package slangc.api;

import slang.data.Map;
import slangc.bytecode.FieldSignature;
import slangc.bytecode.MethodSignature;
import slangc.bytecode.TypeSignature;
import slangc.sdk.SimpleBytecodeOutput;

public class BytecodeHeap {
	private Record[] records = new Record[0];
	private int numberFree;
	private final int maximumRecords;
	private Map<String, ConstString> constStringMap = new Map<String, ConstString>(99999);
	private Map<String, ObjectLike> constStringUnprocessedMap = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> packageMap = new Map<String, ObjectLike>(99);
	private Map<TypeSignature, ObjectLike> typeSignatureMap = new Map<TypeSignature, ObjectLike>(999);
	private Map<FieldSignature, ObjectLike> fieldSignatureMap = new Map<FieldSignature, ObjectLike>(9999);
	private Map<MethodSignature, ObjectLike> methodSignatureMap = new Map<MethodSignature, ObjectLike>(12345);
	private Map<String, ObjectLike> constStringInt32Map = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> constStringInt64Map = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> constStringUint32Map = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> constStringUint64Map = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> constStringFloat32Map = new Map<String, ObjectLike>();
	private Map<String, ObjectLike> constStringFloat64Map = new Map<String, ObjectLike>();
	
	public enum RecordType {
		INVALID,
		
		STRING_UTF8,
		ARRAY_INT8,
		ARRAY_INT16,
		ARRAY_INT32,
		ARRAY_INT64,
		ARRAY_FLOAT32,
		ARRAY_FLOAT64,
		
		OBJECT_LIKE,
		
		CONST_INT32,
		CONST_INT64,
		CONST_FLOAT32,
		CONST_FLOAT64
	}
	
	/** This is used to specify the "class" of an encoded OBJECT_LIKE typeName */
	public enum StandardClass {
		NULL,
		FALSE,
		TRUE,
		SIMPLEARRAY,
		SIMPLETYPEREF,
		ARRAYTYPEREF, // TODO...
		SPECIALTYPEREF, // TODO...
		STATICFIELDREF,
		STATICMETHODREF,
		INSTANCEFIELDREF,
		INSTANCEMETHODREF,
		INTERFACEMETHODREF, // TODO...
		
		/** Used to defer number-processing to a secondary stage. This may allow future versions of the
		 * compiler to work on platforms that don't have full number stack such as JavaScript, as well as
		 * being a reference encoding for future e.g. bigint/bigdecimal types) */
		STRING_INT32,
		STRING_INT64,
		STRING_FLOAT32,
		STRING_FLOAT64,
		
		STRING_UTF8, // Processed UTF-8 string data
		STRING_UNPROCESSED, // A string with arbitrary \escape sequences encoded as written in source
		CONST_INT32,
		CONST_INT64,
		CONST_FLOAT32,
		CONST_FLOAT64,
		
		ARRAY_INT8,
		ARRAY_INT16,
		ARRAY_INT32,
		ARRAY_INT64,
		ARRAY_FLOAT32,
		ARRAY_FLOAT64,
		ARRAY_BYTECODE, // TODO...
		ARRAY_DEBUG16, // TODO...
		ARRAY_LABELS, // TODO...
		
		PACKAGE,
		TYPE,
		STATIC_FIELD,
		INSTANCE_FIELD,
		STATIC_METHOD,
		INSTANCE_METHOD,
		INTERFACE_METHOD,
		
		FILE,
		FILE_BYTES,
		DEPENDS,
		PROVIDES,
		ENTRYPOINT,
		RUNTIMEDATA,
		METADATA,
		
		CONSTRUCTORMETHODREF,
		STATICINITMETHODREF,
		INSTANCE_CONSTRUCTOR,
		STATIC_INIT,
		
		STRING_UINT32,
		STRING_UINT64
	}
	
	public static abstract class Record {
		public final BytecodeHeap heap;
		public final int recordIndex;
		
		public Record(BytecodeHeap heap, int recordIndex) {
			super();
			this.heap = heap;
			this.recordIndex = recordIndex;
			heap.assignRecord(this);
		}
		
		public boolean usingCompressedFormat() {
			return false;
		}

		public BytecodeHeap getHeap() {
			return heap;
		}
		
		public int getRecordIndex() {
			return recordIndex;
		}
		
		public abstract RecordType getRecordType();
		public abstract StandardClass getStandardClass();
		
		public void writeArrayPart(BytecodeOutput o) {
			/* No array part by default. */
		}
		
		public int elementsLength() {
			return 0;
		}

        private int cachedSize = -1;
        public void clearCachedSize() {
            cachedSize = -1;
        }
		
		public int getArraySizeInBytes() {
            if (cachedSize >= 0) {
                return cachedSize;
            }
			if (isEmbeddedData()) {
				return 0;
			}
			/*if (elementsLength() == 0) {
				return 0;
			}*/
			BytecodeOutput o = new SimpleBytecodeOutput();
			writeArrayPart(o);
			int result = o.getCount();
			o.endOfFile();
            cachedSize = result;
			return result;
		}
		
		public void writeObjectHead(BytecodeOutput output) {
			output.write8((byte) getRecordType().value);
			output.write8((byte) getStandardClass().value);
			output.write8((byte) 0);
			output.write8((byte) 0);
			output.write32(0);
		}
		
		public boolean isEmbeddedData() {
			return false;
		}
		
		protected void innerWriteEmbeddedData(BytecodeOutput output) {
			throw new Error("innerWriteEmbeddedData should be overridden for types with embedded data");
		}
		
		public final void writeEmbeddedData(BytecodeOutput output) {
			if (!isEmbeddedData()) {
				throw new Error("This record doesn't have embedded data (a pointer should be written instead)");
			}
			int countBefore = output.getCount();
			
			innerWriteEmbeddedData(output);
			
			/* Automatically pad if necessary. */
			while (output.getCount() < countBefore + 8) {
				output.write8((byte)0);
			}
			
			if (output.getCount() != countBefore + 8) {
				throw new Error("Embedded data was too large! Expected 8 bytes but got " + (output.getCount() - countBefore));
			}
		}

		public int getTableEntrySize(int compressionLevel) {
			switch (compressionLevel) {
			case 0:
				return 16;
			case 1:
				return 8;
			case 2:
				return 4;
			case 3:
				if (getArraySizeInBytes() < 256) {
					return 2;
				} else {
					return 4;
				}
			default:
				throw new Error("Invalid compression level: " + compressionLevel + " (expecting 0-3)");
			}
		}

		public String innerDebugString() {
			return "TODO";
		}

		public String debugString() {
			return getRecordType().name() + "#" + recordIndex + "(" + innerDebugString() + ")";
		}
	}
	
	public static class ConstString extends Record {
		private final String value;
		
		public ConstString(BytecodeHeap heap, int recordIndex, String value) {
			super(heap, recordIndex);
			if (value == null) {
				throw new Error("Bad string (got null)");
			}
			this.value = value;
		}
		
		public String getStringValue() {
			return value;
		}

		public String innerDebugString() {
			return "\"" + getStringValue() + "\"";
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.STRING_UTF8;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return StandardClass.STRING_UTF8;
		}
		
		@Override
		public void writeArrayPart(BytecodeOutput output) {
			try {
				byte[] bytes = getStringValue().signedBytes();
				for (int i = 0; i < bytes.length; i++) {
					output.write8(bytes[i]);
				}
			} catch (Error e) {
				throw new Error("Unable to encode string as UTF-8", e);
			}
		}
	}
	
	public static class ConstInt32 extends Record {
		private final int value;
		
		public ConstInt32(BytecodeHeap heap, int recordIndex, int value) {
			super(heap, recordIndex);
			this.value = value;
		}
		
		public int getValue() {
			return value;
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.CONST_INT32;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return StandardClass.CONST_INT32;
		}
	}
	
	public static class ConstInt64 extends Record {
		private final long value;
		
		public ConstInt64(BytecodeHeap heap, int recordIndex, long value) {
			super(heap, recordIndex);
			this.value = value;
		}
		
		public long getValue() {
			return value;
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.CONST_INT64;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return StandardClass.CONST_INT64;
		}
	}
	
	public static class ConstFloat32 extends Record {
		private final float value;
		
		public ConstFloat32(BytecodeHeap heap, int recordIndex, float value) {
			super(heap, recordIndex);
			this.value = value;
		}
		
		public float getValue() {
			return value;
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.CONST_FLOAT32;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return StandardClass.CONST_FLOAT32;
		}
	}
	
	public static class ConstFloat64 extends Record {
		private final double value;
		
		public ConstFloat64(BytecodeHeap heap, int recordIndex, double value) {
			super(heap, recordIndex);
			this.value = value;
		}
		
		public double getValue() {
			return value;
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.CONST_FLOAT64;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return StandardClass.CONST_FLOAT64;
		}
	}
	
	public static class ObjectLike extends Record {
		private final StandardClass standardClass;
		private Record[] elements;
		
		public ObjectLike(BytecodeHeap heap, int recordIndex, StandardClass standardClass, int size) {
			super(heap, recordIndex);
			this.standardClass = standardClass;
			elements = new Record[size];
			for (int i = 0; i < size; i++) {
				elements[i] = heap.getNull();
			}
		}

		public String innerDebugString() {
			String result = "";
			for (int i = 0; i < elements.length; i++) {
				if (i > 0) {
					result = result + ",";
				}
				result = result+elements[i].debugString();
			}
			return result;
		}
		
		@Override
		public boolean usingCompressedFormat() {
			for (int i = 0; i < elements.length; i++) {
				if (elements[i].getRecordIndex() >= 65536) {
					return false;
				}
			}
			return true;
		}
		
		public void resizeElements(int newSize) {
			Record[] newElements = new Record[newSize];
			for (int i = 0; i < newElements.length; i++) {
				if (i < elements.length) {
					newElements[i] = elements[i];
				} else {
					newElements[i] = getHeap().getNull();
				}
			}
			elements = newElements;
		}
		
		public void appendElement(Record r) {
			int idx = elementsLength();
			resizeElements(idx + 1);
			setElement(idx, r);
		}
		
		public StandardClass getStandardClass() {
			return standardClass;
		}
		
		@Override
		public int elementsLength() {
			return elements.length;
		}
		
		public Record getElement(int i) {
			return elements[i];
		}
		
		public void setElement(int i, Record r) {
            clearCachedSize();
			elements[i] = r;
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.OBJECT_LIKE;
		}
		
		@Override
		public void writeArrayPart(BytecodeOutput output) {
			if (usingCompressedFormat()) {
				for (int i = 0; i < elements.length; i++) {
					output.write16((short) elements[i].getRecordIndex());
				}
			} else {
				for (int i = 0; i < elements.length; i++) {
					output.write32(elements[i].getRecordIndex());
				}
			}
		}
	}
	
	public static class ArrayInt8 extends Record {
		private final StandardClass standardClass;
		private byte[] elements;
		
		public ArrayInt8(BytecodeHeap heap, int recordIndex, StandardClass standardClass, int size) {
			super(heap, recordIndex);
			this.standardClass = standardClass;
			elements = new byte[size];
		}
		
		@Override
		public int elementsLength() {
			return elements.length;
		}
		
		public byte getElement(int i) {
			return elements[i];
		}
		
		public void setElement(int i, byte r) {
            clearCachedSize();
			elements[i] = r;
		}

		public void resizeElements(int newSize) {
			byte[] newElements = new byte[newSize];
			for (int i = 0; i < newElements.length; i++) {
				if (i < elements.length) {
					newElements[i] = elements[i];
				} else {
					//newElements[i] = 0;
				}
			}
			elements = newElements;
		}
		
		public void appendElement(byte r) {
			int idx = elementsLength();
			resizeElements(idx + 1);
			setElement(idx, r);
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.ARRAY_INT8;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return standardClass;
		}
		
		@Override
		public void writeArrayPart(BytecodeOutput output) {
			boolean cmp = usingCompressedFormat();
			for (int i = 0; i < elements.length; i++) {
				output.write8(elements[i]);
			}
		}
		
		@Override
		public boolean usingCompressedFormat() {
			return false;
		}
	}
	
	public static class ArrayInt16 extends Record {
		private final StandardClass standardClass;
		private short[] elements;
		
		public ArrayInt16(BytecodeHeap heap, int recordIndex, StandardClass standardClass, int size) {
			super(heap, recordIndex);
			this.standardClass = standardClass;
			elements = new short[size];
		}
		
		@Override
		public int elementsLength() {
			return elements.length;
		}
		
		public short getElement(int i) {
			return elements[i];
		}
		
		public void setElement(int i, short r) {
            clearCachedSize();
			elements[i] = r;
		}

		public void resizeElements(int newSize) {
			short[] newElements = new short[newSize];
			for (int i = 0; i < newElements.length; i++) {
				if (i < elements.length) {
					newElements[i] = elements[i];
				} else {
					//newElements[i] = 0;
				}
			}
			elements = newElements;
		}
		
		public void appendElement(short r) {
			int idx = elementsLength();
			resizeElements(idx + 1);
			setElement(idx, r);
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.ARRAY_INT16;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return standardClass;
		}
		
		@Override
		public void writeArrayPart(BytecodeOutput output) {
			boolean cmp = usingCompressedFormat();
			for (int i = 0; i < elements.length; i++) {
				if (cmp) {
					output.write8((byte)elements[i]);
				} else {
					output.write16(elements[i]);
				}
			}
		}
		
		@Override
		public boolean usingCompressedFormat() {
			for (int i = 0; i < elements.length; i++) {
				byte tmp = (byte) elements[i];
				if ((((short) tmp) & 0xFF) != elements[i]) {
					return false;
				}
			}
			return true;
		}
	}
	
	public static class ArrayInt32 extends Record {
		private final StandardClass standardClass;
		private int[] elements;
		
		public ArrayInt32(BytecodeHeap heap, int recordIndex, StandardClass standardClass, int size) {
			super(heap, recordIndex);
			this.standardClass = standardClass;
			elements = new int[size];
		}
		
		@Override
		public int elementsLength() {
			return elements.length;
		}
		
		public int getElement(int i) {
			return elements[i];
		}
		
		public void setElement(int i, int r) {
			//if ((r & 0xFFFF) != r) throw new Error("XXX temporary error: Can't compress " + r);
            clearCachedSize();
			elements[i] = r;
		}

		public void resizeElements(int newSize) {
			int[] newElements = new int[newSize];
			for (int i = 0; i < newElements.length; i++) {
				if (i < elements.length) {
					newElements[i] = elements[i];
				} else {
					//newElements[i] = 0;
				}
			}
			elements = newElements;
		}
		
		public void appendElement(int r) {
			int idx = elementsLength();
			resizeElements(idx + 1);
			setElement(idx, r);
		}
		
		@Override
		public RecordType getRecordType() {
			return RecordType.ARRAY_INT32;
		}
		
		@Override
		public StandardClass getStandardClass() {
			return standardClass;
		}
		
		@Override
		public void writeArrayPart(BytecodeOutput output) {
			boolean cmp = usingCompressedFormat();
			for (int i = 0; i < elements.length; i++) {
				if (cmp) {
					output.write16((short)elements[i]);
				} else {
					output.write32(elements[i]);
				}
			}
		}
		
		@Override
		public boolean usingCompressedFormat() {
			for (int i = 0; i < elements.length; i++) {
				int tmp = elements[i];
				if ((tmp & 0xFFFF) != elements[i]) {
					return false;
				}
			}
			return true;
		}
	}

	public BytecodeHeap(int maximumRecords, boolean initialise) {
		this.maximumRecords = maximumRecords;
		
		if (initialise) {
			initialiseHeap();
		}
	}
	
	public void initialiseHeap() {
		int nullId = nextFreeRecordIndex();
		if (nullId != 0) {
			throw new Error("Can't initialise heap, null id already seems to exist!");
		}
		if (newObjectLike(StandardClass.NULL, 0).getRecordIndex() != 0) {
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.FALSE, 0).getRecordIndex() != 1) {
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.TRUE, 0).getRecordIndex() != 2) {
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 0).getRecordIndex() != 3) { // Package array
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 0).getRecordIndex() != 4) { // Provides/depends array
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 0).getRecordIndex() != 5) { // Entrypoints array
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 32).getRecordIndex() != 6) { // Runtimedata array
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 0).getRecordIndex() != 7) { // Important metadata array
			throw new Error("Failed to create initial records");
		}
		if (newObjectLike(StandardClass.SIMPLEARRAY, 0).getRecordIndex() != 8) { // Other metadata array
			throw new Error("Failed to create initial records");
		}
	}
	
	public ObjectLike getNull() {
		ObjectLike result = (ObjectLike)records[0];
		if (result == null) {
			throw new Error("Invalid null record");
		}
		return result;
	}
	
	public ObjectLike getFalse() {
		ObjectLike result = (ObjectLike)records[1];
		if (result == null) {
			throw new Error("Invalid false record");
		}
		return result;
	}
	
	public ObjectLike getTrue() {
		ObjectLike result = (ObjectLike)records[2];
		if (result == null) {
			throw new Error("Invalid true record");
		}
		return result;
	}
	
	public ObjectLike getPackageArray() {
		ObjectLike result = (ObjectLike)records[3];
		if (result == null) {
			throw new Error("Invalid package-array record");
		}
		return result;
	}
	
	public ObjectLike getDependsArray() {
		ObjectLike result = (ObjectLike)records[4];
		if (result == null) {
			throw new Error("Invalid depends-array record");
		}
		return result;
	}
	
	public ObjectLike getEntrypointsArray() {
		ObjectLike result = (ObjectLike)records[5];
		if (result == null) {
			throw new Error("Invalid entrypoints-array record");
		}
		return result;
	}
	
	public ObjectLike getRuntimedataArray() {
		ObjectLike result = (ObjectLike)records[6];
		if (result == null) {
			throw new Error("Invalid runtimeinfo-array record");
		}
		return result;
	}
	
	public ObjectLike getImportantMetadataArray() {
		ObjectLike result = (ObjectLike)records[7];
		if (result == null) {
			throw new Error("Invalid importantmetadata-array record");
		}
		return result;
	}
	
	public ObjectLike getOtherMetadataArray() {
		ObjectLike result = (ObjectLike)records[8];
		if (result == null) {
			throw new Error("Invalid othermetadata-array record");
		}
		return result;
	}
	
	public int getCurrentHeapSize() {
		return records.length;
	}
	
	public int getHeapAllocationGranularity() {
		return 1024;
	}
	
	public void expandHeap(int atLeast) {
		int newLimit = getCurrentHeapSize() + atLeast;
		while (newLimit < getMaximumRecords() && (newLimit % getHeapAllocationGranularity()) != 0) {
			newLimit++;
		}
		if (newLimit > getMaximumRecords()) {
			throw new Error("Unable to expand heap (hit the maximum of " + getMaximumRecords() + " records)");
		}
		numberFree += (newLimit - getCurrentHeapSize());
		Record[] newRecords = new Record[newLimit];
		for (int i = 0; i < getCurrentHeapSize(); i++) {
			newRecords[i] = records[i];
		}
		records = newRecords;
	}
	
	public int objectTableSize(int compressionLevel) {
		return objectTableSize(compressionLevel, getCurrentHeapSize());
	}
	
	public int objectTableSize(int compressionLevel, int upto) {
		switch (compressionLevel) {
		case 0:
			return (highestUsedRecordIndex() + 1) * 16;
		case 1:
			return (highestUsedRecordIndex() + 1) * 8;
		case 2:
			return (highestUsedRecordIndex() + 1) * 4;
		default: {
			int sz = 0;
			for (int i = 0; i < upto; i++) {
				if (records[i] != null) {
					sz += records[i].getTableEntrySize(compressionLevel);
				}
			}
			return sz;
		}
		}
	}
	
	public void writeObjectTable(BytecodeOutput output, int compressionLevel, int dataGranularity) {
		int dataOffset = 0;
		for (int i = 0; i <= highestUsedRecordIndex(); i++) {
			Record r = records[i];
			if (r == null) {
				switch (compressionLevel) {
				case 0:
					output.write64(0);
					output.write64(0);
					break;
				case 1:
					output.write64(0);
					break;
				case 2:
					output.write32(0);
					break;
				case 3:
					output.write16((short) 0);
					break;
				default:
					throw new Error("Bad compression level " + compressionLevel);
				}
			} else {
				int cl = r.getStandardClass().value;
				if (r.usingCompressedFormat()) {
					cl |= (1<<7);
				}
				int len = r.getArraySizeInBytes();
				switch (compressionLevel) {
				case 0:
					output.write32(cl);
					output.write32(len);
					output.write64(dataOffset);
					break;
				case 1:
					output.write32((len << 8) | (cl & 0xFF));
					output.write32(dataOffset);
					break;
				case 2:
					output.write32((len << 8) | (cl & 0xFF));
					break;
				case 3:
					if (r.getTableEntrySize(compressionLevel) == 2) {
						output.write16((short) ((len << 8) | ((cl | (1<<6)) & 0xFF)));
					} else {
						output.write32((len << 8) | (cl & 0xFF));
					}
					break;
				default:
					throw new Error("Bad compression level " + compressionLevel);
				}

				dataOffset += records[i].getArraySizeInBytes();
				while ((dataOffset % dataGranularity) != 0) {
					dataOffset++;
				}
			}
		}
	}
	
	public int objectTableIndexSize(int compressionLevel, int maxpool) {
		switch (compressionLevel) {
		case 3: {
			int sz = 0;
			int top = this.highestUsedRecordIndex();
			for (int i = 0; i <= top; i++) {
				if (i % maxpool == 0) {
					sz += 16;
				}
			}
			return sz;
		}
		default:
			return 0; // An index is not required unless the object table is compressed
		}
	}
	
	public int writeObjectTableIndex(BytecodeOutput output, int compressionLevel, int maxpool, int dataGranularity) {
		switch (compressionLevel) {
		case 3: {
			int sz = 0;
			int tableoffset = 0;
			int top = this.highestUsedRecordIndex();
			boolean writtenDots = false;
			for (int i = 0; i <= top; i++) {
				Record r = records[i];
				if (i % maxpool == 0) {
					output.write64(tableoffset);
					output.write64(dataOffset(i, dataGranularity));
					if (i > maxpool*4 && i < top-maxpool*4) {
						if (!writtenDots) {
							Log.line("...");
							writtenDots = true;
						}
					} else {
						Log.line("Writing index #" + (i/maxpool) + ": table offset " + tableoffset + " data offset " + dataOffset(i, dataGranularity));
					}
					sz += 16;
				}
				tableoffset += r.getTableEntrySize(compressionLevel);
			}
			return sz;
		}
		default:
			return 0; // An index is not required unless the object table is compressed
		}
	}
	
	public void writeData(BytecodeOutput output, int granularity) {
		int offset = 0;
		for (int i = 0; i <= highestUsedRecordIndex(); i++) {
			Record r = records[i];
			if (r != null) {
				r.writeArrayPart(output);
				offset += r.getArraySizeInBytes();
				while ((offset % granularity) != 0) {
					output.write8((byte)0);
					offset++;
				}
			}
		}
	}
	
	public int fileHeaderSize(int compressionLevel, int maxpool, int dataGranularity, int sectionGranularity) {
		return 64 * 4;
	}
	
	private void writeStringTag(BytecodeOutput output, String data, int size) {
		try {
			byte[] x = data.signedBytes();
			if (x.length > size) {
				throw new Error("String is too long (expected maximum of " + size + " bytes but got " + x.length + " bytes)");
			}
			for (int i = 0; i < size; i++) {
				output.write8((byte) (i < x.length ? x[i] : 0));
			}
		} catch (Error e) {
			throw new Error("Unable to encode string (system error?)", e);
		}
	}

	private void writeFileHeader(BytecodeOutput output, String tagdata, int compressionLevel, int maxpool,
			int dataGranularity, int sectionGranularity) {
		// Section 0 (file top header)
		writeStringTag(output, tagdata, 32); // Optional user-defined tag, may reference interpreter on Unix-like systems
		writeStringTag(output, "BYTECODE FILE01", 16); // Magic number
		output.write8((byte)1); // File format version
		output.write8((byte)4); // Number of file headers (including this top-header part)
		output.write16((short)64);
		output.write32(0); // Reserved for checksum
		output.write64(fileSize(compressionLevel, maxpool, dataGranularity, sectionGranularity));
		
		int sectionDataOffset = fileHeaderSize(compressionLevel, maxpool, dataGranularity, sectionGranularity);
		while ((sectionDataOffset % sectionGranularity) != 0) {
			sectionDataOffset++;
		}
		
		// Section 1 (index, if provided)
		if (objectTableIndexSize(compressionLevel, maxpool) == 0) {
			for (int i = 0; i < 64; i++) {
				output.write8((byte)0);
			}
		} else {
			output.write32(maxpool);
			output.write32(compressionLevel);
			output.write32(0);
			output.write32(0);
			output.write32(0);
			output.write32(0);
			output.write32(0);
			output.write32(0);
			
			writeStringTag(output, "INDEX", 8);
			output.write64(0);
			output.write64(sectionDataOffset);
			output.write64(objectTableIndexSize(compressionLevel, maxpool));
			sectionDataOffset += objectTableIndexSize(compressionLevel, maxpool);
			while ((sectionDataOffset % sectionGranularity) != 0) {
				sectionDataOffset++;
			}
		}
		
		// Section 2 (object table)
		output.write32(highestUsedRecordIndex() + 1);
		output.write32(compressionLevel);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		
		writeStringTag(output, "TABLE", 8);
		output.write64(0);
		output.write64(sectionDataOffset);
		output.write64(objectTableSize(compressionLevel));
		sectionDataOffset += objectTableSize(compressionLevel);
		while ((sectionDataOffset % sectionGranularity) != 0) {
			sectionDataOffset++;
		}
		
		// Section 3 (object data)
		
		output.write32(dataGranularity);//sectionDataOffset += objectTableIndexSize(compressionLevel, maxpool);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		output.write32(0);
		
		writeStringTag(output, "DATA", 8);
		output.write64(0);
		output.write64(sectionDataOffset);
		output.write64(dataSize(dataGranularity));
		sectionDataOffset += dataSize(dataGranularity);
		while ((sectionDataOffset % sectionGranularity) != 0) {
			sectionDataOffset++;
		}
	}
	
	public int fileSize(int compressionLevel, int maxpool, int dataGranularity, int sectionGranularity) {
		int sz = fileHeaderSize(compressionLevel, maxpool, dataGranularity, sectionGranularity);
		
		while (sz % sectionGranularity != 0) {
			sz++;
		}
		
		sz += objectTableIndexSize(compressionLevel, maxpool);
		
		while (sz % sectionGranularity != 0) {
			sz++;
		}
		
		sz += objectTableSize(compressionLevel);
		
		while (sz % sectionGranularity != 0) {
			sz++;
		}
		
		sz += dataSize(dataGranularity);
		
		while (sz % sectionGranularity != 0) {
			sz++;
		}
		
		return sz;
	}
	
	public void writeAll(BytecodeOutput output, String tagdata, int compressionLevel, int maxpool, int dataGranularity, int sectionGranularity) {
		Log.line("aA");
		int base = output.getCount();
		int expectedOffset = 0;

		Log.line("A");
		writeFileHeader(output, tagdata, compressionLevel, maxpool, dataGranularity, sectionGranularity);
		Log.line("B");
		expectedOffset = fileHeaderSize(compressionLevel, maxpool, dataGranularity, sectionGranularity);
		Log.line("C");
		while (expectedOffset % sectionGranularity != 0) {
			output.write8((byte)0);
			expectedOffset++;
		}
		Log.line("D");
		
		writeObjectTableIndex(output, compressionLevel, maxpool, dataGranularity);
		expectedOffset += objectTableIndexSize(compressionLevel, maxpool);
		while (expectedOffset % sectionGranularity != 0) {
			output.write8((byte)0);
			expectedOffset++;
		}
		Log.line("E");
		
		writeObjectTable(output, compressionLevel, dataGranularity);
		expectedOffset += objectTableSize(compressionLevel);
		while (expectedOffset % sectionGranularity != 0) {
			output.write8((byte)0);
			expectedOffset++;
		}
		Log.line("F");
		
		writeData(output, dataGranularity);
		expectedOffset += dataSize(dataGranularity);
		while (expectedOffset % sectionGranularity != 0) {
			output.write8((byte)0);
			expectedOffset++;
		}
		Log.line("G");
	}

	public int dataOffset(int index, int granularity) {
		int total = 0;
		for (int i = 0; i < index; i++) {
			if (records[i] != null) {
				total += records[i].getArraySizeInBytes();
				while ((total % granularity) != 0) {
					total++;
				}
			}
		}
		return total;
	}
	
	public int dataSize(int granularity) {
		return dataOffset(getCurrentHeapSize(), granularity);
	}
	
	public int highestUsedRecordIndex() {
        return highestUsedIndex;
        ///*
		int highestUsed = -1;
		for (int i = 0; i < getCurrentHeapSize(); i++) {
			if (records[i] != null) {
				highestUsed = i;
			}
		}
		return highestUsed;
        //*/
	}

    private int nextFreeHint = 0;
	
	public int nextFreeRecordIndex() {
		if (numberFree < 1) {
			expandHeap(1);
		}
		if (numberFree < 1) {
			throw new Error("Heap expansion failed unexpectedly");
		}
		
		for (int i = nextFreeHint; i < getCurrentHeapSize(); i++) {
			if (records[i] == null) {
                nextFreeHint = i;
				return i;
			}
		}
		
		throw new Error("Internal free count doesn't match - no free records found");
	}
	
    private int highestUsedIndex = -1;
    
	/* This is called internally from the Record constructor, so the creator only needs to find a free index. */
	private void assignRecord(Record r) {
		assert r.heap == this;
		assert records[r.recordIndex] == null;
		records[r.recordIndex] = r;
        if (r.recordIndex > highestUsedIndex) {
            highestUsedIndex = r.recordIndex;
        }
		numberFree--;
	}
	
	public ObjectLike newObjectLike(StandardClass cl, int size) {
		int idx = nextFreeRecordIndex();
		return new ObjectLike(this, idx, cl, size);
	}
	
	public ArrayInt8 newArrayInt8(StandardClass standardClass, int size) {
		int idx = nextFreeRecordIndex();
		return new ArrayInt8(this, idx, standardClass, size);
	}
	
	public ArrayInt16 newArrayInt16(StandardClass standardClass, int size) {
		int idx = nextFreeRecordIndex();
		return new ArrayInt16(this, idx, standardClass, size);
	}
	
	public ArrayInt32 newArrayInt32(StandardClass standardClass, int size) {
		int idx = nextFreeRecordIndex();
		return new ArrayInt32(this, idx, standardClass, size);
	}
	
	public ArrayInt32 newInstructions(int size) {
		return newArrayInt32(StandardClass.ARRAY_BYTECODE, size);
	}
	
	public ArrayInt32 newLabels(int size) {
		return newArrayInt32(StandardClass.ARRAY_LABELS, size);
	}
	
	public ArrayInt16 newDebug(int size) {
		return newArrayInt16(StandardClass.ARRAY_DEBUG16, size);
	}
	
	public ConstString getConstString(String value) {
		if (constStringMap.hasKey(value)) {
			return constStringMap.get(value);
		}
		int idx = nextFreeRecordIndex();
		ConstString str = new ConstString(this, idx, value);
		constStringMap.set(value, str);
		return str;
	}
	
	/** Used for encoding quoted strings which may contain escape codes. If the
	 * string doesn't contain any fancy formatting, then it's encoded directly as
	 * a regular string constant (in UTF-8 format). Otherwise it's encoded as 
	 * STRING_UNPROCESSED object containing a reference to the string exactly
	 * as written in the source code (including quotes, since future versions
	 * may allow string modifiers to specify a certain encoding or even regex
	 * syntax etc.).
	 */
	public Record getConstStringLiteral(String value) {
		if (value.startsWith("\"") && value.endsWith("\"") && !value.search("\\")) {
			return getConstString(value.sub(1, value.ints().length - 1));
		}
		if (constStringUnprocessedMap.hasKey(value)) {
			return constStringUnprocessedMap.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_UNPROCESSED, 1);
		result.setElement(0, strval);
		
		constStringUnprocessedMap.set(value, result);
		
		return result;
	}
	
	public Record getConstInt32(String value) {
		if (constStringInt32Map.hasKey(value)) {
			return constStringInt32Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_INT32, 1);
		result.setElement(0, strval);
		
		constStringInt32Map.set(value, result);
		
		return result;
	}
	
	public Record getConstInt64(String value) {
		if (constStringInt64Map.hasKey(value)) {
			return constStringInt64Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_INT64, 1);
		result.setElement(0, strval);
		
		constStringInt64Map.set(value, result);
		
		return result;
	}
	
	public Record getConstUint32(String value) {
		if (constStringUint32Map.hasKey(value)) {
			return constStringUint32Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_UINT32, 1);
		result.setElement(0, strval);
		
		constStringUint32Map.set(value, result);
		
		return result;
	}
	
	public Record getConstUint64(String value) {
		if (constStringUint64Map.hasKey(value)) {
			return constStringUint64Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_UINT64, 1);
		result.setElement(0, strval);
		
		constStringUint64Map.set(value, result);
		
		return result;
	}
	
	public Record getConstFloat32(String value) {
		if (constStringFloat32Map.hasKey(value)) {
			return constStringFloat32Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_FLOAT32, 1);
		result.setElement(0, strval);
		
		constStringFloat32Map.set(value, result);
		
		return result;
	}
	
	public Record getConstFloat64(String value) {
		if (constStringFloat64Map.hasKey(value)) {
			return constStringFloat64Map.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.STRING_FLOAT64, 1);
		result.setElement(0, strval);
		
		constStringFloat64Map.set(value, result);
		
		return result;
	}
	
	public ObjectLike getPackage(String value) {
		if (packageMap.hasKey(value)) {
			return packageMap.get(value);
		}
		ConstString strval = getConstString(value);
		ObjectLike result = newObjectLike(StandardClass.PACKAGE, 3);
		result.setElement(0, strval);
		result.setElement(1, getNull());
		result.setElement(2, newObjectLike(StandardClass.SIMPLEARRAY, 0));
		getPackageArray().appendElement(result);
		
		packageMap.set(value, result);
		
		return result;
	}
	
	public ObjectLike getTypeSignature(TypeSignature value) {
		//Log.line("Looking up type signature " + value.toString());
		if (typeSignatureMap.hasKey(value)) {
			//Log.line("Using " + typeSignatureMap.get(value).debugString());
			return typeSignatureMap.get(value);
		}
		ObjectLike result = newObjectLike(StandardClass.SIMPLETYPEREF, 2);
		result.setElement(0, value.packageName == null ? getNull() : (ObjectLike) getConstString(value.packageName));
		result.setElement(1, getConstString(value.typeName));
		
		typeSignatureMap.set(value, result);
		
		//Log.line("Created " + typeSignatureMap.get(value).debugString());

		return result;
	}
	
	public ObjectLike getFieldSignature(FieldSignature value) {
		if (fieldSignatureMap.hasKey(value)) {
			return fieldSignatureMap.get(value);
		}
		ObjectLike result = newObjectLike(value.isStatic ? StandardClass.STATICFIELDREF : StandardClass.INSTANCEFIELDREF, 3);
		result.setElement(0, getTypeSignature(value.owner));
		result.setElement(1, getTypeSignature(value.storageType));
		result.setElement(2, getConstString(value.name));
		
		fieldSignatureMap.set(value, result);
		
		return result;
	}
	
	public ObjectLike getMethodSignature(MethodSignature value) {
		if (methodSignatureMap.hasKey(value)) {
			return methodSignatureMap.get(value);
		}
		StandardClass cl;
		switch (value.kind) {
		case MethodSignature.Kind.CONSTRUCTOR:
			cl = StandardClass.CONSTRUCTORMETHODREF;
			break;
		case MethodSignature.Kind.STATIC_INIT:
			cl = StandardClass.STATICINITMETHODREF;
			break;
		case MethodSignature.Kind.STATIC_METHOD:
			cl = StandardClass.STATICMETHODREF;
			break;
		case MethodSignature.Kind.INSTANCE_METHOD:
			cl = StandardClass.INSTANCEMETHODREF;
			break;
		case MethodSignature.Kind.INTERFACE_METHOD:
			cl = StandardClass.INTERFACEMETHODREF;
			break;
		default:
			throw new Error("Internal error: Unrecognised method kind " + value.kind);
		}
		ObjectLike result = newObjectLike(cl, 4);
		result.setElement(0, getTypeSignature(value.owner));
		result.setElement(1, getTypeSignature(value.returnType));
		result.setElement(2, getConstString(value.name));
		if (value.argumentTypes != null && value.argumentTypes.length > 0) {
			ObjectLike argtypes = newObjectLike(StandardClass.SIMPLEARRAY, value.argumentTypes.length);
			result.setElement(3, argtypes);
			for (int i = 0; i < value.argumentTypes.length; i++) {
				argtypes.setElement(i, getTypeSignature(value.argumentTypes[i]));
			}
		}
		
		methodSignatureMap.set(value, result);
		
		return result;
	}
	
	public static enum FileFields {
		PACKAGENAME,
		INNERNAME,
		DATA,
		META,
		DEBUGNAME
	}
	
	public ObjectLike newFile(String packagename, String innername,  byte[] data, String typeinfo, String debugname) {
		ObjectLike result = newObjectLike(StandardClass.FILE, FileFields.lookupCount(FileFields.class));
		result.setElement(FileFields.PACKAGENAME.value, packagename == null ? getNull() : (ObjectLike) getConstString(packagename));
		result.setElement(FileFields.INNERNAME.value, getConstString(innername));
		result.setElement(FileFields.META.value, typeinfo == null ? getNull() : (ObjectLike) getConstString(typeinfo));
		result.setElement(FileFields.DEBUGNAME.value, debugname == null ? getNull() : (ObjectLike) getConstString(debugname));
		
		ArrayInt8 dataarray = newArrayInt8(StandardClass.FILE_BYTES, data.length);
		for (int i = 0; i < data.length; i++) {
			dataarray.setElement(i, data[i]);
		}
		result.setElement(FileFields.DATA.value, dataarray);
		
		ObjectLike pkgtypes = (ObjectLike) getPackage(packagename).getElement(2);
		pkgtypes.appendElement(result);
		
		return result;
	}
	
	public static enum DependsFields {
		NAME,
		VERSION,
		HINT,
		HASH
	}
	
	public ObjectLike newDepends(String name, String version, String hint, String hash) {
		ObjectLike result = newObjectLike(StandardClass.DEPENDS, DependsFields.lookupCount(DependsFields.class));
		result.setElement(DependsFields.NAME.value, name == null ? getNull() : (ObjectLike) getConstString(name));
		result.setElement(DependsFields.VERSION.value, version == null ? getNull() : (ObjectLike) getConstString(version));
		result.setElement(DependsFields.HINT.value, hint == null ? getNull() : (ObjectLike) getConstString(hint));
		result.setElement(DependsFields.HASH.value, hash == null ? getNull() : (ObjectLike) getConstString(hash));
		
		getDependsArray().appendElement(result);
		
		return result;
	}
	
	public static enum ProvidesFields {
		NAME,
		VERSION
	}
	
	public ObjectLike newProvides(String name, String version) {
		ObjectLike result = newObjectLike(StandardClass.PROVIDES, ProvidesFields.lookupCount(ProvidesFields.class));
		result.setElement(ProvidesFields.NAME.value, name == null ? getNull() : (ObjectLike) getConstString(name));
		result.setElement(ProvidesFields.VERSION.value, version == null ? getNull() : (ObjectLike) getConstString(version));
		
		getDependsArray().appendElement(result);
		
		return result;
	}
	
	public static enum MetadataFields {
		KEY,
		VALUE,
	}
	
	public ObjectLike newMetadata(boolean important, String key, String value) {
		ObjectLike result = newObjectLike(StandardClass.METADATA, MetadataFields.lookupCount(MetadataFields.class));
		result.setElement(MetadataFields.KEY.value, key == null ? getNull() : (ObjectLike) getConstString(key));
		result.setElement(MetadataFields.VALUE.value, value == null ? getNull() : (ObjectLike) getConstString(value));
		
		if (important) {
			getImportantMetadataArray().appendElement(result);
		} else {
			getOtherMetadataArray().appendElement(result);
		}
		
		return result;
	}
	
	public static enum RuntimedataFields {
		TYPE,
		FORMATOPTS,
		FLAGS
	}
	
	public ObjectLike registerRuntimeType(int indexOrNeg, int kind, TypeSignature type, String formatopts, boolean isBuiltin, boolean isNumber, boolean isFloat, boolean isSigned, int nbits) {
		int flags = kind;
		if (isBuiltin) {
			flags |= (1 << 8);
		}
		if (isNumber) {
			flags |= (1 << 9);
		}
		if (isFloat) {
			flags |= (1 << 10);
		}
		if (isSigned) {
			flags |= (1 << 11);
		}
		flags |= (nbits << 16);
		
		ObjectLike result = newObjectLike(StandardClass.RUNTIMEDATA, RuntimedataFields.lookupCount(RuntimedataFields.class));
		//System.err.println("Adding runtime data #" + indexOrNeg + " at index #" + result.getRecordIndex());
		result.setElement(RuntimedataFields.TYPE.value, type == null ? getNull() : getTypeSignature(type));
		result.setElement(RuntimedataFields.FORMATOPTS.value, formatopts == null ? getNull() : (ObjectLike) getConstString(formatopts));
		result.setElement(RuntimedataFields.FLAGS.value, getConstInt32("" + flags));
		
		if (indexOrNeg < 0) {
			getRuntimedataArray().appendElement(result);
		} else {
			getRuntimedataArray().setElement(indexOrNeg, result);
		}
		
		return result;
	}

	public static enum TypeFields {
		SIGNATURE,
		FLAGS,
		BASE,
		INTERFACES,
		MEMBERS,
		FILENAME
	}
	
	public ObjectLike newType(int flags, TypeSignature sig) {
		ObjectLike result = newObjectLike(StandardClass.TYPE, TypeFields.lookupCount(TypeFields.class));
		result.setElement(0, getTypeSignature(sig));
		result.setElement(1, getNull());//newObjectLike(StandardClass.SIMPLEARRAY, 0));
		result.setElement(2, getNull());
		result.setElement(3, getNull());//newObjectLike(StandardClass.SIMPLEARRAY, 0));
		result.setElement(4, getNull());
		result.setElement(TypeFields.FLAGS.value, getConstInt32("" + flags));
		
		ObjectLike pkgtypes = (ObjectLike) getPackage(sig.packageName).getElement(2);
		pkgtypes.appendElement(result);
		
		return result;
	}
	
	public void addMember(ObjectLike type, Record member) {
		if (type.getElement(TypeFields.MEMBERS.value) == getNull()) {
			type.setElement(TypeFields.MEMBERS.value, newObjectLike(StandardClass.SIMPLEARRAY, 0));
		}
		ObjectLike memberArray = (ObjectLike) type.getElement(TypeFields.MEMBERS.value);
		memberArray.appendElement(member);
	}
	
	public static enum FieldFields {
		SIGNATURE,
		FLAGS
	}


	public ObjectLike newField(ObjectLike type, int flags, FieldSignature sig) {
		ObjectLike result = newObjectLike(sig.isStatic ? StandardClass.STATIC_FIELD : StandardClass.INSTANCE_FIELD, FieldFields.lookupCount(FieldFields.class));
		result.setElement(FieldFields.SIGNATURE.value, getFieldSignature(sig));
		result.setElement(FieldFields.FLAGS.value, getConstInt32("" + flags));
		
		addMember(type, result);
		
		return result;
	}
	
	public static enum MethodFields {
		SIGNATURE,
		FLAGS,
		BYTECODE,
		EXCEPTIONS,
		DEBUG,
		LOCALS,
		MAXSTACK,
		THROWS
	}
    static int methodFieldsCount = MethodFields.lookupCount(MethodFields.class);
	
	public ObjectLike newMethod(ObjectLike type, int flags, MethodSignature sig, int nlocals) {
		StandardClass t;
		switch (sig.kind) {
		case MethodSignature.Kind.INSTANCE_METHOD:
			t = StandardClass.INSTANCE_METHOD;
			break;
		case MethodSignature.Kind.STATIC_METHOD:
			t = StandardClass.STATIC_METHOD;
			break;
		case MethodSignature.Kind.CONSTRUCTOR:
			t = StandardClass.INSTANCE_CONSTRUCTOR;
			break;
		case MethodSignature.Kind.STATIC_INIT:
			t = StandardClass.STATIC_INIT;
			break;
		case MethodSignature.Kind.INTERFACE_METHOD:
			t = StandardClass.INTERFACE_METHOD;
			break;
		default:
			throw new Error("Unexpected method signature kind: " + sig.kind);
		}
		ObjectLike result = newObjectLike(t, methodFieldsCount);
		result.setElement(MethodFields.SIGNATURE.value, getMethodSignature(sig));
		result.setElement(MethodFields.FLAGS.value, getConstInt32("" + flags));
		result.setElement(MethodFields.LOCALS.value, getConstInt32("" + nlocals));
		
		addMember(type, result);
		
		return result;
	}

	public int getMaximumRecords() {
		return maximumRecords;
	}
	
	public ObjectLike getMemberExtendedFlags(ObjectLike member) {
		if (member.getElement(MethodFields.FLAGS.value).getStandardClass() != StandardClass.SIMPLEARRAY) {
			ObjectLike result = newObjectLike(StandardClass.SIMPLEARRAY, 1);
			result.setElement(0, member.getElement(MethodFields.FLAGS.value));
			member.setElement(MethodFields.FLAGS.value, result);
		}
		return (ObjectLike) member.getElement(MethodFields.FLAGS.value);
	}

	public void addMemberTranslation(ObjectLike member, String language, String name) {
		ObjectLike tr = newObjectLike(StandardClass.METADATA, MetadataFields.lookupCount(MetadataFields.class));
		tr.setElement(MetadataFields.KEY.value, language == null ? getNull() : (ObjectLike) getConstString(language));
		tr.setElement(MetadataFields.VALUE.value, name == null ? getNull() : (ObjectLike) getConstString(name));
		getMemberExtendedFlags(member).appendElement(tr);
	}
}