/*
    * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
    * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
    * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
   * SPDX-License-Identifier: BSD-3-Clause
   */
  
  package org.eclipse.jgit.lib;
  
  import java.io.Serializable;
  import java.text.SimpleDateFormat;
  import java.time.Instant;
  import java.time.ZoneId;
  import java.util.Date;
  import java.util.Locale;
  import java.util.TimeZone;
  
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.util.SystemReader;
  import org.eclipse.jgit.util.time.ProposedTimestamp;
  
  /**
   * A combination of a person identity and time in Git.
   *
   * Git combines Name + email + time + time zone to specify who wrote or
   * committed something.
   */
  public class PersonIdent implements Serializable {
  	private static final long serialVersionUID = 1L;
  
  	/**
  	 * Get timezone object for the given offset.
  	 *
  	 * @param tzOffset
  	 *            timezone offset as in {@link #getTimeZoneOffset()}.
  	 * @return time zone object for the given offset.
  	 * @since 4.1
  	 */
  	public static TimeZone getTimeZone(int tzOffset) {
  		StringBuilder tzId = new StringBuilder(8);
  		tzId.append("GMT"); //$NON-NLS-1$
  		appendTimezone(tzId, tzOffset);
  		return TimeZone.getTimeZone(tzId.toString());
  	}
  
  	/**
  	 * Format a timezone offset.
  	 *
  	 * @param r
  	 *            string builder to append to.
  	 * @param offset
  	 *            timezone offset as in {@link #getTimeZoneOffset()}.
  	 * @since 4.1
  	 */
  	public static void appendTimezone(StringBuilder r, int offset) {
  		final char sign;
  		final int offsetHours;
  		final int offsetMins;
  
  		if (offset < 0) {
  			sign = '-';
  			offset = -offset;
  		} else {
  			sign = '+';
  		}
  
  		offsetHours = offset / 60;
  		offsetMins = offset % 60;
  
  		r.append(sign);
  		if (offsetHours < 10) {
  			r.append('0');
  		}
  		r.append(offsetHours);
  		if (offsetMins < 10) {
  			r.append('0');
  		}
  		r.append(offsetMins);
  	}
  
  	/**
  	 * Sanitize the given string for use in an identity and append to output.
  	 * <p>
  	 * Trims whitespace from both ends and special characters {@code \n < >} that
  	 * interfere with parsing; appends all other characters to the output.
  	 * Analogous to the C git function {@code strbuf_addstr_without_crud}.
  	 *
  	 * @param r
  	 *            string builder to append to.
  	 * @param str
  	 *            input string.
  	 * @since 4.4
  	 */
  	public static void appendSanitized(StringBuilder r, String str) {
 		// Trim any whitespace less than \u0020 as in String#trim().
 		int i = 0;
 		while (i < str.length() && str.charAt(i) <= ' ') {
 			i++;
 		}
 		int end = str.length();
 		while (end > i && str.charAt(end - 1) <= ' ') {
 			end--;
 		}
 
 		for (; i < end; i++) {
 			char c = str.charAt(i);
 			switch (c) {
 				case '\n':
 				case '<':
 				case '>':
 					continue;
 				default:
 					r.append(c);
 					break;
 			}
 		}
 	}
 
 	private final String name;
 
 	private final String emailAddress;
 
 	private final long when;
 
 	private final int tzOffset;
 
 	/**
 	 * Creates new PersonIdent from config info in repository, with current time.
 	 * This new PersonIdent gets the info from the default committer as available
 	 * from the configuration.
 	 *
 	 * @param repo a {@link org.eclipse.jgit.lib.Repository} object.
 	 */
 	public PersonIdent(Repository repo) {
 		this(repo.getConfig().get(UserConfig.KEY));
 	}
 
 	/**
 	 * Copy a {@link org.eclipse.jgit.lib.PersonIdent}.
 	 *
 	 * @param pi
 	 *            Original {@link org.eclipse.jgit.lib.PersonIdent}
 	 */
 	public PersonIdent(PersonIdent pi) {
 		this(pi.getName(), pi.getEmailAddress());
 	}
 
 	/**
 	 * Construct a new {@link org.eclipse.jgit.lib.PersonIdent} with current
 	 * time.
 	 *
 	 * @param aName
 	 *            a {@link java.lang.String} object.
 	 * @param aEmailAddress
 	 *            a {@link java.lang.String} object.
 	 */
 	public PersonIdent(String aName, String aEmailAddress) {
 		this(aName, aEmailAddress, SystemReader.getInstance().getCurrentTime());
 	}
 
 	/**
 	 * Construct a new {@link org.eclipse.jgit.lib.PersonIdent} with current
 	 * time.
 	 *
 	 * @param aName
 	 *            a {@link java.lang.String} object.
 	 * @param aEmailAddress
 	 *            a {@link java.lang.String} object.
 	 * @param when
 	 *            a {@link org.eclipse.jgit.util.time.ProposedTimestamp} object.
 	 * @since 4.6
 	 */
 	public PersonIdent(String aName, String aEmailAddress,
 			ProposedTimestamp when) {
 		this(aName, aEmailAddress, when.millis());
 	}
 
 	/**
 	 * Copy a PersonIdent, but alter the clone's time stamp
 	 *
 	 * @param pi
 	 *            original {@link org.eclipse.jgit.lib.PersonIdent}
 	 * @param when
 	 *            local time
 	 * @param tz
 	 *            time zone
 	 */
 	public PersonIdent(PersonIdent pi, Date when, TimeZone tz) {
 		this(pi.getName(), pi.getEmailAddress(), when, tz);
 	}
 
 	/**
 	 * Copy a {@link org.eclipse.jgit.lib.PersonIdent}, but alter the clone's
 	 * time stamp
 	 *
 	 * @param pi
 	 *            original {@link org.eclipse.jgit.lib.PersonIdent}
 	 * @param aWhen
 	 *            local time
 	 */
 	public PersonIdent(PersonIdent pi, Date aWhen) {
 		this(pi.getName(), pi.getEmailAddress(), aWhen.getTime(), pi.tzOffset);
 	}
 
 	/**
 	 * Copy a {@link org.eclipse.jgit.lib.PersonIdent}, but alter the clone's
 	 * time stamp
 	 *
 	 * @param pi
 	 *            original {@link org.eclipse.jgit.lib.PersonIdent}
 	 * @param aWhen
 	 *            local time as Instant
 	 * @since 6.1
 	 */
 	public PersonIdent(PersonIdent pi, Instant aWhen) {
 		this(pi.getName(), pi.getEmailAddress(), aWhen.toEpochMilli(), pi.tzOffset);
 	}
 
 	/**
 	 * Construct a PersonIdent from simple data
 	 *
 	 * @param aName a {@link java.lang.String} object.
 	 * @param aEmailAddress a {@link java.lang.String} object.
 	 * @param aWhen
 	 *            local time stamp
 	 * @param aTZ
 	 *            time zone
 	 */
 	public PersonIdent(final String aName, final String aEmailAddress,
 			final Date aWhen, final TimeZone aTZ) {
 		this(aName, aEmailAddress, aWhen.getTime(), aTZ.getOffset(aWhen
 				.getTime()) / (60 * 1000));
 	}
 
 	/**
 	 * Construct a PersonIdent from simple data
 	 *
 	 * @param aName
 	 *            a {@link java.lang.String} object.
 	 * @param aEmailAddress
 	 *            a {@link java.lang.String} object.
 	 * @param aWhen
 	 *            local time stamp
 	 * @param zoneId
 	 *            time zone id
 	 * @since 6.1
 	 */
 	public PersonIdent(final String aName, String aEmailAddress, Instant aWhen,
 			ZoneId zoneId) {
 		this(aName, aEmailAddress, aWhen.toEpochMilli(),
 				TimeZone.getTimeZone(zoneId)
 						.getOffset(aWhen
 				.toEpochMilli()) / (60 * 1000));
 	}
 
 	/**
 	 * Copy a PersonIdent, but alter the clone's time stamp
 	 *
 	 * @param pi
 	 *            original {@link org.eclipse.jgit.lib.PersonIdent}
 	 * @param aWhen
 	 *            local time stamp
 	 * @param aTZ
 	 *            time zone
 	 */
 	public PersonIdent(PersonIdent pi, long aWhen, int aTZ) {
 		this(pi.getName(), pi.getEmailAddress(), aWhen, aTZ);
 	}
 
 	private PersonIdent(final String aName, final String aEmailAddress,
 			long when) {
 		this(aName, aEmailAddress, when, SystemReader.getInstance()
 				.getTimezone(when));
 	}
 
 	private PersonIdent(UserConfig config) {
 		this(config.getCommitterName(), config.getCommitterEmail());
 	}
 
 	/**
 	 * Construct a {@link org.eclipse.jgit.lib.PersonIdent}.
 	 * <p>
 	 * Whitespace in the name and email is preserved for the lifetime of this
 	 * object, but are trimmed by {@link #toExternalString()}. This means that
 	 * parsing the result of {@link #toExternalString()} may not return an
 	 * equivalent instance.
 	 *
 	 * @param aName
 	 *            a {@link java.lang.String} object.
 	 * @param aEmailAddress
 	 *            a {@link java.lang.String} object.
 	 * @param aWhen
 	 *            local time stamp
 	 * @param aTZ
 	 *            time zone
 	 */
 	public PersonIdent(final String aName, final String aEmailAddress,
 			final long aWhen, final int aTZ) {
 		if (aName == null)
 			throw new IllegalArgumentException(
 					JGitText.get().personIdentNameNonNull);
 		if (aEmailAddress == null)
 			throw new IllegalArgumentException(
 					JGitText.get().personIdentEmailNonNull);
 		name = aName;
 		emailAddress = aEmailAddress;
 		when = aWhen;
 		tzOffset = aTZ;
 	}
 
 	/**
 	 * Get name of person
 	 *
 	 * @return Name of person
 	 */
 	public String getName() {
 		return name;
 	}
 
 	/**
 	 * Get email address of person
 	 *
 	 * @return email address of person
 	 */
 	public String getEmailAddress() {
 		return emailAddress;
 	}
 
 	/**
 	 * Get timestamp
 	 *
 	 * @return timestamp
 	 */
 	public Date getWhen() {
 		return new Date(when);
 	}
 
 	/**
 	 * Get when attribute as instant
 	 *
 	 * @return timestamp
 	 * @since 6.1
 	 */
 	public Instant getWhenAsInstant() {
 		return Instant.ofEpochMilli(when);
 	}
 
 	/**
 	 * Get this person's declared time zone
 	 *
 	 * @return this person's declared time zone; null if time zone is unknown.
 	 */
 	public TimeZone getTimeZone() {
 		return getTimeZone(tzOffset);
 	}
 
 	/**
 	 * Get the time zone id
 	 *
 	 * @return the time zone id
 	 * @since 6.1
 	 */
 	public ZoneId getZoneId() {
 		return getTimeZone().toZoneId();
 	}
 
 	/**
 	 * Get this person's declared time zone as minutes east of UTC.
 	 *
 	 * @return this person's declared time zone as minutes east of UTC. If the
 	 *         timezone is to the west of UTC it is negative.
 	 */
 	public int getTimeZoneOffset() {
 		return tzOffset;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Hashcode is based only on the email address and timestamp.
 	 */
 	@Override
 	public int hashCode() {
 		int hc = getEmailAddress().hashCode();
 		hc *= 31;
 		hc += (int) (when / 1000L);
 		return hc;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public boolean equals(Object o) {
 		if (o instanceof PersonIdent) {
 			final PersonIdent p = (PersonIdent) o;
 			return getName().equals(p.getName())
 					&& getEmailAddress().equals(p.getEmailAddress())
 					&& when / 1000L == p.when / 1000L;
 		}
 		return false;
 	}
 
 	/**
 	 * Format for Git storage.
 	 *
 	 * @return a string in the git author format
 	 */
 	public String toExternalString() {
 		final StringBuilder r = new StringBuilder();
 		appendSanitized(r, getName());
 		r.append(" <"); //$NON-NLS-1$
 		appendSanitized(r, getEmailAddress());
 		r.append("> "); //$NON-NLS-1$
 		r.append(when / 1000);
 		r.append(' ');
 		appendTimezone(r, tzOffset);
 		return r.toString();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	@SuppressWarnings("nls")
 	public String toString() {
 		final StringBuilder r = new StringBuilder();
 		final SimpleDateFormat dtfmt;
 		dtfmt = new SimpleDateFormat("EEE MMM d HH:mm:ss yyyy Z", Locale.US);
 		dtfmt.setTimeZone(getTimeZone());
 
 		r.append("PersonIdent[");
 		r.append(getName());
 		r.append(", ");
 		r.append(getEmailAddress());
 		r.append(", ");
 		r.append(dtfmt.format(Long.valueOf(when)));
 		r.append("]");
 
 		return r.toString();
 	}
 }