package slangc.model;

public class BuiltinTypeBehaviour {

	public boolean isAssignableFrom(TypeModel otherType) {
		// TODO Auto-generated method stub
		return false;
	}
	
	/** If it waddles like a duck and quacks like a duck then it's a duck. */
	public static class DuckBehaviour extends BuiltinTypeBehaviour {
		
		@Override
		public boolean isAssignableFrom(TypeModel otherType) {
			return true;
		}
	}

	public static class NumberBehaviour extends BuiltinTypeBehaviour {
		private boolean isFloat;
		private boolean isSigned;
		private int numberOfBits;
		public NumberBehaviour(boolean isFloat, boolean isSigned, int numberOfBits) {
			super();
			this.isFloat = isFloat;
			this.isSigned = isSigned;
			this.numberOfBits = numberOfBits;
		}
		
		@Override
		public boolean isAssignableFrom(TypeModel otherType) {
			if (otherType instanceof BuiltinTypeModel) {
				BuiltinTypeModel otherBuiltin = (BuiltinTypeModel) otherType;
				BuiltinTypeBehaviour otherBehaviour = otherBuiltin.getBuiltinTypeBehaviour();
				if (otherBehaviour instanceof NumberBehaviour) {
					return isAssignableFrom((NumberBehaviour)otherBehaviour);
				} else if (otherBehaviour instanceof DuckBehaviour) {
					return true;
				} else {
					return false;
				}
			} else {
				return false;
			}
		}

		private boolean isAssignableFrom(NumberBehaviour otherBehaviour) {
			// Handle floats first
			if (this.isFloat && !otherBehaviour.isFloat) {
				return true;
			} else if (!this.isFloat && otherBehaviour.isFloat) {
				return false;
			} else if (this.isFloat && otherBehaviour.isFloat) {
				return this.numberOfBits >= otherBehaviour.numberOfBits;
			}
			// Otherwise we know it's an integer
			if (this.numberOfBits == otherBehaviour.numberOfBits && this.isSigned == otherBehaviour.isSigned) {
				return true;
			} else if (this.numberOfBits > otherBehaviour.numberOfBits) {
				return true;
			} else {
				return false;
			}
		}
	}
}