import { h } from 'preact';
import { useEffect, useRef } from 'preact/hooks';
import type { SignalRef, SignalMeta } from './lib/types';
import { getMetaStore } from './lib/stores';
import { useState } from 'preact/hooks';

interface Props {
  visible: boolean;
  x: number;
  y: number;
  signal: SignalRef | null;
  onClose: () => void;
  onInfo?: () => void;
  onPlot?: () => void;
}

export default function ContextMenu({ visible, x, y, signal, onClose, onInfo, onPlot }: Props) {
  const [meta, setMeta] = useState<SignalMeta | null>(null);
  const menuRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (!signal) { setMeta(null); return; }
    const unsub = getMetaStore(signal).subscribe(setMeta);
    return unsub;
  }, [signal?.ds, signal?.name]);

  useEffect(() => {
    if (!visible) return;
    function handleClick(e: MouseEvent) {
      if (menuRef.current && !menuRef.current.contains(e.target as Node)) {
        onClose();
      }
    }
    document.addEventListener('mousedown', handleClick);
    return () => document.removeEventListener('mousedown', handleClick);
  }, [visible, onClose]);

  if (!visible) return null;

  function copySignalName() {
    if (signal) navigator.clipboard.writeText(signal.name).catch(() => {});
    onClose();
  }

  function openInfo() {
    onClose();
    onInfo?.();
  }

  function openPlot() {
    onClose();
    onPlot?.();
  }

  function exportCSV() {
    // Phase 5+: export CSV data
    onClose();
  }

  return (
    <div
      class="ctx-menu"
      ref={menuRef}
      style={`left:${x}px;top:${y}px;`}
    >
      {signal ? (
        <div>
          <div class="ctx-signal-info">
            <div>{signal.ds} / {signal.name}</div>
            {meta && (
              <div>{meta.type}{meta.unit ? ` [${meta.unit}]` : ''}</div>
            )}
          </div>
          <div class="ctx-divider" />
          <button class="ctx-item" onClick={openInfo}>Signal info</button>
          <button class="ctx-item" onClick={openPlot}>Plot</button>
          <div class="ctx-divider" />
          <button class="ctx-item" onClick={copySignalName}>Copy signal name</button>
          <button class="ctx-item" onClick={exportCSV}>Export data to CSV</button>
        </div>
      ) : (
        <button class="ctx-item" onClick={onClose}>Close</button>
      )}
    </div>
  );
}