/*
 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
 * Copyright (C) $$Year-Rel$$ The Jalview Authors
 * 
 * This file is part of Jalview.
 * 
 * Jalview is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *  
 * Jalview is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty 
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
 * PURPOSE.  See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
package jalview.bin;

import java.io.File;
import java.io.IOException;
import java.net.URLDecoder;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import jalview.util.Platform;

public class ArgParser
{
  private static final String NEGATESTRING = "no";

  private static final String DEFAULTLINKEDID = "";

  private static enum Opt
  {
    BOOLEAN, STRING, UNARY, MULTI, LINKED, NODUPLICATEVALUES
  }

  // These bootstrap args are simply parsed before a full parse of arguments and
  // so are accessible at an earlier stage to (e.g.) set debug log leve, provide
  // a props file (that might set log level), run headlessly, read an argfile
  // instead of other args.
  private static final Collection<Arg> bootstrapArgs = new ArrayList(
          Arrays.asList(Arg.PROPS, Arg.DEBUG, Arg.HEADLESS, Arg.ARGFILE));

  public enum Arg
  {
    /*
    NOCALCULATION, NOMENUBAR, NOSTATUS, SHOWOVERVIEW, ANNOTATIONS, COLOUR,
    FEATURES, GROOVY, GROUPS, HEADLESS, JABAWS, NOANNOTATION, NOANNOTATION2,
    NODISPLAY, NOGUI, NONEWS, NOQUESTIONNAIRE, NOSORTBYTREE, NOUSAGESTATS,
    OPEN, OPEN2, PROPS, QUESTIONNAIRE, SETPROP, SORTBYTREE, TREE, VDOC,
    VSESS;
    */
    HELP("h"), CALCULATION, MENUBAR, STATUS, SHOWOVERVIEW, ANNOTATIONS,
    COLOUR, FEATURES, GROOVY, GROUPS, HEADLESS, JABAWS, ANNOTATION,
    ANNOTATION2, DISPLAY, GUI, NEWS, NOQUESTIONNAIRE, SORTBYTREE,
    USAGESTATS, OPEN, OPEN2, PROPS, QUESTIONNAIRE, SETPROP, TREE, VDOC,
    VSESS, OUTPUT, OUTPUTTYPE, SSANNOTATION, NOTEMPFAC, TEMPFAC,
    TEMPFAC_LABEL, TEMPFAC_DESC, TEMPFAC_SHADING, TITLE, PAEMATRIX, WRAP,
    NOSTRUCTURE, STRUCTURE, IMAGE, QUIT, DEBUG("d"), ARGFILE;

    static
    {
      HELP.setOptions(Opt.UNARY);
      CALCULATION.setOptions(true, Opt.BOOLEAN); // default "true" implies only
                                                 // expecting "--nocalculation"
      MENUBAR.setOptions(true, Opt.BOOLEAN);
      STATUS.setOptions(true, Opt.BOOLEAN);
      SHOWOVERVIEW.setOptions(Opt.UNARY, Opt.LINKED);
      ANNOTATIONS.setOptions(Opt.STRING, Opt.LINKED);
      COLOUR.setOptions(Opt.STRING, Opt.LINKED);
      FEATURES.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);
      GROOVY.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);
      GROUPS.setOptions(Opt.STRING, Opt.LINKED);
      HEADLESS.setOptions(Opt.UNARY);
      JABAWS.setOptions(Opt.STRING);
      ANNOTATION.setOptions(true, Opt.BOOLEAN);
      ANNOTATION2.setOptions(true, Opt.BOOLEAN);
      DISPLAY.setOptions(true, Opt.BOOLEAN);
      GUI.setOptions(true, Opt.BOOLEAN);
      NEWS.setOptions(true, Opt.BOOLEAN);
      NOQUESTIONNAIRE.setOptions(Opt.UNARY); // unary as --questionnaire=val
                                             // expects a string value
      SORTBYTREE.setOptions(true, Opt.BOOLEAN);
      USAGESTATS.setOptions(true, Opt.BOOLEAN);
      OPEN.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);
      OPEN2.setOptions(Opt.STRING, Opt.LINKED);
      PROPS.setOptions(Opt.STRING);
      QUESTIONNAIRE.setOptions(Opt.STRING);
      SETPROP.setOptions(Opt.STRING);
      TREE.setOptions(Opt.STRING);

      VDOC.setOptions(Opt.UNARY);
      VSESS.setOptions(Opt.UNARY);

      OUTPUT.setOptions(Opt.STRING, Opt.LINKED);
      OUTPUTTYPE.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);

      SSANNOTATION.setOptions(Opt.BOOLEAN, Opt.LINKED);
      NOTEMPFAC.setOptions(Opt.UNARY, Opt.LINKED);
      TEMPFAC.setOptions(Opt.STRING, Opt.LINKED);
      TEMPFAC_LABEL.setOptions(Opt.STRING, Opt.LINKED);
      TEMPFAC_DESC.setOptions(Opt.STRING, Opt.LINKED);
      TEMPFAC_SHADING.setOptions(Opt.BOOLEAN, Opt.LINKED);
      TITLE.setOptions(Opt.STRING, Opt.LINKED);
      PAEMATRIX.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);
      NOSTRUCTURE.setOptions(Opt.UNARY, Opt.LINKED);
      STRUCTURE.setOptions(Opt.STRING, Opt.LINKED, Opt.MULTI);
      WRAP.setOptions(Opt.BOOLEAN, Opt.LINKED);
      IMAGE.setOptions(Opt.STRING, Opt.LINKED);
      QUIT.setOptions(Opt.UNARY);
      DEBUG.setOptions(Opt.BOOLEAN);
      ARGFILE.setOptions(Opt.STRING);
    }

    private final String[] argNames;

    private Opt[] argOptions;

    private boolean defaultBoolValue = false;

    public String toLongString()
    {
      StringBuilder sb = new StringBuilder();
      sb.append("Arg: ").append(this.name());
      for (String name : getNames())
      {
        sb.append(", '").append(name).append("'");
      }
      sb.append("\nOptions: ");
      boolean first = true;
      for (Opt o : argOptions)
      {
        if (!first)
        {
          sb.append(", ");
        }
        sb.append(o.toString());
        first = false;
      }
      sb.append("\n");
      return sb.toString();
    }

    private Arg()
    {
      this(new String[0]);
    }

    private Arg(String... names)
    {
      int length = (names == null || names.length == 0
              || (names.length == 1 && names[0] == null)) ? 1
                      : names.length + 1;
      this.argNames = new String[length];
      this.argNames[0] = this.getName();
      if (length > 1)
        System.arraycopy(names, 0, this.argNames, 1, names.length);
    }

    public String[] getNames()
    {
      return argNames;
    }

    public String getName()
    {
      return this.name().toLowerCase(Locale.ROOT).replace('_', '-');
    }

    @Override
    public final String toString()
    {
      return getName();
    }

    public boolean hasOption(Opt o)
    {
      if (argOptions == null)
        return false;
      for (Opt option : argOptions)
      {
        if (o == option)
          return true;
      }
      return false;
    }

    protected void setOptions(Opt... options)
    {
      setOptions(false, options);
    }

    protected void setOptions(boolean defaultBoolValue, Opt... options)
    {
      this.defaultBoolValue = defaultBoolValue;
      argOptions = options;
    }

    protected boolean getDefaultBoolValue()
    {
      return defaultBoolValue;
    }
  }

  public static class ArgValues
  {
    private static final String ID = "id";

    private Arg arg;

    private int argCount = 0;

    private boolean boolValue = false;

    private boolean negated = false;

    private int boolIndex = -1;

    private List<Integer> argsIndexes;

    private List<ArgValue> argValueList;

    private Map<String, ArgValue> idMap = new HashMap<>();

    protected ArgValues(Arg a)
    {
      this.arg = a;
      this.argValueList = new ArrayList<ArgValue>();
      this.boolValue = arg.getDefaultBoolValue();
    }

    public Arg arg()
    {
      return arg;
    }

    protected int getCount()
    {
      return argCount;
    }

    protected void incrementCount()
    {
      argCount++;
    }

    protected void setNegated(boolean b)
    {
      this.negated = b;
    }

    protected boolean isNegated()
    {
      return this.negated;
    }

    protected void setBoolean(boolean b, int i)
    {
      this.boolValue = b;
      this.boolIndex = i;
    }

    protected boolean getBoolean()
    {
      return this.boolValue;
    }

    @Override
    public String toString()
    {
      if (argValueList == null)
        return null;
      StringBuilder sb = new StringBuilder();
      sb.append(arg.toLongString());
      if (arg.hasOption(Opt.BOOLEAN) || arg.hasOption(Opt.UNARY))
        sb.append("Boolean: ").append(boolValue).append("; Default: ")
                .append(arg.getDefaultBoolValue()).append("; Negated: ")
                .append(negated).append("\n");
      if (arg.hasOption(Opt.STRING))
      {
        sb.append("Values:");
        boolean first = true;
        for (ArgValue av : argValueList)
        {
          String v = av.getValue();
          if (!first)
            sb.append(",");
          sb.append("\n  '");
          sb.append(v).append("'");
          first = false;
        }
        sb.append("\n");
      }
      sb.append("Count: ").append(argCount).append("\n");
      return sb.toString();
    }

    protected void addValue()
    {
      addValue(null, -1);
    }

    protected void addValue(String val, int argIndex)
    {
      addArgValue(new ArgValue(val, argIndex));
    }

    protected void addArgValue(ArgValue av)
    {
      if ((!arg.hasOption(Opt.MULTI) && argValueList.size() > 0)
              || (arg.hasOption(Opt.NODUPLICATEVALUES)
                      && argValueList.contains(av.getValue())))
        return;
      if (argValueList == null)
      {
        argValueList = new ArrayList<ArgValue>();
      }
      SubVals sv = ArgParser.getSubVals(av.getValue());
      if (sv.has(ID))
      {
        String id = sv.get(ID);
        av.setId(id);
        idMap.put(id, av);
      }
      argValueList.add(av);
    }

    protected boolean hasValue(String val)
    {
      return argValueList.contains(val);
    }

    protected ArgValue getArgValue()
    {
      if (arg.hasOption(Opt.MULTI))
        Console.warn("Requesting single value for multi value argument");
      return argValueList.size() > 0 ? argValueList.get(0) : null;
    }

    protected List<ArgValue> getArgValueList()
    {
      return argValueList;
    }

    protected boolean hasId(String id)
    {
      return idMap.containsKey(id);
    }

    protected ArgValue getId(String id)
    {
      return idMap.get(id);
    }
  }

  // old style
  private List<String> vargs = null;

  private boolean isApplet;

  // private AppletParams appletParams;

  public boolean isApplet()
  {
    return isApplet;
  }

  public String nextValue()
  {
    return vargs.remove(0);
  }

  public int getSize()
  {
    return vargs.size();
  }

  public String getValue(String arg)
  {
    return getValue(arg, false);
  }

  public String getValue(String arg, boolean utf8decode)
  {
    int index = vargs.indexOf(arg);
    String dc = null;
    String ret = null;
    if (index != -1)
    {
      ret = vargs.get(index + 1).toString();
      vargs.remove(index);
      vargs.remove(index);
      if (utf8decode && ret != null)
      {
        try
        {
          dc = URLDecoder.decode(ret, "UTF-8");
          ret = dc;
        } catch (Exception e)
        {
          // TODO: log failure to decode
        }
      }
    }
    return ret;
  }

  /*
  public Object getAppletValue(String key, String def, boolean asString)
  {
    Object value;
    return (appletParams == null ? null
            : (value = appletParams.get(key.toLowerCase())) == null ? def
                    : asString ? "" + value : value);
  }
  */

  // new style
  private static final Map<String, Arg> argMap;

  private Map<String, ArgValuesMap> linkedArgs = new HashMap<>();

  private List<String> linkedOrder = null;

  private List<Arg> argList;

  static
  {
    argMap = new HashMap<>();
    for (Arg a : EnumSet.allOf(Arg.class))
    {
      ARGNAME: for (String argName : a.getNames())
      {
        if (argMap.containsKey(argName))
        {
          Console.warn("Trying to add argument name multiple times: '"
                  + argName + "'"); // RESTORE THIS WHEN MERGED
          if (argMap.get(argName) != a)
          {
            Console.error(
                    "Trying to add argument name multiple times for different Args: '"
                            + argMap.get(argName).getName() + ":" + argName
                            + "' and '" + a.getName() + ":" + argName
                            + "'");
          }
          continue ARGNAME;
        }
        argMap.put(argName, a);
      }
    }
  }

  public ArgParser(String[] args)
  {
    // old style
    vargs = new ArrayList<>();
    isApplet = (args.length > 0 && args[0].startsWith("<applet"));
    if (isApplet)
    {
      // appletParams = AppletParams.getAppletParams(args, vargs);
    }
    else
    {
      if (Platform.isJS())

      {
        isApplet = true;
        // appletParams =
        // AppletParams.getAppletParams(Platform.getAppletInfoAsMap(), vargs);
      }
      for (int i = 0; i < args.length; i++)
      {
        String arg = args[i].trim();
        if (arg.charAt(0) == '-')
        {
          arg = arg.substring(1);
        }
        vargs.add(arg);
      }
    }

    // new style
    Enumeration<String> argE = Collections.enumeration(Arrays.asList(args));
    int argIndex = 0;
    while (argE.hasMoreElements())
    {
      String arg = argE.nextElement();
      String argName = null;
      String val = null;
      String linkedId = null;
      if (arg.startsWith("--"))
      {
        int equalPos = arg.indexOf('=');
        if (equalPos > -1)
        {
          argName = arg.substring(2, equalPos);
          val = arg.substring(equalPos + 1);
        }
        else
        {
          argName = arg.substring(2);
        }
        int idOpen = argName.indexOf('[');
        int idClose = argName.indexOf(']');

        if (idOpen > -1 && idClose == argName.length() - 1)
        {
          linkedId = argName.substring(idOpen + 1, idClose);
          argName = argName.substring(0, idOpen);
        }

        Arg a = argMap.get(argName);
        // check for boolean prepended by "no"
        boolean negated = false;
        if (a == null && argName.startsWith(NEGATESTRING) && argMap
                .containsKey(argName.substring(NEGATESTRING.length())))
        {
          argName = argName.substring(NEGATESTRING.length());
          a = argMap.get(argName);
          negated = true;
        }

        // check for config errors
        if (a == null)
        {
          // arg not found
          Console.error("Argument '" + arg + "' not recognised. Ignoring.");
          continue;
        }
        if (!a.hasOption(Opt.BOOLEAN) && negated)
        {
          // used "no" with a non-boolean option
          Console.error("Argument '--" + NEGATESTRING + argName
                  + "' not a boolean option. Ignoring.");
          continue;
        }
        if (!a.hasOption(Opt.STRING) && equalPos > -1)
        {
          // set --argname=value when arg does not accept values
          Console.error("Argument '--" + argName
                  + "' does not expect a value (given as '" + arg
                  + "').  Ignoring.");
          continue;
        }
        if (!a.hasOption(Opt.LINKED) && linkedId != null)
        {
          // set --argname[linkedId] when arg does not use linkedIds
          Console.error("Argument '--" + argName
                  + "' does not expect a linked id (given as '" + arg
                  + "'). Ignoring.");
          continue;
        }

        if (a.hasOption(Opt.STRING) && equalPos == -1)
        {
          // take next arg as value if required, and '=' was not found
          if (!argE.hasMoreElements())
          {
            // no value to take for arg, which wants a value
            Console.error("Argument '" + a.getName()
                    + "' requires a value, none given. Ignoring.");
            continue;
          }
          val = argE.nextElement();
        }

        // use default linkedId for linked arguments
        if (a.hasOption(Opt.LINKED) && linkedId == null)
          linkedId = DEFAULTLINKEDID;

        if (!linkedArgs.containsKey(linkedId))
          linkedArgs.put(linkedId, new ArgValuesMap());

        ArgValuesMap avm = linkedArgs.get(linkedId);

        if (a.hasOption(Opt.NODUPLICATEVALUES) && avm.hasValue(a, val))
        {
          Console.error("Argument '--" + argName
                  + "' cannot contain a duplicate value ('" + val
                  + "'). Ignoring this and subsequent occurrences.");
          continue;
        }

        // check for unique id
        SubVals sv = ArgParser.getSubVals(val);
        String id = sv.get(ArgValues.ID);
        if (id != null && avm.hasId(a, id))
        {
          Console.error("Argument '--" + argName + "' has a duplicate id ('"
                  + id + "'). Ignoring.");
          continue;
        }

        ArgValues avs = avm.getOrCreateArgValues(a);
        if (avs == null)
        {
          avs = new ArgValues(a);
        }
        // store appropriate value
        if (a.hasOption(Opt.STRING))
        {
          avs.addValue(val, argIndex);
        }
        else if (a.hasOption(Opt.BOOLEAN))
        {
          avs.setBoolean(!negated, argIndex);
          avs.setNegated(negated);
        }
        else if (a.hasOption(Opt.UNARY))
        {
          avs.setBoolean(true, argIndex);
        }
        avs.incrementCount();

        // store in appropriate place
        if (a.hasOption(Opt.LINKED))
        {
          // allow a default linked id for single usage
          if (linkedId == null)
            linkedId = DEFAULTLINKEDID;
          // store the order of linkedIds
          if (linkedOrder == null)
            linkedOrder = new ArrayList<>();
          if (!linkedOrder.contains(linkedId))
            linkedOrder.add(linkedId);
        }

        // store arg in the list of args used
        if (argList == null)
          argList = new ArrayList<>();
        if (!argList.contains(a))
          argList.add(a);
      }
    }
  }

  public boolean isSet(Arg a)
  {
    return a.hasOption(Opt.LINKED) ? isSet("", a) : isSet(null, a);
  }

  public boolean isSet(String linkedId, Arg a)
  {
    ArgValuesMap avm = linkedArgs.get(linkedId);
    return avm == null ? false : avm.containsArg(a);
  }

  public boolean getBool(Arg a)
  {
    if (!a.hasOption(Opt.BOOLEAN) && !a.hasOption(Opt.UNARY))
    {
      Console.warn("Getting boolean from non boolean Arg '" + a.getName()
              + "'.");
    }
    return a.hasOption(Opt.LINKED) ? getBool("", a) : getBool(null, a);
  }

  public boolean getBool(String linkedId, Arg a)
  {
    ArgValuesMap avm = linkedArgs.get(linkedId);
    if (avm == null)
      return a.getDefaultBoolValue();
    ArgValues avs = avm.getArgValues(a);
    return avs == null ? a.getDefaultBoolValue() : avs.getBoolean();
  }

  public List<String> linkedIds()
  {
    return linkedOrder;
  }

  public ArgValuesMap linkedArgs(String id)
  {
    return linkedArgs.get(id);
  }

  @Override
  public String toString()
  {
    StringBuilder sb = new StringBuilder();
    sb.append("UNLINKED\n");
    sb.append(argValuesMapToString(linkedArgs.get(null)));
    if (linkedIds() != null)
    {
      sb.append("LINKED\n");
      for (String id : linkedIds())
      {
        // already listed these as UNLINKED args
        if (id == null)
          continue;

        ArgValuesMap avm = linkedArgs(id);
        sb.append("ID: '").append(id).append("'\n");
        sb.append(argValuesMapToString(avm));
      }
    }
    return sb.toString();
  }

  private static String argValuesMapToString(ArgValuesMap avm)
  {
    if (avm == null)
      return null;
    StringBuilder sb = new StringBuilder();
    for (Arg a : avm.getArgKeys())
    {
      ArgValues v = avm.getArgValues(a);
      sb.append(v.toString());
      sb.append("\n");
    }
    return sb.toString();
  }

  public static SubVals getSubVals(String item)
  {
    return new SubVals(item);
  }

  /**
   * A helper class to keep an index of argument position with argument values
   */
  public static class ArgValue
  {
    private int argIndex;

    private String value;

    private String id;

    protected ArgValue(String value, int argIndex)
    {
      this.value = value;
      this.argIndex = argIndex;
    }

    protected String getValue()
    {
      return value;
    }

    protected int getArgIndex()
    {
      return argIndex;
    }

    protected void setId(String i)
    {
      id = i;
    }

    protected String getId()
    {
      return id;
    }
  }

  /**
   * A helper class to parse a string of the possible forms "content"
   * "[index]content", "[keyName=keyValue]content" and return the integer index,
   * the strings keyName and keyValue, and the content after the square brackets
   * (if present). Values not set `will be -1 or null.
   */
  public static class SubVals
  {
    private static int NOTSET = -1;

    private int index = NOTSET;

    private Map<String, String> subVals = null;

    private static char SEPARATOR = ';';

    private String content = null;

    public SubVals(String item)
    {
      this.parseVals(item);
    }

    public void parseVals(String item)
    {
      if (item == null)
        return;
      if (item.indexOf('[') == 0 && item.indexOf(']') > 1)
      {
        int openBracket = item.indexOf('[');
        int closeBracket = item.indexOf(']');
        String subvalsString = item.substring(openBracket + 1,
                closeBracket);
        this.content = item.substring(closeBracket + 1);
        boolean setIndex = false;
        for (String subvalString : subvalsString
                .split(Character.toString(SEPARATOR)))
        {
          int equals = subvalString.indexOf('=');
          if (equals > -1)
          {
            if (subVals == null)
              subVals = new HashMap<>();
            subVals.put(subvalString.substring(0, equals),
                    subvalString.substring(equals + 1));
          }
          else
          {
            try
            {
              this.index = Integer.parseInt(subvalString);
              setIndex = true;
            } catch (NumberFormatException e)
            {
              Console.warn("Failed to obtain subvalue or index from '"
                      + item + "'. Setting index=0 and using content='"
                      + content + "'.");
            }
          }
        }
        if (!setIndex)
          this.index = NOTSET;
      }
      else
      {
        this.content = item;
      }
    }

    public boolean notSet()
    {
      // notSet is true if content present but nonsensical
      return index == NOTSET && subVals == null;
    }

    public String get(String key)
    {
      return subVals == null ? null : subVals.get(key);
    }

    public boolean has(String key)
    {
      return subVals == null ? false : subVals.containsKey(key);
    }

    public int getIndex()
    {
      return index;
    }

    public String getContent()
    {
      return content;
    }
  }

  /**
   * Helper class to allow easy extraction of information about specific
   * argument values (without having to check for null etc all the time)
   */
  protected static class ArgValuesMap
  {
    protected Map<Arg, ArgValues> m;

    protected ArgValuesMap()
    {
      this.newMap();
    }

    protected ArgValuesMap(Map<Arg, ArgValues> map)
    {
      this.m = map;
    }

    private Map<Arg, ArgValues> getMap()
    {
      return m;
    }

    private void newMap()
    {
      m = new HashMap<Arg, ArgValues>();
    }

    private void newArg(Arg a)
    {
      if (m == null)
        newMap();
      if (!containsArg(a))
        m.put(a, new ArgValues(a));
    }

    protected void addArgValue(Arg a, ArgValue av)
    {
      if (getMap() == null)
        m = new HashMap<Arg, ArgValues>();

      if (!m.containsKey(a))
        m.put(a, new ArgValues(a));
      ArgValues avs = m.get(a);
      avs.addArgValue(av);
    }

    protected ArgValues getArgValues(Arg a)
    {
      return m == null ? null : m.get(a);
    }

    protected ArgValues getOrCreateArgValues(Arg a)
    {
      ArgValues avs = m.get(a);
      if (avs == null)
        newArg(a);
      return getArgValues(a);
    }

    protected List<ArgValue> getArgValueList(Arg a)
    {
      ArgValues avs = getArgValues(a);
      return avs == null ? new ArrayList<>() : avs.getArgValueList();
    }

    protected ArgValue getArgValue(Arg a)
    {
      List<ArgValue> vals = getArgValueList(a);
      return (vals == null || vals.size() == 0) ? null : vals.get(0);
    }

    protected String getValue(Arg a)
    {
      ArgValue av = getArgValue(a);
      return av == null ? null : av.getValue();
    }

    protected boolean containsArg(Arg a)
    {
      if (m == null || !m.containsKey(a))
        return false;
      return a.hasOption(Opt.STRING) ? getArgValue(a) != null
              : this.getBoolean(a);
    }

    protected boolean hasValue(Arg a, String val)
    {
      if (m == null || !m.containsKey(a))
        return false;
      for (ArgValue av : getArgValueList(a))
      {
        String avVal = av.getValue();
        if ((val == null && avVal == null)
                || (val != null && val.equals(avVal)))
        {
          return true;
        }
      }
      return false;
    }

    protected boolean getBoolean(Arg a)
    {
      ArgValues av = getArgValues(a);
      return av == null ? false : av.getBoolean();
    }

    protected Set<Arg> getArgKeys()
    {
      return m.keySet();
    }

    protected ArgValue getClosestPreviousArgValueOfArg(ArgValue thisAv,
            Arg a)
    {
      ArgValue closestAv = null;
      int thisArgIndex = thisAv.getArgIndex();
      ArgValues compareAvs = this.getArgValues(a);
      int closestPreviousIndex = -1;
      for (ArgValue av : compareAvs.getArgValueList())
      {
        int argIndex = av.getArgIndex();
        if (argIndex < thisArgIndex && argIndex > closestPreviousIndex)
        {
          closestPreviousIndex = argIndex;
          closestAv = av;
        }
      }
      return closestAv;
    }

    protected ArgValue getClosestNextArgValueOfArg(ArgValue thisAv, Arg a)
    {
      // this looks for the *next* arg that *might* be referring back to
      // a thisAv. Such an arg would have no subValues (if it does it should
      // specify an id in the subValues so wouldn't need to be guessed).
      ArgValue closestAv = null;
      int thisArgIndex = thisAv.getArgIndex();
      ArgValues compareAvs = this.getArgValues(a);
      int closestNextIndex = Integer.MAX_VALUE;
      for (ArgValue av : compareAvs.getArgValueList())
      {
        int argIndex = av.getArgIndex();
        if (argIndex > thisArgIndex && argIndex < closestNextIndex)
        {
          closestNextIndex = argIndex;
          closestAv = av;
        }
      }
      return closestAv;
    }

    protected ArgValue[] getArgValuesReferringTo(String key, String value,
            Arg a)
    {
      // this looks for the *next* arg that *might* be referring back to
      // a thisAv. Such an arg would have no subValues (if it does it should
      // specify an id in the subValues so wouldn't need to be guessed).
      List<ArgValue> avList = new ArrayList<>();
      Arg[] args = a == null ? (Arg[]) this.getMap().keySet().toArray()
              : new Arg[]
              { a };
      for (Arg keyArg : args)
      {
        for (ArgValue av : this.getArgValueList(keyArg))
        {

        }
      }
      return (ArgValue[]) avList.toArray();
    }

    protected boolean hasId(Arg a, String id)
    {
      ArgValues avs = this.getArgValues(a);
      return avs == null ? false : avs.hasId(id);
    }

    protected ArgValue getId(Arg a, String id)
    {
      ArgValues avs = this.getArgValues(a);
      return avs == null ? null : avs.getId(id);
    }
  }

  public static Map<Arg, String> bootstrapArgs(String[] args)
  {
    Map<Arg, String> bootstrapArgMap = new HashMap<>();
    if (args == null)
      return bootstrapArgMap;
    Enumeration<String> argE = Collections.enumeration(Arrays.asList(args));
    while (argE.hasMoreElements())
    {
      String arg = argE.nextElement();
      String argName = null;
      String val = null;
      if (arg.startsWith("--"))
      {
        int equalPos = arg.indexOf('=');
        if (equalPos > -1)
        {
          argName = arg.substring(2, equalPos);
          val = arg.substring(equalPos + 1);
        }
        else
        {
          argName = arg.substring(2);
        }
        Arg a = argMap.get(argName);
        if (a != null && bootstrapArgs.contains(a))
          bootstrapArgMap.put(a, val);
      }
    }
    return bootstrapArgMap;
  }

  public static ArgParser parseArgFile(String argFilename)
  {
    List<String> argsList = null;
    File argFile = new File(argFilename);
    if (!argFile.exists())
    {
      System.err.println("--" + Arg.ARGFILE.name().toLowerCase(Locale.ROOT)
              + "=\"" + argFilename + "\": File does not exist.");
      System.exit(2);
    }
    try
    {
      argsList = Files.readAllLines(Paths.get(argFilename));
    } catch (IOException e)
    {
      System.err.println("--" + Arg.ARGFILE.name().toLowerCase(Locale.ROOT)
              + "=\"" + argFilename + "\": File could not be read.");
      System.exit(3);
    }
    return new ArgParser((String[]) argsList.toArray());
  }
}