package slangc.model.expressions;

import slangc.api.BytecodeInstructionWriter;
import slangc.api.Reporter;
import slangc.bytecode.TypeSignature;
import slangc.model.ExpressionModel;
import slangc.model.ExpressionOwner;
import slangc.model.ExpressionResult;
import slangc.model.InnerTypeScope;
import slangc.model.MemberModel;
import slangc.model.TypeModel;
import slangc.parser.Branch;
import slangc.parser.Node;

public class CountExpression extends ExpressionModel implements ExpressionOwner {
	ExpressionModel leftHandSide;
	String operator;

	public CountExpression(ExpressionOwner owner, Node source) {
		super(owner, source);
		leftHandSide = ExpressionModel.construct(this, ((Branch)source).getSubnode(0));
		operator = BinaryExpression.getOpName(((Branch)source).getSubnode(1));
	}

	@Override
	public void dump(Reporter reporter, String indent, String incr) {
		reporter.note("DUMP", indent + "> Count expression (" + getSource().getNodeType() + ")");
		dumpResolved(reporter, indent + incr, incr);
		leftHandSide.dump(reporter, indent + incr, incr);
	}

	@Override
	public ExpressionModel[] getSubexpressions() {
		return new ExpressionModel[] {leftHandSide};
	}
	
	@Override
	public TypeModel getExpectedResult(ExpressionModel e) {
		// TODO not sure if relevant here
		return null;
	}

	@Override
	public InnerTypeScope getTypeScope() {
		return getOwner().getTypeScope();
	}


	@Override
	public TypeModel resolveType(Node subnode) {
		return getOwner().resolveType(subnode);
	}


	@Override
	public MemberModel getMethodOrField() {
		return getOwner().getMethodOrField();
	}
	
	@Override
	protected ExpressionResult resolveResult() {
		if (leftHandSide.getResult().resolvesToValue()) {
			return new ExpressionResult.TypedValue(leftHandSide.getResult().getValueType());
		} else {
			return ExpressionResult.INVALID;
		}
	}
	
	@Override
	public TypeSignature innerGenerate(BytecodeInstructionWriter w) {
		TypeSignature lhsType = leftHandSide.generate(w);
		w.genDup(lhsType);
		w.genConst(w.getTarget().getHeap().getConstInt32("1"));
		if (operator.equals("++")) {
			TypeModel rt = BinaryExpression.generateALUOp(w, leftHandSide.getResult().getValueType(), "+", getSystem().getDefaultInt32Type());
			if (!rt.getTypeSignature().mappableEquals(leftHandSide.getResult().getValueType().getTypeSignature())) {
				w.genConvert(rt.getTypeSignature(), leftHandSide.getResult().getValueType().getTypeSignature());
			}
			leftHandSide.generateStore(w, leftHandSide.getResult().getValueType().getTypeSignature());
			return lhsType;
		} else if (operator.equals("--")) {
			TypeModel rt = BinaryExpression.generateALUOp(w, leftHandSide.getResult().getValueType(), "-", getSystem().getDefaultInt32Type());
			if (!rt.getTypeSignature().mappableEquals(leftHandSide.getResult().getValueType().getTypeSignature())) {
				w.genConvert(rt.getTypeSignature(), leftHandSide.getResult().getValueType().getTypeSignature());
			}
			leftHandSide.generateStore(w, leftHandSide.getResult().getValueType().getTypeSignature());
			return lhsType;
		} else {
			w.genError("TODO: innerGenerate for " + Type.of(this) + " with '" + operator + "'");
			return null;
		}
	}
}