classdef HasSameSizeAs < matlab.unittest.constraints.BooleanConstraint
    
    properties(SetAccess = immutable)
        ValueWithExpectedSize
    end
    
    methods
        % Class constructor
        function constraint = HasSameSizeAs(value)
            constraint.ValueWithExpectedSize = value;
        end
        
        % Determine if the actual value satisfies the constraint
        function bool = satisfiedBy(constraint,actual)
            bool = constraint.sizeMatchesExpected(actual);
        end
        
        % Produce a diagnostic for the constraint
        function diag = getDiagnosticFor(constraint,actual)
            import matlab.unittest.diagnostics.StringDiagnostic
            
            if constraint.sizeMatchesExpected(actual)
                diag = StringDiagnostic('HasSameSizeAs passed.');
            else
                diag = StringDiagnostic(sprintf(...
                    'HasSameSizeAs failed.\nActual Size: [%s]\nExpectedSize: [%s]',...
                    int2str(size(actual)),...
                    int2str(size(constraint.ValueWithExpectedSize))));
            end
        end
    end
    
    methods(Access = protected)
        % Produce a diagnostic for the negated constraint
        function diag = getNegativeDiagnosticFor(constraint,actual)
            import matlab.unittest.diagnostics.StringDiagnostic
            if constraint.sizeMatchesExpected(actual) % Constraint satisfied incorrectly
                diag = StringDiagnostic(sprintf(...
                    ['Negated HasSameSizeAs failed.\nSize [%s] of '...
                    'Actual Value and Expected Value were the same '...
                    'but should not have been.'],int2str(size(actual))));
            else
                diag = StringDiagnostic('Negated HasSameSizeAs passed.');
            end
        end
    end

    methods(Access = private)
        % Determine if the actual and expected values have the same size
        function bool = sizeMatchesExpected(constraint,actual)
            bool = isequal(size(actual),size(constraint.ValueWithExpectedSize));
        end
    end

end