// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
// under NSF AWARD 1414736 and by the respective contributors.
// All rights reserved.
//
// SPDX-License-Identifier: BSD-3-Clause

#pragma once

#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "Error.hpp"
#include "StringTools.hpp"

namespace CLI {
namespace detail {

// Returns false if not a short option. Otherwise, sets opt name and rest and returns true
inline bool split_short(const std::string &current, std::string &name, std::string &rest) {
    if(current.size() > 1 && current[0] == '-' && valid_first_char(current[1])) {
        name = current.substr(1, 1);
        rest = current.substr(2);
        return true;
    }
    return false;
}

// Returns false if not a long option. Otherwise, sets opt name and other side of = and returns true
inline bool split_long(const std::string &current, std::string &name, std::string &value) {
    if(current.size() > 2 && current.substr(0, 2) == "--" && valid_first_char(current[2])) {
        auto loc = current.find_first_of('=');
        if(loc != std::string::npos) {
            name = current.substr(2, loc - 2);
            value = current.substr(loc + 1);
        } else {
            name = current.substr(2);
            value = "";
        }
        return true;
    }
    return false;
}

// Returns false if not a windows style option. Otherwise, sets opt name and value and returns true
inline bool split_windows_style(const std::string &current, std::string &name, std::string &value) {
    if(current.size() > 1 && current[0] == '/' && valid_first_char(current[1])) {
        auto loc = current.find_first_of(':');
        if(loc != std::string::npos) {
            name = current.substr(1, loc - 1);
            value = current.substr(loc + 1);
        } else {
            name = current.substr(1);
            value = "";
        }
        return true;
    }
    return false;
}

// Splits a string into multiple long and short names
inline std::vector<std::string> split_names(std::string current) {
    std::vector<std::string> output;
    std::size_t val;
    while((val = current.find(",")) != std::string::npos) {
        output.push_back(trim_copy(current.substr(0, val)));
        current = current.substr(val + 1);
    }
    output.push_back(trim_copy(current));
    return output;
}

/// extract default flag values either {def} or starting with a !
inline std::vector<std::pair<std::string, std::string>> get_default_flag_values(const std::string &str) {
    std::vector<std::string> flags = split_names(str);
    flags.erase(std::remove_if(flags.begin(),
                               flags.end(),
                               [](const std::string &name) {
                                   return ((name.empty()) || (!(((name.find_first_of('{') != std::string::npos) &&
                                                                 (name.back() == '}')) ||
                                                                (name[0] == '!'))));
                               }),
                flags.end());
    std::vector<std::pair<std::string, std::string>> output;
    output.reserve(flags.size());
    for(auto &flag : flags) {
        auto def_start = flag.find_first_of('{');
        std::string defval = "false";
        if((def_start != std::string::npos) && (flag.back() == '}')) {
            defval = flag.substr(def_start + 1);
            defval.pop_back();
            flag.erase(def_start, std::string::npos);
        }
        flag.erase(0, flag.find_first_not_of("-!"));
        output.emplace_back(flag, defval);
    }
    return output;
}

/// Get a vector of short names, one of long names, and a single name
inline std::tuple<std::vector<std::string>, std::vector<std::string>, std::string>
get_names(const std::vector<std::string> &input) {

    std::vector<std::string> short_names;
    std::vector<std::string> long_names;
    std::string pos_name;

    for(std::string name : input) {
        if(name.length() == 0) {
            continue;
        }
        if(name.length() > 1 && name[0] == '-' && name[1] != '-') {
            if(name.length() == 2 && valid_first_char(name[1]))
                short_names.emplace_back(1, name[1]);
            else
                throw BadNameString::OneCharName(name);
        } else if(name.length() > 2 && name.substr(0, 2) == "--") {
            name = name.substr(2);
            if(valid_name_string(name))
                long_names.push_back(name);
            else
                throw BadNameString::BadLongName(name);
        } else if(name == "-" || name == "--") {
            throw BadNameString::DashesOnly(name);
        } else {
            if(pos_name.length() > 0)
                throw BadNameString::MultiPositionalNames(name);
            pos_name = name;
        }
    }

    return std::tuple<std::vector<std::string>, std::vector<std::string>, std::string>(
        short_names, long_names, pos_name);
}

}  // namespace detail
}  // namespace CLI
