#pragma once

// Distributed under the LGPL v2.1 license.  See accompanying
// file LICENSE or https://github.com/henryiii/CLI11 for details.

#include <string>
#include <sstream>
#include <iomanip>
#include <locale>
#include <type_traits>
#include <algorithm>

namespace CLI {
namespace detail {


/// Simple function to join a string
template <typename T>
std::string join(const T& v, std::string delim = ",") {
    std::ostringstream s;
    size_t start = 0;
    for (const auto& i : v) {
        if(start++ > 0)
            s << delim;
        s << i;
    }
    return s.str();
}

/// Join a string in reverse order
template<typename T>
std::string rjoin(const T& v, std::string delim = ",") {
    std::ostringstream s;
    for(size_t start=0; start<v.size(); start++) {
        if(start > 0)
            s << delim;
        s << v[v.size() - start - 1];
    }
    return s.str();
}

// Based roughly on http://stackoverflow.com/questions/25829143/c-trim-whitespace-from-a-string

/// Trim whitespace from left of string
std::string& ltrim(std::string &str) {
    auto it = std::find_if(str.begin(), str.end(), [](char ch){ return !std::isspace<char>(ch , std::locale());});
    str.erase(str.begin(), it);
    return str;   
}

/// Trim anything from left of string
std::string& ltrim(std::string &str, const std::string &filter) {
    auto it = std::find_if(str.begin(), str.end(), [&filter](char ch){return filter.find(ch) == std::string::npos;}); 
    str.erase(str.begin(), it);
    return str;
}


/// Trim whitespace from right of string
std::string& rtrim(std::string &str) {
    auto it = std::find_if(str.rbegin(), str.rend(), [](char ch){ return !std::isspace<char>(ch, std::locale());});
    str.erase(it.base() , str.end() );
    return str;   
}

/// Trim anything from right of string
std::string& rtrim(std::string &str, const std::string &filter) {
    auto it = std::find_if(str.rbegin(), str.rend(), [&filter](char ch){return filter.find(ch) == std::string::npos;}); 
    str.erase(it.base(), str.end());
    return str;   
}

/// Trim whitespace from string
std::string& trim(std::string &str) {
    return ltrim(rtrim(str));
}

/// Trim anything from string
std::string& trim(std::string &str, const std::string filter) {
    return ltrim(rtrim(str, filter), filter);
}

/// Make a copy of the string and then trim it
std::string trim_copy(const std::string &str) {
    std::string s = str;
    return trim(s);
}

/// Make a copy of the string and then trim it, any filter string can be used (any char in string is filtered)
std::string trim_copy(const std::string &str, const std::string &filter) {
    std::string s = str;
    return rtrim(s, filter);
}
/// Print a two part "help" string
void format_help(std::stringstream &out, std::string name, std::string description, size_t wid) {
    name = "  " + name;
    out << std::setw(wid) << std::left << name;
    if(description != "") {
        if(name.length()>=wid)
            out << std::endl << std::setw(wid) << "";
        out << description;
    }
    out << std::endl;
}

/// Verify the first character of an option
template<typename T>
bool valid_first_char(T c) {
    return std::isalpha(c, std::locale()) || c=='_';
}

/// Verify following characters of an option
template<typename T>
bool valid_later_char(T c) {
    return std::isalnum(c, std::locale()) || c=='_' || c=='.' || c=='-';
}

/// Verify an option name
inline bool valid_name_string(const std::string &str) {
    if(str.size()<1 || !valid_first_char(str[0]))
        return false;
    for(auto c : str.substr(1))
        if(!valid_later_char(c))
            return false;
    return true;
}

/// Return a lower case version of a string
std::string inline to_lower(std::string str) {
    std::transform(std::begin(str), std::end(str), std::begin(str),
        [](const std::string::value_type &x){return std::tolower(x,std::locale());});
    return str;
}

}
}