/*******************************************************************************
 * Copyright (c) 2012 IT Just working.
 * 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:
 *     IT Just working - initial API and implementation
 *******************************************************************************/
package com.minres.scviewer.database.text;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.GZIPInputStream;

import org.mapdb.BTreeMap;
import org.mapdb.DB;
import org.mapdb.DB.TreeMapSink;
import org.mapdb.DBMaker;
import org.mapdb.Serializer;
import org.mapdb.serializer.SerializerArrayTuple;

import com.minres.scviewer.database.AssociationType;
import com.minres.scviewer.database.DataType;
import com.minres.scviewer.database.EventKind;
import com.minres.scviewer.database.IWaveform;
import com.minres.scviewer.database.IWaveformDb;
import com.minres.scviewer.database.IWaveformDbLoader;
import com.minres.scviewer.database.InputFormatException;
import com.minres.scviewer.database.RelationType;
import com.minres.scviewer.database.tx.ITx;
import com.minres.scviewer.database.tx.ITxAttributeType;

public class TextDbLoader implements IWaveformDbLoader{

	private Long maxTime=0L;

	Map<String, RelationType> relationTypes=new HashMap<String, RelationType>();

	DB mapDb;
    
    TreeMap<Long, TxStream> txStreams;
    
    TreeMap<Long, TxGenerator> txGenerators;
    
    BTreeMap<Long, ScvTx> transactions;
    
    BTreeMap<Long[], ScvRelation> relations; 

    BTreeMap<String[], TxAttributeType> attributeTypes; 

    HashMap<Long, Tx> txCache = new HashMap<>();

    @Override
	public Long getMaxTime() {
		return maxTime;
	}

	@Override
	public Collection<IWaveform> getAllWaves() {
		return new ArrayList<>(txStreams.values());
	}

	static final byte[] x = "scv_tr_stream".getBytes();

	@SuppressWarnings("unchecked")
	@Override
	public	boolean load(IWaveformDb db, File file) throws InputFormatException {
		if(file.isDirectory() || !file.exists()) return false;
		TextDbParser parser = new TextDbParser(this);
		boolean gzipped = isGzipped(file);
		try {
		if(!isTxfile(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file)))
			return false;
		} catch(Exception e) {
			throw new InputFormatException();
		}
		File mapDbFile;
		try {
			mapDbFile = File.createTempFile("."+file.getName(), null /*"tmp"*/, null /*file.parentFile*/);
		} catch (IOException e1) {
			return false;
		}
		mapDbFile.delete(); // we just need a file name
		mapDbFile.deleteOnExit();
		mapDb = DBMaker
				.fileDB(mapDbFile)
				.fileMmapEnableIfSupported()
				.fileMmapPreclearDisable()
				.cleanerHackEnable()
				.allocateStartSize(64*1024*1024)
				.allocateIncrement(64*1024*1024)
				.make();
		TreeMapSink<Long, ScvTx> txSink = mapDb.treeMap("transactions", Serializer.LONG,Serializer.JAVA).createFromSink();
		relations = mapDb
				.treeMap("relations", new SerializerArrayTuple(Serializer.LONG, Serializer.LONG) ,Serializer.JAVA)
				.createOrOpen();
		attributeTypes = mapDb
				.treeMap("attributeTypes", new SerializerArrayTuple(Serializer.STRING, Serializer.STRING) ,Serializer.JAVA)
				.createOrOpen();
		try {
		      parser.setTransactionSink(txSink).setRelationMap(relations);
		      parser.parseInput(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file));
		} catch(IllegalArgumentException|ArrayIndexOutOfBoundsException e) {
		} catch(Exception e) {
			System.out.println("---->>> Exception "+e.toString()+" caught while loading database");
			e.printStackTrace();
			return false;
		}
		transactions=txSink.create();
		txStreams=new TreeMap<>(parser.streamsById);
		txGenerators=new TreeMap<>(parser.generatorsById);
		txCache.clear();
		return true;
	}

	private static boolean isTxfile(InputStream istream) {
		byte[] buffer = new byte[x.length];
		try {
			int readCnt = istream.read(buffer, 0, x.length);
			istream.close();
			if(readCnt==x.length){
				for(int i=0; i<x.length; i++)
					if(buffer[i]!=x[i]) return false;
			}
			return true;
		} catch (IOException e) {
			return false;
		}
	}

	private static boolean isGzipped(File f) {
		try(InputStream is = new FileInputStream(f)) {
			byte [] signature = new byte[2];
			int nread = is.read( signature ); //read the gzip signature
			return nread == 2 && signature[ 0 ] == (byte) 0x1f && signature[ 1 ] == (byte) 0x8b;
		} catch (IOException e) {
			return false;
		}
	}

	public Collection<RelationType> getAllRelationTypes(){
		return relationTypes.values();
	}

	static class TextDbParser {
		static final Pattern scv_tr_stream = Pattern.compile("^scv_tr_stream\\s+\\(ID (\\d+),\\s+name\\s+\"([^\"]+)\",\\s+kind\\s+\"([^\"]+)\"\\)$");
		static final Pattern scv_tr_generator = Pattern.compile("^scv_tr_generator\\s+\\(ID\\s+(\\d+),\\s+name\\s+\"([^\"]+)\",\\s+scv_tr_stream\\s+(\\d+),$");
		static final Pattern begin_attribute = Pattern.compile("^begin_attribute \\(ID (\\d+), name \"([^\"]+)\", type \"([^\"]+)\"\\)$");
		static final Pattern end_attribute = Pattern.compile("^end_attribute \\(ID (\\d+), name \"([^\"]+)\", type \"([^\"]+)\"\\)$");

		HashMap<Long, TxStream> streamsById = new HashMap<>();
		
		HashMap<Long, TxGenerator> generatorsById = new HashMap<>();
		
		HashMap<Long, ScvTx> transactionsById = new HashMap<>();
				
		final TextDbLoader loader;
		
		BufferedReader reader = null;
		
		TxGenerator generator = null;
		
		private TreeMapSink<Long, ScvTx> txSink;

		private BTreeMap<Long[], ScvRelation> relations;

		public TextDbParser(TextDbLoader loader) {
			super();
			this.loader = loader;
		}

		public TextDbParser setTransactionSink(TreeMapSink<Long, ScvTx> sink) {
			this.txSink=sink;
			return this;
		}

		public TextDbParser setRelationMap(BTreeMap<Long[], ScvRelation> relations) {
			this.relations=relations;
			return this;
		}

		void parseInput(InputStream inputStream) throws IOException{
			reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
			String curLine = reader.readLine();
			String nextLine = null;
			while((nextLine=reader.readLine())!=null && curLine!=null) {
				curLine=parseLine(curLine, nextLine);
			}
			if(curLine!=null)
				parseLine(curLine, nextLine);
		}

		private TxAttributeType getAttrType(String name, DataType dataType, AssociationType type){
			String[] key = new String[] {name, dataType.toString()};
			TxAttributeType res;
			if(loader.attributeTypes.containsKey(key)){
				res=loader.attributeTypes.get(key);
			} else {
				res=new TxAttributeType(name, dataType, type);
				loader.attributeTypes.put(key, res);
			}
			return res;
		}

		private String parseLine(String curLine, String nextLine) throws IOException{
			String[] tokens = curLine.split("\\s+");
			if("tx_record_attribute".equals(tokens[0])){//matcher = line =~ /^tx_record_attribute\s+(\d+)\s+"([^"]+)"\s+(\S+)\s*=\s*(.+)$/
				Long id = Long.parseLong(tokens[1]);
				String name = tokens[2].substring(1, tokens[2].length());
				DataType type = DataType.valueOf(tokens[3]);
				String remaining = tokens.length>5?String.join(" ", Arrays.copyOfRange(tokens, 5, tokens.length-1)):"";
				TxAttributeType attrType = getAttrType(name, type, AssociationType.RECORD);
				transactionsById.get(id).attributes.add(new TxAttribute(attrType, remaining));
			} else if("tx_begin".equals(tokens[0])){
				Long id = Long.parseLong(tokens[1]);
				Long genId = Long.parseLong(tokens[2]);
				TxGenerator gen=generatorsById.get(genId);
				ScvTx tx = new ScvTx(id, gen.stream.getId(), genId, Long.parseLong(tokens[3])*stringToScale(tokens[4]));
				transactionsById.put(id, tx);
				loader.maxTime = loader.maxTime>tx.beginTime?loader.maxTime:tx.beginTime;
				TxStream stream = streamsById.get(gen.stream.getId());
				stream.setConcurrency(stream.getConcurrency()+1);
				if(nextLine!=null && nextLine.charAt(0)=='a') {
					int idx=0;
					while(nextLine!=null && nextLine.charAt(0)=='a') {
						String[] attrTokens=nextLine.split("\\s+");
						TxAttribute attr = new TxAttribute(gen.beginAttrs.get(idx), attrTokens[1]);
						tx.attributes.add(attr);
						idx++;
						nextLine=reader.readLine();
					}
				}
				txSink.put(tx.id, tx);
			} else if("tx_end".equals(tokens[0])){//matcher = line =~ /^tx_end\s+(\d+)\s+(\d+)\s+(\d+)\s+([munpf]?s)/
				Long id = Long.parseLong(tokens[1]);
				ScvTx tx = transactionsById.get(id);
				assert Long.parseLong(tokens[2])==tx.generatorId;
				tx.endTime=Long.parseLong(tokens[3])*stringToScale(tokens[4]);
				loader.maxTime = loader.maxTime>tx.endTime?loader.maxTime:tx.endTime;
				TxGenerator gen = generatorsById.get(tx.generatorId);
				TxStream stream = streamsById.get(gen.stream.getId());
				if(tx.beginTime==tx.endTime)
					stream.addEvent(new TxEvent(loader, EventKind.SINGLE, id, tx.beginTime));
				else {
					stream.addEvent(new TxEvent(loader, EventKind.BEGIN, id, tx.beginTime));
					stream.addEvent(new TxEvent(loader, EventKind.END, id, tx.endTime));
				}
				stream.setConcurrency(stream.getConcurrency()-1);
				if(nextLine!=null && nextLine.charAt(0)=='a') {
					int idx=0;
					while(nextLine!=null && nextLine.charAt(0)=='a') {
						String[] attrTokens=nextLine.split("\\s+");
						TxAttribute attr = new TxAttribute(gen.endAttrs.get(idx), attrTokens[1]);
						tx.attributes.add(attr);
						idx++;
						nextLine=reader.readLine();
					}
				}
				transactionsById.remove(tx.id);
			} else if("tx_relation".equals(tokens[0])){//matcher = line =~ /^tx_relation\s+\"(\S+)\"\s+(\d+)\s+(\d+)$/
				Long tr2= Long.parseLong(tokens[2]);
				Long tr1= Long.parseLong(tokens[3]);
				String relType=tokens[1].substring(1, tokens[1].length()-2);
				if(!loader.relationTypes.containsKey(relType))
					loader.relationTypes.put(relType, RelationType.create(relType));
				ScvRelation rel = new ScvRelation(loader.relationTypes.get(relType), tr1, tr2);
				relations.put(new Long[]{tr1, tr2}, rel);
			} else if("scv_tr_stream".equals(tokens[0])){
				Matcher matcher = scv_tr_stream.matcher(curLine);
				if (matcher.matches()) {
					Long id = Long.parseLong(matcher.group(1));
					TxStream stream = new TxStream(loader, id, matcher.group(2), matcher.group(3));
					streamsById.put(id, stream);
				}
			} else if("scv_tr_generator".equals(tokens[0])){
				Matcher matcher = scv_tr_generator.matcher(curLine);
				if ((matcher.matches())) {
					Long id = Long.parseLong(matcher.group(1));
					TxStream stream=streamsById.get(Long.parseLong(matcher.group(3)));
					generator=new TxGenerator(id, stream, matcher.group(2));
					generatorsById.put(id,  generator);
				}
			} else if("begin_attribute".equals(tokens[0])){
				Matcher matcher = begin_attribute.matcher(curLine);
				if ((matcher.matches())) {
					TxAttributeType attrType = getAttrType(matcher.group(2), DataType.valueOf(matcher.group(3)), AssociationType.BEGIN);
					generator.beginAttrs.add(attrType);
				}
			} else if("end_attribute".equals(tokens[0])){
				Matcher matcher = end_attribute.matcher(curLine);
				if ((matcher.matches())) {
					TxAttributeType attrType = getAttrType(matcher.group(2), DataType.valueOf(matcher.group(3)), AssociationType.END);
					generator.endAttrs.add(attrType);
				}
			} else if(")".equals(tokens[0])){
				generator=null;
			} else if("a".equals(tokens[0])){//matcher = line =~ /^a\s+(.+)$/
				System.out.println("Don't know what to do with: '"+curLine+"'");
			} else
				System.out.println("Don't know what to do with: '"+curLine+"'");
			return nextLine;
		}
		
		private long stringToScale(String scale){
			String cmp = scale.trim();
			if("fs".equals(cmp)) return 1L;
			if("ps".equals(cmp)) return 1000L;
			if("ns".equals(cmp)) return 1000000L;
			if("us".equals(cmp)) return 1000000000L;
			if("ms".equals(cmp)) return 1000000000000L;
			if("s".equals(cmp) ) return 1000000000000000L;
			return 1L;
		}
	}

	public ITx getTransaction(Long txId) {
		if(txCache.containsKey(txId))
			return txCache.get(txId);
		Tx tx = new Tx(this, txId);
		txCache.put(txId, tx);
		return tx;
	}
}