package slangc.model.statements;

import slang.data.List;
import slangc.api.BytecodeInstructionWriter;
import slangc.api.Reporter;
import slangc.bytecode.TypeSignature;
import slangc.model.InnerTypeScope;
import slangc.model.LocalVariableSlot;
import slangc.model.MemberModel;
import slangc.model.StatementModel;
import slangc.model.StatementOwner;
import slangc.model.TypeModel;
import slangc.parser.Branch;
import slangc.parser.Node;

public class VariableStatement extends StatementModel implements StatementOwner {
	private TypeModel type;
	private List<LocalVariableSlot> slots = new List<LocalVariableSlot>();

	public VariableStatement(StatementOwner owner, Branch source) {
		super(owner, source);
		
		type = owner.resolveType(source.getSubnode(1));
		
		Branch l = (Branch) source.getSubnode(2);
		for (int i = 0; i < l.countSubnodes(); i++) {
			slots.append(new LocalVariableSlot(this, (Branch)l.getSubnode(i), type));
		}
	}

	@Override
	public void dump(Reporter reporter, String indent, String incr) {
		reporter.note("DUMP", indent + "> Variable statement:");
		// do not recurse: type.dump(reporter, indent + incr, incr);
		for (int i = 0; i < slots.count(); i++) {
			slots.get(i).dump(reporter, indent + incr, incr);
		}
	}

	@Override
	public int resolveExpressions() {
		int nresolved = 0;
		for (int i = 0; i < slots.count(); i++) {
			nresolved += slots.get(i).resolveExpressions();
		}
		return nresolved;
	}

	public boolean hasVariable(String name) {
		for (int i = 0; i < slots.count(); i++) {
			if (slots.get(i).getName().equals(name)) {
				return true;
			}
		}
		return false;
	}

	public LocalVariableSlot getVariable(String name) {
		for (int i = 0; i < slots.count(); i++) {
			if (slots.get(i).getName().equals(name)) {
				return slots.get(i);
			}
		}
		return null;
	}

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

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

	public MethodModel[] lookupSimpleMethod(String name) {
		// TODO: Better interface support
		return super.lookupSimpleMethod(name);
	}

	//@Override
	public MemberModel getMethodOrField() {
		return getOwner().getMethodOrField();
	}
	
	@Override
	public void innerGenerate(BytecodeInstructionWriter w) {
		// The first pass declares each of the variables (this will reset them to default values)
		for (int i = 0; i < slots.count(); i++) {
			LocalVariableSlot s = slots.get(i);
			w.genDeclareLocal(s.getStorageType().getTypeSignature(), s.getIndex());
		}
		// The second pass generates any initialisers
		for (int i = 0; i < slots.count(); i++) {
			LocalVariableSlot s = slots.get(i);
			if (s.hasInitialiser()) {
				TypeSignature storing = s.getInitialiser().generate(w);
				if (!storing.mappableEquals(s.getInitialiser().getResult().getValueTypeWithNullType(s.getStorageType()).getTypeSignature())) {
					w.genConvert(storing, s.getStorageType().getTypeSignature());
					storing = s.getStorageType().getTypeSignature();
				}
				w.genStoreLocalOrParam(s.getStorageType().getTypeSignature(), s.getIndex());
			}
		}
	}
}