import { Editor } from '../../editor/Editor.js';
import { ContextMenuDirectory, ContextMenuEntry, ContextMenuReadOnlyEntry, ContextMenuSeparator } from '../context-menu/context-menu.js';
import { showConfirmDialog } from '../confirm-dialog/confirm-dialog.js';

interface FileNode {
  name: string;
  path: string;
  type: 'file' | 'directory';
  children?: FileNode[];
}

class FileTreePanel extends HTMLElement {
  selectedPath: string | null = null;
  _rootPath: string = '';
  _initialized = false;

  async connectedCallback(): Promise<void> {
    if ( this._initialized ) return;
    this._initialized = true;

    this.className = 'file-tree-panel';
    this.innerHTML = `
      <div class="ftp-header">
        <button class="ftp-btn" data-action="add-file" title="Add file">+F</button>
        <button class="ftp-btn" data-action="add-dir" title="Add directory">+D</button>
      </div>
      <div class="ftp-tree">Loading…</div>
    `;

    this.querySelector( '[data-action="add-file"]' )!.addEventListener( 'click', () => this.addFile() );
    this.querySelector( '[data-action="add-dir"]' )!.addEventListener( 'click', () => this.addDirectory() );

    Editor.get().onFilesChanged.addListener( () => this.refresh() );

    await this.refresh();
  }

  addContextMenuEntries( dir: ContextMenuDirectory ): void {
    dir.add( new ContextMenuReadOnlyEntry( dir, 'File Tree' ) );
  }

  _updateTabLabel(): void {
    const label = '📁 ' + this._dirnameDisplay();
    this.dispatchEvent( new CustomEvent( 'panel:label-change', { bubbles: true, detail: { label } } ) );
  }

  _dirnameDisplay(): string {
    if ( !this._rootPath ) return '/';
    const lastSlash = this._rootPath.lastIndexOf( '/' );
    return lastSlash === -1 ? this._rootPath : this._rootPath.slice( lastSlash + 1 );
  }

  _findNode( nodes: FileNode[], targetPath: string ): FileNode | null {
    for ( const n of nodes ) {
      if ( n.path === targetPath ) return n;
      if ( n.children ) {
        const found = this._findNode( n.children, targetPath );
        if ( found ) return found;
      }
    }
    return null;
  }

  _goUp(): void {
    const lastSlash = this._rootPath.lastIndexOf( '/' );
    this._rootPath = lastSlash === -1 ? '' : this._rootPath.slice( 0, lastSlash );
    this.selectedPath = null;
    this.refresh();
  }

  async refresh(): Promise<void> {
    const state = Editor.get();
    const res = await fetch( `/api/files/${state.projectId}/tree` );
    const allNodes = await res.json() as FileNode[];
    const tree = this.querySelector( '.ftp-tree' )!;

    let nodes: FileNode[];

    if ( this._rootPath ) {
      const rootNode = this._findNode( allNodes, this._rootPath );
      nodes = rootNode ? ( rootNode.children ?? [] ) : [];
    }
    else {
      nodes = allNodes;
    }

    let html = '';

    if ( this._rootPath ) {
      html += `<div class="ftp-up" data-action="go-up">[ .. ]</div>`;
    }

    html += nodes.length ? this.renderNodes( nodes ) : '<span class="ftp-empty">Empty</span>';
    tree.innerHTML = html;

    const upBtn = tree.querySelector( '[data-action="go-up"]' );
    if ( upBtn ) {
      upBtn.addEventListener( 'click', () => this._goUp() );
    }

    this._updateTabLabel();
    this.bindTree( tree );
  }

  bindTree( tree: Element ): void {
    const state = Editor.get();
    tree.querySelectorAll( '.ftp-file' ).forEach( el => {
      el.addEventListener( 'click', () => {
        const path = ( el as HTMLElement ).dataset.path!;
        this.selectedPath = path;
        tree.querySelectorAll( '.ftp-file, .ftp-dir-label' ).forEach( f => f.classList.remove( 'active' ) );
        el.classList.add( 'active' );
        state.openDocument( path );
      } );
      el.addEventListener( 'contextmenu', ( e: Event ) => {
        e.preventDefault();
        const me = e as MouseEvent;
        this.showItemMenu( ( el as HTMLElement ).dataset.path!, me.clientX, me.clientY );
      } );
    } );
    tree.querySelectorAll( '.ftp-dir-label' ).forEach( el => {
      el.addEventListener( 'click', () => {
        const li = el.closest( 'li' )!;
        li.classList.toggle( 'open' );
        const path = ( el as HTMLElement ).dataset.path!;
        this.selectedPath = path;
        tree.querySelectorAll( '.ftp-file, .ftp-dir-label' ).forEach( f => f.classList.remove( 'active' ) );
        el.classList.add( 'active' );
      } );
      el.addEventListener( 'dblclick', () => {
        const path = ( el as HTMLElement ).dataset.path!;
        this._rootPath = path;
        this.selectedPath = null;
        this.refresh();
      } );
      el.addEventListener( 'contextmenu', ( e: Event ) => {
        e.preventDefault();
        const me = e as MouseEvent;
        this.showItemMenu( ( el as HTMLElement ).dataset.path!, me.clientX, me.clientY );
      } );
    } );
  }

  showItemMenu( targetPath: string, x: number, y: number ): void
  {
    this.selectedPath = targetPath;
    const tree = this.querySelector( '.ftp-tree' )!;
    tree.querySelectorAll( '.ftp-file, .ftp-dir-label' ).forEach( f => f.classList.remove( 'active' ) );
    tree.querySelector( `[data-path="${CSS.escape( targetPath )}"]` )?.classList.add( 'active' );

    const menu = new ContextMenuDirectory( null );
    menu.add( new ContextMenuReadOnlyEntry( menu, targetPath ) );
    menu.add( new ContextMenuSeparator( menu ) );
    menu.add( new ContextMenuEntry( menu, 'Rename…', () => this.startInlineRename( targetPath ) ) );
    menu.add( new ContextMenuEntry( menu, 'Delete', () => this.deleteEntry( targetPath ) ) );
    menu.show( x, y );
  }

  startInlineRename( oldPath: string ): void
  {
    const tree = this.querySelector( '.ftp-tree' )!;
    const lastSlash = oldPath.lastIndexOf( '/' );
    const currentName = lastSlash === -1 ? oldPath : oldPath.slice( lastSlash + 1 );

    const overlay = document.createElement( 'div' );
    overlay.className = 'ftp-inline-create';

    const input = document.createElement( 'input' );
    input.className = 'ftp-rename-input';
    input.value = currentName;
    input.type = 'text';

    overlay.innerHTML = `<span class="ftp-inline-label">✎ Rename: ${oldPath}</span>`;
    overlay.appendChild( input );

    const btnRename = document.createElement( 'button' );
    btnRename.textContent = 'Rename';
    btnRename.className = 'ftp-btn';
    const btnCancel = document.createElement( 'button' );
    btnCancel.textContent = 'Cancel';
    btnCancel.className = 'ftp-btn';

    overlay.appendChild( btnRename );
    overlay.appendChild( btnCancel );
    tree.prepend( overlay );
    input.focus();
    input.select();

    const confirm = async () =>
    {
      const newName = input.value.trim();
      if ( !newName || newName === currentName ) { overlay.remove(); return; }
      await this.renameEntry( oldPath, newName );
      overlay.remove();
    };

    const cancel = () => overlay.remove();

    btnRename.addEventListener( 'click', confirm );
    btnCancel.addEventListener( 'click', cancel );
    input.addEventListener( 'keydown', ( e: KeyboardEvent ) =>
    {
      if ( 'Enter' === e.key ) confirm();
      if ( 'Escape' === e.key ) cancel();
    } );
  }

  async renameEntry( oldPath: string, newName: string ): Promise<void>
  {
    const state = Editor.get();
    const res = await fetch( `/api/files/${state.projectId}/rename`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify( { path: oldPath, newName } ),
    } );

    if ( !res.ok ) return;

    const lastSlash = oldPath.lastIndexOf( '/' );
    const parent = lastSlash === -1 ? '' : oldPath.slice( 0, lastSlash );
    this.selectedPath = parent ? `${parent}/${newName}` : newName;
    Editor.get().onFilesChanged.dispatch();
  }

  async deleteEntry( targetPath: string ): Promise<void>
  {
    const lastSlash = targetPath.lastIndexOf( '/' );
    const name = lastSlash === -1 ? targetPath : targetPath.slice( lastSlash + 1 );
    const confirmed = await showConfirmDialog( {
      icon: '🗑',
      title: 'Delete',
      message: `Delete "${name}"? This cannot be undone.`,
      confirmLabel: 'Delete',
      cancelLabel: 'Cancel',
      danger: true,
    } );

    if ( !confirmed ) return;

    const state = Editor.get();
    const res = await fetch( `/api/files/${state.projectId}/delete`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify( { path: targetPath } ),
    } );

    if ( !res.ok ) return;

    if ( this.selectedPath === targetPath ) this.selectedPath = null;
    Editor.get().onFilesChanged.dispatch();
  }

  resolveTargetDir(): string {
    if ( !this.selectedPath ) return this._rootPath;

    const tree = this.querySelector( '.ftp-tree' )!;
    const dirLabel = tree.querySelector( `.ftp-dir-label[data-path="${CSS.escape( this.selectedPath )}"]` );
    if ( dirLabel ) return this.selectedPath;

    const lastSlash = this.selectedPath.lastIndexOf( '/' );
    return lastSlash === -1 ? this._rootPath : this.selectedPath.slice( 0, lastSlash );
  }

  async addFile(): Promise<void> {
    const state = Editor.get();
    const dir = this.resolveTargetDir();
    const name = await this.findFreeName(state.projectId, dir, 'file', 'txt');
    const filePath = dir ? `${dir}/${name}` : name;
    this.startInlineCreate(filePath, 'file', name);
  }

  async addDirectory(): Promise<void> {
    const state = Editor.get();
    const dir = this.resolveTargetDir();
    const name = await this.findFreeName(state.projectId, dir, 'directory', '');
    const dirPath = dir ? `${dir}/${name}` : name;
    this.startInlineCreate(dirPath, 'directory', name);
  }

  async findFreeName(projectId: string, dir: string, type: 'file' | 'directory', ext: string): Promise<string> {
    const baseName = type === 'file' ? 'file' : 'directory';
    const res = await fetch(`/api/files/${projectId}/tree`);
    const tree = await res.json() as FileNode[];
    for (let i = 1; i <= 999; i++) {
      const name = ext ? `${baseName}${i > 1 ? i : ''}.${ext}` : `${baseName}${i > 1 ? i : ''}`;
      const testPath = dir ? `${dir}/${name}` : name;
      if (!this.pathExistsInTree(tree, testPath)) return name;
    }
    return `${baseName}-${Date.now()}${ext ? '.' + ext : ''}`;
  }

  pathExistsInTree(nodes: FileNode[], targetPath: string): boolean {
    for (const n of nodes) {
      if (n.path === targetPath) return true;
      if (n.children && this.pathExistsInTree(n.children, targetPath)) return true;
    }
    return false;
  }

  startInlineCreate(fullPath: string, type: 'file' | 'directory', defaultName: string): void {
    const tree = this.querySelector('.ftp-tree')!;
    const overlay = document.createElement('div');
    overlay.className = 'ftp-inline-create';

    const input = document.createElement('input');
    input.className = 'ftp-rename-input';
    input.value = defaultName;
    input.type = 'text';

    overlay.innerHTML = `<span class="ftp-inline-label">${type === 'file' ? '📄' : '📁'} New ${type} in: ${fullPath.includes('/') ? fullPath.slice(0, fullPath.lastIndexOf('/')) || '/' : '/'}</span>`;
    overlay.appendChild(input);

    const btnCreate = document.createElement('button');
    btnCreate.textContent = 'Create';
    btnCreate.className = 'ftp-btn';
    const btnCancel = document.createElement('button');
    btnCancel.textContent = 'Cancel';
    btnCancel.className = 'ftp-btn';

    overlay.appendChild(btnCreate);
    overlay.appendChild(btnCancel);
    tree.prepend(overlay);
    input.focus();
    input.select();

    const confirm = async () => {
      const name = input.value.trim();
      if (!name) return;
      const dir = fullPath.includes('/') ? fullPath.slice(0, fullPath.lastIndexOf('/')) : '';
      const finalPath = dir ? `${dir}/${name}` : name;
      await this.createEntry(type, finalPath);
      overlay.remove();
    };

    const cancel = () => overlay.remove();

    btnCreate.addEventListener('click', confirm);
    btnCancel.addEventListener('click', cancel);
    input.addEventListener('keydown', (e: KeyboardEvent) => {
      if (e.key === 'Enter') confirm();
      if (e.key === 'Escape') cancel();
    });
  }

  async createEntry(type: 'file' | 'directory', path: string): Promise<void> {
    const state = Editor.get();
    const endpoint = type === 'file' ? 'create-file' : 'create-directory';
    const res = await fetch(`/api/files/${state.projectId}/${endpoint}`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ path }),
    });
    if ( res.ok )
    {
      if ( type === 'file' )
      {
        this.selectedPath = path;
      }

      Editor.get().onFilesChanged.dispatch();
    }
  }

  renderNodes(nodes: FileNode[], depth = 0): string {
    return `<ul class="ftp-list" style="--depth:${depth}">` + nodes.map(n => {
      if (n.type === 'directory') {
        return `<li class="ftp-dir open">
          <span class="ftp-dir-label" data-path="${n.path}">▸ ${n.name}</span>
          ${this.renderNodes(n.children ?? [], depth + 1)}
        </li>`;
      }
      const isHtml = n.name.endsWith('.html');
      return `<li class="ftp-file${isHtml ? ' ftp-html' : ''}" data-path="${n.path}">${n.name}</li>`;
    }).join('') + '</ul>';
  }
}

customElements.define('file-tree-panel', FileTreePanel);