/**
 * This implementation of components replaces the old components of rivets following the Web Components v1 specs
 *
 * @see https://developer.mozilla.org/de/docs/Web/Web_Components/Using_custom_elements
 */
import { View } from "../view.js";
import { Riba } from "../riba.js";
import { Binder } from "../binder.js";
import { BasicComponent } from "./basic-component.js";
import { Formatter } from "../types/index.js";
import { EventDispatcher } from "@ribajs/events";
import type {
  ComponentLifecycleEventData,
  ComponentLifecycleOptions,
} from "../types/index.js";

export abstract class Component extends BasicComponent {
  protected view?: View | null = null;
  protected riba?: Riba;
  /** true when binding is in progress */
  protected _binds = false;
  /** true when binding is done */
  protected _bound = false;
  /** true when bindIfReady is in progress (prevents concurrent execution) */
  private _bindIfReadyInProgress = false;
  /** true when component is connected to the dom */
  protected _connected = false;
  /** true when component is disconnected from the dom */
  protected _disconnected = false;
  protected lifecycleEvents = EventDispatcher.getInstance("lifecycle");

  protected lifecycleOptions: ComponentLifecycleOptions = {};

  /** true when binding is in progress */
  public get binds() {
    return this._binds;
  }

  /** true when binding is done */
  public get bound() {
    return this._bound;
  }

  /** true when component is connected to the dom */
  public get connected() {
    return this._connected;
  }

  /** true when component is disconnected from the dom */
  public get disconnected() {
    return this._disconnected;
  }

  /**
   * If true the component will automatically bind the component to riba if all required attributes are set.
   */
  protected autobind = true;

  constructor() {
    super();
    this.lifecycleEvents.trigger(
      "Component:constructor",
      this.getLifecycleEventData(),
    );
    this.lifecycleEvents.on(
      "ComponentLifecycle:allBound",
      this.afterAllBind,
      this,
    );
  }

  protected async init(observedAttributes: string[]) {
    try {
      await super.init(observedAttributes);
      this.lifecycleEvents.trigger(
        "Component:init",
        this.getLifecycleEventData(),
      );
      return await this.bindIfReady();
    } catch (error) {
      this.throw(error as Error);
    }
  }

  /**
   * Use this to throw critical errors within the component
   *
   * @protected
   * @param {Error} error
   * @memberof Component
   */
  protected throw(error: any) {
    if (error.message) {
      console.error(`[${this.tagName}] ${error.message}`);
    }
    this.lifecycleEvents.trigger(
      "Component:error",
      error,
      this.getLifecycleEventData(),
    );
    this.error(error);
  }

  /**
   * If `autobind` is true this component will bind riba automatically in this component if all all passed observed and required attributes are initialized
   */
  protected async bindIfReady() {
    /**
     * Prevent concurrent execution. During element upgrade, attributeChangedCallback
     * fires multiple times before connectedCallback. Without this guard, a second call
     * can skip loadTemplate (templateLoaded is set synchronously) and reach bind/afterBind
     * before the async template import has completed and set innerHTML.
     */
    if (this._bindIfReadyInProgress || this._binds || this._bound) {
      return;
    }
    /**
     * After all required and passed attributes are set we load the template and bind the component
     */
    if (this.ready()) {
      this._bindIfReadyInProgress = true;
      try {
        await this.beforeTemplate();
        const template = await this.loadTemplate();
        await this.afterTemplate(template);
        if (this.autobind) {
          await this.bind();
        }
        await this.onReady();
      } catch (error) {
        this._bindIfReadyInProgress = false;
        throw error;
      }
      return;
    }
    this.debug(
      `Not all required or passed attributes are set to load and bind the template`,
      this.observedAttributesToCheck,
      this.scope,
    );
    return;
  }

  /** Only internal used */
  private async _beforeBind(): Promise<any> {
    this._binds = true;
    this.debug("Start to bind Riba");
    this.lifecycleEvents.trigger(
      "Component:beforeBind",
      this.getLifecycleEventData(),
    );
  }

  /** Used to handle stuff before binding starts */
  protected async beforeBind(): Promise<any> {
    // this.debug("beforeBind", this.scope);
  }

  /** Only internal used */
  private async _afterBind(): Promise<any> {
    this._binds = false;
    this._bound = true;
    this.lifecycleEvents.trigger(
      "Component:afterBind",
      this.getLifecycleEventData(),
    );
  }

  /** Used to handle stuff after binding is done */
  protected async afterBind(): Promise<any> {
    // this.debug("afterBind", this.scope);
  }

  /**
   * Called after component binding is done for all current components.
   * Please note: this method is called every time a route changes, so be careful with this method.
   */
  protected async afterAllBind(): Promise<any> {
    // this.debug("afterBind", this.scope);
  }

  protected getLifecycleEventData() {
    const data: ComponentLifecycleEventData = {
      tagName: this.tagName.toLowerCase(),
      // scope: this.scope,
      component: this,
      // id: this.id,
      options: this.lifecycleOptions,
    };
    return data;
  }

  /**
   * Event handler to listen for publish binder event for two-way-binding in web components
   */
  // protected publish(name: string, newValue: any, namespace: string | null) {
  //   this.dispatchEvent(
  //     new CustomEvent("publish-binder-change:" + name, {
  //       detail: {
  //         name,
  //         newValue,
  //         namespace: null, // TODO
  //       },
  //     })
  //   );
  // }

  /**
   * Default custom Element method
   * Invoked when the custom element is disconnected from the document's DOM.
   */
  protected disconnectedCallback() {
    try {
      this._disconnected = true;
      this._connected = false;
      super.disconnectedCallback();
      // IMPORTANT ROUTE FIXME, if we unbind the component then it will no longer work if it is retrieved from the cache and the connectedCallback is called
      // because the riba attributes are removed. We need a solution for that, maybe we do not remove the attributes or we recreate the attributes
      // See view bind / unbind methods for that.
      // only unbind if cache is not enabled?
      // if (this._binds && this.view) {
      //   this.unbind();
      // }
      this.lifecycleEvents.trigger(
        "Component:disconnected",
        this.getLifecycleEventData(),
      );
      this.lifecycleEvents.off(
        "ComponentLifecycle:allBound",
        this.afterAllBind,
        this,
      );
      this.lifecycleEvents.off(
        "ComponentLifecycle:error",
        this.afterAllBind,
        this,
      );
    } catch (error) {
      this.throw(error as Error);
    }
  }

  /**
   * Default custom Element method
   * Invoked when the custom element is first connected to the document's DOM.
   */
  protected connectedCallback() {
    try {
      this._disconnected = false;
      this._connected = true;
      super.connectedCallback();
      this.lifecycleEvents.trigger(
        "Component:connected",
        this.getLifecycleEventData(),
      );
    } catch (error) {
      this.throw(error as Error);
    }
  }

  /**
   * Default custom Element method
   * Invoked when one of the custom element's attributes is added, removed, or changed.
   * @param attributeName
   * @param oldValue
   * @param newValue
   * @param namespace
   */
  protected async attributeChangedCallback(
    attributeName: string,
    oldValue: any,
    newValue: any,
    namespace: string | null,
  ) {
    try {
      super.attributeChangedCallback(
        attributeName,
        oldValue,
        newValue,
        namespace,
      );
      await this.bindIfReady();
    } catch (error) {
      this.throw(error as Error);
    }
  }

  /**
   * Extra call formatter to avoid the "this" context problem
   */
  protected callFormatterHandler(self: this): any {
    return {
      name: "call",
      read: (fn: (...args: any[]) => any, ...args: any[]) => {
        if (!fn) {
          throw new Error(
            `[${self.tagName}] Can not use "call" formatter: fn is undefined!`,
          );
        }
        return fn.apply(self, args);
      },
    };
  }

  /**
   * Extra args formatter to avoid the "this" context problem
   *
   * Sets arguments to a function without directly call them
   * @param fn The function you wish to call
   * @param args the parameters you wish to call the function with
   */
  protected argsFormatterHandler(self: this): Formatter {
    return {
      name: "args",
      read: (fn: (...args: any[]) => any, ...fnArgs: any[]) => {
        return (event: Event, scope: any, el: HTMLElement, binding: Binder) => {
          if (!fn) {
            throw new Error(
              `[${self.tagName}] Can not use "args" formatter: fn is undefined!`,
            );
          }

          // append the event handler args to passed args
          fnArgs.push(event);
          fnArgs.push(scope);
          fnArgs.push(el);
          fnArgs.push(binding);
          return fn.apply(self, fnArgs);
        };
      },
    };
  }

  protected async bind() {
    if (this.binds || this.bound) {
      // this.debug("component already bound");
      return this.view;
    }

    if (!this.checkRequiredAttributes()) {
      this.debug("Not all required attributes are set for bind");
      return;
    }

    try {
      await this._beforeBind();
      await this.beforeBind();

      this.riba = new Riba();
      this.view = this.getView();
      if (this.view) {
        this.scope = this.view.models;
        this.view.bind();
      }

      await this._afterBind();
      await this.afterBind();
    } catch (error) {
      this._binds = false;
      this._bound = false;
      this.throw(error as Error);
    }

    return this.view;
  }

  protected getView() {
    try {
      const viewOptions = this.riba?.getViewOptions({
        handler: this.eventHandler(this),
        formatters: {
          call: this.callFormatterHandler(this),
          args: this.argsFormatterHandler(this),
        },
      });

      if (viewOptions) {
        const view = new View(
          Array.prototype.slice.call(this.childNodes),
          this.scope,
          viewOptions,
        );
        return view;
      }
      return null;
    } catch (error) {
      this.throw(error as Error);
    }
  }

  public async unbind() {
    try {
      if (this.view) {
        this._binds = false;
        this._bound = false;
        this.view.unbind();
        this.view = null;
      }
    } catch (error) {
      this.throw(error as Error);
    }
  }

  protected async build() {
    try {
      if (this.view) {
        this.view.build();
      }
    } catch (error) {
      this.throw(error as Error);
    }
  }
}