"use client";

import { useEffect, useState } from "react";
import { AdminSettingsActions, AdminSettingsGroup } from "@/components/admin";
import { apiUpdateSiteSettings, type PublicSettings } from "@/lib/api";
import { announcementPath, leaderboardPath, pagePath, postPath, userPath, type UrlStyle } from "@/lib/urlStyle";
import { toast } from "@/lib/toast";

/** 三档风格展示信息：示例 id/slug 固定，方便站长对比形态 */
const STYLE_OPTIONS: { value: UrlStyle; label: string; desc: string }[] = [
  { value: "default", label: "标准动态", desc: "框架默认路由，带路径分段" },
  { value: "html", label: "静态页 .html", desc: "常见 CMS 伪静态形态" },
  { value: "discuz", label: "Discuz 风格", desc: "经典论坛 thread- 形态" },
];

function samplePaths(style: UrlStyle) {
  return [
    { kind: "帖子", path: postPath(style, 123) },
    { kind: "用户", path: userPath(style, 5) },
    { kind: "公告", path: announcementPath(style, 1) },
    { kind: "自建页", path: pagePath(style, "about") },
    { kind: "排行榜", path: leaderboardPath(style) },
  ];
}

export default function UrlStylePanel({
  initial,
  onSaved,
  onDirtyChange,
}: {
  initial: PublicSettings;
  onSaved?: (next: PublicSettings) => void;
  onDirtyChange?: (dirty: boolean) => void;
}) {
  const [style, setStyle] = useState<UrlStyle>(initial.url_style);
  const [savedStyle, setSavedStyle] = useState<UrlStyle>(initial.url_style);
  const [saving, setSaving] = useState(false);
  const [error, setError] = useState("");

  const dirty = style !== savedStyle;

  useEffect(() => {
    onDirtyChange?.(dirty);
  }, [dirty, onDirtyChange]);

  const discard = () => {
    setStyle(savedStyle);
    setError("");
  };

  const save = async () => {
    if (saving || !dirty) return;
    setSaving(true);
    setError("");
    try {
      const res = await apiUpdateSiteSettings({ url_style: style });
      setSavedStyle(res.url_style);
      setStyle(res.url_style);
      onSaved?.(res);
      toast("已保存，全站链接风格已切换", "ok");
    } catch (e) {
      const msg = e instanceof Error ? e.message : "保存失败";
      setError(msg);
      toast(msg);
    } finally {
      setSaving(false);
    }
  };

  return (
    <AdminSettingsGroup
      id="settings-url-style"
      title="链接风格（伪静态）"
      description="帖子、用户主页、公告等详情页的 URL 形态。"
      footer={
        <AdminSettingsActions
          dirty={dirty}
          saving={saving}
          saveLabel="保存"
          error={error}
          onSave={() => void save()}
          onDiscard={discard}
        />
      }
    >
      <div className="grid gap-3 sm:grid-cols-3" role="radiogroup" aria-label="链接风格">
        {STYLE_OPTIONS.map((opt) => {
          const on = style === opt.value;
          return (
            <button
              key={opt.value}
              type="button"
              role="radio"
              aria-checked={on}
              className={`admin-url-style-card${on ? " is-on" : ""}`}
              onClick={() => setStyle(opt.value)}
            >
              <span className="flex items-center justify-between gap-2">
                <span className="text-[13.5px] font-semibold">{opt.label}</span>
                <span className={`admin-url-style-dot${on ? " is-on" : ""}`} aria-hidden />
              </span>
              <span className="meta mt-0.5 block text-[11.5px]">{opt.desc}</span>
              <span className="admin-url-style-examples">
                {samplePaths(opt.value).map((s) => (
                  <span key={s.kind} className="admin-url-style-example">
                    <span className="meta">{s.kind}</span>
                    <code>{s.path}</code>
                  </span>
                ))}
              </span>
            </button>
          );
        })}
      </div>

      <ul className="admin-url-style-notes meta mt-3 text-[12px]">
        <li>保存后全站前台链接立即按新风格生成；旧风格链接自动 301 到新风格，收录与外链不断链。</li>
        <li>301 会被浏览器长期缓存，切换前请想清楚；建议长期固定一种风格，不要频繁来回切换。</li>
        <li>自建页与排行榜同样参与伪静态；自建页 slug 含中文时自动 URL 编码，地址栏多数浏览器仍显示中文。</li>
      </ul>
    </AdminSettingsGroup>
  );
}