"use client";

import { useCallback, useState } from "react";
import { useRouter } from "next/navigation";
import { Check } from "lucide-react";
import { apiUpdateProfile, type User } from "@/lib/api";
import AvatarPicker from "@/components/AvatarPicker";

interface ProfileFormProps {
  user: User;
}

/**
 * 个人资料编辑表单：头像（上传/裁剪/历史选择）、昵称、邮箱、签名。
 * 头像由独立上传链路处理，不随本表单提交；保存成功后 router.refresh()
 * 让 Header 等 SSR 区域同步最新昵称。
 */
export default function ProfileForm({ user }: ProfileFormProps) {
  const router = useRouter();
  const [nickname, setNickname] = useState(user.nickname || "");
  const [email, setEmail] = useState(user.email || "");
  const [signature, setSignature] = useState(user.signature || "");
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState("");
  const [success, setSuccess] = useState("");
  const [avatarDragOver, setAvatarDragOver] = useState(false);
  const [incomingAvatarFile, setIncomingAvatarFile] = useState<File | null>(null);

  const clearIncomingAvatar = useCallback(() => setIncomingAvatarFile(null), []);

  const handleAvatarDragOver = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    if (e.dataTransfer.types.includes("Files")) setAvatarDragOver(true);
  };

  const handleAvatarDragLeave = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    // 仅在离开整块卡片时取消高亮（避免子元素冒泡闪烁）
    const related = e.relatedTarget as Node | null;
    if (related && e.currentTarget.contains(related)) return;
    setAvatarDragOver(false);
  };

  const handleAvatarDrop = (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    setAvatarDragOver(false);
    const file = e.dataTransfer.files?.[0];
    if (!file) return;
    setIncomingAvatarFile(file);
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError("");
    setSuccess("");

    const trimmed = nickname.trim();
    if (!trimmed) {
      setError("昵称不能为空");
      return;
    }
    if (trimmed.length > 64) {
      setError("昵称不能超过 64 个字符");
      return;
    }
    if (signature.length > 255) {
      setError("签名不能超过 255 个字符");
      return;
    }

    setSubmitting(true);
    try {
      const res = await apiUpdateProfile({
        nickname: trimmed,
        email: email.trim(),
        signature,
      });
      if (res.user) {
        setSuccess("资料已保存");
        router.refresh();
      } else {
        setError(res.error || "保存失败");
      }
    } catch {
      setError("网络错误，请重试");
    } finally {
      setSubmitting(false);
    }
  };

  return (
    <form onSubmit={handleSubmit} className="panel p-5 sm:p-7 space-y-5">
      {success && (
        <div className="alert-ok flex items-center gap-2" role="status">
          <Check size={15} /> {success}
        </div>
      )}
      {error && <div className="alert-error" role="alert">{error}</div>}

      {/* 头像：点击上传/裁剪，或拖放图片到本区域 */}
      <div
        className="flex items-center gap-4 p-4 rounded-xl transition-colors"
        style={{
          background: avatarDragOver
            ? "color-mix(in srgb, var(--accent) 12%, var(--panel-2))"
            : "var(--panel-2)",
          border: `1px solid ${avatarDragOver ? "var(--accent)" : "var(--line)"}`,
        }}
        onDragOver={handleAvatarDragOver}
        onDragLeave={handleAvatarDragLeave}
        onDrop={handleAvatarDrop}
      >
        <AvatarPicker
          name={nickname || user.username}
          src={user.avatar || ""}
          size={56}
          incomingFile={incomingAvatarFile}
          onIncomingConsumed={clearIncomingAvatar}
        />
        <div className="flex-1 min-w-0">
          <p className="text-[13.5px] font-bold" style={{ color: "var(--ink)" }}>头像</p>
          <p className="text-[12px] mt-1" style={{ color: "var(--ink-3)" }}>
            {avatarDragOver
              ? "松开即可上传并裁剪"
              : "点击头像或拖放图片到此处；支持拖动裁剪，统一转为 WebP，裁剪后不超过 2MB"}
          </p>
        </div>
      </div>

      {/* 昵称 + 邮箱：桌面双列高密度排布 */}
      <div className="grid sm:grid-cols-2 gap-5">
        <div>
          <label className="field-label" htmlFor="pf-nickname">昵称</label>
          <input
            id="pf-nickname"
            type="text"
            value={nickname}
            onChange={(e) => setNickname(e.target.value)}
            required
            maxLength={64}
            className="field"
            placeholder="请输入昵称"
          />
        </div>
        <div>
          <label className="field-label" htmlFor="pf-email">邮箱</label>
          <input
            id="pf-email"
            type="email"
            value={email}
            onChange={(e) => setEmail(e.target.value)}
            maxLength={128}
            className="field"
            placeholder="your@email.com"
          />
        </div>
      </div>

      {/* 个性签名 */}
      <div>
        <label className="field-label" htmlFor="pf-signature">
          个性签名
          <span className="font-normal ml-1.5" style={{ color: "var(--ink-3)" }}>
            ({signature.length}/255)
          </span>
        </label>
        <textarea
          id="pf-signature"
          value={signature}
          onChange={(e) => setSignature(e.target.value)}
          maxLength={255}
          rows={3}
          className="field"
          placeholder="介绍一下自己吧"
        />
      </div>

      {/* 操作区：桌面右对齐 */}
      <div className="flex justify-end pt-1 border-t" style={{ borderColor: "var(--line)" }}>
        <button
          type="submit"
          disabled={submitting}
          className="btn btn-primary w-full sm:w-auto"
        >
          {submitting ? "保存中..." : "保存资料"}
        </button>
      </div>
    </form>
  );
}