import * as plugins from './domtools.plugins.js';
import { type TViewport } from './domtools.css.breakpoints.js';
import { Scroller } from './domtools.classes.scroller.js';
import { WebSetup } from '@push.rocks/websetup';
import { ThemeManager } from './domtools.classes.thememanager.js';
import { Keyboard } from './domtools.classes.keyboard.js';

declare global {
  var deesDomTools: DomTools | undefined;
}

export interface IDomToolsState {
  virtualViewport: TViewport;
  jwt: string;
}

export interface IDomToolsContructorOptions {
  ignoreGlobal?: boolean;
}

export class DomTools {
  // ======
  // STATIC
  // ======
  private static initializationPromise: Promise<DomTools> | null = null;

  /**
   * setups domtools
   */
  public static async setupDomTools(optionsArg: IDomToolsContructorOptions = {}): Promise<DomTools> {
    if (optionsArg.ignoreGlobal) {
      const domToolsInstance = new DomTools(optionsArg);
      await domToolsInstance.initializationPromise;
      return domToolsInstance;
    }

    if (globalThis.deesDomTools && !globalThis.deesDomTools.disposed) {
      await globalThis.deesDomTools.initializationPromise;
      return globalThis.deesDomTools;
    }

    if (!DomTools.initializationPromise) {
      const domToolsInstance = new DomTools(optionsArg);
      globalThis.deesDomTools = domToolsInstance;
      DomTools.initializationPromise = domToolsInstance.initializationPromise
        .then(() => domToolsInstance)
        .catch((error) => {
          if (globalThis.deesDomTools === domToolsInstance) {
            globalThis.deesDomTools = undefined;
          }
          DomTools.initializationPromise = null;
          throw error;
        });
    }

    return await DomTools.initializationPromise;
  }

  /**
   * if you can, use the static asysnc .setupDomTools() function instead since it is safer to use.
   */
  public static getGlobalDomToolsSync(): DomTools {
    const globalDomTools = globalThis.deesDomTools;
    if (!globalDomTools || globalDomTools.disposed) {
      throw new Error('You tried to access domtools synchronously too early');
    }
    return globalDomTools;
  }

  // ========
  // INSTANCE
  // ========
  // elements
  public elements: {
    headElement: HTMLElement | null;
    bodyElement: HTMLElement | null;
  } = {
    headElement: null,
    bodyElement: null,
  };

  public websetup: WebSetup = new WebSetup({
    metaObject: {
      title: '',
    },
  });

  public smartstate = new plugins.smartstate.Smartstate();
  public domToolsStatePart = this.smartstate.getStatePart<IDomToolsState>('domtools', {
    virtualViewport: 'native',
    jwt: '' as string,
  });

  public router = new plugins.smartrouter.SmartRouter({
    debug: false,
  });

  public convenience = {
    typedrequest: plugins.typedrequest,
    smartdelay: plugins.smartdelay,
    smartjson: plugins.smartjson,
    smarturl: plugins.smarturl,
  };

  public deesComms = new plugins.deesComms.DeesComms();
  public scroller = new Scroller(this);
  public themeManager = new ThemeManager(this);
  public keyboard: Keyboard | null = null; // Initialized after DOM ready to avoid accessing document.body before it exists
  public disposed = false;

  public domToolsReady = plugins.smartpromise.defer();
  public domReady = plugins.smartpromise.defer();
  public globalStylesReady = plugins.smartpromise.defer();

  private readonly initializationPromise: Promise<void>;
  private readonly managedDomNodes: Element[] = [];
  private readonly readyStateChangedFunc = () => {
    this.tryMarkDomReady();
  };

  constructor(optionsArg: IDomToolsContructorOptions) {
    this.initializationPromise = this.initialize();
  }

  private runOncePromiseMap = new Map<string, Promise<unknown>>();

  private async initialize() {
    this.tryMarkDomReady();
    if (this.domReady.status === 'pending') {
      document.addEventListener('readystatechange', this.readyStateChangedFunc);
    }
    if (this.domToolsReady.status === 'pending') {
      this.domToolsReady.resolve();
    }
  }

  private tryMarkDomReady() {
    if (this.disposed || this.domReady.status !== 'pending') {
      return;
    }

    if (document.readyState !== 'interactive' && document.readyState !== 'complete') {
      return;
    }

    if (!document.head || !document.body) {
      return;
    }

    this.elements.headElement = document.head;
    this.elements.bodyElement = document.body;
    if (!this.keyboard) {
      this.keyboard = new Keyboard(document.body);
    }
    document.removeEventListener('readystatechange', this.readyStateChangedFunc);
    this.domReady.resolve();
  }

  private trackManagedDomNode<T extends Element>(elementArg: T): T {
    this.managedDomNodes.push(elementArg);
    return elementArg;
  }

  private getHeadOrBodyElement() {
    const targetElement = this.elements.headElement || document.head || this.elements.bodyElement || document.body;
    if (!targetElement) {
      throw new Error('DomTools could not find a DOM target element to attach resources to');
    }
    return targetElement;
  }

  /**
   * run a function once and always get the Promise of the first execution
   * @param identifierArg the indentifier arg identifies functions. functions with the same identifier are considered equal
   * @param funcArg the actual func arg to run
   */
  public async runOnce<T>(identifierArg: string, funcArg: () => Promise<T>) {
    let runOncePromise = this.runOncePromiseMap.get(identifierArg) as Promise<T> | undefined;
    if (!runOncePromise) {
      runOncePromise = Promise.resolve().then(async () => {
        return await funcArg();
      });
      this.runOncePromiseMap.set(identifierArg, runOncePromise);
    }
    return await runOncePromise;
  }

  // setStuff
  /**
   * allows to set global styles
   * @param stylesText the css text you want to set
   */
  public async setGlobalStyles(stylesText: string) {
    await this.domReady.promise;
    const styleElement = this.trackManagedDomNode(document.createElement('style'));
    styleElement.type = 'text/css';
    styleElement.appendChild(document.createTextNode(stylesText));
    this.getHeadOrBodyElement().appendChild(styleElement);
  }

  /**
   * allows to set global styles
   * @param stylesText the css text you want to set
   */
  public async setExternalScript(scriptLinkArg: string) {
    await this.domReady.promise;
    const done = plugins.smartpromise.defer<void>();
    const script = this.trackManagedDomNode(document.createElement('script'));
    script.src = scriptLinkArg;
    script.addEventListener('load', () => {
      done.resolve();
    });
    script.addEventListener('error', () => {
      done.reject(new Error(`Failed to load external script: ${scriptLinkArg}`));
    });
    this.getHeadOrBodyElement().append(script);
    await done.promise;
  }

  /**
   * allows setting external css files
   * @param cssLinkArg a url to an external stylesheet
   */
  public async setExternalCss(cssLinkArg: string) {
    await this.domReady.promise;
    const done = plugins.smartpromise.defer<void>();
    const cssTag = this.trackManagedDomNode(document.createElement('link'));
    cssTag.rel = 'stylesheet';
    cssTag.crossOrigin = 'anonymous';
    cssTag.href = cssLinkArg;
    cssTag.addEventListener('load', () => {
      done.resolve();
    });
    cssTag.addEventListener('error', () => {
      done.reject(new Error(`Failed to load external stylesheet: ${cssLinkArg}`));
    });
    this.getHeadOrBodyElement().append(cssTag);
    await done.promise;
  }

  /**
   * allows setting of website infos
   * @param optionsArg the website info
   */
  public async setWebsiteInfo(optionsArg: plugins.websetup.IWebSetupConstructorOptions) {
    await this.websetup.setup(optionsArg);
    await this.websetup.readyPromise;
  }

  public dispose() {
    if (this.disposed) {
      return;
    }

    this.disposed = true;
    document.removeEventListener('readystatechange', this.readyStateChangedFunc);

    this.keyboard?.dispose();
    this.keyboard = null;
    this.scroller.dispose();
    this.themeManager.dispose();

    for (const managedDomNode of this.managedDomNodes) {
      managedDomNode.remove();
    }
    this.managedDomNodes.length = 0;

    if (globalThis.deesDomTools === this) {
      globalThis.deesDomTools = undefined;
      DomTools.initializationPromise = null;
    }
  }
}