//          Copyright Joakim Karlsson & Kim Gräsman 2010-2012.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#ifndef SNOWHOUSE_HASLENGTHCONSTRAINT_H
#define SNOWHOUSE_HASLENGTHCONSTRAINT_H

#include "expressions/expression.h"

namespace snowhouse
{
    template <typename ExpectedType>
    struct HasLengthConstraint : Expression<HasLengthConstraint<ExpectedType>>
    {
        HasLengthConstraint(const ExpectedType& expected): m_expected(expected)
        {
        }

        template <typename ActualType>
        bool operator()(const ActualType& actual) const
        {
            using SizeType = typename ActualType::size_type;
            SizeType expectedSize = static_cast<SizeType>(m_expected);
            return (actual.size() == expectedSize);
        }

        ExpectedType m_expected;
    };

    template <typename ExpectedType>
    inline HasLengthConstraint<ExpectedType> HasLength(
        const ExpectedType& expected)
    {
        return HasLengthConstraint<ExpectedType>(expected);
    }

    inline HasLengthConstraint<std::string> HasLength(const char* expected)
    {
        return HasLengthConstraint<std::string>(expected);
    }

    template <typename ExpectedType>
    struct Stringizer<HasLengthConstraint<ExpectedType>>
    {
        static std::string ToString(
            const HasLengthConstraint<ExpectedType>& constraint)
        {
            std::ostringstream builder;
            builder << "of length "
                    << snowhouse::Stringize(constraint.m_expected);

            return builder.str();
        }
    };
}

#endif
