package org.simantics.db.impl.query;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.simantics.db.impl.ClusterTraitsBase;

import gnu.trove.list.array.TByteArrayList;
import gnu.trove.map.hash.TLongIntHashMap;
import gnu.trove.procedure.TLongIntProcedure;

public class QuerySerializer {

    private QueryProcessor processor;
    private QuerySupport querySupport;
    private TByteArrayList bytes = new TByteArrayList();
    private TLongIntHashMap clusterKeys = new TLongIntHashMap();
    private Map<String,Integer> ids = new HashMap<String,Integer>();

    public QuerySerializer(QueryProcessor processor) {
        this.processor = processor;
        this.querySupport = processor.querySupport;
    }

    public int writeUnknownSize() {
        int pos = bytes.size();
        bytes.add((byte)0);
        bytes.add((byte)0);
        bytes.add((byte)0);
        bytes.add((byte)0);
        return pos;
    }

    public void setUnknownSize(int pos, int value) {
        bytes.set(pos, (byte) (value & 0xFF));
        bytes.set(pos+1, (byte) ((value >>> 8) & 0xFF));
        bytes.set(pos+2, (byte) ((value >>> 16) & 0xFF));
        bytes.set(pos+3, (byte) ((value >>> 24) & 0xFF));
    }

    public void serializeId(String classId) {
        Integer id = ids.get(classId);
        if(id == null) {
            id = ids.size() + 1;
            ids.put(classId, id);
        }
        writeLE(id);
    }

    public void addResource(int r) {
        if(r < 0) {
            writeLE(r);
        } else {
            long clusterId = querySupport.getClusterId(r);
            int clusterKey = clusterKeys.get(clusterId);
            if(clusterKey == 0) {
                clusterKey = clusterKeys.size() + 1;
                clusterKeys.put(clusterId, clusterKey);
            }
            int i = ClusterTraitsBase.createResourceKeyNoThrow(clusterKey, ClusterTraitsBase.getResourceIndexFromResourceKeyNoThrow(r));
            writeLE(i);
        }
    }

    public void addString(String s) {
        byte[] b = s.getBytes();
        writeLE(b.length);
        bytes.add(b);
    }

    public void add(byte b) {
        bytes.add(b);
    }

    public void add(byte[] bs) {
        bytes.add(bs);
    }

    public byte[] bytes() {
        TByteArrayList header = new TByteArrayList();
        writeLE(header, ids.size());
        for(Entry<String,Integer> entry : ids.entrySet()) {
            String id = entry.getKey();
            writeLE(header, id.length());
            header.add(id.getBytes());
            writeLE(header, entry.getValue());
        }

        writeLE(header, clusterKeys.size());
        clusterKeys.forEachEntry(new TLongIntProcedure() {

            @Override
            public boolean execute(long a, int b) {
                writeLE(header, a);
                writeLE(header, b);
                return true;
            }

        });

        header.add(bytes.toArray());
        return header.toArray();
    }

    public void writeLE(int value) {
        writeLE(bytes, value);
    }

    public static void writeLE(TByteArrayList bytes, int value) {
        bytes.add((byte) (value & 0xFF));
        bytes.add((byte) ((value >>> 8) & 0xFF));
        bytes.add((byte) ((value >>> 16) & 0xFF));
        bytes.add((byte) ((value >>> 24) & 0xFF));
    }

    public void writeLE(long value) {
        writeLE(bytes, value);
    }

    public static void writeLE(TByteArrayList bytes, long value) {
        bytes.add((byte) (value & 0xFF));
        bytes.add((byte) ((value >>> 8) & 0xFF));
        bytes.add((byte) ((value >>> 16) & 0xFF));
        bytes.add((byte) ((value >>> 24) & 0xFF));
        bytes.add((byte) ((value >>> 32) & 0xFF));
        bytes.add((byte) ((value >>> 40) & 0xFF));
        bytes.add((byte) ((value >>> 48) & 0xFF));
        bytes.add((byte) ((value >>> 56) & 0xFF));
    }

    public QueryProcessor getQueryProcessor() {
        return processor;
    }

}