frontend/src/components/QueryHistory.tsx

import { useEffect, useState } from "react";
import { getQueryHistory } from "../api/client";
import type { QueryHistoryItem } from "../types";

interface Props {
  onSelect: (item: QueryHistoryItem) => void;
}

function relativeTime(dateStr: string): string {
  const diff = Date.now() - new Date(dateStr).getTime();
  const mins = Math.floor(diff / 60_000);
  if (mins < 1) return "just now";
  if (mins < 60) return `${mins}m ago`;
  const hours = Math.floor(mins / 60);
  if (hours < 24) return `${hours}h ago`;
  return `${Math.floor(hours / 24)}d ago`;
}

export default function QueryHistory({ onSelect }: Props) {
  const [history, setHistory] = useState<QueryHistoryItem[]>([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    getQueryHistory(10)
      .then(setHistory)
      .catch(console.error)
      .finally(() => setLoading(false));
  }, []);

  if (loading) {
    return (
      <div className="space-y-1.5 px-1" aria-busy="true" aria-label="Loading history">
        {Array.from({ length: 4 }).map((_, i) => (
          <div key={i} className="h-8 shimmer-dark rounded-md" style={{ opacity: 1 - i * 0.15 }} />
        ))}
      </div>
    );
  }

  if (!history.length) {
    return (
      <div className="px-2 py-4 text-center">
        <svg className="w-5 h-5 text-slate-600 mx-auto mb-1.5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
          <path strokeLinecap="round" strokeLinejoin="round" d="M12 8v4l3 3m6-3a9 9 0 11-18 0 9 9 0 0118 0z" />
        </svg>
        <p className="text-xs text-slate-500">No queries yet</p>
      </div>
    );
  }

  return (
    <div className="space-y-0.5">
      {history.map((item) => (
        <button
          key={item.id}
          onClick={() => onSelect(item)}
          title={item.query_text}
          className="w-full text-left px-2 py-2 rounded-md transition-colors group hover:bg-slate-800"
        >
          <p className="text-xs text-slate-400 group-hover:text-slate-200 truncate leading-snug transition-colors">
            {item.query_text}
          </p>
          <p className="text-[10px] text-slate-600 group-hover:text-slate-500 mt-0.5 transition-colors">
            {relativeTime(item.created_at)}
          </p>
        </button>
      ))}
    </div>
  );
}