#include <algorithm>
#include <cstring>
#include <fstream>
#include <string>
#include <vector>

#include "usenetsearch/StringUtils.h"

namespace usenetsearch {

std::ostream& operator<<(std::ofstream& out, const std::string& str)
{
    const std::uint64_t size = str.size();
    out.write(reinterpret_cast<const char*>(&size), sizeof(size));
    out.write(reinterpret_cast<const char*>(str.c_str()), size);
    return out;
}

std::ifstream& operator>>(std::ifstream& in, std::string& str)
{
    std::uint64_t size{0};
    in.read(reinterpret_cast<char*>(&size), sizeof(size));
    char buf[size];
    in.read(buf, size);
    buf[size] = 0;
    str = buf;
    return in; 
}

std::ostream& operator<<(std::ofstream& out, const std::wstring& str)
{
    const std::uint64_t size = str.size();
    out.write(reinterpret_cast<const char*>(&size), sizeof(size));
    out.write(
        reinterpret_cast<const char*>(str.c_str()),
        size * sizeof(wchar_t)
    );
    return out;
}

std::ifstream& operator>>(std::ifstream& in, std::wstring& str)
{
    std::uint64_t size{0};
    in.read(reinterpret_cast<char*>(&size), sizeof(size));
    wchar_t buf[size];
    in.read(reinterpret_cast<char*>(buf), size * sizeof(wchar_t));
    buf[size] = 0;
    str = buf;
    return in; 
}

std::string StringLeftTrim(const std::string& str)
{
    std::string s = str;
    s.erase(s.begin(), std::find_if(s.begin(), s.end(),
    std::not1(std::ptr_fun<int, int>(std::isspace))));
    return s;
}

std::string StringRightTrim(const std::string& str)
{
    std::string s = str;
    s.erase(std::find_if(s.rbegin(), s.rend(), 
        std::not1(std::ptr_fun<int, int>(std::isspace))).base(), 
        s.end());
    return s;
}

bool StringStartsWith(const std::string& needle, const std::string& haystack)
{
    return (std::strncmp(haystack.c_str(),needle.c_str(),needle.size()) == 0);
}

bool StringToBoolean(const std::string& str)
{
    const std::string lstr = StringTrim(StringToLower(str));
    if ((lstr == "true") || (lstr == "yes") || (lstr == "1")) return true;
    if ((lstr == "false") || (lstr == "no") || (lstr == "0")) return false;
    throw StringException(EINVAL,
        "The string \"" + str + "\" is not a valid boolean value."
    );
}

std::string StringToLower(const std::string& str)
{
    std::string copy = str;
    std::transform(copy.begin(),copy.end(),copy.begin(),::tolower);
    return copy;
}

std::string StringTrim(const std::string& str)
{
    return StringLeftTrim(StringRightTrim(str));
}

} // namespace usenetsearch