"use client";

import { useState, useEffect } from "react";
import { useRouter } from "next/navigation";
import Link from "next/link";
import { Trash2 } from "lucide-react";
import { apiCreateComment, apiDeleteComment, apiMe, type Comment, type User } from "@/lib/api";

interface CommentSectionProps {
  postId: string;
  comments: Comment[];
}

export default function CommentSection({ postId, comments }: CommentSectionProps) {
  const router = useRouter();
  const [content, setContent] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [user, setUser] = useState<User | null>(null);
  const [deletingId, setDeletingId] = useState<number | null>(null);

  useEffect(() => {
    apiMe()
      .then((res) => setUser(res.user || null))
      .catch(() => setUser(null));
  }, []);

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!content.trim()) return;

    setSubmitting(true);
    try {
      const res = await apiCreateComment(postId, content);
      if (res.comment) {
        setContent("");
        router.refresh();
      } else if (res.error === "未登录") {
        router.push("/login");
      } else {
        alert(res.error || "评论失败");
      }
    } finally {
      setSubmitting(false);
    }
  };

  const handleDelete = async (commentId: number) => {
    if (!confirm("确定要删除这条评论吗？")) return;
    setDeletingId(commentId);
    try {
      const res = await apiDeleteComment(postId, commentId);
      if (res.message) {
        router.refresh();
      } else {
        alert(res.error || "删除失败");
      }
    } finally {
      setDeletingId(null);
    }
  };

  const canDelete = (comment: Comment) =>
    user && (user.id === comment.user.id || user.role === "admin");

  return (
    <section className="mt-8 pt-6 border-t" style={{ borderColor: "var(--border)" }}>
      <h2 className="text-xl font-bold mb-4">评论 ({comments.length})</h2>

      <form onSubmit={handleSubmit} className="mb-6">
        <textarea
          value={content}
          onChange={(e) => setContent(e.target.value)}
          placeholder="写下你的评论..."
          className="w-full p-3 rounded-lg border resize-none h-24"
          style={{ borderColor: "var(--border)", background: "var(--bg)", color: "var(--text)" }}
        />
        <button
          type="submit"
          disabled={submitting || !content.trim()}
          className="mt-2 px-4 py-2 rounded-lg text-white disabled:opacity-50"
          style={{ background: "var(--primary)" }}
        >
          {submitting ? "发送中..." : "发表评论"}
        </button>
      </form>

      <div className="space-y-4">
        {comments.map((comment) => (
          <div key={comment.id} className="p-4 rounded-lg" style={{ background: "var(--bg-secondary)" }}>
            <div className="flex items-center justify-between mb-2">
              <div className="flex items-center gap-2">
                <Link href={`/u/${comment.user.id}`} className="font-medium hover:underline" style={{ color: "var(--primary)" }}>
                  {comment.user.nickname}
                </Link>
                <span className="text-sm" style={{ color: "var(--text-secondary)" }}>
                  {new Date(comment.created_at).toLocaleString("zh-CN")}
                </span>
              </div>
              {canDelete(comment) && (
                <button
                  onClick={() => handleDelete(comment.id)}
                  disabled={deletingId === comment.id}
                  className="flex items-center gap-1 text-sm text-red-600 hover:opacity-80 disabled:opacity-50"
                >
                  <Trash2 size={14} />
                  {deletingId === comment.id ? "删除中" : "删除"}
                </button>
              )}
            </div>
            <p style={{ color: "var(--text)" }}>{comment.content}</p>
          </div>
        ))}
        {comments.length === 0 && (
          <p className="text-center py-8" style={{ color: "var(--text-secondary)" }}>
            暂无评论，来抢沙发吧！
          </p>
        )}
      </div>
    </section>
  );
}