/*-
 * #%L
 * Chat Assistant Add-on
 * %%
 * Copyright (C) 2023 - 2024 Flowing Code
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package com.flowingcode.vaadin.addons.chatassistant;

import com.flowingcode.vaadin.addons.chatassistant.model.Message;
import com.flowingcode.vaadin.addons.markdown.MarkdownViewer;
import com.vaadin.flow.component.Component;
import com.vaadin.flow.component.HasComponents;
import com.vaadin.flow.component.Tag;
import com.vaadin.flow.component.dependency.CssImport;
import com.vaadin.flow.component.dependency.JsModule;
import com.vaadin.flow.component.html.Div;
import java.time.format.DateTimeFormatter;
import lombok.EqualsAndHashCode;

/**
 * Component that wraps the vaadin-message web component and builds it based on a Message.
 *
 * @author mmlopez
 */
@SuppressWarnings("serial")
@JsModule("@vaadin/message-list/src/vaadin-message.js")
@Tag("vaadin-message")
@CssImport("./styles/fc-chat-message-styles.css")
@EqualsAndHashCode(callSuper=false)
public class ChatMessage<T extends Message> extends Component implements HasComponents {
  
  private T message;
  private boolean markdownEnabled;
  private Div loader;
  private MarkdownViewer markdownViewer;
  
  /**
   * Creates a new ChatMessage based on the supplied message without markdown support.
   * 
   * @param message message used to populate the ChatMessage instance
   */
  public ChatMessage(T message) {
    this(message, false);
  }
  
  /**
   * Creates a new ChatMessage based on the supplied message.
   * 
   * @param message message used to populate the ChatMessage instance
   * @param markdownEnabled whether the message supports markdown or not
   */
  public ChatMessage(T message, boolean markdownEnabled) {
    this.markdownEnabled = markdownEnabled;
    loader = new Div(new Div(),new Div(), new Div(), new Div());
    loader.setClassName("lds-ellipsis");
    loader.setVisible(false);
    this.add(loader);
    if (markdownEnabled) {
      markdownViewer = new MarkdownViewer(message.getContent());
      this.add(markdownViewer);
    }
    setMessage(message);
  }

  /**
   * Updates the component by setting the current underlying message.
   * 
   * @param message message used to populate the ChatMessage instance
   */
  public void setMessage(T message) {
    this.message = message;
    updateMessage(message);
    if (message.getName()!=null) {
      this.setUserName(message.getName());
      if (message.getAvatar()!=null) {
        this.setUserImg(message.getAvatar());
      }
    }
    if (message.getMessageTime()!=null) {
      String formattedTime = message.getMessageTime().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
      this.setTime(formattedTime);
    }
  }

  /**
   * Updates the displayed message content and loading state.
   * @param message
   */
  private void updateMessage(T message) {
    loader.setVisible(message.isLoading());
    if (!message.isLoading()) {
      if (markdownEnabled) {
        markdownViewer.setContent(message.getContent());
      } else {
        this.getElement().executeJs("[...this.childNodes].forEach(node => node.nodeType === 3 && this.removeChild(node));");
        this.getElement().executeJs("this.appendChild(document.createTextNode($0));", message.getContent());
      }
    }
  }
  
  /**
   * Returns the underlying message.
   * 
   * @return the message object used to populate this ChatMessage
   */
  public T getMessage() {
    return message;
  }
  
  private void setUserName(String username) {
    getElement().setAttribute("user-name", username);
  }
  
  private void setUserImg(String imageUrl) {
    getElement().setAttribute("user-img", imageUrl);
  }
  
  private void setTime(String time) {
    getElement().setAttribute("time", time);
  }
  
}