/*
 *                    BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 * Created on 01-21-2010
 */
package org.biojava.nbio.core.sequence.io;

import org.biojava.nbio.core.exceptions.ParserException;
import org.biojava.nbio.core.sequence.compound.AminoAcidCompound;
import org.biojava.nbio.core.sequence.compound.NucleotideCompound;
import org.biojava.nbio.core.sequence.io.util.ClasspathResource;
import org.biojava.nbio.core.sequence.io.util.IOUtils;
import org.biojava.nbio.core.sequence.template.AbstractCompoundSet;
import org.biojava.nbio.core.sequence.template.CompoundSet;
import org.biojava.nbio.core.sequence.transcription.Table;

import java.io.InputStream;
import java.util.*;


/**
 * Available translations
 *
 * <ul>
 * <li>1 - UNIVERSAL</li>
 * <li>2 - VERTEBRATE_MITOCHONDRIAL</li>
 * <li>3 - YEAST_MITOCHONDRIAL</li>
 * <li>4 - MOLD_MITOCHONDRIAL</li>
 * <li>5 - INVERTEBRATE_MITOCHONDRIAL</li>
 * <li>6 - CILIATE_NUCLEAR</li>
 * <li>9 - ECHINODERM_MITOCHONDRIAL</li>
 * <li>10 - EUPLOTID_NUCLEAR</li>
 * <li>11 - BACTERIAL</li>
 * <li>12 - ALTERNATIVE_YEAST_NUCLEAR</li>
 * <li>13 - ASCIDIAN_MITOCHONDRIAL</li>
 * <li>14 - FLATWORM_MITOCHONDRIAL</li>
 * <li>15 - BLEPHARISMA_MACRONUCLEAR</li>
 * <li>16 - 2CHLOROPHYCEAN_MITOCHONDRIAL</li>
 * <li>21 - TREMATODE_MITOCHONDRIAL</li>
 * <li>23 - SCENEDESMUS_MITOCHONDRIAL</li>
 * </ul>
 *
 * Taken from <a
 * href="http://www.ncbi.nlm.nih.gov/Taxonomy/Utils/wprintgc.cgi?mode=c"
 * >NCBI</a> with slight modification and put into the classpath resource.
 *
 * Takes in an ID, name, amino acid string and the locations of amino acids
 * which acts as start codons in the translation table. You can give the 3 codon
 * position strings that correspond to the amino acid string or if you are using
 * the default IUPAC codes you can use the hardcoded ones which are consistent
 * amongst all <a
 * href="http://www.ncbi.nlm.nih.gov/Taxonomy/Utils/wprintgc.cgi?mode=c"> codon
 * tables</a>.
 *
 * The generated {@link IUPACTable} objects do not parse the data further until
 * requested so if you do not use a translation table your only penalty is the
 * loading of the IUPAC data from the classpath.
 *
 * @author Andy Yates
 */
public class IUPACParser {

	private static class IOD {
		public static final IUPACParser INSTANCE = new IUPACParser();
	}

	public static IUPACParser getInstance() {
		return IOD.INSTANCE;
	}

	public static final String      IUPAC_LOCATION = "org/biojava/nbio/core/sequence/iupac.txt";

	private InputStream              is;
	private List<IUPACTable>         tables;
	private Map<String, IUPACTable>  nameLookup;
	private Map<Integer, IUPACTable> idLookup;

	/**
	 * Default version and uses the classpath based IUPAC table
	 */
	public IUPACParser() {
		//use the preCache version to make sure we don't keep a IO handle open
		is = new ClasspathResource(IUPAC_LOCATION, true).getInputStream();
	}

	/**
	 * Allows you to specify a different IUPAC table.
	 */
	public IUPACParser(InputStream is) {
		this.is = is;
	}

	/**
	 * Returns a list of all available IUPAC tables
	 */
	public List<IUPACTable> getTables() {
		if (tables == null) {
			tables = parseTables();
		}
		return tables;
	}

	/**
	 * Returns a table by its name
	 */
	public IUPACTable getTable(String name) {
		populateLookups();
		return nameLookup.get(name);
	}

	/**
	 * Returns a table by its identifier i.e. 1 means universal codon tables
	 */
	public IUPACTable getTable(Integer id) {
		populateLookups();
		return idLookup.get(id);
	}

	private void populateLookups() {
		if(nameLookup == null) {
			nameLookup = new HashMap<String, IUPACTable>();
			idLookup = new HashMap<Integer, IUPACTable>();
			for(IUPACTable t: getTables()) {
				nameLookup.put(t.getName(), t);
				idLookup.put(t.getId(), t);
			}
		}
	}

	private List<IUPACTable> parseTables() {
		List<IUPACTable> localTables = new ArrayList<IUPACTable>();
		List<String> lines = IOUtils.getList(is);
		Integer id = null;
		String name, aa, starts, baseone, basetwo, basethree;
		name = aa = starts = baseone = basetwo = basethree = null;
		for (String line : lines) {
			if (line.equalsIgnoreCase("//")) {
				localTables.add(new IUPACTable(name, id, aa, starts, baseone, basetwo,
						basethree));
				name = aa = starts = baseone = basetwo = basethree = null;
				id = null;
			}
			else {
				String[] keyValue = line.split("\\s*=\\s*");
				if (keyValue[0].equals("AAs")) {
					aa = keyValue[1];
				}
				else if (keyValue[0].equals("Starts")) {
					starts = keyValue[1];
				}
				else if (keyValue[0].equals("Base1")) {
					baseone = keyValue[1];
				}
				else if (keyValue[0].equals("Base2")) {
					basetwo = keyValue[1];
				}
				else if (keyValue[0].equals("Base3")) {
					basethree = keyValue[1];
				}
				else {
					name = keyValue[0];
					id = Integer.parseInt(keyValue[1]);
				}
			}
		}

		return localTables;
	}

	/**
	 * Holds the concept of a codon table from the IUPAC format
	 *
	 * @author Andy Yates
	 */
	public static class IUPACTable implements Table {

		private final Integer      id;
		private final String       name;
		private final String       aminoAcidString;
		private final String       startCodons;
		private final String       baseOne;
		private final String       baseTwo;
		private final String       baseThree;

		private final List<Codon>  codons    = new ArrayList<Codon>();
		private CompoundSet<Codon> compounds = null;

		public IUPACTable(String name, int id, String aminoAcidString,
				String startCodons, String baseOne, String baseTwo, String baseThree) {
			this.aminoAcidString = aminoAcidString;
			this.startCodons = startCodons;
			this.name = name;
			this.id = id;
			this.baseOne = baseOne;
			this.baseTwo = baseTwo;
			this.baseThree = baseThree;
		}

		/**
		 * Constructor which uses the basic IUPAC codon table format. Useful
		 * if you need to specify your own IUPAC table with minimal
		 * definitions from your side.
		 */
		public IUPACTable(String name, Integer id, String aminoAcidString,
				String startCodons) {
			this(name, id, aminoAcidString, startCodons,
					"TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG",
					"TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG",
					"TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG");
		}

		public Integer getId() {
			return id;
		}

		public String getName() {
			return name;
		}

		/**
		 * Returns true if the given compound was a start codon in this
		 * codon table. This will report true if the compound could ever have
		 * been a start codon.
		 *
		 * @throws IllegalStateException Thrown if
		 * {@link #getCodons(CompoundSet, CompoundSet)} was not called first.
		 */
				@Override
		public boolean isStart(AminoAcidCompound compound) throws IllegalStateException {
			if(this.codons.isEmpty()) {
				throw new IllegalStateException("Codons are empty; please request getCodons() fist before asking this");
			}
			for(Codon codon: codons) {
				//Only check if the codon was a start codon and then ask if the compound was encoded by it
				if(codon.isStart()) {
					if(codon.getAminoAcid().equalsIgnoreCase(compound)) {
						return true;
					}
				}
			}
			return false;
		}

		/**
		 * Returns a list of codons where the source and target compounds
		 * are the same as those given by the parameters.
		 *
		 * @param nucleotides The nucleotide set to use when building BioJava
		 * representations of codons
		 * @param aminoAcids The target amino acid compounds objects
		 */
				@Override
		public List<Codon> getCodons(CompoundSet<NucleotideCompound> nucelotides,
				CompoundSet<AminoAcidCompound> aminoAcids) {

			if (this.codons.isEmpty()) {
				List<String> aminoAcidStrings = aminoAcids();
				List<String> startCodonStrings = startCodons();
				List<List<String>> codonStrings = codonStrings();

				for (int i = 0; i < aminoAcidStrings.size(); i++) {

					List<String> codonString    = codonStrings.get(i);
					NucleotideCompound one      = getCompound(codonString, 0, nucelotides);
					NucleotideCompound two      = getCompound(codonString, 1, nucelotides);
					NucleotideCompound three    = getCompound(codonString, 2, nucelotides);
					boolean start               = ("M".equals(startCodonStrings.get(i)));
					boolean stop                = ("*".equals(aminoAcidStrings.get(i)));
					AminoAcidCompound aminoAcid = aminoAcids
							.getCompoundForString(aminoAcidStrings.get(i));
					codons.add(new Codon(new CaseInsensitiveTriplet(one, two, three), aminoAcid, start, stop));
				}
			}

			return codons;
		}

		private NucleotideCompound getCompound(List<String> compounds,
				int position, CompoundSet<NucleotideCompound> nucelotides) {
			String compound = compounds.get(position);
			NucleotideCompound returnCompound = nucelotides
					.getCompoundForString(compound);
			if (returnCompound == null) {
				if ("T".equalsIgnoreCase(compound)) {
						returnCompound = nucelotides.getCompoundForString("U");
				}
				else {
					throw new ParserException("Cannot find a compound for string "
							+ compound);
				}
			}
			return returnCompound;
		}

		/**
		 * Returns the compound set of codons
		 */
		@Override
	public CompoundSet<Codon> getCodonCompoundSet(
				final CompoundSet<NucleotideCompound> rnaCompounds,
				final CompoundSet<AminoAcidCompound> aminoAcidCompounds) {
			if (compounds == null) {
				compounds = new AbstractCompoundSet<Codon>() {
					{
						for (Codon c : getCodons(rnaCompounds, aminoAcidCompounds)) {
							addCompound(c);
						}
					}
				};
			}
			return compounds;
		}

		private List<List<String>> codonStrings() {
			List<List<String>> codons = new ArrayList<List<String>>();
			for (int i = 0; i < baseOne.length(); i++) {
				List<String> codon = Arrays.asList(Character
						.toString(baseOne.charAt(i)),
						Character.toString(baseTwo.charAt(i)), Character.toString(baseThree
								.charAt(i)));
				codons.add(codon);
			}
			return codons;
		}

		private List<String> aminoAcids() {
			return split(aminoAcidString);
		}

		private List<String> startCodons() {
			return split(startCodons);
		}

		private List<String> split(String string) {
			List<String> split = new ArrayList<String>();
			for (int i = 0; i < string.length(); i++) {
				split.add(Character.toString(string.charAt(i)));
			}
			return split;
		}
	}
}
