package com.box.sdk;

import com.eclipsesource.json.Json;
import com.eclipsesource.json.JsonObject;
import com.eclipsesource.json.JsonValue;
import java.net.URL;
import java.util.Date;
import java.util.regex.Pattern;

/**
 * Represents a comment on a file. Comments can be added directly to a file or they can be created
 * as replies to other comments.
 *
 * <p>Unless otherwise noted, the methods in this class can throw an unchecked {@link
 * BoxAPIException} (unchecked meaning that the compiler won't force you to handle it) if an error
 * occurs. If you wish to implement custom error handling for errors related to the Box REST API,
 * you should capture this exception explicitly.
 */
@BoxResourceType("comment")
public class BoxComment extends BoxResource {

  /** Add Comment URL Template. */
  public static final URLTemplate ADD_COMMENT_URL_TEMPLATE = new URLTemplate("comments");
  /** Comment URL Template. */
  public static final URLTemplate COMMENT_URL_TEMPLATE = new URLTemplate("comments/%s");

  private static final Pattern MENTION_REGEX = Pattern.compile("@\\[.+:.+\\]");

  /**
   * Constructs a BoxComment for a comment with a given ID.
   *
   * @param api the API connection to be used with the comment.
   * @param id the ID of the comment.
   */
  public BoxComment(BoxAPIConnection api, String id) {
    super(api, id);
  }

  /**
   * Determines if a comment message contains an @mention.
   *
   * @param message the comment message.
   * @return true if the message contains an @mention; otherwise false.
   */
  static boolean messageContainsMention(String message) {
    return MENTION_REGEX.matcher(message).find();
  }

  /**
   * Gets information about this comment.
   *
   * @return info about this comment.
   */
  public Info getInfo() {
    URL url = COMMENT_URL_TEMPLATE.build(this.getAPI().getBaseURL(), this.getID());
    BoxJSONRequest request = new BoxJSONRequest(this.getAPI(), url, "GET");
    try (BoxJSONResponse response = request.send()) {
      JsonObject jsonResponse = Json.parse(response.getJSON()).asObject();

      return new Info(jsonResponse);
    }
  }

  /**
   * Changes the message of this comment.
   *
   * @param newMessage the new message for this comment.
   * @return updated info about this comment.
   */
  public Info changeMessage(String newMessage) {
    Info newInfo = new Info();
    newInfo.setMessage(newMessage);

    URL url = COMMENT_URL_TEMPLATE.build(this.getAPI().getBaseURL(), this.getID());
    BoxJSONRequest request = new BoxJSONRequest(this.getAPI(), url, "PUT");
    request.setBody(newInfo.getPendingChanges());
    try (BoxJSONResponse response = request.send()) {
      JsonObject jsonResponse = Json.parse(response.getJSON()).asObject();

      return new Info(jsonResponse);
    }
  }

  /**
   * Replies to this comment with another message.
   *
   * @param message the message for the reply.
   * @return info about the newly created reply comment.
   */
  public BoxComment.Info reply(String message) {
    JsonObject itemJSON = new JsonObject();
    itemJSON.add("type", "comment");
    itemJSON.add("id", this.getID());

    JsonObject requestJSON = new JsonObject();
    requestJSON.add("item", itemJSON);
    if (BoxComment.messageContainsMention(message)) {
      requestJSON.add("tagged_message", message);
    } else {
      requestJSON.add("message", message);
    }

    URL url = ADD_COMMENT_URL_TEMPLATE.build(this.getAPI().getBaseURL());
    BoxJSONRequest request = new BoxJSONRequest(this.getAPI(), url, "POST");
    request.setBody(requestJSON.toString());
    try (BoxJSONResponse response = request.send()) {
      JsonObject responseJSON = Json.parse(response.getJSON()).asObject();

      BoxComment addedComment = new BoxComment(this.getAPI(), responseJSON.get("id").asString());
      return addedComment.new Info(responseJSON);
    }
  }

  /** Deletes this comment. */
  public void delete() {
    URL url = COMMENT_URL_TEMPLATE.build(this.getAPI().getBaseURL(), this.getID());
    BoxAPIRequest request = new BoxAPIRequest(this.getAPI(), url, "DELETE");
    request.send().close();
  }

  /** Contains information about a BoxComment. */
  public class Info extends BoxResource.Info {
    private boolean isReplyComment;
    private String message;
    private String taggedMessage;
    private BoxUser.Info createdBy;
    private Date createdAt;
    private BoxResource.Info item;
    private BoxUser.Info modifiedBy;
    private Date modifiedAt;

    /** Constructs an empty Info object. */
    public Info() {
      super();
    }

    /**
     * Constructs an Info object by parsing information from a JSON string.
     *
     * @param json the JSON string to parse.
     */
    public Info(String json) {
      super(json);
    }

    /**
     * Constructs an Info object using an already parsed JSON object.
     *
     * @param jsonObject the parsed JSON object.
     */
    Info(JsonObject jsonObject) {
      super(jsonObject);
    }

    /**
     * Gets whether or not the comment is a reply to another comment.
     *
     * @return true if this comment is a reply to another comment; otherwise false.
     */
    public boolean getIsReplyComment() {
      return this.isReplyComment;
    }

    /**
     * Gets the comment's message.
     *
     * @return the comment's message.
     */
    public String getMessage() {
      if (this.taggedMessage != null) {
        return this.taggedMessage;
      }

      return this.message;
    }

    /**
     * Sets the comment's message. The message can contain @mentions by using the
     * string @[userid:username] anywhere within the message, where userid and username are the ID
     * and username of the person being mentioned.
     *
     * @param message the comment's new message.
     */
    public void setMessage(String message) {
      if (messageContainsMention(message)) {
        this.taggedMessage = message;
        this.addPendingChange("tagged_message", message);
        this.removePendingChange("message");
      } else {
        this.message = message;
        this.addPendingChange("message", message);
        this.removePendingChange("tagged_message");
      }
    }

    /**
     * Gets info about the user who created the comment.
     *
     * @return info about the user who created the comment.
     */
    public BoxUser.Info getCreatedBy() {
      return this.createdBy;
    }

    /**
     * Gets the time the comment was created.
     *
     * @return the time the comment was created.
     */
    public Date getCreatedAt() {
      return this.createdAt;
    }

    /**
     * Gets info about the item this comment is attached to. If the comment is a reply, then the
     * item will be another BoxComment. Otherwise, the item will be a {@link BoxFile}.
     *
     * @return the item this comment is attached to.
     */
    public BoxResource.Info getItem() {
      return this.item;
    }

    /**
     * Gets info about the user who last modified the comment.
     *
     * @return info about the user who last modified the comment.
     */
    public BoxUser.Info getModifiedBy() {
      return this.modifiedBy;
    }

    /**
     * Gets the time the comment was last modified.
     *
     * @return the time the comment was last modified.
     */
    public Date getModifiedAt() {
      return this.modifiedAt;
    }

    @Override
    public BoxComment getResource() {
      return BoxComment.this;
    }

    @Override
    protected void parseJSONMember(JsonObject.Member member) {
      super.parseJSONMember(member);
      String memberName = member.getName();
      JsonValue value = member.getValue();

      try {

        if (memberName.equals("is_reply_comment")) {
          this.isReplyComment = value.asBoolean();

        } else if (memberName.equals("message")) {
          this.message = value.asString();

        } else if (memberName.equals("tagged_message")) {
          this.taggedMessage = value.asString();

        } else if (memberName.equals("created_by")) {
          JsonObject userJSON = value.asObject();
          if (this.createdBy == null) {
            String userID = userJSON.get("id").asString();
            BoxUser user = new BoxUser(getAPI(), userID);
            this.createdBy = user.new Info(userJSON);
          } else {
            this.createdBy.update(userJSON);
          }

        } else if (memberName.equals("created_at")) {
          this.createdAt = BoxDateFormat.parse(value.asString());

        } else if (memberName.equals("item")) {
          this.parseItem(value);

        } else if (memberName.equals("modified_by")) {
          JsonObject userJSON = value.asObject();
          if (this.modifiedBy == null) {
            String userID = userJSON.get("id").asString();
            BoxUser user = new BoxUser(getAPI(), userID);
            this.modifiedBy = user.new Info(userJSON);
          } else {
            this.modifiedBy.update(userJSON);
          }
        } else if (memberName.equals("modified_at")) {
          this.modifiedAt = BoxDateFormat.parse(value.asString());
        }
      } catch (Exception e) {
        throw new BoxDeserializationException(memberName, value.toString(), e);
      }
    }

    private void parseItem(JsonValue value) {
      JsonObject itemJSON = value.asObject();
      String itemType = itemJSON.get("type").asString();
      if (itemType.equals("file")) {
        this.updateItemAsFile(itemJSON);
      } else if (itemType.equals("comment")) {
        this.updateItemAsComment(itemJSON);
      }
    }

    private void updateItemAsFile(JsonObject itemJSON) {
      String itemID = itemJSON.get("id").asString();
      if (this.item != null
          && this.item instanceof BoxFile.Info
          && this.item.getID().equals(itemID)) {
        this.item.update(itemJSON);
      } else {
        BoxFile file = new BoxFile(getAPI(), itemID);
        this.item = file.new Info(itemJSON);
      }
    }

    private void updateItemAsComment(JsonObject itemJSON) {
      String itemID = itemJSON.get("id").asString();
      if (this.item != null
          && this.item instanceof BoxComment.Info
          && this.item.getID().equals(itemID)) {
        this.item.update(itemJSON);
      } else {
        BoxComment comment = new BoxComment(getAPI(), itemID);
        this.item = comment.new Info(itemJSON);
      }
    }
  }
}