import {Alert, Button, Form, Input, Typography, message} from "antd";
import { LockOutlined, LogoutOutlined } from "@ant-design/icons";
import {useEffect, useMemo, useState} from "react";
import { useNavigate } from "react-router-dom";
import { getCurrentUser, updateMyPassword } from "@/api";
import {fetchPublicPasswordPolicy, type PasswordPolicyPublic} from "@/api/auth";
import {buildPasswordPolicyValidator, buildPolicyHints} from "@/utils/password";
import AuthShell from "../components/AuthShell";

const {Text} = Typography;

type ResetPasswordFormValues = {
  oldPassword: string;
  newPassword: string;
  confirmPassword: string;
};

const RESET_HIGHLIGHTS = [
  "首次登录必须完成密码更新，避免继续使用初始凭证。",
  "修改成功后保持当前登录态，无需再次验证。",
  "若不是本人操作，请立即退出并联系管理员。"
];

export default function ResetPassword() {
  const [loading, setLoading] = useState(false);
  const [policy, setPolicy] = useState<PasswordPolicyPublic | null>(null);
  const [username, setUsername] = useState<string>();
  const navigate = useNavigate();
  const [form] = Form.useForm<ResetPasswordFormValues>();

  const policyHints = useMemo(() => buildPolicyHints(policy), [policy]);

  useEffect(() => {
    const init = async () => {
      const [profileResult, policyResult] = await Promise.allSettled([getCurrentUser(), fetchPublicPasswordPolicy()]);

      if (profileResult.status === "fulfilled") {
        setUsername(profileResult.value.username);
      }

      setPolicy(policyResult.status === "fulfilled" ? policyResult.value : null);
    };

    void init();
  }, []);

  const goToLogin = () => {
    localStorage.removeItem("accessToken");
    localStorage.removeItem("refreshToken");
    localStorage.removeItem("displayName");
    localStorage.removeItem("username");
    localStorage.removeItem("availableTenants");
    localStorage.removeItem("activeTenantId");
    sessionStorage.removeItem("userProfile");
    navigate("/login", { replace: true });
  };

  const onFinish = async (values: ResetPasswordFormValues) => {
    setLoading(true);
    try {
      await updateMyPassword({
        oldPassword: values.oldPassword,
        newPassword: values.newPassword
      });
      const profile = await getCurrentUser();
      sessionStorage.setItem("userProfile", JSON.stringify(profile));
      window.dispatchEvent(new Event("user-profile-updated"));
      message.success("密码已更新");
      navigate("/", { replace: true });
    } finally {
      setLoading(false);
    }
  };

  return (
    <AuthShell
      eyebrow="首次登录校验"
      asideTitle="先完成一次安全换密，再进入系统"
      asideDescription="初始密码只用于验证当前账号的合法持有者。设置新的个人密码后，系统会继续保持登录并同步最新的账户资料。"
      asideHighlights={RESET_HIGHLIGHTS}
      title="修改初始密码"
      subtitle="请输入当前密码并设置一个符合策略的新密码。"
      footer={<Text type="secondary">如需稍后处理，请先退出当前账号。</Text>}
    >
      <Alert
        showIcon
        type="info"
        message="密码更新后将直接进入系统首页"
        description="新密码提交成功后立即生效，旧密码会同时失效。"
        style={{marginBottom: 20, borderRadius: 14}}
      />

      <Form form={form} layout="vertical" onFinish={onFinish} requiredMark={false} className="auth-form">
        <Form.Item label="当前密码" name="oldPassword" rules={[{required: true, message: "请输入当前密码"}]}>
          <Input.Password size="large" prefix={<LockOutlined/>} autoComplete="current-password"/>
        </Form.Item>

        {policyHints.length > 0 ? (
          <div className="auth-form__policy-hints">
            <span className="auth-form__policy-hints-title">密码规则</span>
            <ul className="auth-form__policy-list">
              {policyHints.map((hint) => (
                <li key={hint}>{hint}</li>
              ))}
            </ul>
          </div>
        ) : null}

        <Form.Item
          label="新密码"
          name="newPassword"
          validateFirst
          rules={[
            {required: true, min: 6, message: "新密码至少 6 位"},
            {validator: buildPasswordPolicyValidator(policy, () => username)}
          ]}
        >
          <Input.Password size="large" prefix={<LockOutlined/>} autoComplete="new-password"/>
        </Form.Item>

        <Form.Item
          label="确认新密码"
          name="confirmPassword"
          dependencies={["newPassword"]}
          rules={[
            {required: true, message: "请再次输入新密码"},
            ({getFieldValue}) => ({
              validator(_, value) {
                if (!value || getFieldValue("newPassword") === value) {
                  return Promise.resolve();
                }
                return Promise.reject(new Error("两次输入的新密码不一致"));
              }
            })
          ]}
        >
          <Input.Password size="large" prefix={<LockOutlined/>} autoComplete="new-password"/>
        </Form.Item>

        <div className="auth-form__actions">
          <Button type="primary" htmlType="submit" block size="large" loading={loading}>
            提交并保持登录
          </Button>
          <Button block size="large" icon={<LogoutOutlined/>} onClick={goToLogin}>
            退出登录
          </Button>
        </div>
      </Form>
    </AuthShell>
  );
}