/*
 * 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.structures.models;

import jalview.api.AlignmentViewPanel;
import jalview.api.FeatureRenderer;
import jalview.api.SequenceRenderer;
import jalview.api.StructureSelectionManagerProvider;
import jalview.api.structures.JalviewStructureDisplayI;
import jalview.datamodel.AlignmentI;
import jalview.datamodel.HiddenColumns;
import jalview.datamodel.PDBEntry;
import jalview.datamodel.SequenceI;
import jalview.io.DataSourceType;
import jalview.schemes.ColourSchemeI;
import jalview.schemes.ResidueProperties;
import jalview.structure.AtomSpec;
import jalview.structure.StructureCommandsI;
import jalview.structure.StructureListener;
import jalview.structure.StructureMapping;
import jalview.structure.StructureSelectionManager;
import jalview.util.Comparison;
import jalview.util.MessageManager;

import java.awt.Color;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.swing.SwingUtilities;

/**
 * 
 * A base class to hold common function for protein structure model binding.
 * Initial version created by refactoring JMol and Chimera binding models, but
 * other structure viewers could in principle be accommodated in future.
 * 
 * @author gmcarstairs
 *
 */
public abstract class AAStructureBindingModel
        extends SequenceStructureBindingModel
        implements StructureListener, StructureSelectionManagerProvider
{
  private static final String COLOURING_STRUCTURES = MessageManager
          .getString("status.colouring_structures");

  /*
   * the Jalview panel through which the user interacts
   * with the structure viewer
   */
  private JalviewStructureDisplayI viewer;

  /*
   * helper that generates command syntax
   */
  private StructureCommandsI commandGenerator;

  private StructureSelectionManager ssm;

  /*
   * modelled chains, formatted as "pdbid:chainCode"
   */
  private List<String> chainNames;

  /*
   * lookup of pdb file name by key "pdbid:chainCode"
   */
  private Map<String, String> chainFile;

  /*
   * distinct PDB entries (pdb files) associated
   * with sequences
   */
  private PDBEntry[] pdbEntry;

  /*
   * sequences mapped to each pdbentry
   */
  private SequenceI[][] sequence;

  /*
   * array of target chains for sequences - tied to pdbentry and sequence[]
   */
  private String[][] chains;

  /*
   * datasource protocol for access to PDBEntrylatest
   */
  DataSourceType protocol = null;

  protected boolean colourBySequence = true;

  private boolean nucleotide;

  private boolean finishedInit = false;

  /**
   * current set of model filenames loaded in the Jmol instance
   */
  protected String[] modelFileNames = null;

  public String fileLoadingError;

  /**
   * Data bean class to simplify parameterisation in superposeStructures
   */
  protected class SuperposeData
  {
    /**
     * Constructor with alignment width argument
     * 
     * @param width
     */
    public SuperposeData(int width)
    {
      pdbResNo = new int[width];
    }

    public String filename;

    public String pdbId;

    public String chain = "";

    public boolean isRna;

    /*
     * The pdb residue number (if any) mapped to each column of the alignment
     */
    public int[] pdbResNo;
  }

  /**
   * Constructor
   * 
   * @param ssm
   * @param seqs
   */
  public AAStructureBindingModel(StructureSelectionManager ssm,
          SequenceI[][] seqs)
  {
    this.ssm = ssm;
    this.sequence = seqs;
    chainNames = new ArrayList<>();
    chainFile = new HashMap<>();
  }

  /**
   * Constructor
   * 
   * @param ssm
   * @param pdbentry
   * @param sequenceIs
   * @param protocol
   */
  public AAStructureBindingModel(StructureSelectionManager ssm,
          PDBEntry[] pdbentry, SequenceI[][] sequenceIs,
          DataSourceType protocol)
  {
    this(ssm, sequenceIs);
    this.nucleotide = Comparison.isNucleotide(sequenceIs);
    this.pdbEntry = pdbentry;
    this.protocol = protocol;
    resolveChains();
  }

  private boolean resolveChains()
  {
    /**
     * final count of chain mappings discovered
     */
    int chainmaps = 0;
    // JBPNote: JAL-2693 - this should be a list of chain mappings per
    // [pdbentry][sequence]
    String[][] newchains = new String[pdbEntry.length][];
    int pe = 0;
    for (PDBEntry pdb : pdbEntry)
    {
      SequenceI[] seqsForPdb = sequence[pe];
      if (seqsForPdb != null)
      {
        newchains[pe] = new String[seqsForPdb.length];
        int se = 0;
        for (SequenceI asq : seqsForPdb)
        {
          String chain = (chains != null && chains[pe] != null)
                  ? chains[pe][se]
                  : null;
          SequenceI sq = (asq.getDatasetSequence() == null) ? asq
                  : asq.getDatasetSequence();
          if (sq.getAllPDBEntries() != null)
          {
            for (PDBEntry pdbentry : sq.getAllPDBEntries())
            {
              if (pdb.getFile() != null && pdbentry.getFile() != null
                      && pdb.getFile().equals(pdbentry.getFile()))
              {
                String chaincode = pdbentry.getChainCode();
                if (chaincode != null && chaincode.length() > 0)
                {
                  chain = chaincode;
                  chainmaps++;
                  break;
                }
              }
            }
          }
          newchains[pe][se] = chain;
          se++;
        }
        pe++;
      }
    }

    chains = newchains;
    return chainmaps > 0;
  }
  public StructureSelectionManager getSsm()
  {
    return ssm;
  }

  /**
   * Returns the i'th PDBEntry (or null)
   * 
   * @param i
   * @return
   */
  public PDBEntry getPdbEntry(int i)
  {
    return (pdbEntry != null && pdbEntry.length > i) ? pdbEntry[i] : null;
  }

  /**
   * Answers true if this binding includes the given PDB id, else false
   * 
   * @param pdbId
   * @return
   */
  public boolean hasPdbId(String pdbId)
  {
    if (pdbEntry != null)
    {
      for (PDBEntry pdb : pdbEntry)
      {
        if (pdb.getId().equals(pdbId))
        {
          return true;
        }
      }
    }
    return false;
  }

  /**
   * Returns the number of modelled PDB file entries.
   * 
   * @return
   */
  public int getPdbCount()
  {
    return pdbEntry == null ? 0 : pdbEntry.length;
  }

  public SequenceI[][] getSequence()
  {
    return sequence;
  }

  public String[][] getChains()
  {
    return chains;
  }

  public DataSourceType getProtocol()
  {
    return protocol;
  }

  // TODO may remove this if calling methods can be pulled up here
  protected void setPdbentry(PDBEntry[] pdbentry)
  {
    this.pdbEntry = pdbentry;
  }

  protected void setSequence(SequenceI[][] sequence)
  {
    this.sequence = sequence;
  }

  protected void setChains(String[][] chains)
  {
    this.chains = chains;
  }

  /**
   * Construct a title string for the viewer window based on the data Jalview
   * knows about
   * 
   * @param viewerName
   *          TODO
   * @param verbose
   * 
   * @return
   */
  public String getViewerTitle(String viewerName, boolean verbose)
  {
    if (getSequence() == null || getSequence().length < 1
            || getPdbCount() < 1 || getSequence()[0].length < 1)
    {
      return ("Jalview " + viewerName + " Window");
    }
    // TODO: give a more informative title when multiple structures are
    // displayed.
    StringBuilder title = new StringBuilder(64);
    final PDBEntry pdbe = getPdbEntry(0);
    title.append(viewerName + " view for " + getSequence()[0][0].getName()
            + ":" + pdbe.getId());

    if (verbose)
    {
      String method = (String) pdbe.getProperty("method");
      if (method != null)
      {
        title.append(" Method: ").append(method);
      }
      String chain = (String) pdbe.getProperty("chains");
      if (chain != null)
      {
        title.append(" Chain:").append(chain);
      }
    }
    return title.toString();
  }

  /**
   * Called by after closeViewer is called, to release any resources and
   * references so they can be garbage collected. Override if needed.
   */
  protected void releaseUIResources()
  {
  }

  @Override
  public void releaseReferences(Object svl)
  {
  }

  public boolean isColourBySequence()
  {
    return colourBySequence;
  }

  /**
   * Called when the binding thinks the UI needs to be refreshed after a
   * structure viewer state change. This could be because structures were
   * loaded, or because an error has occurred. Default does nothing, override as
   * required.
   */
  public void refreshGUI()
  {
  }

  /**
   * Instruct the Jalview binding to update the pdbentries vector if necessary
   * prior to matching the jmol view's contents to the list of structure files
   * Jalview knows about. By default does nothing, override as required.
   */
  public void refreshPdbEntries()
  {
  }

  public void setColourBySequence(boolean colourBySequence)
  {
    this.colourBySequence = colourBySequence;
  }

  protected void addSequenceAndChain(int pe, SequenceI[] seq,
          String[] tchain)
  {
    if (pe < 0 || pe >= getPdbCount())
    {
      throw new Error(MessageManager.formatMessage(
              "error.implementation_error_no_pdbentry_from_index",
              new Object[]
              { Integer.valueOf(pe).toString() }));
    }
    final String nullChain = "TheNullChain";
    List<SequenceI> s = new ArrayList<>();
    List<String> c = new ArrayList<>();
    if (getChains() == null)
    {
      setChains(new String[getPdbCount()][]);
    }
    if (getSequence()[pe] != null)
    {
      for (int i = 0; i < getSequence()[pe].length; i++)
      {
        s.add(getSequence()[pe][i]);
        if (getChains()[pe] != null)
        {
          if (i < getChains()[pe].length)
          {
            c.add(getChains()[pe][i]);
          }
          else
          {
            c.add(nullChain);
          }
        }
        else
        {
          if (tchain != null && tchain.length > 0)
          {
            c.add(nullChain);
          }
        }
      }
    }
    for (int i = 0; i < seq.length; i++)
    {
      if (!s.contains(seq[i]))
      {
        s.add(seq[i]);
        if (tchain != null && i < tchain.length)
        {
          c.add(tchain[i] == null ? nullChain : tchain[i]);
        }
      }
    }
    SequenceI[] tmp = s.toArray(new SequenceI[s.size()]);
    getSequence()[pe] = tmp;
    if (c.size() > 0)
    {
      String[] tch = c.toArray(new String[c.size()]);
      for (int i = 0; i < tch.length; i++)
      {
        if (tch[i] == nullChain)
        {
          tch[i] = null;
        }
      }
      getChains()[pe] = tch;
    }
    else
    {
      getChains()[pe] = null;
    }
  }

  /**
   * add structures and any known sequence associations
   * 
   * @returns the pdb entries added to the current set.
   */
  public synchronized PDBEntry[] addSequenceAndChain(PDBEntry[] pdbe,
          SequenceI[][] seq, String[][] chns)
  {
    List<PDBEntry> v = new ArrayList<>();
    List<int[]> rtn = new ArrayList<>();
    for (int i = 0; i < getPdbCount(); i++)
    {
      v.add(getPdbEntry(i));
    }
    for (int i = 0; i < pdbe.length; i++)
    {
      int r = v.indexOf(pdbe[i]);
      if (r == -1 || r >= getPdbCount())
      {
        rtn.add(new int[] { v.size(), i });
        v.add(pdbe[i]);
      }
      else
      {
        // just make sure the sequence/chain entries are all up to date
        addSequenceAndChain(r, seq[i], chns[i]);
      }
    }
    pdbe = v.toArray(new PDBEntry[v.size()]);
    setPdbentry(pdbe);
    if (rtn.size() > 0)
    {
      // expand the tied sequence[] and string[] arrays
      SequenceI[][] sqs = new SequenceI[getPdbCount()][];
      String[][] sch = new String[getPdbCount()][];
      System.arraycopy(getSequence(), 0, sqs, 0, getSequence().length);
      System.arraycopy(getChains(), 0, sch, 0, this.getChains().length);
      setSequence(sqs);
      setChains(sch);
      pdbe = new PDBEntry[rtn.size()];
      for (int r = 0; r < pdbe.length; r++)
      {
        int[] stri = (rtn.get(r));
        // record the pdb file as a new addition
        pdbe[r] = getPdbEntry(stri[0]);
        // and add the new sequence/chain entries
        addSequenceAndChain(stri[0], seq[stri[1]], chns[stri[1]]);
      }
    }
    else
    {
      pdbe = null;
    }
    return pdbe;
  }

  /**
   * Add sequences to the pe'th pdbentry's sequence set.
   * 
   * @param pe
   * @param seq
   */
  public void addSequence(int pe, SequenceI[] seq)
  {
    addSequenceAndChain(pe, seq, null);
  }

  /**
   * add the given sequences to the mapping scope for the given pdb file handle
   * 
   * @param pdbFile
   *          - pdbFile identifier
   * @param seq
   *          - set of sequences it can be mapped to
   */
  public void addSequenceForStructFile(String pdbFile, SequenceI[] seq)
  {
    for (int pe = 0; pe < getPdbCount(); pe++)
    {
      if (getPdbEntry(pe).getFile().equals(pdbFile))
      {
        addSequence(pe, seq);
      }
    }
  }

  @Override
  public abstract void highlightAtoms(List<AtomSpec> atoms);

  protected boolean isNucleotide()
  {
    return this.nucleotide;
  }

  /**
   * Returns a readable description of all mappings for the wrapped pdbfile to
   * any mapped sequences
   * 
   * @param pdbfile
   * @param seqs
   * @return
   */
  public String printMappings()
  {
    if (pdbEntry == null)
    {
      return "";
    }
    StringBuilder sb = new StringBuilder(128);
    for (int pdbe = 0; pdbe < getPdbCount(); pdbe++)
    {
      String pdbfile = getPdbEntry(pdbe).getFile();
      List<SequenceI> seqs = Arrays.asList(getSequence()[pdbe]);
      sb.append(getSsm().printMappings(pdbfile, seqs));
    }
    return sb.toString();
  }

  /**
   * Returns the mapped structure position for a given aligned column of a given
   * sequence, or -1 if the column is gapped, beyond the end of the sequence, or
   * not mapped to structure.
   * 
   * @param seq
   * @param alignedPos
   * @param mapping
   * @return
   */
  protected int getMappedPosition(SequenceI seq, int alignedPos,
          StructureMapping mapping)
  {
    if (alignedPos >= seq.getLength())
    {
      return -1;
    }

    if (Comparison.isGap(seq.getCharAt(alignedPos)))
    {
      return -1;
    }
    int seqPos = seq.findPosition(alignedPos);
    int pos = mapping.getPDBResNum(seqPos);
    return pos;
  }

  /**
   * Helper method to identify residues that can participate in a structure
   * superposition command. For each structure, identify a sequence in the
   * alignment which is mapped to the structure. Identify non-gapped columns in
   * the sequence which have a mapping to a residue in the structure. Returns
   * the index of the first structure that has a mapping to the alignment.
   * 
   * @param alignment
   *          the sequence alignment which is the basis of structure
   *          superposition
   * @param matched
   *          a BitSet, where bit j is set to indicate that every structure has
   *          a mapped residue present in column j (so the column can
   *          participate in structure alignment)
   * @param structures
   *          an array of data beans corresponding to pdb file index
   * @return
   */
  protected int findSuperposableResidues(AlignmentI alignment,
          BitSet matched, SuperposeData[] structures)
  {
    int refStructure = -1;
    String[] files = getStructureFiles();
    if (files == null)
    {
      return -1;
    }
    for (int pdbfnum = 0; pdbfnum < files.length; pdbfnum++)
    {
      StructureMapping[] mappings = getSsm().getMapping(files[pdbfnum]);
      int lastPos = -1;

      /*
       * Find the first mapped sequence (if any) for this PDB entry which is in
       * the alignment
       */
      final int seqCountForPdbFile = getSequence()[pdbfnum].length;
      for (int s = 0; s < seqCountForPdbFile; s++)
      {
        for (StructureMapping mapping : mappings)
        {
          final SequenceI theSequence = getSequence()[pdbfnum][s];
          if (mapping.getSequence() == theSequence
                  && alignment.findIndex(theSequence) > -1)
          {
            if (refStructure < 0)
            {
              refStructure = pdbfnum;
            }
            for (int r = 0; r < alignment.getWidth(); r++)
            {
              if (!matched.get(r))
              {
                continue;
              }
              int pos = getMappedPosition(theSequence, r, mapping);
              if (pos < 1 || pos == lastPos)
              {
                matched.clear(r);
                continue;
              }
              lastPos = pos;
              structures[pdbfnum].pdbResNo[r] = pos;
            }
            String chain = mapping.getChain();
            if (chain != null && chain.trim().length() > 0)
            {
              structures[pdbfnum].chain = chain;
            }
            structures[pdbfnum].pdbId = mapping.getPdbId();
            structures[pdbfnum].isRna = theSequence.getRNA() != null;

            /*
             * move on to next pdb file (ignore sequences for other chains
             * for the same structure)
             */
            s = seqCountForPdbFile;
            break;
          }
        }
      }
    }
    return refStructure;
  }

  /**
   * Returns true if the structure viewer has loaded all of the files of
   * interest (identified by the file mapping having been set up), or false if
   * any are still not loaded after a timeout interval.
   * 
   * @param files
   */
  protected boolean waitForFileLoad(String[] files)
  {
    /*
     * give up after 10 secs plus 1 sec per file
     */
    long starttime = System.currentTimeMillis();
    long endTime = 10000 + 1000 * files.length + starttime;
    String notLoaded = null;

    boolean waiting = true;
    while (waiting && System.currentTimeMillis() < endTime)
    {
      waiting = false;
      for (String file : files)
      {
        notLoaded = file;
        if (file == null)
        {
          continue;
        }
        try
        {
          StructureMapping[] sm = getSsm().getMapping(file);
          if (sm == null || sm.length == 0)
          {
            waiting = true;
          }
        } catch (Throwable x)
        {
          waiting = true;
        }
      }
    }

    if (waiting)
    {
      System.err.println(
              "Timed out waiting for structure viewer to load file "
                      + notLoaded);
      return false;
    }
    return true;
  }

  @Override
  public boolean isListeningFor(SequenceI seq)
  {
    if (sequence != null)
    {
      for (SequenceI[] seqs : sequence)
      {
        if (seqs != null)
        {
          for (SequenceI s : seqs)
          {
            if (s == seq || (s.getDatasetSequence() != null
                    && s.getDatasetSequence() == seq.getDatasetSequence()))
            {
              return true;
            }
          }
        }
      }
    }
    return false;
  }

  public boolean isFinishedInit()
  {
    return finishedInit;
  }

  public void setFinishedInit(boolean fi)
  {
    this.finishedInit = fi;
  }

  /**
   * Returns a list of chains mapped in this viewer, formatted as
   * "pdbid:chainCode"
   * 
   * @return
   */
  public List<String> getChainNames()
  {
    return chainNames;
  }

  /**
   * Returns the Jalview panel hosting the structure viewer (if any)
   * 
   * @return
   */
  public JalviewStructureDisplayI getViewer()
  {
    return viewer;
  }

  public void setViewer(JalviewStructureDisplayI v)
  {
    viewer = v;
  }

  /**
   * Constructs and sends a command to align structures against a reference
   * structure, based on one or more sequence alignments. May optionally return
   * an error or warning message for the alignment command.
   * 
   * @param alignments
   *          an array of alignments to process
   * @param structureIndices
   *          an array of corresponding reference structures (index into pdb
   *          file array); if a negative value is passed, the first PDB file
   *          mapped to an alignment sequence is used as the reference for
   *          superposition
   * @param hiddenCols
   *          an array of corresponding hidden columns for each alignment
   * @return
   */
  public abstract String superposeStructures(AlignmentI[] alignments,
          int[] structureIndices, HiddenColumns[] hiddenCols);

  /**
   * returns the current sequenceRenderer that should be used to colour the
   * structures
   * 
   * @param alignment
   * 
   * @return
   */
  public abstract SequenceRenderer getSequenceRenderer(
          AlignmentViewPanel alignment);

  /**
   * Sends a command to the structure viewer to colour each chain with a
   * distinct colour (to the extent supported by the viewer)
   */
  public void colourByChain()
  {
    colourBySequence = false;

    // TODO: JAL-628 colour chains distinctly across all visible models

    executeCommand(commandGenerator.colourByChain(), false,
            COLOURING_STRUCTURES);
  }

  /**
   * Sends a command to the structure viewer to colour each chain with a
   * distinct colour (to the extent supported by the viewer)
   */
  public void colourByCharge()
  {
    colourBySequence = false;

    executeCommand(commandGenerator.colourByCharge(), false,
            COLOURING_STRUCTURES);
  }

  /**
   * Sends a command to the structure to apply a colour scheme (defined in
   * Jalview but not necessarily applied to the alignment), which defines a
   * colour per residue letter. More complex schemes (e.g. that depend on
   * consensus) cannot be used here and are ignored.
   * 
   * @param cs
   */
  public void colourByJalviewColourScheme(ColourSchemeI cs)
  {
    colourBySequence = false;

    if (cs == null || !cs.isSimple())
    {
      return;
    }
    
    /*
     * build a map of {Residue3LetterCode, Color}
     */
    Map<String, Color> colours = new HashMap<>();
    List<String> residues = ResidueProperties.getResidues(isNucleotide(),
            false);
    for (String resName : residues)
    {
      char res = resName.length() == 3
              ? ResidueProperties.getSingleCharacterCode(resName)
              : resName.charAt(0);
      Color colour = cs.findColour(res, 0, null, null, 0f);
      colours.put(resName, colour);
    }

    /*
     * pass to the command constructor, and send the command
     */
    String cmd = commandGenerator.colourByResidues(colours);
    executeCommand(cmd, false, COLOURING_STRUCTURES);
  }

  public void setBackgroundColour(Color col)
  {
    String cmd = commandGenerator.setBackgroundColour(col);
    executeCommand(cmd, false, null);
  }

  /**
   * Sends one command to the structure viewer. If {@code getReply} is true, the
   * command is sent synchronously, otherwise in a deferred thread.
   * <p>
   * If a progress message is supplied, this is displayed before command
   * execution, and removed afterwards.
   * 
   * @param cmd
   * @param getReply
   * @param msg
   * @return
   */
  private List<String> executeCommand(String cmd, boolean getReply,
          String msg)
  {
    if (getReply)
    {
      return executeSynchronous(cmd, msg, getReply);
    }
    else
    {
      executeAsynchronous(cmd, msg);
      return null;
    }
  }

  /**
   * Sends the command in the current thread. If a message is supplied, this is
   * shown before the thread is started, and removed when it completes. May
   * return a reply to the command if requested.
   * 
   * @param cmd
   * @param msg
   * @param getReply
   * @return
   */
  private List<String> executeSynchronous(String cmd, String msg, boolean getReply)
  {
    final JalviewStructureDisplayI theViewer = getViewer();
    final long handle = msg == null ? 0 : theViewer.startProgressBar(msg);
    try
    {
      return executeCommand(cmd, getReply);
    } finally
    {
      if (msg != null)
      {
        theViewer.stopProgressBar(null, handle);
      }
    }
  }

  /**
   * Sends the command in a separate thread. If a message is supplied, this is
   * shown before the thread is started, and removed when it completes. No value
   * is returned.
   * 
   * @param cmd
   * @param msg
   */
  private void executeAsynchronous(String cmd, String msg)
  {
    final JalviewStructureDisplayI theViewer = getViewer();
    final long handle = msg == null ? 0 : theViewer.startProgressBar(msg);

    SwingUtilities.invokeLater(new Runnable()
    {
      @Override
      public void run()
      {
        try
        {
          executeCommand(cmd, false);
        } finally
        {
          if (msg != null)
          {
            theViewer.stopProgressBar(null, handle);
          }
        }
      }
    });
  }

  protected abstract List<String> executeCommand(String command,
          boolean getReply);

  protected List<String> executeCommands(boolean getReply,
          String... commands)
  {
    List<String> response = null;
    for (String cmd : commands)
    {
      response = executeCommand(cmd, getReply);
    }
    return response;
  }

  /**
   * colour any structures associated with sequences in the given alignment
   * using the getFeatureRenderer() and getSequenceRenderer() renderers but only
   * if colourBySequence is enabled.
   */
  public void colourBySequence(AlignmentViewPanel alignmentv)
  {
    if (!colourBySequence || !isLoadingFinished())
    {
      return;
    }
    if (getSsm() == null)
    {
      return;
    }
    String[] files = getStructureFiles();

    SequenceRenderer sr = getSequenceRenderer(alignmentv);

    String[] colourBySequenceCommands = commandGenerator
            .colourBySequence(getSsm(), files, getSequence(), sr,
                    alignmentv);
    executeCommands(false, colourBySequenceCommands);
  }

  /**
   * Centre the display in the structure viewer
   */
  public void focusView()
  {
    executeCommand(commandGenerator.focusView(), false);
  }

  /**
   * Generates and executes a command to show only specified chains in the
   * structure viewer. The list of chains to show should contain entries
   * formatted as "pdbid:chaincode".
   * 
   * @param toShow
   */
  public void showChains(List<String> toShow)
  {
    // todo or reformat toShow list entries as modelNo:pdbId:chainCode ?

    /*
     * Reformat the pdbid:chainCode values as modelNo:chainCode
     * since this is what is needed to construct the viewer command
     * todo: find a less messy way to do this
     */
    List<String> showThese = new ArrayList<>();
    for (String chainId : toShow)
    {
      String[] tokens = chainId.split("\\:");
      if (tokens.length == 2)
      {
        String pdbFile = getFileForChain(chainId);
        int modelNo = getModelNoForFile(pdbFile);
        String model = modelNo == -1 ? "" : String.valueOf(modelNo);
        showThese.add(model + ":" + tokens[1]);
      }
    }
    executeCommand(commandGenerator.showChains(showThese), false);
  }

  /**
   * Answers the structure viewer's model number given a PDB file name. Returns
   * -1 if model number is not found.
   * 
   * @param chainId
   * @return
   */
  protected abstract int getModelNoForFile(String chainId);

  public boolean hasFileLoadingError()
  {
    return fileLoadingError != null && fileLoadingError.length() > 0;
  }

  /**
   * Returns the FeatureRenderer for the given alignment view, or null if
   * feature display is turned off in the view.
   * 
   * @param avp
   * @return
   */
  public FeatureRenderer getFeatureRenderer(AlignmentViewPanel avp)
  {
    AlignmentViewPanel ap = (avp == null) ? getViewer().getAlignmentPanel()
            : avp;
    return ap.getAlignViewport().isShowSequenceFeatures()
            ? ap.getFeatureRenderer()
            : null;
  }

  protected void setStructureCommands(StructureCommandsI cmd)
  {
    commandGenerator = cmd;
  }

  /**
   * Records association of one chain id (formatted as "pdbid:chainCode") with
   * the corresponding PDB file name
   * 
   * @param chainId
   * @param fileName
   */
  public void addChainFile(String chainId, String fileName)
  {
    chainFile.put(chainId, fileName);
  }

  /**
   * Returns the PDB filename for the given chain id (formatted as
   * "pdbid:chainCode"), or null if not found
   * 
   * @param chainId
   * @return
   */
  protected String getFileForChain(String chainId)
  {
    return chainFile.get(chainId);
  }

  @Override
  public void updateColours(Object source)
  {
    AlignmentViewPanel ap = (AlignmentViewPanel) source;
    // ignore events from panels not used to colour this view
    if (!getViewer().isUsedForColourBy(ap))
    {
      return;
    }
    if (!isLoadingFromArchive())
    {
      colourBySequence(ap);
    }
  }
}