package gov.nasa.gsfc.spdf.cdfj;
import java.nio.*;
import java.util.*;
import java.lang.reflect.*;
public abstract class BaseVarContainer implements Runnable {
    static final int chunkSize = 1024;
    final CDFImpl thisCDF;
    final Variable var;
    final int[] pt;
    final int[] overlap;
    final int type;
    final int itemSize;
    final int elements;
    final ByteOrder order;
    final Class _class;
    final int recordsPerChunk;
    final int csize;
    final boolean chunking;
    final Vector buffers = new Vector();
    final int fillCount;
    final boolean singlePoint;
    Boolean allocationMode;
    protected BaseVarContainer(CDFImpl thisCDF, Variable var, int[] pt,
        boolean preserve, ByteOrder bo, Class cl) throws IllegalAccessException,
        InvocationTargetException, Throwable {
        type = var.getType();
        if (!isCompatible(type, preserve, cl)) {
                throw new Throwable("Variable " + var.getName() + 
                " may result in loss of precision");
        } 
        this.thisCDF = (CDFImpl)thisCDF;
        this.var = var;
        order = bo;
        _class = cl;
        itemSize = var.getDataItemSize();
        elements = itemSize/DataTypes.size[type];
        int[] range = var.getRecordRange();
        if (range == null) {
//          if (pt == null) {  
                throw new Throwable("Variable " + var.getName() + " has no " +
                "records.");
//          }
        }
        if (pt == null) {
            singlePoint = false;
            this.pt = range;
        } else {
            singlePoint = (pt.length == 1);
            this.pt = (pt.length == 1)?new int[] {pt[0], pt[0]}:
                 new int[] {pt[0], pt[1]};
        }
        int _fillCount = 0;
        int[] _overlap = null;
        if (pt != null) {
            if (var.recordVariance()) {
                if (pt[0] < 0) {
                    throw new Throwable("Negative start of Record Range ");
                }
                if (pt.length > 1) {
                    if (pt[0] > pt[1]) {
                        throw new Throwable("Invalid record Range " +
                        "first " + pt[0] + ", last " + pt[1]);
                    }
                }
                
                if (!(var.missingRecordValueIsPad() ||
                     var.missingRecordValueIsPrevious())) {
                    if ((range[0] > pt[0]) || (range[1] < pt[0])) {
                        throw new Throwable("Invalid start of Record " +
                        "Range " + pt[0] + ". Available record range is " +
                        range[0] + " - " + range[1]);
                    }
                    if (pt.length > 1) {
                        if (range[1] < pt[1]) {
                            throw new Throwable("Invalid end of Record Range " +
                            pt[1] + ". Last available record is " + range[1]);
                        }
                        _overlap = new int[] {pt[0], pt[1]};
                    } else {
                        _overlap = new int[] {pt[0], pt[0]};
                    }
                } else {
                    if (pt.length == 1) {
                        if ((pt[0] < range[0]) || (pt[0] > range[1])) {
                            _fillCount = 1;
                        } else {
                            _overlap = new int[] {pt[0], pt[0]};
                        }
                    } else {
                        if ((pt[0] > range[1]) || (pt[1] < range[0])) {
                            _fillCount = pt[1] - pt[0] + 1;
                        } else { // partial overlap
                            if (pt[0] < range[0]) {
                                _fillCount = range[0] - pt[0];
                                _overlap = new int[] {range[0], pt[1]};
                            } else {
                                _overlap = new int[] {pt[0], pt[1]};
                            }
                        }
                    }
                }
            } else {
                _overlap = new int[] {0,0};
            }
        } else {
            _overlap = new int[] {range[0], range[1]};
        }
        fillCount = _fillCount;
        overlap = _overlap;
        if ((DataTypes.size[type] > 1) || (_class != Byte.TYPE)) {
            int _recordsPerChunk = (chunkSize/elements);
            recordsPerChunk = (_recordsPerChunk == 0)?1:_recordsPerChunk;
            csize = recordsPerChunk*elements;
            chunking = true;
        } else {
            recordsPerChunk = -1;
            csize = -1;
            chunking = false;
        }
    }

    public void setDirect(boolean direct) {
        if (allocationMode == null) allocationMode = new Boolean(direct);
    }

    ByteBuffer userBuffer;
    public boolean setUserBuffer(ByteBuffer buf) {
        if (allocationMode != null) return false;
        userBuffer = buf;
        return true;
    }
        
    public ByteBuffer getBuffer() {
        if (buffers.size() == 0) return null;
        ContentDescriptor cd = (ContentDescriptor)buffers.get(0);
        return cd.getBuffer();
    }

    public int[] getRecordRange() {
        if (buffers.size() == 0) return null;
        ContentDescriptor cd = (ContentDescriptor)buffers.get(0);
        return new int[] {cd.getFirstRecord(), cd.getLastRecord()};
    }

    public void run() {
        if (buffers.size() > 0) return;
        int numberOfValues = pt[1] - pt[0] + 1;
        int words = elements*numberOfValues;
        ByteBuffer _buf;
        if ( words > Integer.MAX_VALUE/getLength() ) {
            throw new IllegalArgumentException("Variable is too large to read, any variable must be less than 2GB in length.");
        }
        int _words = words*getLength();
        if (allocationMode == null) {
            if (userBuffer == null) {
                _buf = ByteBuffer.allocateDirect(_words);
            } else {
                 _buf = userBuffer;
            }
        } else {
            if (allocationMode.booleanValue()) {
                _buf = ByteBuffer.allocateDirect(_words);
             } else {
                _buf = ByteBuffer.allocate(_words);
             }
        }
        _buf.order(order);
        Object data = null;
        if (overlap == null) {
            data = allocateDataArray(words);
            doMissing(fillCount, _buf, data, -1);
            if (buffers.size() == 0) {
                buffers.add(new ContentDescriptor(_buf, pt[0], pt[1]));
            }
            return;
        }
        int begin = overlap[0];
        int end = overlap[1];
        if (chunking) {
            data = allocateDataArray((words < csize)?words:csize);
        }
        if (fillCount > 0) {
            doMissing(fillCount, _buf, data, -1);
        }
        Vector locations = ((CDFImpl.DataLocator)var.getLocator()).locations;
        ByteBuffer bv;
        int blk = 0;
        int next = begin;
        if (next > 0) {// position to first needed block
            int _first = -1;
            int prev = -1;
            for (; blk < locations.size(); blk++) {
                long [] loc = (long [])locations.elementAt(blk);
                _first = (int)loc[0];
                if (loc[1] >= next) break;
                prev = (int)loc[1];
            }
            int tofill = 0;
            if (blk == locations.size()) { // past prev available
                tofill = end - begin + 1;
                if (!(var.missingRecordValueIsPad() ||
                     var.missingRecordValueIsPrevious())) return;
            } else {
                if (next < _first) { // some missing records
                    tofill = _first - next;
                    if (end < _first) tofill = end + 1 - next;
                }
            }
            if (tofill > 0) {
                if (var.missingRecordValueIsPrevious()) {
                    doMissing(tofill, _buf, data, (blk == 0)?-1:prev);
                } else {
                    doMissing(tofill, _buf, data,  -1);
                }
                next += tofill;
                if (next > end) {
                    if (buffers.size() == 0) {
                        buffers.add(new ContentDescriptor(_buf, begin, end));
                    }
                    return;
                }
            }
        }
        // there is valid data to send back
        // begin may lie before blk. This is handled later
        boolean firstBlock = true;
        for (; blk < locations.size(); blk++) {
            long [] loc = (long [])locations.elementAt(blk);
            int first = (int)loc[0];
            int last = (int)loc[1];

            int count = (last - first + 1);
            bv = thisCDF.positionBuffer( var, loc[2], count);
            if (firstBlock) {
                if (pt != null) {
                    if (begin > first) {
                        int pos = bv.position() + (begin - first)*itemSize;
                        bv.position(pos);
                    }
                    if (end == begin) { // single point needed
                        try {
                            doData(bv, type, elements, 1, _buf, data);
                        } catch (Throwable ex) {
                            ex.printStackTrace();
                        }
                        if (buffers.size() == 0) {
                            buffers.add(new ContentDescriptor(_buf,
                            begin, end));
                        }
                        return;
                    }
                }
                firstBlock = false;
            } else {
                // pad if necessary
                if (next < first) { // next cannot exceed first
                    int target = (end >= first)?first:end + 1 ;
                    int n = target - next;
                    if (var.missingRecordValueIsPrevious()) {
                        int rec = (int)
                            ((long [])locations.elementAt(blk - 1))[1];
                        doMissing(n, _buf, data, rec);
                    } else {
                        doMissing(n, _buf, data,  -1);
                    }
                    if (target > end) break;
                    next = first;
                }
            }
            while (next <= end) {
                int rem = end - next + 1;
                int _count = last - next + 1;
                if (chunking) {
                    if (_count > recordsPerChunk) _count = recordsPerChunk;
                }
                if (_count > rem) _count = rem;
                try {
                    doData(bv, type, elements, _count, _buf, data);
                } catch (Throwable ex) {
                    ex.printStackTrace();
                    return;
                }
                //System.out.println(bv);
                //System.out.println(_buf);
                next += _count;
                if (next > last) break;
            }
            if (next > end) break;
        }
        if (next <= end) {
            if (var.missingRecordValueIsPrevious()) {
                doMissing(end - next + 1, _buf, data, (next - 1));
            } else {
                doMissing(end - next + 1, _buf, data,  -1);
            }
        }
        if (buffers.size() == 0) {
            buffers.add(new ContentDescriptor(_buf, begin, end));
        }
    }

    class ContentDescriptor {
        final ByteBuffer buf;
        final int first;
        final int last;
        protected ContentDescriptor(final ByteBuffer _buf, final int _first,
        final int _last) {
            buf = _buf;
            first = _first;
            last = _last;
        }
        ByteBuffer getBuffer() {
            ByteBuffer rbuf = buf.asReadOnlyBuffer();
            rbuf.order(buf.order());
            rbuf.position(0);
            return rbuf;
        }
        int getFirstRecord() {return first;}
        int getLastRecord() {return last;}
    }
    /* compatible means value is valid java type -- */
    public static boolean isCompatible(int type, boolean preserve, Class cl) {
        if (cl == Long.TYPE) {
            if (((DataTypes.typeCategory[type] == DataTypes.SIGNED_INTEGER) ||
               (DataTypes.typeCategory[type] == DataTypes.UNSIGNED_INTEGER))) {
                return true;
            }
            return (DataTypes.typeCategory[type] == DataTypes.LONG);
        }
        if (cl == Double.TYPE) {
            if (type > 50) return false;
            if (DataTypes.typeCategory[type] == DataTypes.LONG) {
                if (preserve) return false;
            }
            return true;
        }
        if (cl == Float.TYPE) {
            if (type > 50) return false;
            if (DataTypes.typeCategory[type] == DataTypes.FLOAT) return true;
            if ((DataTypes.typeCategory[type] == DataTypes.LONG) ||
               (DataTypes.typeCategory[type] == DataTypes.DOUBLE)) {
                if (preserve) return false;
            } else {
                if (preserve) {
                    if ((type == 4) || (type == 14)) return false;
                }
            }
            return true;
        }
        if (cl == Integer.TYPE) {
            if (type > 50) return false;
            if (!((DataTypes.typeCategory[type] == DataTypes.SIGNED_INTEGER) ||
               (DataTypes.typeCategory[type] == DataTypes.UNSIGNED_INTEGER))) {
                return false;
            } else {
                if (preserve && (type == 14)) return false;
            }
            return true;
        }
        if (cl == Short.TYPE) {
            if (type > 50) return false;
            if ((type == 1) || (type == 41) || (type == 2)) return true;
            if (type == 11) return true;
            if ((type == 12) && !preserve) return true;
            return false;
        }
        if (cl == Byte.TYPE) {
            if (preserve) {
                if ((type == 1) || (type == 41) || (type == 11)) return true;
                if (type > 50) return true;
                return false;
            }
            return true;
        }
        return false;
    }

    public int getCapacity() {
        int numberOfValues = pt[1] - pt[0] + 1;
        int words = elements*numberOfValues;
        return words*getLength();
    }

    abstract ByteBuffer allocateBuffer(int words);

    abstract Object allocateDataArray(int size);

    abstract void doData(ByteBuffer bv, int type, int elements, int toprocess,
        ByteBuffer buf, Object data) throws Throwable;

    abstract void doMissing(int records, ByteBuffer buf, Object data, int rec);

    int getLength() {
        if (_class == Long.TYPE) return 8;
        if (_class == Double.TYPE) return 8;
        if (_class == Float.TYPE) return 4;;
        if (_class == Integer.TYPE) return 4;
        if (_class == Short.TYPE) return 2;
        if (_class == Byte.TYPE) return 1;
        return -1;
    }

    static boolean validElement(Variable var, int[] idx) {
        int elements =
            (((Integer)var.getElementCount().elementAt(0))).intValue();
        for (int i = 0; i < idx.length; i++) {
            if ((idx[i] >= 0) && (idx[i] < elements)) continue;
            return false;
        }
        return true;
    }

    public Object asSampledArray(Stride stride) {
        int[] range = getRecordRange();
        int numberOfValues = range[1] - range[0] + 1;
        int _stride = stride.getStride(numberOfValues);
        if (_stride > 1) {
            int n = (numberOfValues/_stride);
            if ((numberOfValues % _stride) != 0) n++;
            numberOfValues = n;
        }
        ByteBuffer buf = getBuffer();
        if (buf == null) return null;
        int words = elements*numberOfValues;
        int advance = _stride*elements;
        int pos = 0;
        int off = 0;
        if (_class == Float.TYPE) {
            FloatBuffer _buf = buf.asFloatBuffer();
            float[] sampled = new float[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        if (_class == Double.TYPE) {
            DoubleBuffer _buf = buf.asDoubleBuffer();
            double[] sampled = new double[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        if (_class == Integer.TYPE) {
            IntBuffer _buf = buf.asIntBuffer();
            int[] sampled = new int[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        if (_class == Short.TYPE) {
            ShortBuffer _buf = buf.asShortBuffer();
            short[] sampled = new short[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        if (_class == Byte.TYPE) {
            ByteBuffer _buf = buf.duplicate();
            byte[] sampled = new byte[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        if (_class == Long.TYPE) {
            LongBuffer _buf = buf.asLongBuffer();
            long[] sampled = new long[words];
            for (int i = 0; i < numberOfValues; i++) {
                _buf.position(pos);
                _buf.get(sampled, off, elements);
                off += elements;    
                pos += advance;
            }
            return sampled;
        }
        return null;
    }

/*
    public static ArrayStore getArrayStore() {return new ArrayStore();}
    public static ArrayStore getArrayStore(Object o, int offset,
        int first, int last) throws Throwable {
        return new ArrayStore(o, offset, first, last);
    }
    static class ArrayStore {
        Object array;
        int offset;
        int length = -1;
        int first;
        ArrayStore() {
        }
        ArrayStore(Object o, int offset, int first, int last) throws 
            Throwable {
            Class c = componentType(o);
            if (c == null) throw new Throwable("not an array");
            if (!c.equals(_class)) throw new Throwable("incompatible type");
            length = elements*(last - first + 1);
            array = o;
            offset = off;
        }
        public Object getArray() {return array;}
        int getSize() {return length;}
        int getOffset() {return offset;}
    }
*/
    public Object as1DArray() {
        ByteBuffer b = getBuffer();
        if (b == null) return null;
        if (_class == Long.TYPE) {
            long[] la = new long[(b.remaining())/8];
            b.asLongBuffer().get(la);
            return la;
        }
        if (_class == Double.TYPE) {
            double[] da = new double[(b.remaining())/8];
            b.asDoubleBuffer().get(da);
            return da;
        }
        if (_class == Float.TYPE) {
            float[] fa = new float[(b.remaining())/4];
            b.asFloatBuffer().get(fa);
            return fa;
        }
        if (_class == Integer.TYPE) {
            int[] ia = new int[(b.remaining())/4];
            b.asIntBuffer().get(ia);
            return ia;
        }
        if (_class == Short.TYPE) {
            short[] sa = new short[(b.remaining())/2];
            b.asShortBuffer().get(sa);
            return sa;
        }
        byte[] ba = new byte[(b.remaining())];
        b.get(ba);
        return ba;
    }
    Class componentType(Object o) {
        if (!o.getClass().isArray()) return null;
        Class _cl = o.getClass();
        while (_cl.isArray()) {
            _cl = _cl.getComponentType();
        }
        return _cl;
    }
    public Variable getVariable() {return var;}
    public Object asOneDArray(boolean cmtarget) {
        return asOneDArray(cmtarget, null);
    }
    public Object asOneDArray(boolean cmtarget, Stride stride) {
        int[] dim = var.getEffectiveDimensions();
        if ((dim.length <= 1) ||
            (!cmtarget && var.rowMajority()) ||
            (cmtarget && !var.rowMajority())) {
            if (stride == null) return as1DArray();
            return asSampledArray(stride);
        }
        int[] _dim = dim;
        if (!var.rowMajority()) {
            _dim = new int[dim.length];
            for (int i = 0; i < dim.length; i++) {
                _dim[i] = dim[dim.length -1 -i];
            }
        }
        return makeArray(_dim, stride);
    }
    Object makeArray(int[] _dim, Stride stride) {
        ByteBuffer b = getBuffer();
        if (b == null) return null;
        int pt_size = -1;
        if (_dim.length == 2) pt_size = _dim[0]*_dim[1];
        if (_dim.length == 3) pt_size = _dim[0]*_dim[1]*_dim[2];
        int _stride = 1;
        int[] range = getRecordRange();
        int pts = range[1] - range[0] + 1;
        if (stride != null) {
            _stride = stride.getStride(pts);
            if (_stride > 1) {
                int n = (pts/_stride);
                if ((pts % _stride) != 0) n++;
                pts = n;
            }
        }
        int words = elements*pts;
        int advance = _stride*pt_size;
        int offset = 0;
        int n = 0;
        if (_class == Long.TYPE) {
            long[] la = new long[words];
            //pts = la.length/pt_size;
            LongBuffer lbuf = b.asLongBuffer();
            if (_dim.length == 2) {
                for (int p = 0; p < pts; p++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            la[n++] = lbuf.get(offset + i*_dim[1] + j);
                        }
                    }
                    offset += advance;
                }
            }
            if (_dim.length == 3) {
                for (int p = 0; p < pts; p++) {
                    for (int k = 0; k < _dim[2]; k++) {
                        for (int j = 0; j < _dim[1]; j++) {
                            for (int i = 0; i < _dim[0]; i++) {
                                la[n++] = lbuf.get(offset +
                                    i*_dim[1]*_dim[2] + j*_dim[2] + k);
                            }
                        }
                    }
                    offset += advance;
                }
            }
            return la;
        }
        if (_class == Double.TYPE) {
            double[] da = new double[words];
            //pts = da.length/pt_size;
            DoubleBuffer dbuf = b.asDoubleBuffer();
            if (_dim.length == 2) {
                for (int p = 0; p < pts; p++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            da[n++] = dbuf.get(offset + i*_dim[1] + j);
                        }
                    }
                    offset += advance;
                }
            }
            if (_dim.length == 3) {
                for (int p = 0; p < pts; p++) {
                    for (int k = 0; k < _dim[2]; k++) {
                        for (int j = 0; j < _dim[1]; j++) {
                            for (int i = 0; i < _dim[0]; i++) {
                                da[n++] = dbuf.get(offset +
                                    i*_dim[1]*_dim[2] + j*_dim[2] + k);
                            }
                        }
                    }
                    offset += advance;
                }
            }
            return da;
        }
        if (_class == Float.TYPE) {
            float[] fa = new float[words];
            //pts = fa.length/pt_size;
            FloatBuffer fbuf = b.asFloatBuffer();
            if (_dim.length == 2) {
                for (int p = 0; p < pts; p++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            fa[n++] = fbuf.get(offset + i*_dim[1] + j);
                        }
                    }
                    offset += advance;
                }
            }
            if (_dim.length == 3) {
                for (int p = 0; p < pts; p++) {
                    for (int k = 0; k < _dim[2]; k++) {
                        for (int j = 0; j < _dim[1]; j++) {
                            for (int i = 0; i < _dim[0]; i++) {
                                fa[n++] = fbuf.get(offset +
                                    i*_dim[1]*_dim[2] + j*_dim[2] + k);
                            }
                        }
                    }
                    offset += advance;
                }
            }
            return fa;
        }
        if (_class == Integer.TYPE) {
            int[] ia = new int[words];
            //pts = ia.length/pt_size;
            IntBuffer ibuf = b.asIntBuffer();
            if (_dim.length == 2) {
                for (int p = 0; p < pts; p++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            ia[n++] = ibuf.get(offset + i*_dim[1] + j);
                        }
                    }
                    offset += advance;
                }
            }
            if (_dim.length == 3) {
                for (int p = 0; p < pts; p++) {
                    for (int k = 0; k < _dim[2]; k++) {
                        for (int j = 0; j < _dim[1]; j++) {
                            for (int i = 0; i < _dim[0]; i++) {
                                ia[n++] = ibuf.get(offset +
                                    i*_dim[1]*_dim[2] + j*_dim[2] + k);
                            }
                        }
                    }
                    offset += advance;
                }
            }
            return ia;
        }
        if (_class == Short.TYPE) {
            short[] sa = new short[words];
            //pts = sa.length/pt_size;
            ShortBuffer sbuf = b.asShortBuffer();
            if (_dim.length == 2) {
                for (int p = 0; p < pts; p++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            sa[n++] = sbuf.get(offset + i*_dim[1] + j);
                        }
                    }
                    offset += advance;
                }
            }
            if (_dim.length == 3) {
                for (int p = 0; p < pts; p++) {
                    for (int k = 0; k < _dim[2]; k++) {
                        for (int j = 0; j < _dim[1]; j++) {
                            for (int i = 0; i < _dim[0]; i++) {
                                sa[n++] = sbuf.get(offset +
                                    i*_dim[1]*_dim[2] + j*_dim[2] + k);
                            }
                        }
                    }
                    offset += advance;
                }
            }
            return sa;
        }
        byte[] ba = new byte[words];
        //pts = ba.length/pt_size;
        if (_dim.length == 2) {
            for (int p = 0; p < pts; p++) {
                for (int j = 0; j < _dim[1]; j++) {
                    for (int i = 0; i < _dim[0]; i++) {
                        ba[n++] = b.get(offset + i*_dim[1] + j);
                    }
                }
                offset += advance;
            }
        }
        if (_dim.length == 3) {
            for (int p = 0; p < pts; p++) {
                for (int k = 0; k < _dim[2]; k++) {
                    for (int j = 0; j < _dim[1]; j++) {
                        for (int i = 0; i < _dim[0]; i++) {
                            ba[n++] = b.get(offset +
                                i*_dim[1]*_dim[2] + j*_dim[2] + k);
                        }
                    }
                }
                offset += advance;
            }
        }
        b.flip();
        return ba;
    }
}