import { EventSlot } from '../library-ts/browser/events/EventSlot.js';
import { FileEditorRegistry } from './FileEditorRegistry.js';


export interface DocumentOpenedEvent
{
  path: string;
  content: string;
  editorTag: string;
  targetElement?: HTMLElement;
}

export interface DocumentPathEvent
{
  path: string;
}

export class Editor
{
  static _instance: Editor = null;

  static get(): Editor
  {
    if ( ! this._instance )
    {
      this._instance = new Editor();
    }

    return this._instance;
  }

  projectId: string = '';
  projectName: string = '';
  openDocs: Map<string, { content: string; dirty: boolean }> = new Map();
  activeDoc: string | null = null;
  fileEditorRegistry: FileEditorRegistry = new FileEditorRegistry();

  readonly onDocumentOpened: EventSlot<DocumentOpenedEvent> = new EventSlot();
  readonly onDocumentDirty: EventSlot<DocumentPathEvent> = new EventSlot();
  readonly onDocumentSaved: EventSlot<DocumentPathEvent> = new EventSlot();
  readonly onFilesChanged: EventSlot<void> = new EventSlot();
  readonly onFileTypeUnknown: EventSlot<DocumentPathEvent> = new EventSlot();

  async openDocument( filePath: string ): Promise<void>
  {
    await this.fileEditorRegistry.load( this.projectId );

    const editorTag = this.fileEditorRegistry.resolve( filePath );

    if ( editorTag === null )
    {
      this.onFileTypeUnknown.dispatch( { path: filePath } );
      return;
    }

    if ( ! this.openDocs.has( filePath ) )
    {
      const res = await fetch( `/api/files/${this.projectId}/${filePath}` );
      const content = await res.text();
      this.openDocs.set( filePath, { content, dirty: false } );
    }

    this.activeDoc = filePath;
    const entry = this.openDocs.get( filePath )!;
    this.onDocumentOpened.dispatch( { path: filePath, content: entry.content, editorTag } );
  }

  markDirty( filePath: string, content: string ): void
  {
    const doc = this.openDocs.get( filePath );

    if ( ! doc )
    {
      return;
    }

    doc.content = content;
    doc.dirty = true;
    this.onDocumentDirty.dispatch( { path: filePath } );
  }

  async openDocumentIn( filePath: string, panelElement: HTMLElement ): Promise<void>
  {
    await this.fileEditorRegistry.load( this.projectId );
    const editorTag = this.fileEditorRegistry.resolve( filePath );

    if ( editorTag === null )
    {
      this.onFileTypeUnknown.dispatch( { path: filePath } );
      return;
    }

    if ( !this.openDocs.has( filePath ) )
    {
      const res = await fetch( `/api/files/${this.projectId}/${filePath}` );
      const content = await res.text();
      this.openDocs.set( filePath, { content, dirty: false } );
    }

    this.activeDoc = filePath;
    const entry = this.openDocs.get( filePath )!;
    this.onDocumentOpened.dispatch( { path: filePath, content: entry.content, editorTag, targetElement: panelElement } );
  }

  async save( filePath: string ): Promise<void>
  {
    const doc = this.openDocs.get( filePath );

    if ( ! doc || ! doc.dirty )
    {
      return;
    }

    await fetch(
      `/api/files/${this.projectId}/${filePath}`,
      {
        method: 'PUT',
        headers: { 'Content-Type': 'text/plain' },
        body: doc.content
      }
    );

    doc.dirty = false;
    this.onDocumentSaved.dispatch( { path: filePath } );
  }
}