"use client";

import { useEffect, useRef, useState } from "react";
import type { FormEvent } from "react";
import Image from "next/image";
import { Loader2, LogIn } from "lucide-react";
import { pulseFeedback, revealChildren, runScopedMotion } from "@/lib/ui/motion";
import { useBrowserAuth } from "@/components/browser-auth";
import { safeBrowserNext } from "@/lib/client/browser-auth";

export function AuthLoginPanel({
  title = "账户登录",
  submitLabel = "登录"
}: {
  title?: string;
  submitLabel?: string;
}) {
  const auth = useBrowserAuth();
  const [phone, setPhone] = useState("");
  const [password, setPassword] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [next, setNext] = useState("/create");
  const [message, setMessage] = useState<string | null>(null);
  const screenRef = useRef<HTMLDivElement | null>(null);
  const feedbackRef = useRef<HTMLDivElement | null>(null);
  const configured = auth.status === "ready" && auth.authConfigured;
  const hasMissingConfig = auth.status === "ready" && auth.authRequired && !auth.authConfigured;

  useEffect(() => {
    return runScopedMotion(screenRef, (scope) => revealChildren(scope));
  }, []);

  useEffect(() => {
    const params = new URLSearchParams(window.location.search);
    setNext(safeBrowserNext(params.get("next")));
    const errorCode = params.get("error");
    if (errorCode) setMessage(errorMessages[errorCode] || "登录失败，请重新登录。");
    else if (params.get("loggedOut") === "1") setMessage("已退出登录。");
  }, []);

  useEffect(() => {
    if (auth.status === "ready" && auth.user) window.location.replace(next);
  }, [auth.status, auth.user, next]);

  useEffect(() => {
    pulseFeedback(feedbackRef.current);
  }, [error, message, hasMissingConfig]);

  async function submit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!configured || submitting) return;
    const formData = new FormData(event.currentTarget);
    const submittedPhone = formStringValue(formData.get("phone"));
    const submittedPassword = formStringValue(formData.get("password"));
    if (!submittedPhone || !submittedPassword) {
      setError("手机号和密码不能为空。");
      return;
    }
    setSubmitting(true);
    setError(null);
    try {
      const payload: Record<string, string> = { phone: submittedPhone, password: submittedPassword, next };
      const response = await fetch("/api/auth/password", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload)
      });
      const result = await response.json().catch(() => ({})) as { error?: string; redirectTo?: string };
      if (!response.ok) throw new Error(result.error || "登录失败");
      window.location.assign(safeBrowserNext(result.redirectTo, next));
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setSubmitting(false);
    }
  }

  return (
    <div className="auth-page" ref={screenRef}>
      <section className="auth-brand-panel" aria-label="智念AIGC平台" data-animate>
        <Image className="auth-brand-logo" src="/logo/zhinian-logo.png" alt="" width={168} height={38} priority />
        <h1>智念AIGC平台</h1>
      </section>

      <section className="panel auth-panel" data-animate>
        <h2>{title}</h2>

        {message || hasMissingConfig || auth.status === "error" || error ? (
          <div ref={feedbackRef}>
            {message ? <div className="callout" role="alert">{message}</div> : null}
            {hasMissingConfig ? (
              <div className="callout" role="alert">
                账号认证配置不完整，请联系管理员。
              </div>
            ) : null}
            {auth.status === "error" ? <div className="callout" role="alert">{auth.error || "无法读取认证状态。"}</div> : null}
            {error ? <div className="callout" role="alert">{error}</div> : null}
          </div>
        ) : null}

        <form className="auth-password-form" onSubmit={submit}>
          <label className="field" data-animate>
            <span>手机号</span>
            <input
              autoComplete="username"
              inputMode="tel"
              name="phone"
              required
              value={phone}
              onChange={(event) => setPhone(event.target.value)}
              disabled={!configured || submitting}
              placeholder="请输入手机号"
            />
          </label>
          <label className="field" data-animate>
            <span>密码</span>
            <input
              autoComplete="current-password"
              name="password"
              required
              type="password"
              value={password}
              onChange={(event) => setPassword(event.target.value)}
              disabled={!configured || submitting}
              placeholder="请输入密码"
            />
          </label>
          <button className="button primary auth-submit" type="submit" disabled={!configured || submitting} data-animate>
            {submitting ? <Loader2 className="spin" size={18} /> : <LogIn size={18} />}
            {submitLabel}
          </button>
        </form>
      </section>
    </div>
  );
}

function formStringValue(value: FormDataEntryValue | null): string {
  return typeof value === "string" ? value.trim() : "";
}

const errorMessages: Record<string, string> = {
  auth_not_configured: "账号认证配置不完整，请联系管理员。",
  callback_failed: "登录失败，请重新登录。",
  state_invalid: "登录状态已失效，请重新登录。"
};