import React from 'react';
import { useSessionStore } from '../store/session';
import { useHistoryStore } from '../store/history';
import { useUIStore } from '../store/ui';
import { useHistory } from '../api/hooks';

export function Header() {
  const { isLoaded, tableName, rowCount } = useSessionStore();
  const { canUndo, canRedo } = useHistoryStore();
  const { toggleUploadDialog, toggleSidebar, showSidebar } = useUIStore();
  const { undoAction, redoAction } = useHistory();

  const handleUndo = async () => {
    const result = await undoAction();
    if (result) useHistoryStore.getState().updateCurrent(result.state_id);
  };

  const handleRedo = async () => {
    const result = await redoAction();
    if (result) useHistoryStore.getState().updateCurrent(result.state_id);
  };

  return (
    <header className="bg-white border-b border-gray-200 sticky top-0 z-50">
      <div className="w-full px-4 py-2.5 flex items-center justify-between">
        {/* Left: sidebar toggle + logo + dataset info */}
        <div className="flex items-center gap-3 min-w-0">
          {isLoaded && (
            <button
              onClick={toggleSidebar}
              className="p-1.5 text-gray-500 hover:text-gray-700 hover:bg-gray-100 rounded-lg transition-colors flex-shrink-0"
              title={showSidebar ? 'Hide sidebar' : 'Show sidebar'}
            >
              <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                {showSidebar ? (
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 19l-7-7 7-7m8 14l-7-7 7-7" />
                ) : (
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 6h16M4 12h16M4 18h16" />
                )}
              </svg>
            </button>
          )}

          <div className="w-8 h-8 bg-brand-600 rounded-lg flex items-center justify-center flex-shrink-0">
            <svg className="w-5 h-5 text-white" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 17V7m0 10a2 2 0 01-2 2H5a2 2 0 01-2-2V7a2 2 0 012-2h2a2 2 0 012 2m0 10a2 2 0 002 2h2a2 2 0 002-2M9 7a2 2 0 012-2h2a2 2 0 012 2m0 10V7m0 10a2 2 0 002 2h2a2 2 0 002-2V7a2 2 0 00-2-2h-2a2 2 0 00-2 2" />
            </svg>
          </div>
          <h1 className="text-lg font-bold text-gray-900 flex-shrink-0">Visual Notebook</h1>
          {isLoaded && (
            <span className="text-sm text-gray-500 ml-1 hidden sm:inline truncate">
              <span className="text-gray-400 mx-1">·</span>
              {tableName}
              <span className="text-gray-400 mx-1">·</span>
              {rowCount.toLocaleString()} rows
            </span>
          )}
        </div>

        {/* Right: undo/redo + new file */}
        <div className="flex items-center gap-1.5 flex-shrink-0">
          {isLoaded && (
            <>
              <button
                onClick={handleUndo}
                disabled={!canUndo}
                className="p-1.5 text-gray-500 hover:text-gray-700 hover:bg-gray-100 rounded-lg disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
                title="Undo"
              >
                <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 10h10a5 5 0 015 5v2M3 10l4-4M3 10l4 4" />
                </svg>
              </button>
              <button
                onClick={handleRedo}
                disabled={!canRedo}
                className="p-1.5 text-gray-500 hover:text-gray-700 hover:bg-gray-100 rounded-lg disabled:opacity-30 disabled:cursor-not-allowed transition-colors"
                title="Redo"
              >
                <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M21 10H11a5 5 0 00-5 5v2M21 10l-4-4M21 10l-4 4" />
                </svg>
              </button>

              <div className="w-px h-5 bg-gray-200 mx-1" />

              <button onClick={toggleUploadDialog} className="btn-secondary text-xs py-1.5">
                <span className="flex items-center gap-1.5">
                  <svg className="w-3.5 h-3.5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
                  </svg>
                  New File
                </span>
              </button>
            </>
          )}
        </div>
      </div>
    </header>
  );
}