//======================================================================
//-----------------------------------------------------------------------
/**
 * @file        iutest_expression_assertion.hpp
 * @brief       iris unit test 式アサーション 定義 ファイル
 *
 * @author      t.shirayanagi
 * @par         copyright
 * Copyright (C) 2014-2016, Takazumi Shirayanagi\n
 * This software is released under the new BSD License,
 * see LICENSE
*/
//-----------------------------------------------------------------------
//======================================================================
#ifndef INCG_IRIS_IUTEST_EXPRESSION_ASSERTION_HPP_B9783316_33CF_4CA7_81D0_0BF44B048A4A_
#define INCG_IRIS_IUTEST_EXPRESSION_ASSERTION_HPP_B9783316_33CF_4CA7_81D0_0BF44B048A4A_

//======================================================================
// define
/**
 * @brief   式展開用 operand マクロ
 * @note    IUTEST_ASSERT(f() != 42 IUTEST_OPERAND(||) f() == 32 )
*/
#define IUTEST_OPERAND(op)      op IIUT_EXPRESSION_DECOMPOSE()

/**
 * @brief   式展開用マクロ
 * @note    IUTEST_ASSERT_TRUE(IUTEST_EXPRESSION(f() != 42) || IUTEST_EXPRESSION(f() == 10))
*/
#define IUTEST_EXPRESSION(expr) (IIUT_EXPRESSION_DECOMPOSE() expr).GetResult()


/**
 * @private
 * @{
*/

#if IUTEST_HAS_ARITHMETIC_EXPRESSION_DECOMPOSE
#  define IIUT_EXPRESSION_DECOMPOSE()   ::iutest::detail::ExpressionDecomposer()->*
#else
#  define IIUT_EXPRESSION_DECOMPOSE()   ::iutest::detail::ExpressionDecomposer()>>
#endif

#define IUTEST_TEST_EXPRESSION_(expr, expected, on_failure) \
    IUTEST_TEST_TRUE( ( IIUT_EXPRESSION_DECOMPOSE() expr ).GetResult(expected), #expr, on_failure )

#define IIUT_DECL_EXPRESSION_RESULT_OP(op)                                      \
    template<typename RHS>ExpressionResult operator op (const RHS& rhs) const { \
        const bool b = result() op rhs ? true : false;                          \
        return ExpressionResult(AssertionResult(b)                              \
                    << m_result.message() << " " #op " " << rhs);               \
    }                                                                           \
    ExpressionResult operator op (const ExpressionResult& rhs) const {          \
        const bool b = result() op rhs.result() ? true : false;                 \
        return ExpressionResult(AssertionResult(b)                              \
                    << m_result.message() << " " #op " " << rhs.message());     \
    }                                                                           \
    ExpressionResult operator op (const AssertionResult& rhs) const {           \
        const bool b = result() op rhs.passed() ? true : false;                 \
        return ExpressionResult(AssertionResult(b)                              \
                    << m_result.message() << " " #op " " << rhs.message());     \
    }

#define IIUT_DECL_EXPRESSION_OP(op)                                                     \
    template<typename RHS>ExpressionResult operator op (const RHS& rhs) const {         \
        const bool b = (m_lhs op rhs) ? true : false;                                   \
        return ExpressionResult(AssertionResult(b) << m_message << " " #op " " << rhs); \
    }

#if IUTEST_HAS_ARITHMETIC_EXPRESSION_DECOMPOSE || IUTEST_HAS_BITWISE_EXPRESSION_DECOMPOSE

#if IUTEST_HAS_DECLTYPE && IUTEST_HAS_STD_DECLVAL

#define IIUT_DECL_EXPRESSION_OP_LHS(op)                                 \
    template<typename RHS>auto operator op (const RHS& rhs) const       \
    -> ExpressionLHS< decltype( expression_op_helper::operand_result(   \
        ( ::std::declval<T>() op rhs ) ) )> {                           \
        return OperandResult(m_lhs op rhs) << " " #op " " << rhs;       \
    }

#else

#define IIUT_DECL_EXPRESSION_OP_LHS(op) \
    template<typename RHS>ExpressionLHS<RHS> operator op (const RHS& rhs) const {   \
    return OperandResult(m_lhs op rhs) << " " #op " " << rhs;   \
    }

#endif

#endif

/**
 * @}
*/

namespace iutest {
namespace detail
{

//======================================================================
// class

/**
 * @brief   expression result
*/
class ExpressionResult
{
public:
    explicit ExpressionResult(const AssertionResult& ar)
        : m_result(ar) {}

public:
    IIUT_DECL_EXPRESSION_RESULT_OP(||)
    IIUT_DECL_EXPRESSION_RESULT_OP(&&)

public:
    AssertionResult GetResult(bool expected) const
    {
        return AssertionResult(result() == expected) << "expansion: " << m_result.message();
    }
    AssertionResult GetResult() const
    {
        return AssertionResult(result()) << m_result.message();
    }
private:
    bool result() const { return m_result.passed(); }
    const char* message() const { return m_result.message(); }
private:
    AssertionResult m_result;
};

namespace expression_op_helper
{
    template<typename T>
    T operand_result(const T&);
}

/**
 * @brief   expression lhs
 * @tparam  T=type
*/
template<typename T>
class ExpressionLHS
{
    typedef ExpressionLHS<T> _Myt;
public:
#if IUTEST_HAS_RVALUE_REFS
    explicit ExpressionLHS(T&& lhs) : m_lhs( ::std::forward<T>(lhs) )
    {
        AppendMessage(m_lhs);
    }
#else
    explicit ExpressionLHS(T lhs) : m_lhs(lhs)
    {
        AppendMessage(lhs);
    }
#endif
    ExpressionLHS(T lhs, const ::std::string& msg) : m_lhs(lhs), m_message(msg) {}

public:
    IIUT_DECL_EXPRESSION_OP(==)
    IIUT_DECL_EXPRESSION_OP(!=)
    IIUT_DECL_EXPRESSION_OP(<)
    IIUT_DECL_EXPRESSION_OP(<=)
    IIUT_DECL_EXPRESSION_OP(>)
    IIUT_DECL_EXPRESSION_OP(>=)
    IIUT_DECL_EXPRESSION_OP(&&)
    IIUT_DECL_EXPRESSION_OP(||)

#if IUTEST_HAS_ARITHMETIC_EXPRESSION_DECOMPOSE
    IIUT_DECL_EXPRESSION_OP_LHS(+)
    IIUT_DECL_EXPRESSION_OP_LHS(-)
    IIUT_DECL_EXPRESSION_OP_LHS(*)
    IIUT_DECL_EXPRESSION_OP_LHS(/)
    IIUT_DECL_EXPRESSION_OP_LHS(%)
#endif

#if IUTEST_HAS_BITWISE_EXPRESSION_DECOMPOSE
    IIUT_DECL_EXPRESSION_OP_LHS(&)
    IIUT_DECL_EXPRESSION_OP_LHS(|)
    IIUT_DECL_EXPRESSION_OP_LHS(^)
    IIUT_DECL_EXPRESSION_OP_LHS(<<)
    IIUT_DECL_EXPRESSION_OP_LHS(>>)
#endif

private:
    template<typename U>
    ExpressionLHS<U> OperandResult(const U& lhs) const
    {
        return ExpressionLHS<U>(lhs, m_message);
    }

public:
    /**
     * @brief   メッセージ追加
    */
    template<typename U>
    _Myt& operator << (const U& value)
    {
        AppendMessage(value);
        return *this;
    }

public:
    /** @private */
    AssertionResult GetResult(bool expected) const
    {
        const bool b = m_lhs ? true : false;
        return AssertionResult(b == expected) << "expansion: " << m_message;
    }
    AssertionResult GetResult() const
    {
        const bool b = m_lhs ? true : false;
        return AssertionResult(b) << m_message;
    }

private:
    template<typename U>
    void AppendMessage(const U& value)
    {
        Message msg;
        msg << value;
        m_message += msg.GetString();
    }

private:
    IUTEST_PP_DISALLOW_ASSIGN(ExpressionLHS);
private:
    T m_lhs;
    ::std::string m_message;
};

#undef IIUT_DECL_EXPRESSION_RESULT_OP
#undef IIUT_DECL_EXPRESSION_OP
#ifdef IIUT_DECL_EXPRESSION_OP_LHS
#  undef IIUT_DECL_EXPRESSION_OP_LHS
#endif

/**
 * @brief   expression decomposer
*/
class ExpressionDecomposer
{
public:
#if IUTEST_HAS_ARITHMETIC_EXPRESSION_DECOMPOSE
#if IUTEST_HAS_RVALUE_REFS
    template<typename T>
    ExpressionLHS<T> operator ->*(T&& expr)
    {
        return ExpressionLHS<T>(::std::forward<T>(expr));
    }
#else
    template<typename T>
    ExpressionLHS<const T&> operator ->*(const T& expr)
    {
        return ExpressionLHS<const T&>(expr);
    }
#endif
#else
    template<typename T>
    ExpressionLHS<const T&> operator >>(const T& expr)
    {
        return ExpressionLHS<const T&>(expr);
    }
#endif
};

}   // end of namespace detail
}   // end of namespace iutest

#endif // INCG_IRIS_IUTEST_EXPRESSION_ASSERTION_HPP_B9783316_33CF_4CA7_81D0_0BF44B048A4A_
