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.TypeModel;
import slangc.parser.Branch;
import slangc.parser.ErrorType;
import slangc.parser.Node;
import slangc.parser.NodeType;
import slangc.parser.Token;

public class LiteralExpression extends ExpressionModel {
	public static enum SimpleType {
		INT32,
		INT64,
		UINT32,
		UINT64,
		FLOAT32,
		FLOAT64,
		STRING,
		NULL,
		BOOLEAN,
		OTHER
	}
	private SimpleType simpleType = null;
	private boolean negated = false;

	public LiteralExpression(ExpressionOwner owner, Node source) {
		super(owner, source);
		//sourceFile.annotate(ErrorType.INTERNAL_ERROR, "Unrecognised expression (Internal error/TODO)");
	}

	@Override
	public void dump(Reporter reporter, String indent, String incr) {
		reporter.note("DUMP", indent + "> Literal expression (" + getSource().getNodeType() + ")");
		dumpResolved(reporter, indent + incr, incr);
	}
	@Override
	public ExpressionModel[] getSubexpressions() {
		return NO_SUBEXPRESSIONS;
	}
	
	@Override
	protected ExpressionResult resolveResult() {
		if (getSource().getNodeType() == NodeType.STRING_LITERAL_EXPRESSION) {
			simpleType = SimpleType.STRING;
			return new ExpressionResult.TypedValue(getSystem().getDefaultStringType());//(TypeModel) lookupSimpleName("String")); // TODO: Better lookup
		} else if (getSource().getNodeType() == NodeType.INTEGER_LITERAL_EXPRESSION || getSource().getNodeType() == NodeType.FLOAT_LITERAL_EXPRESSION) {
			String lit = ((Token)((Branch)getSource()).getSubnode(0)).getSnippet().getSource();
			if (getSource().getNodeType() == NodeType.FLOAT_LITERAL_EXPRESSION) {
				// TODO: Translations for d/D
				if (lit.search("f") || lit.search("F")) {
					simpleType = SimpleType.FLOAT32;
					return new ExpressionResult.TypedValue(getSystem().getDefaultFloat32Type());
				} else {
					simpleType = SimpleType.FLOAT64;
					return new ExpressionResult.TypedValue(getSystem().getDefaultFloat64Type());
				}
			} else {
				// TODO: Translations for l/L
				if (lit.search("l") || lit.search("L")) {
					// TODO: Translations for u/U
					if (lit.search("u") || lit.search("U")) {
						simpleType = SimpleType.UINT64;
					} else {
						simpleType = SimpleType.INT64;
					}
					return new ExpressionResult.TypedValue(
							simpleType == SimpleType.UINT64
							? getSystem().getDefaultUint64Type()
									: getSystem().getDefaultInt64Type());
				} else {
					// Integer literals need some special handling for when they're assigning a field
					// or variable with a known type. This applies to all of the types smaller than
					// ints (otherwise they'd need casts everywhere they're used).
					// TODO: Translations for u/U
					if (lit.search("u") || lit.search("U")) {
						simpleType = SimpleType.UINT32;
					} else {
						simpleType = SimpleType.INT32;
					}
					TypeModel expected = getOwner().getExpectedResult(this);
					TypeModel byteType = (TypeModel) lookupSimpleName("byte");
					TypeModel shortType = (TypeModel) lookupSimpleName("short");
					TypeModel charType = (TypeModel) lookupSimpleName("char");
					if (expected != null) {
						if (expected.simplify() == byteType.simplify()) {
							// TODO: Check that literal typeName actually fits in the expected type
							return new ExpressionResult.TypedValue(byteType);
						} else if (expected.simplify() == shortType.simplify()) {
							return new ExpressionResult.TypedValue(shortType);
						} else if (expected.simplify() == charType.simplify()) {
							return new ExpressionResult.TypedValue(charType);
						}
					}
					return new ExpressionResult.TypedValue(simpleType == SimpleType.UINT32 ?
							getSystem().getDefaultUint32Type()
							: getSystem().getDefaultInt32Type());
				}
			}
		} else if (getSource().getNodeType() == NodeType.CHAR_LITERAL_EXPRESSION) {
			simpleType = SimpleType.INT32;
			return new ExpressionResult.TypedValue((TypeModel) lookupSimpleName("int"/*"char"*/));
		} else if (getSource().getNodeType() == NodeType.NULL_LITERAL_EXPRESSION) {
			simpleType = SimpleType.NULL;
			return ExpressionResult.NULL;
		} else if (getSource().getNodeType() == NodeType.BOOLEAN_LITERAL_EXPRESSION) {
			simpleType = SimpleType.BOOLEAN;
			return new ExpressionResult.TypedValue(getSystem().getDefaultBooleanType());
		} else {
			simpleType = null;
			getSource().annotate(ErrorType.INTERNAL_ERROR, "Unrecognised expression type " + getSource().getNodeType());
			return ExpressionResult.INVALID;
		}
	}
	
	public SimpleType getSimpleType() {
		return simpleType;
	}
	
	public String getRawSource() {
		return ((Token)((Branch)getSource()).getSubnode(0)).getSnippet().getSource();
	}
	
	public String getProcessedString() {
		String start = getRawSource();
		return start.sub(1, start.ints().length-1);
	}
	
	public boolean canNegate() {
		switch (getSimpleType()) {
		case SimpleType.INT32:
		case SimpleType.INT64:
		case SimpleType.FLOAT32:
		case SimpleType.FLOAT64:
			return true;
		default:
			return false;
		}
	}
	
	public void negate() {
		if (!canNegate()) {
			throw new Error("Internal error, this literal can't be negated");
		}
		negated = true;
	}
	
	@Override
	public TypeSignature innerGenerate(BytecodeInstructionWriter w) {
		switch (getSimpleType()) {
		case SimpleType.BOOLEAN:
			if (getRawSource().equals("true")) {
				w.genBoolean(true);
			} else { // false
				w.genBoolean(false);
			}
			break;
		case SimpleType.INT32:
			w.genConst(w.getTarget().getHeap().getConstInt32((negated ? "-" : "") + getRawSource()));
			break;
		case SimpleType.INT64:
			w.genConst(w.getTarget().getHeap().getConstInt64((negated ? "-" : "") + getRawSource()));
			break;
		case SimpleType.UINT32:
			w.genConst(w.getTarget().getHeap().getConstUint32(getRawSource()));
			break;
		case SimpleType.UINT64:
			w.genConst(w.getTarget().getHeap().getConstUint64(getRawSource()));
			break;
		case SimpleType.FLOAT32:
			w.genConst(w.getTarget().getHeap().getConstFloat32(getRawSource()));
			break;
		case SimpleType.FLOAT64:
			w.genConst(w.getTarget().getHeap().getConstFloat64(getRawSource()));
			break;
		case SimpleType.STRING:
			w.genConst(w.getTarget().getHeap().getConstStringLiteral(getRawSource()));
			break;
		case SimpleType.NULL:
			w.genConst(w.getTarget().getHeap().getNull());
			break;
		default:
			w.genError("TODO: innerGenerate for " + Type.of(this));
			return null;
		}
		
		return getResult().getValueTypeWithNullType(getSystem().getDefaultBaseType()).getTypeSignature();
	}

	public TypeModel resolveType(Node n) {
		return super.resolveType(n); // TODO: Better support for interfaces
	}
}