"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";

export function AuthLoginPanel({
  next,
  configured,
  message,
  missing
}: {
  next: string;
  configured: boolean;
  message?: string | null;
  missing?: string[];
}) {
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const screenRef = useRef<HTMLDivElement | null>(null);
  const feedbackRef = useRef<HTMLDivElement | null>(null);
  const hasMissingConfig = !configured && Boolean(missing?.length);

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

  useEffect(() => {
    pulseFeedback(feedbackRef.current);
  }, [error, message, missing?.join(",")]);

  async function submit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!configured || submitting) return;
    setSubmitting(true);
    setError(null);
    try {
      const payload: Record<string, string> = { username, password, 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(result.redirectTo || next || "/create");
    } 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>账户登录</h2>

        {message || hasMissingConfig || error ? (
          <div ref={feedbackRef}>
            {message ? <div className="callout" role="alert">{message}</div> : null}
            {hasMissingConfig ? (
              <div className="callout" role="alert">
                缺少配置：{missing?.join("、")}
              </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>账号</span>
            <input
              autoComplete="username"
              value={username}
              onChange={(event) => setUsername(event.target.value)}
              disabled={!configured || submitting}
              placeholder="请输入账号"
            />
          </label>
          <label className="field" data-animate>
            <span>密码</span>
            <input
              autoComplete="current-password"
              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 || !username.trim() || !password} data-animate>
            {submitting ? <Loader2 className="spin" size={18} /> : <LogIn size={18} />}
            登录
          </button>
        </form>
      </section>
    </div>
  );
}