import { useState } from 'react';

// 'agents-md', 'browser-sessions', 'mcp', 'skills', 'pets', 'ssh-connections' are virtual subdirs (not raw file editor directories)
// ('scripts' / 'templates' were retired 2026-06 — superseded by Skills + the Bash tool)
export type SubdirId = 'agents-md' | 'browser-macros' | 'recordings' | 'trash' | 'memory' | 'browser-sessions' | 'mcp' | 'skills' | 'pets' | 'ssh-connections' | 'notes' | 'subscribed-notes';

/** True for subdirs that have actual files on disk */
export const FILE_SUBDIRS: SubdirId[] = ['browser-macros', 'recordings', 'trash', 'memory', 'notes'];

export interface FileEntry {
  name: string;
  size: number;
  mtime: string;
}

export interface SubdirFiles {
  subdir: SubdirId;
  files: FileEntry[];
  loading: boolean;
}

interface FileTreeProps {
  subdirData: SubdirFiles[];
  selectedSubdir: SubdirId | null;
  selectedFile: string | null;
  onSelectSubdir: (subdir: SubdirId) => void;
  onSelectFile: (subdir: SubdirId, file: string) => void;
  onDeleteFile: (subdir: SubdirId, file: string) => void;
}

const SUBDIR_LABELS: Record<SubdirId, string> = {
  'agents-md': 'AGENTS.md',
  'browser-macros': 'browser-macros',
  recordings: 'recordings',
  trash: 'trash',
  memory: 'memory',
  'browser-sessions': 'browser-sessions',
  mcp: 'MCP',
  skills: 'Skills',
  pets: 'pets',
  'ssh-connections': 'ssh-connections',
  notes: 'Notes (共有)',
  'subscribed-notes': 'Subscribed Notes',
};

const SUBDIR_ICONS: Record<SubdirId, string> = {
  'agents-md': '📖',
  'browser-macros': '🤖',
  recordings: '🎬',
  trash: '🗑',
  memory: '🧠',
  'browser-sessions': '🌐',
  mcp: '🔌',
  skills: '📚',
  pets: '◉',
  'ssh-connections': '🔐',
  notes: '📝',
  'subscribed-notes': '🔔',
};

/** Virtual subdirs that don't show a file list (they render custom panel content instead). */
const VIRTUAL_SUBDIRS = new Set<SubdirId>(['agents-md', 'browser-sessions', 'mcp', 'skills', 'pets', 'ssh-connections', 'subscribed-notes']);

export function FileTree({
  subdirData,
  selectedSubdir,
  selectedFile,
  onSelectSubdir,
  onSelectFile,
  onDeleteFile,
}: FileTreeProps) {
  const [hoveredFile, setHoveredFile] = useState<string | null>(null);

  return (
    <div className="flex flex-col h-full overflow-y-auto">
      {subdirData.map(({ subdir, files, loading }) => {
        const isOpen = selectedSubdir === subdir;
        const isVirtual = VIRTUAL_SUBDIRS.has(subdir);
        return (
          <div key={subdir}>
            {/* Subdir header */}
            <button
              type="button"
              onClick={() => onSelectSubdir(subdir)}
              className={`w-full flex items-center gap-2 px-3 py-2 text-xs font-semibold transition-colors hover:bg-surface-2 ${
                isOpen ? 'bg-surface-2 text-slate-900' : 'text-slate-600'
              }`}
            >
              <span className="text-2xs">{isOpen ? '▾' : '▸'}</span>
              <span>{SUBDIR_ICONS[subdir]}</span>
              <span className="flex-1 text-left">{SUBDIR_LABELS[subdir]}{subdir !== 'agents-md' ? '/' : ''}</span>
              {!isVirtual && (
                <span className="text-[10px] font-mono text-slate-400 tabular-nums">
                  {loading ? '…' : files.length}
                </span>
              )}
            </button>

            {/* File list — only for non-virtual subdirs */}
            {isOpen && !isVirtual && (
              <div className="ml-4 border-l border-hairline pl-2 pb-1">
                {loading && (
                  <div className="text-2xs text-slate-400 px-2 py-1.5">Loading…</div>
                )}
                {!loading && files.length === 0 && (
                  <div className="text-2xs text-slate-400 px-2 py-1.5">Empty</div>
                )}
                {!loading && files.map(file => {
                  const fileKey = `${subdir}/${file.name}`;
                  const isSelected = selectedSubdir === subdir && selectedFile === file.name;
                  return (
                    <div
                      key={file.name}
                      className={`group flex items-center gap-1 px-2 py-1 rounded text-2xs cursor-pointer transition-colors ${
                        isSelected
                          ? 'bg-accent text-accent-fg'
                          : 'text-slate-700 hover:bg-surface-2'
                      }`}
                      onMouseEnter={() => setHoveredFile(fileKey)}
                      onMouseLeave={() => setHoveredFile(null)}
                      onClick={() => onSelectFile(subdir, file.name)}
                    >
                      <span className="flex-1 truncate font-mono">{file.name}</span>
                      {(hoveredFile === fileKey || isSelected) && (
                        <button
                          type="button"
                          aria-label={`Delete ${file.name}`}
                          onClick={e => {
                            e.stopPropagation();
                            onDeleteFile(subdir, file.name);
                          }}
                          className={`flex-shrink-0 w-4 h-4 flex items-center justify-center rounded hover:bg-red-100 dark:hover:bg-red-500/15 hover:text-red-600 transition-colors ${
                            isSelected ? 'text-accent-fg/70' : 'text-slate-400'
                          }`}
                        >
                          <svg viewBox="0 0 16 16" className="w-2.5 h-2.5" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
                            <path d="M4 4l8 8M12 4l-8 8" />
                          </svg>
                        </button>
                      )}
                    </div>
                  );
                })}
              </div>
            )}
          </div>
        );
      })}
    </div>
  );
}