/*
 * Copyright (c) 2012-2017 Red Hat, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Red Hat, Inc. - initial API and implementation
 */
package org.eclipse.che.plugin.docker.client;

import org.eclipse.che.plugin.docker.client.json.ProgressStatus;

/**
 * Beatify {@link ProgressStatus} messages.
 *
 * @author Alexander Garagatyi
 */
public class ProgressLineFormatterImpl implements MessageFormatter<ProgressStatus> {
  @Override
  public String format(ProgressStatus progressStatus) {
    final StringBuilder sb = new StringBuilder();
    sb.append("[DOCKER] ");
    final String stream = progressStatus.getStream();
    final String status = progressStatus.getStatus();
    final String error = progressStatus.getError();
    if (error != null) {
      sb.append("[ERROR] ");
      sb.append(error);
    } else if (stream != null) {
      sb.append(stream.trim());
    } else if (status != null) {
      final String id = progressStatus.getId();
      if (id != null) {
        sb.append(id);
        sb.append(':');
        sb.append(' ');
      }
      sb.append(status);
      sb.append(' ');
      sb.append(parseProgressText(progressStatus));
    }
    return sb.toString();
  }

  /**
   * Parses text data from progress string. Typical progress string from docker API: {@code
   * [==================================&gt; ] 9.13 MB/13.38 MB 19s} This method gets text part from
   * progress string, e.g. {@code 9.13 MB/13.38 MB 19s}
   *
   * @return text data from progress string or empty string if progress string is {@code null} or
   *     doesn't contains text date
   */
  protected String parseProgressText(ProgressStatus progressStatus) {
    // "
    final String rawProgress = progressStatus.getProgress();
    if (rawProgress == null) {
      return "";
    }
    // skip progress indicator: ==================================>                ]
    final int l = rawProgress.length();
    int n = 0;
    while (n < l && rawProgress.charAt(n) != '[') {
      n++;
    }
    int p = n;
    while (p < l && rawProgress.charAt(p) != ']') {
      p++;
    }
    if (p == n) {
      // unexpected string
      return "";
    }
    ++p;
    while (p < l && Character.isWhitespace(rawProgress.charAt(p))) {
      p++;
    }
    if (p == l) {
      // unexpected string
      return "";
    }
    return rawProgress.substring(p);
  }
}
