#pragma once

#include <string>
#include <iostream>
#include <limits>
#include <type_traits>

#include "../utility/endian.hpp"


template<typename T> requires std::is_arithmetic_v<T>
struct vec2 {
    T X;
    T Y;

    vec2() = default;
    vec2(const T& val) :
        X(val),
        Y(val)
    {}
};

template<typename T> requires std::is_arithmetic_v<T>
struct vec3 {
    T X;
    T Y;
    T Z;

    vec3() = default;
    vec3(const T& val) :
        X(val),
        Y(val),
        Z(val)
    {}
    vec3(const T& x_, const T& y_, const T& z_) :
        X(x_),
        Y(y_),
        Z(z_)
    {}
};

template<typename T> requires std::is_arithmetic_v<T>
struct vec4 {
    T A;
    T B;
    T C;
    T D;

    vec4() = default;
    vec4(const T& val) :
        A(val),
        B(val),
        C(val),
        D(val)
    {}
};


template<typename T>
bool readVec2(std::istream& in, const std::streamoff offset, vec2<T>& out) {
    in.seekg(offset, std::ios::beg);

    if (!in.read(reinterpret_cast<char*>(&out.X), sizeof(out.X))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.Y), sizeof(out.Y))) return false;

    if constexpr (sizeof(T) > 1) {
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.X);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.Y);
    }

    return true;
}

template<typename T>
void writeVec2(std::ostream& out, const vec2<T>& vec) {
    if constexpr (sizeof(T) > 1) {
        T X_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.X);
        T Y_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.Y);

        out.write(reinterpret_cast<const char*>(&X_BE), sizeof(X_BE));
        out.write(reinterpret_cast<const char*>(&Y_BE), sizeof(Y_BE));
        return;
    }
    else {
        out.write(reinterpret_cast<const char*>(&vec.X), sizeof(vec.X));
        out.write(reinterpret_cast<const char*>(&vec.Y), sizeof(vec.Y));
        return;
    }
}


template<typename T>
bool readVec3(std::istream& in, const std::streamoff offset, vec3<T>& out) {
    in.seekg(offset, std::ios::beg);

    if (!in.read(reinterpret_cast<char*>(&out.X), sizeof(out.X))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.Y), sizeof(out.Y))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.Z), sizeof(out.Z))) return false;

    if constexpr (sizeof(T) > 1) {
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.X);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.Y);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.Z);
    }

    return true;
}

template<typename T>
void writeVec3(std::ostream& out, const vec3<T>& vec) {
    if constexpr (sizeof(T) > 1) {
        T X_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.X);
        T Y_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.Y);
        T Z_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.Z);

        out.write(reinterpret_cast<const char*>(&X_BE), sizeof(X_BE));
        out.write(reinterpret_cast<const char*>(&Y_BE), sizeof(Y_BE));
        out.write(reinterpret_cast<const char*>(&Z_BE), sizeof(Z_BE));
        return;
    }
    else {
        out.write(reinterpret_cast<const char*>(&vec.X), sizeof(vec.X));
        out.write(reinterpret_cast<const char*>(&vec.Y), sizeof(vec.Y));
        out.write(reinterpret_cast<const char*>(&vec.Z), sizeof(vec.Z));
        return;
    }
}


template<typename T>
bool readVec4(std::istream& in, const std::streamoff offset, vec4<T>& out) {
    in.seekg(offset, std::ios::beg);

    if (!in.read(reinterpret_cast<char*>(&out.A), sizeof(out.A))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.B), sizeof(out.B))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.C), sizeof(out.C))) return false;
    if (!in.read(reinterpret_cast<char*>(&out.D), sizeof(out.D))) return false;

    if constexpr (sizeof(T) > 1) {
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.A);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.B);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.C);
        Utility::Endian::toPlatform_inplace(Utility::Endian::Type::Big, out.D);
    }

    return true;
}

template<typename T>
void writeVec4(std::ostream& out, const vec4<T>& vec) {
    if constexpr (sizeof(T) > 1) {
        T A_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.A);
        T B_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.B);
        T C_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.C);
        T D_BE = Utility::Endian::toPlatform(Utility::Endian::Type::Big, vec.D);

        out.write(reinterpret_cast<const char*>(&A_BE), sizeof(A_BE));
        out.write(reinterpret_cast<const char*>(&B_BE), sizeof(B_BE));
        out.write(reinterpret_cast<const char*>(&C_BE), sizeof(C_BE));
        out.write(reinterpret_cast<const char*>(&D_BE), sizeof(D_BE));
        return;
    }
    else {
        out.write(reinterpret_cast<const char*>(&vec.A), sizeof(vec.A));
        out.write(reinterpret_cast<const char*>(&vec.B), sizeof(vec.B));
        out.write(reinterpret_cast<const char*>(&vec.C), sizeof(vec.C));
        out.write(reinterpret_cast<const char*>(&vec.D), sizeof(vec.D));
        return;
    }
}

std::string readNullTerminatedStr(std::istream& in, const unsigned int& offset);

std::u16string readNullTerminatedWStr(std::istream& in, const unsigned int offset);

template<typename error_enum> requires requires {
    requires std::is_enum_v<error_enum>;
    error_enum::NONE;
    error_enum::REACHED_EOF;
    error_enum::UNEXPECTED_VALUE;
}
error_enum readPadding(std::istream& in, const unsigned int& len, const char* val = nullptr) {
    if (in.tellg() % len != 0) {
        const size_t& padding_size = len - (static_cast<size_t>(in.tellg()) % len);

        std::string padding(padding_size, '\0');
        if (!in.read(&padding[0], static_cast<std::streamoff>(padding_size))) return error_enum::REACHED_EOF;

        if(val != nullptr) {
            for (const char& character : padding) {
                if (character != *val) return error_enum::UNEXPECTED_VALUE;
            }
        }
    }

    return error_enum::NONE;
}

size_t padToLen(std::ostream& out, const unsigned int& len, const char pad = '\x00');