import { Injectable, ComponentRef, createComponent, ApplicationRef, Injector } from '@angular/core';
import { ToastComponent } from '../components/toast/toast.component';
import { ToastType, ToastOptions } from '../models/toast.types';

@Injectable({
  providedIn: 'root'
})
export class ToastService {
  private toasts: ComponentRef<ToastComponent>[] = [];
  private container: HTMLElement | null = null;

  constructor(
    private appRef: ApplicationRef,
    private injector: Injector
  ) {}

  private ensureContainer() {
    if (!this.container) {
      this.container = document.createElement('div');
      this.container.className = 'toast-container';
      // 添加一些内联样式
      this.container.style.position = 'fixed';
      this.container.style.top = '20px';
      this.container.style.right = '20px';
      this.container.style.zIndex = '9999';
      this.container.style.display = 'flex';
      this.container.style.flexDirection = 'column';
      this.container.style.alignItems = 'flex-end';
      document.body.appendChild(this.container);
    }
  }

  show(message: string, options?: ToastOptions) {
    this.ensureContainer();
    
    const type = options?.type || 'info';
    const duration = options?.duration || 3000;

    const toastRef = createComponent(ToastComponent, {
      environmentInjector: this.appRef.injector,
      elementInjector: this.injector
    });

    // 设置输入属性（类型安全）
    toastRef.instance.message = message;
    toastRef.instance.type = type;

    // 添加到DOM
    this.container?.appendChild(toastRef.location.nativeElement);
    this.appRef.attachView(toastRef.hostView);

    // 存储引用
    this.toasts.push(toastRef);

    // 自动移除
    setTimeout(() => {
      this.removeToast(toastRef);
    }, duration);

    return toastRef;
  }

  success(message: string, options?: Omit<ToastOptions, 'type'>) {
    return this.show(message, { ...options, type: 'success' });
  }

  error(message: string, options?: Omit<ToastOptions, 'type'>) {
    return this.show(message, { ...options, type: 'error' });
  }

  info(message: string, options?: Omit<ToastOptions, 'type'>) {
    return this.show(message, { ...options, type: 'info' });
  }

  warning(message: string, options?: Omit<ToastOptions, 'type'>) {
    return this.show(message, { ...options, type: 'warning' });
  }

  private removeToast(toastRef: ComponentRef<ToastComponent>) {
    const index = this.toasts.indexOf(toastRef);
    if (index > -1) {
      this.toasts.splice(index, 1);
      this.appRef.detachView(toastRef.hostView);
      toastRef.destroy();
    }
  }

  clearAll() {
    this.toasts.forEach(toastRef => {
      this.appRef.detachView(toastRef.hostView);
      toastRef.destroy();
    });
    this.toasts = [];
  }
}