package org.simantics.scl.compiler.elaboration.expressions;


import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
import org.simantics.scl.compiler.common.names.Names;
import org.simantics.scl.compiler.constants.DoubleConstant;
import org.simantics.scl.compiler.constants.FloatConstant;
import org.simantics.scl.compiler.elaboration.contexts.ReplaceContext;
import org.simantics.scl.compiler.elaboration.contexts.SimplificationContext;
import org.simantics.scl.compiler.elaboration.contexts.TranslationContext;
import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
import org.simantics.scl.compiler.errors.ErrorLog;
import org.simantics.scl.compiler.errors.Locations;
import org.simantics.scl.compiler.types.Type;
import org.simantics.scl.compiler.types.Types;
import org.simantics.scl.compiler.types.exceptions.MatchException;

import gnu.trove.map.hash.TObjectIntHashMap;
import gnu.trove.set.hash.TIntHashSet;

public class ERealLiteral extends SimplifiableExpression {
    public String value;
    public EVariable constraint;

    public ERealLiteral(String value) {
        this.value = value;
    }

    @Override
    public void collectVars(TObjectIntHashMap<Variable> allVars,
            TIntHashSet vars) {
    }

    private Expression tryToConvertToPrimitive(ErrorLog errorLog, Type requiredType) {
        if(requiredType.equals(Types.DOUBLE))
            return new ELiteral(new DoubleConstant(Double.parseDouble(value)));
        else if(requiredType.equals(Types.FLOAT))
            return new ELiteral(new FloatConstant(Float.parseFloat(value)));
        else if(requiredType.equals(Types.INTEGER)) {
            errorLog.log(location, "Cannot convert real literal to Integer.");
            return new EError();
        }
        else if(requiredType.equals(Types.LONG)) {
            errorLog.log(location, "Cannot convert real literal to Long.");
            return new EError();
        }
        else
            return null;
    }
    
    @Override
    public Expression checkBasicType(TypingContext context, Type requiredType) {
        requiredType = Types.canonical(requiredType);
        Expression primitive = tryToConvertToPrimitive(context.getErrorLog(), requiredType);
        if(primitive != null)
            return primitive;
        else {
            setType(requiredType);        
            constraint = new EVariable(location, null);
            constraint.setType(Types.pred(Types.REAL, requiredType));
            context.addConstraintDemand(constraint);
            return this;
        }
    }

    @Override
    protected void updateType() throws MatchException {
        throw new InternalCompilerError("TODO");
    }

    @Override
    public Expression simplify(SimplificationContext context) {
        Expression primitive = tryToConvertToPrimitive(context.getErrorLog(), getType());
        if(primitive != null)
            return primitive;
        return context.apply(
                context.getConstant(Names.Prelude_fromDouble, getType()),
                constraint.simplify(context),
                context.literal(new DoubleConstant(Double.parseDouble(value)))
                );
    }

    @Override
    public Expression resolve(TranslationContext context) {
        return this;
    }
    
    @Override
    public Expression resolveAsPattern(TranslationContext context) {
        return new ELiteral(new DoubleConstant(Double.parseDouble(value)));
    }
    
    @Override
    public Expression replace(ReplaceContext context) {
        ERealLiteral copy = new ERealLiteral(value);
        copy.setType(getType().replace(context.tvarMap));
        return copy;
    }
    
    @Override
    public void setLocationDeep(long loc) {
        if(location == Locations.NO_LOCATION) {
            location = loc;
            if(constraint != null)
                constraint.setLocationDeep(loc);
        }
    }
    
    @Override
    public void accept(ExpressionVisitor visitor) {
        visitor.visit(this);
    }

    public String getValue() {
        return value;
    }
    
    @Override
    public Expression accept(ExpressionTransformer transformer) {
        return transformer.transform(this);
    }

}