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 UnaryExpression extends ExpressionModel implements ExpressionOwner {
	String operator;
	ExpressionModel rightHandSide;

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

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

	@Override
	public ExpressionModel[] getSubexpressions() {
		return new ExpressionModel[] {rightHandSide};
	}
	
	@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 (rightHandSide.getResult().resolvesToValueOrNull() && rightHandSide.getResult().getKind() != ExpressionResult.Kind.NULL) {
			return new ExpressionResult.TypedValue(rightHandSide.getResult().getValueType());
		} else {
			return ExpressionResult.INVALID;
		}
	}
	
	public String getOperator() {
		return operator;
	}
	
	@Override
	public TypeSignature innerGenerate(BytecodeInstructionWriter w) {
		String op = getOperator();
		if (op.equals("+")) {
			w.genConst(w.getTarget().getHeap().getConstInt32("0"));
			rightHandSide.generate(w);
			return BinaryExpression.generateALUOp(w, getSystem().getDefaultInt32Type(), "+", rightHandSide.getResult().getValueType()).getTypeSignature();
		} else if (op.equals("-")) {
			if (rightHandSide instanceof LiteralExpression && ((LiteralExpression)rightHandSide).canNegate()) {
				LiteralExpression lrhs = (LiteralExpression) rightHandSide;
				lrhs.negate();
				return lrhs.generate(w);
			} else {
				w.genConst(w.getTarget().getHeap().getConstInt32("0"));
				rightHandSide.generate(w);
				return BinaryExpression.generateALUOp(w, getSystem().getDefaultInt32Type(), "-", rightHandSide.getResult().getValueType()).getTypeSignature();
			}
		} else if (op.equals("~")) {
			// TODO: Make sure this works for non-int types
			w.genConst(w.getTarget().getHeap().getConstInt32("-1"));
			rightHandSide.generate(w);
			return BinaryExpression.generateALUOp(w, getSystem().getDefaultInt32Type(), "^", rightHandSide.getResult().getValueType()).getTypeSignature();
		} else if (op.equals("!")) {
			rightHandSide.generate(w);
			w.genNot();
			return getSystem().getDefaultBooleanType().getTypeSignature();
		} else if (op.equals("++")) {
			TypeSignature rhsType = rightHandSide.generate(w);
			w.genConst(w.getTarget().getHeap().getConstInt32("1"));
			TypeModel rt = BinaryExpression.generateALUOp(w, rightHandSide.getResult().getValueType(), "+", getSystem().getDefaultInt32Type());
			if (!rt.getTypeSignature().mappableEquals(rightHandSide.getResult().getValueType().getTypeSignature())) {
				w.genConvert(rt.getTypeSignature(), rightHandSide.getResult().getValueType().getTypeSignature());
			}
			rightHandSide.generateStore(w, rightHandSide.getResult().getValueType().getTypeSignature());
			return rightHandSide.generate(w);
		} else if (op.equals("--")) {
			TypeSignature rhsType = rightHandSide.generate(w);
			w.genConst(w.getTarget().getHeap().getConstInt32("1"));
			TypeModel rt = BinaryExpression.generateALUOp(w, rightHandSide.getResult().getValueType(), "-", getSystem().getDefaultInt32Type());
			if (!rt.getTypeSignature().mappableEquals(rightHandSide.getResult().getValueType().getTypeSignature())) {
				w.genConvert(rt.getTypeSignature(), rightHandSide.getResult().getValueType().getTypeSignature());
			}
			rightHandSide.generateStore(w, rightHandSide.getResult().getValueType().getTypeSignature());
			return rightHandSide.generate(w);
		} else {
			w.genError("TODO: innerGenerate for " + Type.of(this) + " with '" + getOperator() + "'");
			return null;
		}
	}
}