import { settingsSectionForLegacyTab } from "@umt/contracts";
import { useEffect } from "react";
import { Link, redirect, useLocation, useNavigate } from "react-router";
import { PageHeader } from "~/components/console/page-header.tsx";
import { parseSettingsHash, SECTIONS, settingsHash } from "~/components/settings/sections.tsx";
import { anchorId } from "~/components/settings/settings-block.tsx";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "~/components/ui/select.tsx";
import { cn } from "~/lib/utils.ts";

export const meta = () => [{ title: "设置 · UHD 媒体自动化控制台" }];

/** 旧链接 `?tab=xxx` → `#分区[/节]`(console-ia.md §3.3) */
export function clientLoader({ request }: { request: Request }) {
  const url = new URL(request.url);
  const tab = url.searchParams.get("tab");
  if (!tab) return null;
  const hit = settingsSectionForLegacyTab(tab);
  url.searchParams.delete("tab");
  const rest = url.searchParams.toString();
  return redirect(`${url.pathname}${rest ? `?${rest}` : ""}${hit ? settingsHash(hit.section, hit.anchor) : ""}`);
}

export default function SettingsPage() {
  const location = useLocation();
  const navigate = useNavigate();
  const { section, anchor } = parseSettingsHash(location.hash);

  // 切分区回到顶部;带节锚点时对齐到该节。节内容多是异步加载的(上游列表、能力清单),
  // 上方内容变高会把目标挤下去,所以在 2.5 秒内反复校正,直到用户自己滚动为止。
  // biome-ignore lint/correctness/useExhaustiveDependencies: location.key 让重复点同一锚点也能再跳一次
  useEffect(() => {
    if (!anchor) {
      window.scrollTo({ top: 0 });
      return;
    }
    const started = performance.now();
    let stopped = false;
    let timer = 0;
    const stop = () => {
      stopped = true;
    };
    const events = ["wheel", "touchstart", "keydown", "pointerdown"] as const;
    for (const e of events) window.addEventListener(e, stop, { passive: true });
    const align = () => {
      if (stopped) return;
      const el = document.getElementById(anchorId(section.id, anchor));
      if (el) {
        const margin = Number.parseFloat(getComputedStyle(el).scrollMarginTop) || 0;
        if (Math.abs(el.getBoundingClientRect().top - margin) > 2) el.scrollIntoView({ block: "start" });
      }
      if (performance.now() - started < 2500) timer = window.setTimeout(align, 120);
    };
    timer = window.setTimeout(align, 0);
    return () => {
      window.clearTimeout(timer);
      for (const e of events) window.removeEventListener(e, stop);
    };
  }, [section.id, anchor, location.key]);

  return (
    <>
      <PageHeader title="设置" description="密钥保存后不再显示。" />
      <div className="grid gap-6 lg:grid-cols-[13.5rem_minmax(0,1fr)] lg:gap-8">
        {/* 窄屏:顶部下拉 */}
        <div className="lg:hidden">
          <Select value={section.id} onValueChange={(id) => navigate({ hash: settingsHash(id) })}>
            <SelectTrigger className="w-full" aria-label="设置分区">
              <SelectValue />
            </SelectTrigger>
            <SelectContent position="popper">
              {SECTIONS.map((s) => (
                <SelectItem key={s.id} value={s.id}>
                  <s.icon />
                  {s.label}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
          <p className="mt-2 text-caption text-muted-foreground">{section.description}</p>
        </div>

        {/* 宽屏:左侧分区导航 */}
        <nav aria-label="设置分区" className="hidden lg:block">
          <ul className="sticky top-20 grid max-h-[calc(100dvh-6rem)] gap-0.5 overflow-y-auto pb-2">
            {SECTIONS.map((s) => {
              const active = s.id === section.id;
              return (
                <li key={s.id}>
                  <Link
                    to={{ hash: settingsHash(s.id) }}
                    aria-current={active ? "page" : undefined}
                    className={cn(
                      "flex items-center gap-2.5 rounded-lg px-3 py-2 text-sm transition-colors duration-micro",
                      active
                        ? "bg-foreground/[0.07] font-medium text-foreground"
                        : "text-muted-foreground hover:bg-foreground/[0.04] hover:text-foreground",
                    )}
                  >
                    <s.icon className="size-4 shrink-0" aria-hidden />
                    {s.label}
                  </Link>
                  {active && s.anchors.length > 1 ? (
                    <ul className="mt-0.5 mb-1.5 ml-[1.375rem] grid gap-0.5 border-l border-border/60 pl-3">
                      {s.anchors.map((a) => (
                        <li key={a.id}>
                          <Link
                            to={{ hash: settingsHash(s.id, a.id) }}
                            className={cn(
                              "block rounded-md px-2 py-1 text-caption transition-colors duration-micro hover:text-foreground",
                              anchor === a.id ? "text-foreground" : "text-muted-foreground",
                            )}
                          >
                            {a.label}
                          </Link>
                        </li>
                      ))}
                    </ul>
                  ) : null}
                </li>
              );
            })}
          </ul>
        </nav>

        <div className="min-w-0">
          {/* 分区页头:标题 + 一句说明;窄屏由上方下拉承担,标题只留给读屏 */}
          <div className="lg:mb-8">
            <h2 className="sr-only text-title font-semibold text-foreground lg:not-sr-only">{section.label}</h2>
            <p className="mt-1 hidden text-caption text-muted-foreground lg:block">{section.description}</p>
          </div>
          <div key={section.id} className="grid grid-cols-1 gap-8">
            {section.render()}
          </div>
        </div>
      </div>
    </>
  );
}