import {
  Directive,
  HostListener,
  InjectionToken,
  Inject,
  Optional,
  input,
  computed,
} from "@angular/core";

import { I18nService } from "@bitwarden/common/platform/abstractions/i18n.service";
import { PlatformUtilsService } from "@bitwarden/common/platform/abstractions/platform-utils.service";

import { ToastService, ToastVariant } from "../";

/**
 * Listener that can be provided to receive copy events to allow for customized behavior.
 */
export interface CopyClickListener {
  onCopy(value: string): void;
}

export const COPY_CLICK_LISTENER = new InjectionToken<CopyClickListener>("CopyClickListener");

@Directive({
  selector: "[appCopyClick]",
})
export class CopyClickDirective {
  private readonly _showToast = computed(() => {
    return this.showToast() !== undefined;
  });

  private readonly toastVariant = computed(() => {
    const showToast = this.showToast();
    // When the `showToast` is set without a value, an empty string will be passed
    if (showToast === "" || showToast === undefined) {
      return "success";
    } else {
      return showToast;
    }
  });

  constructor(
    private platformUtilsService: PlatformUtilsService,
    private toastService: ToastService,
    private i18nService: I18nService,
    @Optional() @Inject(COPY_CLICK_LISTENER) private copyListener?: CopyClickListener,
  ) {}

  readonly valueToCopy = input("", { alias: "appCopyClick" });

  /**
   * When set, the toast displayed will show `<valueLabel> copied`
   * instead of the default messaging.
   */
  readonly valueLabel = input<string>();

  /**
   * When set without a value, a success toast will be shown when the value is copied
   * @example
   * ```html
   *  <app-component [appCopyClick]="value to copy" showToast/></app-component>
   * ```
   * When set with a value, a toast with the specified variant will be shown when the value is copied
   *
   * @example
   * ```html
   *  <app-component [appCopyClick]="value to copy" showToast="info"/></app-component>
   * ```
   */
  readonly showToast = input<ToastVariant | "">();

  @HostListener("click") onClick() {
    const valueToCopy = this.valueToCopy();
    this.platformUtilsService.copyToClipboard(valueToCopy);

    if (this.copyListener) {
      this.copyListener.onCopy(valueToCopy);
    }

    if (this._showToast()) {
      const valueLabel = this.valueLabel();
      const message = valueLabel
        ? this.i18nService.t("valueCopied", valueLabel)
        : this.i18nService.t("copySuccessful");

      this.toastService.showToast({
        variant: this.toastVariant(),
        message,
      });
    }
  }
}