微信扫码", "对接中 · 当前请用用户名 + 密码登录")}>
              <ScanLine size={14} strokeWidth={1.6} aria-hidden="true" /> 微信扫码
            </button>
            <button type="button" className="sso-btn" onClick={() => showToast("飞书 SSO", "对接中 · 当前请用用户名 + 密码登录")}>
              <ShieldCheck size={14} strokeWidth={1.6} aria-hidden="true" /> 飞书 SSO
            </button>
          </div>
          <div className="switch-row">
            还没账号? <a href="/register" onClick={(event) => { event.preventDefault(); switchMode("register"); }}>注册团队 →</a>
          </div>
            </div>
          </form>
        </section>
      </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>
  );
}