import React, { useState, useRef, useEffect, useCallback } from 'react';
import { useEditorStore } from '../../store/useEditorStore';
import './FileExplorer.css';

// SVG icons — same style as EditorToolbar (stroke-based, 16x16)
const IcoFile = () => (
  <svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
    <polyline points="14 2 14 8 20 8" />
  </svg>
);

const IcoHeader = () => (
  <svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
    <polyline points="14 2 14 8 20 8" />
    <line x1="9" y1="13" x2="15" y2="13" />
    <line x1="9" y1="17" x2="13" y2="17" />
  </svg>
);

const IcoNewFile = () => (
  <svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
    <polyline points="14 2 14 8 20 8" />
    <line x1="12" y1="18" x2="12" y2="12" />
    <line x1="9" y1="15" x2="15" y2="15" />
  </svg>
);

const IcoSave = () => (
  <svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z" />
    <polyline points="17 21 17 13 7 13 7 21" />
    <polyline points="7 3 7 8 15 8" />
  </svg>
);

function FileIcon({ name }: { name: string }) {
  const ext = name.split('.').pop()?.toLowerCase() ?? '';
  if (['h', 'hpp'].includes(ext)) return <IcoHeader />;
  return <IcoFile />;
}

interface ContextMenu {
  fileId: string;
  x: number;
  y: number;
}

interface FileExplorerProps {
  onSaveClick: () => void;
}

export const FileExplorer: React.FC<FileExplorerProps> = ({ onSaveClick }) => {
  const { files, activeFileId, openFile, createFile, deleteFile, renameFile } =
    useEditorStore();
  const [contextMenu, setContextMenu] = useState<ContextMenu | null>(null);
  const [renamingId, setRenamingId] = useState<string | null>(null);
  const [renameValue, setRenameValue] = useState('');
  const [creatingFile, setCreatingFile] = useState(false);
  const [newFileName, setNewFileName] = useState('');
  const renameInputRef = useRef<HTMLInputElement>(null);
  const newFileInputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    if (renamingId && renameInputRef.current) {
      renameInputRef.current.focus();
      renameInputRef.current.select();
    }
  }, [renamingId]);

  useEffect(() => {
    if (creatingFile && newFileInputRef.current) {
      newFileInputRef.current.focus();
    }
  }, [creatingFile]);

  // Close context menu on click outside
  useEffect(() => {
    if (!contextMenu) return;
    const handler = () => setContextMenu(null);
    document.addEventListener('click', handler);
    return () => document.removeEventListener('click', handler);
  }, [contextMenu]);

  const handleContextMenu = (e: React.MouseEvent, fileId: string) => {
    e.preventDefault();
    e.stopPropagation();
    setContextMenu({ fileId, x: e.clientX, y: e.clientY });
  };

  const startRename = (fileId: string) => {
    const file = files.find((f) => f.id === fileId);
    if (!file) return;
    setRenamingId(fileId);
    setRenameValue(file.name);
    setContextMenu(null);
  };

  const commitRename = useCallback(() => {
    if (renamingId && renameValue.trim()) {
      renameFile(renamingId, renameValue.trim());
    }
    setRenamingId(null);
  }, [renamingId, renameValue, renameFile]);

  const handleDelete = (fileId: string) => {
    setContextMenu(null);
    if (files.length <= 1) return;
    if (!window.confirm('Delete this file?')) return;
    deleteFile(fileId);
  };

  const startCreateFile = () => {
    setCreatingFile(true);
    setNewFileName('');
    setContextMenu(null);
  };

  const commitCreateFile = useCallback(() => {
    const name = newFileName.trim();
    if (name) createFile(name);
    setCreatingFile(false);
    setNewFileName('');
  }, [newFileName, createFile]);

  return (
    <div className="file-explorer">
      <div className="file-explorer-header">
        <span className="file-explorer-title">WORKSPACE</span>
        <div className="file-explorer-header-actions">
          <button
            className="file-explorer-new-btn"
            title="New File"
            onClick={startCreateFile}
          >
            <IcoNewFile />
          </button>
          <button
            className="file-explorer-save-btn"
            title="Save project (Ctrl+S)"
            onClick={onSaveClick}
          >
            <IcoSave />
          </button>
        </div>
      </div>

      <div className="file-explorer-list">
        {files.map((file) => (
          <div
            key={file.id}
            className={`file-explorer-item${file.id === activeFileId ? ' file-explorer-item-active' : ''}`}
            onClick={() => openFile(file.id)}
            onContextMenu={(e) => handleContextMenu(e, file.id)}
            onDoubleClick={() => startRename(file.id)}
            title={`${file.name}${file.modified ? ' (unsaved)' : ''}`}
          >
            <span className="file-explorer-icon">
              <FileIcon name={file.name} />
            </span>

            {renamingId === file.id ? (
              <input
                ref={renameInputRef}
                className="file-explorer-rename-input"
                value={renameValue}
                onChange={(e) => setRenameValue(e.target.value)}
                onBlur={commitRename}
                onKeyDown={(e) => {
                  if (e.key === 'Enter') commitRename();
                  if (e.key === 'Escape') setRenamingId(null);
                }}
                onClick={(e) => e.stopPropagation()}
              />
            ) : (
              <span className="file-explorer-name">{file.name}</span>
            )}

            {file.modified && (
              <span className="file-explorer-dot" title="Unsaved changes" />
            )}
          </div>
        ))}

        {creatingFile && (
          <div className="file-explorer-item file-explorer-item-new">
            <span className="file-explorer-icon">
              <IcoFile />
            </span>
            <input
              ref={newFileInputRef}
              className="file-explorer-rename-input"
              value={newFileName}
              placeholder="filename.ino"
              onChange={(e) => setNewFileName(e.target.value)}
              onBlur={commitCreateFile}
              onKeyDown={(e) => {
                if (e.key === 'Enter') commitCreateFile();
                if (e.key === 'Escape') {
                  setCreatingFile(false);
                  setNewFileName('');
                }
              }}
              onClick={(e) => e.stopPropagation()}
            />
          </div>
        )}
      </div>

      {contextMenu && (
        <div
          className="file-explorer-context-menu"
          style={{ top: contextMenu.y, left: contextMenu.x }}
          onClick={(e) => e.stopPropagation()}
        >
          <button onClick={() => startRename(contextMenu.fileId)}>
            Rename
          </button>
          <button
            className="ctx-delete"
            onClick={() => handleDelete(contextMenu.fileId)}
            disabled={files.length <= 1}
          >
            Delete
          </button>
        </div>
      )}
    </div>
  );
};