"use client";

import { useState, useEffect, useCallback } from "react";
import { useRouter } from "next/navigation";
import { ArrowLeft, Send, Loader2, Check, FileText } from "lucide-react";

interface PostItem {
  slug: string;
  title: string;
  date: string;
  draft: boolean;
  categories: string[];
  author: string;
}

export default function WechatPage() {
  const router = useRouter();
  const [posts, setPosts] = useState<PostItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState("");
  const [selected, setSelected] = useState<PostItem | null>(null);
  const [syncing, setSyncing] = useState(false);
  const [message, setMessage] = useState<{ type: "success" | "error"; text: string } | null>(null);
  const [ipWhitelistError, setIpWhitelistError] = useState<{ ip: string; detail: string } | null>(null);
  const [syncSuccess, setSyncSuccess] = useState<{ title: string } | null>(null);
  const [status, setStatus] = useState<{ configured: boolean; appId?: string } | null>(null);
  const [coverUrl, setCoverUrl] = useState("");

  const fetchPosts = useCallback(async () => {
    setLoading(true);
    try {
      const res = await fetch("/api/posts?perPage=999&includeDrafts=false");
      const data = await res.json();
      setPosts(data.posts || []);
    } catch {} finally { setLoading(false); }
  }, []);

  useEffect(() => {
    fetchPosts();
    fetch("/api/rss/wechat").then(r => r.json()).then(setStatus).catch(() => {});
  }, [fetchPosts]);

  const filtered = search
    ? posts.filter((p) => p.title.includes(search) || p.slug.includes(search))
    : posts;

  const handleSync = async () => {
    if (!selected) return;
    setSyncing(true);
    setMessage(null);
    try {
      // Fetch full post content
      const res = await fetch(`/api/posts/${selected.slug}`);
      if (!res.ok) throw new Error("文章加载失败");
      const post = await res.json();

      // Send to WeChat via RSS API proxy (60s timeout)
      const controller = new AbortController();
      const timer = setTimeout(() => controller.abort(), 60000);
      const syncRes = await fetch("/api/rss/wechat", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          articles: [{
            title: post.frontMatter.title.slice(0, 32),
            author: (post.frontMatter.author || "小赵").slice(0, 16),
            content: post.content,
            slug: post.frontMatter.slug,
            content_source_url: `https://usj.cc/${post.frontMatter.slug}.html`,
            thumb_media_url: coverUrl || "https://usj.cc/image/avatar/tx7.jpg",
            show_cover_pic: 1,
            need_open_comment: 0,
          }],
        }),
        signal: controller.signal,
      });

      clearTimeout(timer);
      const data = await syncRes.json();
      if (!syncRes.ok || !data.ok) throw new Error(data.error || data.message || "同步失败");

      setSyncSuccess({ title: selected.title });
    } catch (err: unknown) {
      if (err instanceof DOMException && err.name === "AbortError") {
        setMessage({ type: "error", text: "请求超时，微信接口响应较慢，请重试" });
      } else {
        const text = err instanceof Error ? err.message : "网络错误，请检查连接后重试";
        const ipMatch = text.match(/invalid ip\s+([^\s,]+)/i);
        if (/not in whitelist|code=40164|invalid ip/i.test(text)) {
          setIpWhitelistError({ ip: ipMatch?.[1] || "报错中显示的 IP", detail: text });
        }
        setMessage({ type: "error", text });
      }
    } finally { setSyncing(false); }
  };

  return (
    <div className="h-full flex flex-col px-4 py-4 md:px-8 md:py-6">
      <div className="flex items-center justify-between mb-6 shrink-0">
        <div className="flex items-center gap-3">
          <button type="button" aria-label="返回上一页" onClick={() => router.back()} className="p-1 -ml-1 rounded hover:bg-surface text-muted hover:text-text transition-colors">
            <ArrowLeft size={16} />
          </button>
          <h2 className="text-lg font-bold text-text">微信公众号</h2>
          {status && (
            <span className={`text-[11px] px-2 py-0.5 rounded ${status.configured ? "bg-[#d1fae5] text-[#065f46]" : "bg-[#fef3c7] text-[#92400e]"}`}>
              {status.configured ? `已配置 · ${status.appId}` : "未配置"}
            </span>
          )}
        </div>
      </div>

      {message && (
        <div className={`mb-4 px-4 py-2.5 rounded-md text-[13px] flex items-center justify-between shrink-0 ${
          message.type === "success" ? "bg-[#d1fae5] text-[#065f46] border border-[#a7f3d0]" : "bg-[#fee2e2] text-[#991b1b] border border-[#fecaca]"
        }`}>
          {message.text}
          <button type="button" onClick={() => setMessage(null)} className="underline">关闭</button>
        </div>
      )}

      <div className="flex flex-col sm:flex-row gap-4 sm:gap-5 flex-1 min-h-0">
        {/* Left: article list */}
        <div className="w-full sm:w-[260px] sm:max-w-[300px] shrink-0 flex flex-col min-h-0 sm:max-h-full">
          <input
            type="text"
            value={search}
            onChange={(e) => setSearch(e.target.value)}
            placeholder="搜索文章..."
            className="w-full bg-card border border-line rounded-md px-3 py-2 text-[13px] focus:outline-none focus:border-accent/30 mb-3 shrink-0"
          />

          {loading ? (
            <div className="flex-1 flex items-center justify-center text-muted text-sm"><Loader2 size={14} className="animate-spin mr-2" />加载中</div>
          ) : (
            <div className="flex-1 overflow-y-auto bg-card border border-line rounded-md">
              {filtered.map((p, i) => (
                <button key={`${p.slug}-${i}`} type="button" onClick={() => setSelected(p)}
                  className={`w-full text-left px-3.5 py-2.5 border-b border-line/50 text-[13px] transition-colors hover:bg-surface ${
                    selected?.slug === p.slug ? "bg-accent/5 border-l-[3px] border-l-accent pl-[11px]" : ""
                  }`}>
                  <div className="text-text truncate font-medium">{p.title}</div>
                  <div className="text-[11px] text-muted mt-0.5">
                    {new Date(p.date).toLocaleDateString("zh-CN")} · {p.author}
                  </div>
                </button>
              ))}
            </div>
          )}
        </div>

        {/* Right: preview & sync */}
        <div className="flex-1 flex flex-col min-h-0 min-w-0">
          {selected ? (
            <>
              <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-2 mb-3 shrink-0">
                <div className="text-[13px] font-medium text-text truncate min-w-0">{selected.title}</div>
                <button
                  type="button"
                  onClick={handleSync}
                  disabled={syncing}
                  className="shrink-0 w-full sm:w-auto inline-flex items-center justify-center gap-1.5 px-4 py-2 text-[13px] font-medium rounded-md bg-accent text-white hover:bg-accent-hover disabled:opacity-50 transition-colors whitespace-nowrap"
                >
                  {syncing ? <Loader2 size={13} className="animate-spin" /> : <Send size={13} />}
                  <span>{syncing ? "同步中..." : "同步到微信草稿"}</span>
                </button>
              </div>

              <div className="flex-1 bg-card border border-line rounded-md p-4 overflow-y-auto">
                <div className="text-[11px] text-muted/60 mb-3 flex items-center gap-2">
                  <span>预览</span>
                  <span className="text-line">|</span>
                  <span>slug: {selected.slug}</span>
                  <span className="text-line">|</span>
                  <span>{new Date(selected.date).toLocaleDateString("zh-CN")}</span>
                </div>

                <div className="space-y-2 text-[12px] text-muted">
                  <div><span className="font-medium text-text/70">标题：</span>{(selected.title || "").slice(0, 32)}</div>
                  <div><span className="font-medium text-text/70">作者：</span>{(selected.author || "小赵").slice(0, 16)}</div>
                  <div><span className="font-medium text-text/70">原文链接：</span>https://usj.cc/{selected.slug}.html</div>
                  <div className="flex items-center gap-2">
                    <span className="font-medium text-text/70 shrink-0">封面图：</span>
                    <input
                      type="text"
                      value={coverUrl}
                      onChange={(e) => setCoverUrl(e.target.value)}
                      placeholder="https://... 留空则无封面"
                      className="flex-1 bg-bg border border-line rounded px-2 py-1 text-[12px] focus:outline-none focus:border-accent/30"
                    />
                  </div>
                  <div><span className="font-medium text-text/70">分类：</span>{selected.categories?.join("、") || "-"}</div>
                </div>

                <div className="mt-4 p-3 bg-surface rounded-md border border-line/50">
                  <div className="text-[11px] font-medium text-muted mb-1">同步说明</div>
                  <ul className="text-[11px] text-muted/70 space-y-0.5">
                    <li>· 文章将同步到公众号草稿箱，不会自动群发</li>
                    <li>· 封面图使用文章内第一张图片（如有）</li>
                    <li>· Markdown 将由 RSS API 转为微信富文本</li>
                    <li>· 在公众号后台「草稿箱」可预览和修改</li>
                  </ul>
                </div>
              </div>
            </>
          ) : (
            <div className="flex-1 flex items-center justify-center bg-card border border-line rounded-md text-[13px] text-muted">
              <FileText size={18} className="mr-2 text-muted/30" />
              选择左侧文章同步到微信草稿箱
            </div>
          )}
        </div>
      </div>

      {syncSuccess && (
        <div className="fixed inset-0 z-50 flex items-center justify-center bg-[#223d66]/25 px-4 backdrop-blur-sm">
          <div className="w-full max-w-[460px] rounded-2xl border border-line bg-bg p-6 shadow-[0_24px_80px_rgba(34,61,102,0.22)]">
            <div className="mb-4 flex items-start gap-3">
              <div className="mt-0.5 flex h-10 w-10 shrink-0 items-center justify-center rounded-full bg-[#d1fae5] text-[#065f46]">
                <Check size={18} />
              </div>
              <div>
                <h3 className="text-[17px] font-semibold text-text">已同步到微信草稿箱</h3>
                <p className="mt-1 text-[13px] leading-6 text-muted">
                  文章已经进入公众号草稿箱，可以去微信公众平台预览、调整排版，然后再决定是否群发。
                </p>
              </div>
            </div>
            <div className="rounded-xl border border-line bg-surface/70 px-4 py-3 text-[12px] leading-5 text-muted">
              当前文章：<span className="font-medium text-text">{syncSuccess.title}</span>
            </div>
            <div className="mt-6 flex justify-end gap-3">
              <button
                type="button"
                onClick={() => setSyncSuccess(null)}
                className="rounded-md border border-line px-4 py-2 text-[13px] text-muted transition-colors hover:bg-surface hover:text-text"
              >
                我知道了
              </button>
              <a
                href="https://developers.weixin.qq.com/platform"
                target="_blank"
                rel="noopener noreferrer"
                className="rounded-md bg-accent px-4 py-2 text-[13px] font-medium text-white transition-colors hover:bg-accent-hover"
              >
                打开微信公众平台
              </a>
            </div>
          </div>
        </div>
      )}

      {ipWhitelistError && (
        <div className="fixed inset-0 z-50 flex items-center justify-center bg-[#223d66]/25 px-4 backdrop-blur-sm">
          <div className="w-full max-w-[460px] rounded-2xl border border-line bg-bg p-6 shadow-[0_24px_80px_rgba(34,61,102,0.22)]">
            <div className="mb-4 flex items-start gap-3">
              <div className="mt-0.5 flex h-10 w-10 shrink-0 items-center justify-center rounded-full bg-[#fef3c7] text-[#92400e]">
                !
              </div>
              <div>
                <h3 className="text-[17px] font-semibold text-text">需要添加微信公众号 IP 白名单</h3>
                <p className="mt-1 text-[13px] leading-6 text-muted">
                  微信拒绝了当前接口的出口 IP，请到微信公众号后台的「设置与开发 → 基本配置 → IP 白名单」添加下面这个 IP 后再重试。
                </p>
              </div>
            </div>
            <div className="rounded-xl border border-line bg-surface/70 px-4 py-3">
              <div className="text-[11px] text-muted">需要添加的 IP</div>
              <div className="mt-1 select-all font-mono text-[18px] font-semibold text-text">{ipWhitelistError.ip}</div>
            </div>
            <div className="mt-3 max-h-24 overflow-y-auto rounded-lg bg-card px-3 py-2 text-[11px] leading-5 text-muted/80">
              {ipWhitelistError.detail}
            </div>
            <div className="mt-6 flex justify-end gap-3">
              <a
                href="https://developers.weixin.qq.com/platform"
                target="_blank"
                rel="noopener noreferrer"
                className="rounded-md border border-line px-4 py-2 text-[13px] text-muted transition-colors hover:bg-surface hover:text-text"
              >
                打开微信公众平台
              </a>
              <button
                type="button"
                onClick={() => navigator.clipboard?.writeText(ipWhitelistError.ip)}
                className="rounded-md border border-line px-4 py-2 text-[13px] text-muted transition-colors hover:bg-surface hover:text-text"
              >
                复制 IP
              </button>
              <button
                type="button"
                onClick={() => setIpWhitelistError(null)}
                className="rounded-md bg-accent px-4 py-2 text-[13px] font-medium text-white transition-colors hover:bg-accent-hover"
              >
                我知道了
              </button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}