/**
 * @author     frk, ReactiioN
 * @date       08.03.2016
 * @visit      https://github.com/frk1
 *             https://thefrk.xyz
 *             https://www.unknowncheats.me/forum/members/1067779.html
 *
 *             https://github.com/ReactiioN1337 
 *             https://reactiion.pw 
 *             https://www.unknowncheats.me/forum/members/264622.html
 */
#ifndef MATRIX_HPP
#define MATRIX_HPP
#pragma once

#ifndef NOMINMAX
#define NOMINMAX
#endif

#include <array>
#include <string>

template < typename T, size_t T_Rows, size_t T_Cols >
class Matrix
{
public:
    using array_t      = std::array< T, T_Rows * T_Cols >;
    using matrix_t     = Matrix< T, T_Rows, T_Cols >;
    using col_matrix_t = Matrix< T, 1, T_Cols >;
    using row_matrix_t = Matrix< T, T_Rows, 1 >;

private:
    array_t m_cValues;

public:
    Matrix( void )
    {
        static_assert( std::is_arithmetic< T >::value, "Type T has to be arithmetic!" );
        static_assert( T_Rows >= 1 && T_Cols >= 1, "Minimal row and col dimensions are 1." );
        m_cValues.fill( static_cast<T>( 0 ) );
    }

    ~Matrix( void )
    {
    }

    explicit Matrix( std::array< T, ( T_Rows* T_Cols ) > cValues )
        : m_cValues( cValues )
    {
        static_assert( std::is_arithmetic< T >::value, "Type T has to be arithmetic!" );
    }

    template < typename... K >
    Matrix( K ... args )
    {
        static_assert( std::is_arithmetic< T >::value, "Type T has to be arithmetic!" );
        m_cValues = std::array< T, T_Rows* T_Cols > { static_cast<T>( args )... };
    }

    constexpr static size_t rows( void )
    {
        return T_Rows;
    }

    constexpr static size_t cols( void )
    {
        return T_Cols;
    }

    constexpr static size_t size( void )
    {
        return T_Rows * T_Cols;
    }

    constexpr static bool isVector( void )
    {
        return T_Rows == 1 || T_Cols == 1;
    }

    bool empty( void ) const
    {
        return all_of( m_cValues.begin(), m_cValues.end(), []( T i )
        {
            return i == static_cast< T >( 0 );
        } );
    }

    col_matrix_t row( size_t iRow ) const
    {
        std::array< T, T_Cols > values;

        for( size_t i = 0; i < T_Cols; ++i )
            values.at( i ) = at( iRow, i );

        return col_matrix_t{ values };
    }

    row_matrix_t col( size_t iCol ) const
    {
        std::array< T, T_Rows > values;

        for( size_t i = 0; i < T_Rows; ++i )
            values.at( i ) = at( i, iCol );

        return row_matrix_t{ values };
    }

    void row( size_t iRow, col_matrix_t mat )
    {
        for( size_t i = 0; i < T_Cols; ++i )
            at( iRow, i ) = mat( i );
    }

    void col( size_t iCol, row_matrix_t mat )
    {
        for( size_t i = 0; i < T_Rows; ++i )
            at( i, iCol ) = mat( i );
    }

    T& at( size_t i )
    {
        return m_cValues.at( i );
    }

    const T& at( size_t i ) const
    {
        return m_cValues.at( i );
    }

    T& at( size_t iRow, size_t iCol )
    {
        return m_cValues.at( iRow * T_Cols + iCol );
    }

    const T& at( size_t iRow, size_t iCol ) const
    {
        return m_cValues.at( iRow * T_Cols + iCol );
    }

    T& operator () ( size_t i )
    {
        return at( i );
    }

    const T& operator () ( size_t i ) const
    {
        return at( i );
    }

    T& operator () ( size_t iRow, size_t iCol )
    {
        return at( iRow, iCol );
    }

    const T& operator () ( size_t iRow, size_t iCol ) const
    {
        return at( iRow, iCol );
    }

    matrix_t operator + ( T other ) const
    {
        auto buf = *this;
        buf += other;
        return buf;
    }

    matrix_t operator - ( T other ) const
    {
        auto buf = *this;
        buf -= other;
        return buf;
    }

    matrix_t operator * ( T other ) const
    {
        auto buf = *this;
        buf *= other;
        return buf;
    }

    matrix_t operator / ( T other ) const
    {
        auto buf = *this;
        buf /= other;
        return buf;
    }

    matrix_t& operator += ( T other )
    {
        for( auto& val : m_cValues )
            val += other;

        return *this;
    }

    matrix_t& operator -= ( T other )
    {
        for( auto& val : m_cValues )
            val -= other;

        return *this;
    }

    matrix_t& operator *= ( T other )
    {
        for( auto& val : m_cValues )
            val *= other;

        return *this;
    }

    matrix_t& operator /= ( T other )
    {
        for( auto& val : m_cValues )
            val /= other;

        return *this;
    }

    matrix_t operator + ( const matrix_t& other ) const
    {
        auto buf = *this;

        for( size_t i = 0; i < size(); ++i )
            buf( i ) += other( i );

        return buf;
    }

    matrix_t operator - ( const matrix_t& other ) const
    {
        auto buf = *this;

        for( size_t i = 0; i < size(); ++i )
            buf( i ) -= other( i );

        return buf;
    }

    matrix_t& operator += ( const matrix_t& other )
    {
        for( size_t i = 0; i < size(); ++i )
            at( i ) += other( i );

        return ( *this );
    }

    bool operator == ( const matrix_t& other ) const
    {
        for( size_t i = 0; i < size(); ++i )
            if( at( i ) != other.at( i ) )
                return false;

        return true;
    }

    bool operator != ( const matrix_t& other ) const
    {
        return !( ( *this ) == other );
    }

    matrix_t& operator -= ( const matrix_t& other )
    {
        for( size_t i = 0; i < size(); ++i )
            at( i ) -= other( i );

        return ( *this );
    }

    T norm( void ) const
    {
        static_assert( matrix_t::isVector(), "Matrix::norm can only be used on vectors!" );

        T buf = static_cast<T>( 0 );

        for( auto v : m_cValues )
            buf += ( v * v );

        return sqrt( buf );
    }

    void normalize( void )
    {
        static_assert( matrix_t::isVector(), "Matrix::normalize can only be used on vectors!" );
        ( *this ) /= this->norm();
    }

    matrix_t normalized( void ) const
    {
        static_assert( matrix_t::isVector(), "Matrix::normalized can only be used on vectors!" );

        auto buf = *this;
        buf.normalize();
        return buf;
    }

    friend std::ostream& operator <<( std::ostream& os, const matrix_t& v )
    {
        for( size_t i = 0; i < T_Rows; ++i )
        {
            for( size_t j = 0; j < T_Cols; j++ )
                os << v.at( i, j ) << "\t";

            os << "\n";
        }

        return os;
    }

    template < typename K, size_t OROWS, size_t OCOLS >
    T dot( const Matrix< K, OROWS, OCOLS >& other ) const
    {
        static_assert( matrix_t::isVector() && Matrix< K, OROWS, OCOLS >::isVector(), "Matrix::dot can only be used on vectors!" );

        T buf = static_cast<T>( 0 );

        for( size_t i = 0; i < std::min( size(), other.size() ); ++i )
            buf += at( i ) * other.at( i );

        return buf;
    }

    matrix_t cross( const matrix_t& other ) const
    {
        static_assert( matrix_t::size() == 3, "Matrix::cross can only be called for 3 dimensional vectors!" );

        return{
            at( 1 )* other.at( 2 ) - at( 2 )* other.at( 1 ),
            at( 2 )* other.at( 0 ) - at( 0 )* other.at( 2 ),
            at( 0 )* other.at( 1 ) - at( 1 )* other.at( 0 ),
        };
    }

    matrix_t ncross( const matrix_t& other ) const
    {
        static_assert( matrix_t::size() == 3, "Matrix::ncross can only be called for 3 dimensional vectors!" );

        return cross( other ).normalized();
    }
};

#endif