import { Search, X } from "lucide-react";
import { useId, useMemo, useRef, useState } from "react";
import { useNavigate } from "react-router";
import { Input } from "~/components/ui/input.tsx";
import { cn } from "~/lib/utils.ts";
import { type SettingsSearchHit, searchSettings } from "./search-index.ts";
import { settingsHash } from "./sections.tsx";

/** 设置页搜索框:按设置名、节名找位置;选中后跳到该节,字段会被聚焦 */
export function SettingsSearch({ className }: { className?: string }) {
  const navigate = useNavigate();
  const listId = useId();
  const [q, setQ] = useState("");
  const [open, setOpen] = useState(false);
  const [active, setActive] = useState(0);
  const inputRef = useRef<HTMLInputElement>(null);
  const hits = useMemo(() => searchSettings(q), [q]);
  const show = open && q.trim() !== "";

  const pick = (h: SettingsSearchHit) => {
    setOpen(false);
    setQ("");
    navigate({ hash: settingsHash(h.section, h.anchor) }, { state: h.field ? { field: h.field } : null });
  };

  return (
    <div className={cn("relative", className)}>
      <Search
        className="pointer-events-none absolute top-1/2 left-2.5 size-4 -translate-y-1/2 text-muted-foreground"
        aria-hidden
      />
      <Input
        ref={inputRef}
        type="text"
        enterKeyHint="search"
        role="combobox"
        aria-expanded={show}
        aria-controls={listId}
        aria-autocomplete="list"
        aria-label="搜索设置"
        placeholder="搜索设置"
        value={q}
        className="pr-8 pl-8"
        onChange={(e) => {
          setQ(e.target.value);
          setActive(0);
          setOpen(true);
        }}
        onFocus={() => setOpen(true)}
        onBlur={() => window.setTimeout(() => setOpen(false), 120)}
        onKeyDown={(e) => {
          if (e.key === "ArrowDown") {
            e.preventDefault();
            setActive((i) => Math.min(i + 1, hits.length - 1));
          } else if (e.key === "ArrowUp") {
            e.preventDefault();
            setActive((i) => Math.max(i - 1, 0));
          } else if (e.key === "Enter") {
            const h = hits[active];
            if (h) {
              e.preventDefault();
              pick(h);
            }
          } else if (e.key === "Escape") {
            setQ("");
            setOpen(false);
          }
        }}
      />
      {q ? (
        <button
          type="button"
          aria-label="清除搜索"
          className="absolute top-1/2 right-2 -translate-y-1/2 rounded-full p-0.5 text-muted-foreground hover:text-foreground"
          onClick={() => {
            setQ("");
            inputRef.current?.focus();
          }}
        >
          <X className="size-3.5" />
        </button>
      ) : null}
      {show ? (
        <div
          id={listId}
          role="listbox"
          aria-label="搜索结果"
          className="pg-float absolute inset-x-0 top-full z-30 mt-1.5 max-h-80 animate-pg-pop overflow-y-auto rounded-xl p-1"
        >
          {hits.length === 0 ? (
            <p className="px-3 py-2 text-caption text-muted-foreground">没有匹配的设置</p>
          ) : (
            hits.map((h, i) => (
              <button
                key={h.key}
                type="button"
                role="option"
                aria-selected={i === active}
                onMouseDown={(e) => e.preventDefault()}
                onMouseEnter={() => setActive(i)}
                onClick={() => pick(h)}
                className={cn(
                  "block w-full rounded-lg px-3 py-1.5 text-left transition-colors duration-micro",
                  i === active ? "bg-foreground/[0.06]" : "",
                )}
              >
                <span className="block truncate text-sm text-foreground">{h.label}</span>
                <span className="block truncate text-meta text-muted-foreground">{h.where}</span>
              </button>
            ))
          )}
        </div>
      ) : null}
    </div>
  );
}