package org.simantics.scl.compiler.internal.codegen.chr;

import java.util.ArrayList;

import org.cojen.classfile.TypeDesc;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.simantics.scl.compiler.elaboration.chr.CHRRuleset;
import org.simantics.scl.compiler.elaboration.chr.plan.PrioritizedPlan;
import org.simantics.scl.compiler.elaboration.chr.relations.CHRConstraint;
import org.simantics.scl.compiler.elaboration.chr.relations.CHRConstraint.IndexInfo;
import org.simantics.scl.compiler.internal.codegen.references.BoundVar;
import org.simantics.scl.compiler.internal.codegen.types.JavaTypeTranslator;
import org.simantics.scl.compiler.internal.codegen.utils.ClassBuilder;
import org.simantics.scl.compiler.internal.codegen.utils.CodeBuilderUtils;
import org.simantics.scl.compiler.internal.codegen.utils.Constants;
import org.simantics.scl.compiler.internal.codegen.utils.LocalVariable;
import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;
import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilderBase;
import org.simantics.scl.compiler.internal.codegen.utils.ModuleBuilder;

import gnu.trove.list.array.TIntArrayList;
import gnu.trove.set.hash.THashSet;

public class CHRFactCodeGenerator {
    private static final TypeDesc FACT_ID_TYPE = TypeDesc.INT;
    private static final String CHRHashIndex_name = "org/simantics/scl/runtime/chr/CHRHashIndex";
    private static final TypeDesc CHRHashIndex = TypeDesc.forClass(CHRHashIndex_name);
    private static final String FactActivationQueue_name = "org/simantics/scl/runtime/chr/FactActivationQueue";
    private static final TypeDesc FactActivationQueue = TypeDesc.forClass(FactActivationQueue_name);
    private static final String Fact_name = "org/simantics/scl/runtime/chr/Fact";
    private static final TypeDesc Fact = TypeDesc.forClass(Fact_name);
    private static final String QUEUE = "queue";

    private ModuleBuilder moduleBuilder; 
    private JavaTypeTranslator jtt;
    private CHRRuleset ruleset;

    private ClassBuilder storeClassBuilder;
    private CHRConstraint constraint;

    private String factClassName;
    private TypeDesc factTypeDesc;
    private ClassBuilder factClassBuilder;

    private TypeDesc storeTypeDesc;
    private TypeDesc[] storeTypeDescArray;

    private TypeDesc[] parameterTypeDescs;
    private boolean supportsRemoval;

    CHRFactCodeGenerator(ClassBuilder storeClassBuilder, CHRConstraint constraint) {
        this.storeClassBuilder = storeClassBuilder;
        this.constraint = constraint;
        this.ruleset = constraint.parentRuleset;

        this.moduleBuilder = storeClassBuilder.getModuleBuilder();
        this.jtt = moduleBuilder.getJavaTypeTranslator();
        this.storeTypeDesc = storeClassBuilder.getType();
        this.storeTypeDescArray = new TypeDesc[] { storeTypeDesc };

        this.factClassName = storeClassBuilder.getClassName() + "$" + constraint.name;
        this.factTypeDesc = TypeDesc.forClass(factClassName);
        this.factClassBuilder = new ClassBuilder(moduleBuilder, Opcodes.ACC_PUBLIC, factClassName, "java/lang/Object", Fact_name);

        this.parameterTypeDescs = jtt.toTypeDescs(constraint.parameterTypes);
        this.supportsRemoval = constraint.mayBeRemoved();
    }

    public void generate(ArrayList<StoreInitialization> hashIndexInitializations) {
        generateFields(hashIndexInitializations);
        hashIndexInitializations.add(new StoreInitialization(Opcodes.ACC_PRIVATE | Opcodes.ACC_FINAL, constraint.name + "$temp", factTypeDesc, factClassName));

        generateIndices();
        generateAdd();

        if(supportsRemoval)
            generateRemove();

        generateIsAlive();

        for(int i=0;i<constraint.plans.size();++i) 
            generateActivateI(i);
        generateActivate();

        generateConstructor();
        factClassBuilder.addDefaultConstructor();

        moduleBuilder.addClass(factClassBuilder);
    }

    private void generateIndices() {
        // public ExampleFact ExampleFact$bf(int c0) {
        //     ExampleFact$temp.c0 = c0;
        //     return (ExampleFact)ExampleFact_bfIndex.getEqual(ExampleFact$temp);
        // }

        for(IndexInfo indexInfo : constraint.getIndices()) {
            if(indexInfo.indexMask != 0) {
                ArrayList<TypeDesc> getParameterTypeDescs = new ArrayList<TypeDesc>(constraint.parameterTypes.length);
                for(int i=0;i<constraint.parameterTypes.length;++i)
                    if(((indexInfo.indexMask>>i)&1)==1)
                        getParameterTypeDescs.add(parameterTypeDescs[i]);
                MethodBuilderBase mb = storeClassBuilder.addMethodBase(Opcodes.ACC_PUBLIC, constraint.name + "$" + indexInfo.indexName, factTypeDesc,
                        getParameterTypeDescs.toArray(new TypeDesc[getParameterTypeDescs.size()]));

                // ExampleFact$temp.c0 = c0;
                mb.loadThis();
                mb.loadField(storeClassBuilder.getClassName(), constraint.name + "$temp", factTypeDesc);
                LocalVariable tempFactVar = mb.createLocalVariable("temp", factTypeDesc);
                mb.storeLocal(tempFactVar);
                int parameterId=0;
                for(int i=0;i<constraint.parameterTypes.length;++i)
                    if(((indexInfo.indexMask>>i)&1)==1) {
                        TypeDesc typeDesc = parameterTypeDescs[i];
                        if(!typeDesc.equals(TypeDesc.VOID)) {
                            mb.loadLocal(tempFactVar);
                            mb.loadLocal(mb.getParameter(parameterId));
                            mb.storeField(factClassName, fieldName(i), typeDesc);
                        }
                        ++parameterId;
                    }

                // return (ExampleFact)ExampleFact_bfIndex.getEqual(ExampleFact$temp);
                mb.loadThis();
                mb.loadField(storeClassBuilder.getClassName(), constraint.name + "$" + indexInfo.indexName, CHRHashIndex);
                mb.loadLocal(tempFactVar);
                mb.invokeVirtual(CHRHashIndex_name, supportsRemoval ? "getEqual" : "getEqualNoRemovals", TypeDesc.OBJECT, Constants.OBJECTS[1]);
                mb.checkCast(factTypeDesc);
                mb.returnValue(factTypeDesc);
                mb.finish();
            }
        }   
    }

    private THashSet<BoundVar> usedParameters = new THashSet<BoundVar>();

    private void generateActivateI(int i) {
        PrioritizedPlan plan = constraint.plans.get(i);
        MethodBuilder mb = factClassBuilder.addMethod(Opcodes.ACC_PUBLIC, "activate" + i, TypeDesc.BOOLEAN, storeTypeDescArray);
        LocalVariable storeVar = mb.getParameter(0);
        LocalVariable factVar = new LocalVariable(0, factTypeDesc);
        mb.setLocalVariable(ruleset.this_, storeVar);
        mb.setLocalVariable(plan.implementation.getParameters()[0], factVar);

        // Set closure parameters
        usedParameters.clear();
        plan.implementation.forValRefs(valRef -> {
            if(valRef.getBinding() instanceof BoundVar)
                usedParameters.add((BoundVar)valRef.getBinding());
        });
        for(int j=0;j<ruleset.parameters.length;++j) {
            BoundVar parameter = ruleset.parameters[j];
            if(!usedParameters.contains(parameter))
                continue;
            mb.loadLocal(storeVar);
            mb.loadField(storeClassBuilder.getClassName(), "p"+j, ruleset.parameterTypeDescs[j]);
            mb.store(parameter);
        }

        // Generate code
        //System.out.println("=== activate" + i + " ==========================================================");
        //System.out.println(plan.implementation);
        plan.implementation.markGenerateOnFly();
        plan.implementation.generateCodeWithAlreadyPreparedParameters(mb);
        mb.finish();
    }

    private void generateActivate() {
        // @Override
        // public int activate(Object context, int priority) {
        //     return -1;
        // }

        MethodBuilderBase mb = factClassBuilder.addMethodBase(Opcodes.ACC_PUBLIC, "activate", TypeDesc.INT, new TypeDesc[] {TypeDesc.OBJECT, TypeDesc.INT});
        Label defaultLabel = mb.createLabel();

        if(!constraint.isPassive()) {
            // Check if the fact is alive
            mb.loadThis();
            mb.loadField(factClassName, "id", TypeDesc.INT);
            mb.ifZeroComparisonBranch(defaultLabel, "<");

            mb.loadLocal(mb.getParameter(0));
            mb.checkCast(storeTypeDesc);
            LocalVariable storeVariable = new LocalVariable(1, storeTypeDesc);
            mb.storeLocal(storeVariable);

            TIntArrayList priorities = new TIntArrayList(constraint.plans.size());
            ArrayList<Label> labels = new ArrayList<Label>();
            int lastPriority = -1;
            for(PrioritizedPlan plan : constraint.plans)
                if(plan.priority != lastPriority) {
                    priorities.add(plan.priority);
                    labels.add(mb.createLabel());
                    lastPriority = plan.priority;
                }

            mb.loadLocal(mb.getParameter(1));
            mb.switch_(priorities.toArray(), labels.toArray(new Label[labels.size()]), defaultLabel);
            int labelId = -1;
            for(int i=0;i<constraint.plans.size();++i) {
                PrioritizedPlan plan = constraint.plans.get(i);
                if(labelId == -1 || plan.priority != priorities.get(labelId)) {
                    if(labelId >= 0) {
                        mb.loadConstant(plan.priority);
                        mb.returnValue(TypeDesc.INT);
                    }
                    ++labelId;
                    mb.setLocation(labels.get(labelId));
                }
                mb.loadThis();
                mb.loadLocal(storeVariable);
                mb.invokeVirtual(factClassName, "activate" + i, TypeDesc.BOOLEAN, new TypeDesc[] {storeTypeDesc});
                mb.ifZeroComparisonBranch(defaultLabel, "==");
            }
            mb.setLocation(defaultLabel);
        }
        mb.loadConstant(-1);
        mb.returnValue(TypeDesc.INT);
        mb.finish();
    }

    private void generateConstructor() {
        // public ExampleFact(int id, int c0, int c1) {
        //     this.id = id;            
        //     this.c0 = c0;
        //     this.c1 = c1;
        // }

        ArrayList<TypeDesc> constructorParameters = new ArrayList<TypeDesc>(parameterTypeDescs.length+1);
        constructorParameters.add(FACT_ID_TYPE);
        for(TypeDesc typeDesc : parameterTypeDescs) {
            if(typeDesc.equals(TypeDesc.VOID))
                continue;
            constructorParameters.add(typeDesc);
        }
        MethodBuilderBase mb = factClassBuilder.addConstructor(Opcodes.ACC_PUBLIC, constructorParameters.toArray(new TypeDesc[constructorParameters.size()]));
        mb.loadThis();
        mb.invokeConstructor(factClassBuilder.getSuperClassName(), Constants.EMPTY_TYPEDESC_ARRAY);
        mb.loadThis();
        mb.loadLocal(mb.getParameter(0));
        mb.storeField(factClassName, "id", FACT_ID_TYPE);
        for(int i=0,parameterId=1;i<constraint.parameterTypes.length;++i) {
            TypeDesc typeDesc = parameterTypeDescs[i];
            if(typeDesc.equals(TypeDesc.VOID))
                continue;
            mb.loadThis();
            mb.loadLocal(mb.getParameter(parameterId++));
            mb.storeField(factClassName, fieldName(i), typeDesc);
        }
        mb.returnVoid();
        mb.finish();
    }

    private void generateIsAlive() {
        // @Override
        // public boolean isAlive() {
        //     return id >= 0;
        // }

        MethodBuilderBase mb = factClassBuilder.addMethodBase(Opcodes.ACC_PUBLIC, "isAlive", TypeDesc.BOOLEAN, Constants.EMPTY_TYPEDESC_ARRAY);
        if(supportsRemoval) {
            mb.loadThis();
            mb.loadField(factClassName, "id", FACT_ID_TYPE);

            Label thenBranch = mb.createLabel();
            mb.ifZeroComparisonBranch(thenBranch, "<");
            mb.loadConstant(true);
            mb.returnValue(TypeDesc.BOOLEAN);

            mb.setLocation(thenBranch);
            mb.loadConstant(false);
            mb.returnValue(TypeDesc.BOOLEAN);
        }
        else {
            mb.loadConstant(true);
            mb.returnValue(TypeDesc.BOOLEAN);
        }
        mb.finish();
    }

    private void generateAdd() {
        MethodBuilderBase mb = factClassBuilder.addMethodBase(Opcodes.ACC_PUBLIC, "add", TypeDesc.VOID, storeTypeDescArray);
        LocalVariable storeParameter = mb.getParameter(0);
        for(IndexInfo indexInfo : constraint.getIndices()) {
            String linkedListPrev = indexInfo.indexName + "Prev";
            String linkedListNext = indexInfo.indexName + "Next";
            String storeHashIndexName = constraint.name + "$" + indexInfo.indexName;

            // public void add(ExampleStore store) {
            //     bfNext = (ExampleFact)store.ExampleFact_bfIndex.addFreshAndReturnOld(this);
            //     if(bfNext != null)
            //         bfNext.bfPrev = this;
            // }

            if(indexInfo.indexMask == 0) {
                mb.loadThis();
                mb.loadLocal(storeParameter);
                mb.loadField(storeClassBuilder.getClassName(), storeHashIndexName, factTypeDesc);
                if(supportsRemoval)
                    mb.dupX1();
                mb.storeField(factClassName, linkedListNext, factTypeDesc);
                if(supportsRemoval) {
                    Label cont = new Label();
                    mb.ifNullBranch(cont, true);
                    mb.loadThis();
                    mb.loadField(factClassName, linkedListNext, factTypeDesc);
                    mb.loadThis();
                    mb.storeField(factClassName, linkedListPrev, factTypeDesc);
                    mb.setLocation(cont);
                }
                mb.loadLocal(storeParameter);
                mb.loadThis();
                mb.storeField(storeClassBuilder.getClassName(), storeHashIndexName, factTypeDesc);
            }
            else {
                // bfNext = (ExampleFact)store.ExampleFact_bfIndex.addFreshAndReturnOld(this);
                mb.loadThis();
                mb.loadLocal(storeParameter);
                mb.loadField(storeClassBuilder.getClassName(), storeHashIndexName, CHRHashIndex);
                mb.loadThis();
                mb.invokeVirtual(CHRHashIndex_name, supportsRemoval ? "addFreshAndReturnOld" : "addFreshAndReturnOld", TypeDesc.OBJECT, Constants.OBJECTS[1]);
                mb.checkCast(factTypeDesc);
                if(supportsRemoval)
                    mb.dupX1();
                mb.storeField(factClassName, linkedListNext, factTypeDesc);
                // leaves bfNext on the stack

                //if(bfNext != null)
                //    bfNext.bfPrev = this;
                if(supportsRemoval) {
                    Label cont = new Label();
                    mb.ifNullBranch(cont, true);
                    mb.loadThis();
                    mb.loadField(factClassName, linkedListNext, factTypeDesc);
                    mb.loadThis();
                    mb.storeField(factClassName, linkedListPrev, factTypeDesc);
                    mb.setLocation(cont);
                }
            }
        }            
        if(!constraint.isPassive()) {
            mb.loadLocal(storeParameter);
            mb.loadField(storeClassBuilder.getClassName(), QUEUE, FactActivationQueue);
            mb.loadConstant(constraint.getMinimumPriority());
            mb.loadThis();
            mb.invokeVirtual(FactActivationQueue_name, "add", TypeDesc.VOID, new TypeDesc[] {TypeDesc.INT, Fact});
        }
        mb.returnVoid();
        mb.finish();
    }

    private void generateFields(ArrayList<StoreInitialization> hashIndexInitializations) {
        // public int id;
        // public int c0; // key
        // public int c1;
        // public ExampleFact bfPrev;
        // public ExampleFact bfNext;

        factClassBuilder.addField(Opcodes.ACC_PUBLIC, "id", FACT_ID_TYPE);
        for(int i=0;i<constraint.parameterTypes.length;++i) {
            TypeDesc typeDesc = parameterTypeDescs[i];
            if(typeDesc.equals(TypeDesc.VOID))
                continue;
            if(parameterTypeDescs[i] != TypeDesc.VOID)
                factClassBuilder.addField(Opcodes.ACC_PUBLIC, fieldName(i), typeDesc);
        }

        for(IndexInfo indexInfo : constraint.getIndices()) {
            if(supportsRemoval)
                factClassBuilder.addField(Opcodes.ACC_PUBLIC, indexInfo.indexName + "Prev", factTypeDesc);
            factClassBuilder.addField(Opcodes.ACC_PUBLIC, indexInfo.indexName + "Next", factTypeDesc);

            String hashIndexField = constraint.name + "$" + indexInfo.indexName;
            if(indexInfo.indexMask == 0) {
                // If there are no bound parameters, use just a direct reference to a fact
                storeClassBuilder.addField(Opcodes.ACC_PUBLIC, hashIndexField, factTypeDesc);
            }
            else {
                ClassBuilder hashClass = generateSpecializedHashIndex(storeClassBuilder, constraint, indexInfo, factTypeDesc, factClassName);
                moduleBuilder.addClass(hashClass);
                hashIndexInitializations.add(new StoreInitialization(Opcodes.ACC_PUBLIC | Opcodes.ACC_FINAL, hashIndexField, CHRHashIndex, hashClass.getClassName()));
            }
        }
    }

    private void generateRemove() {
        // public void remove(ExampleStore store) {
        //     if(bfPrev == null) {
        //         if(bfNext == null)
        //             store.ExampleFact_bfIndex.removeKnownToExistKey(this);
        //         else {
        //             bfNext.bfPrev = null;
        //             store.ExampleFact_bfIndex.replaceKnownToExistKey(this, bfNext);
        //         }
        //     }
        //     else {
        //         bfPrev.bfNext = bfNext;
        //         if(bfNext != null)
        //             bfNext.bfPrev = bfPrev;
        //     }
        // }

        MethodBuilderBase mb = factClassBuilder.addMethodBase(Opcodes.ACC_PUBLIC, "remove", TypeDesc.VOID, storeTypeDescArray);
        LocalVariable storeParameter = mb.getParameter(0);
        for(IndexInfo indexInfo : constraint.getIndices()) {
            String linkedListPrev = indexInfo.indexName + "Prev";
            String linkedListNext = indexInfo.indexName + "Next";
            String storeHashIndexName = constraint.name + "$" + indexInfo.indexName;

            Label nextIndex = mb.createLabel();

            // if(bfPrev == null) {
            mb.loadThis();
            mb.loadField(factClassName, linkedListPrev, factTypeDesc);
            Label else1 = new Label();
            mb.ifNullBranch(else1, false);

            //     if(bfNext == null)
            mb.loadThis();
            mb.loadField(factClassName, linkedListNext, factTypeDesc);
            Label else2 = new Label();
            mb.ifNullBranch(else2, false);

            //         store.ExampleFact_bfIndex.removeKnownToExistKey(this);
            if(indexInfo.indexMask == 0) {
                mb.loadLocal(storeParameter);
                mb.loadNull();
                mb.storeField(storeClassBuilder.getClassName(), storeHashIndexName, factTypeDesc);
            }
            else {
                mb.loadLocal(storeParameter);
                mb.loadField(storeClassBuilder.getClassName(), storeHashIndexName, CHRHashIndex);
                mb.loadThis();
                mb.invokeVirtual(CHRHashIndex_name, "removeKnownToExistKey", TypeDesc.VOID, Constants.OBJECTS[1]);
            }
            mb.branch(nextIndex);

            //     else {
            mb.setLocation(else2);
            //         bfNext.bfPrev = null;
            mb.loadThis();
            mb.loadField(factClassName, linkedListNext, factTypeDesc);
            mb.loadNull();
            mb.storeField(factClassName, linkedListPrev, factTypeDesc);
            //         store.ExampleFact_bfIndex.replaceKnownToExistKey(this, bfNext);
            if(indexInfo.indexMask == 0) {
                mb.loadLocal(storeParameter);
                mb.loadThis();
                mb.loadField(factClassName, linkedListNext, factTypeDesc);
                mb.storeField(storeClassBuilder.getClassName(), storeHashIndexName, factTypeDesc);
            }
            else {
                mb.loadLocal(storeParameter);
                mb.loadField(storeClassBuilder.getClassName(), storeHashIndexName, CHRHashIndex);
                mb.loadThis();
                mb.loadThis();
                mb.loadField(factClassName, linkedListNext, factTypeDesc);
                mb.invokeVirtual(CHRHashIndex_name, "replaceKnownToExistKey", TypeDesc.VOID, Constants.OBJECTS[2]);
            }
            mb.branch(nextIndex);
            //     }

            // else {
            mb.setLocation(else1);
            //     bfPrev.bfNext = bfNext;
            mb.loadThis();
            mb.loadField(factClassName, linkedListPrev, factTypeDesc);
            mb.loadThis();
            mb.loadField(factClassName, linkedListNext, factTypeDesc);
            mb.storeField(factClassName, linkedListNext, factTypeDesc);
            //     if(bfNext != null)
            mb.loadThis();
            mb.loadField(factClassName, linkedListNext, factTypeDesc);
            Label else3 = new Label();
            mb.ifNullBranch(else3, true);
            //         bfNext.bfPrev = bfPrev;
            mb.loadThis();
            mb.loadField(factClassName, linkedListNext, factTypeDesc);
            mb.loadThis();
            mb.loadField(factClassName, linkedListPrev, factTypeDesc);
            mb.storeField(factClassName, linkedListPrev, factTypeDesc);
            mb.setLocation(else3);
            mb.branch(nextIndex);
            // }

            mb.setLocation(nextIndex);
        }
        mb.loadThis();
        mb.loadConstant(-1);
        mb.storeField(factClassName, "id", FACT_ID_TYPE);
        mb.returnVoid();
        mb.finish();
    }

    public static String fieldName(int id) {
        return "c" + id;
    }

    private static ClassBuilder generateSpecializedHashIndex(ClassBuilder storeClassBuilder, CHRConstraint constraint, IndexInfo indexInfo, TypeDesc factClassTypeDesc, String factClassName) {
        // new CHRHashIndex() {
        //     @Override
        //     protected boolean keyEquals(Object a, Object b) {
        //         return ((ExampleFact)a).c0 == ((ExampleFact)b).c0;
        //     }
        //     @Override
        //     protected int keyHashCode(Object key) {
        //         return ((ExampleFact)key).c0;
        //     }
        // }

        ModuleBuilder moduleBuilder = storeClassBuilder.getModuleBuilder();
        JavaTypeTranslator jtt = moduleBuilder.getJavaTypeTranslator();

        String hashIndexClassName = factClassName + "$" + indexInfo.indexName; 
        ClassBuilder hashIndexClassBuilder = new ClassBuilder(moduleBuilder, Opcodes.ACC_PUBLIC, hashIndexClassName, "org/simantics/scl/runtime/chr/CHRHashIndex");

        // Method: keyEquals

        {

            // @Override
            // protected boolean keyEquals(Object a, Object b) {
            //     return ((ExampleFact)a).c0 == ((ExampleFact)b).c0;
            // }

            MethodBuilderBase mb = hashIndexClassBuilder.addMethodBase(Opcodes.ACC_PROTECTED, "keyEquals", TypeDesc.BOOLEAN, Constants.OBJECTS[2]);
            mb.loadLocal(mb.getParameter(0));
            mb.checkCast(factClassTypeDesc);
            LocalVariable aVar = mb.createLocalVariable("a", factClassTypeDesc);
            mb.storeLocal(aVar);

            mb.loadLocal(mb.getParameter(1));
            mb.checkCast(factClassTypeDesc);
            LocalVariable bVar = mb.createLocalVariable("b", factClassTypeDesc);
            mb.storeLocal(bVar);

            Label failure = mb.createLabel();

            int curMask = indexInfo.indexMask;
            for(int i=0;i<constraint.parameterTypes.length;++i,curMask>>=1)
                if((curMask&1) == 1) {
                    TypeDesc fieldTypeDesc = jtt.toTypeDesc(constraint.parameterTypes[i]);
                    if(fieldTypeDesc.equals(TypeDesc.VOID))
                        continue;
                    mb.loadLocal(aVar);
                    mb.loadField(factClassName, fieldName(i), fieldTypeDesc);

                    mb.loadLocal(bVar);
                    mb.loadField(factClassName, fieldName(i), fieldTypeDesc);

                    CodeBuilderUtils.equals(mb, fieldTypeDesc, failure);
                }
            mb.loadConstant(true);
            mb.returnValue(TypeDesc.BOOLEAN);

            mb.setLocation(failure);
            mb.loadConstant(false);
            mb.returnValue(TypeDesc.BOOLEAN);
            mb.finish();
        }

        // Method: keyHashCode

        {
            // @Override
            // protected int keyHashCode(Object key) {
            //     return (0x811C9DC5^((ExampleFact)key).c0)*16777619;
            // }

            MethodBuilderBase mb = hashIndexClassBuilder.addMethodBase(Opcodes.ACC_PROTECTED, "keyHashCode", TypeDesc.INT, Constants.OBJECTS[1]);
            mb.loadLocal(mb.getParameter(0));
            mb.checkCast(factClassTypeDesc);
            LocalVariable factVar = mb.createLocalVariable("fact", factClassTypeDesc);
            mb.storeLocal(factVar);

            mb.loadConstant(0x811C9DC5);

            int curMask = indexInfo.indexMask;
            for(int i=0;i<constraint.parameterTypes.length;++i,curMask>>=1)
                if((curMask&1) == 1) {
                    TypeDesc fieldTypeDesc = jtt.toTypeDesc(constraint.parameterTypes[i]);
                    if(fieldTypeDesc.equals(TypeDesc.VOID))
                        continue;
                    mb.loadLocal(factVar);
                    mb.loadField(factClassName, fieldName(i), fieldTypeDesc);
                    CodeBuilderUtils.hashCode(mb, fieldTypeDesc);
                    mb.math(Opcodes.IXOR);
                    mb.loadConstant(16777619);
                    mb.math(Opcodes.IMUL);

                }
            mb.returnValue(TypeDesc.INT);
            mb.finish();
        }

        hashIndexClassBuilder.addDefaultConstructor();

        return hashIndexClassBuilder;
    }
}