#pragma once

#include <string>
#include <vector>
#include <sstream>
#include <iostream>
#include <limits>

/**
 * Utility for parsing command line arguments
 */
struct CommandLineArgs
{

    std::vector<std::string>    keys;
    std::vector<std::string>    values;
    std::vector<std::string>    args;

    /**
     * Constructor
     */
    CommandLineArgs(int argc, char **argv) :
        keys(10),
        values(10)
    {
        using namespace std;

        for (int i = 1; i < argc; i++)
        {
            string arg = argv[i];

            if ((arg[0] != '-') || (arg[1] != '-'))
            {
                args.push_back(arg);
                continue;
            }

            string::size_type pos;
            string key, val;
            if ((pos = arg.find('=')) == string::npos) {
                key = string(arg, 2, arg.length() - 2);
                val = "";
            } else {
                key = string(arg, 2, pos - 2);
                val = string(arg, pos + 1, arg.length() - 1);
            }

            keys.push_back(key);
            values.push_back(val);
        }
    }


    /**
     * Checks whether a flag "--<flag>" is present in the commandline
     */
    bool CheckCmdLineFlag(const char* arg_name)
    {
        using namespace std;

        for (int i = 0; i < int(keys.size()); ++i)
        {
            if (keys[i] == string(arg_name))
                return true;
        }
        return false;
    }


    /**
     * Returns number of naked (non-flag and non-key-value) commandline parameters
     */
    template <typename T>
    int NumNakedArgs()
    {
        return args.size();
    }


    /**
     * Returns the commandline parameter for a given index (not including flags)
     */
    template <typename T>
    void GetCmdLineArgument(int index, T &val)
    {
        using namespace std;
        if (index < args.size()) {
            istringstream str_stream(args[index]);
            str_stream >> val;
        }
    }

    /**
     * Returns the value specified for a given commandline parameter --<flag>=<value>
     */
    template <typename T>
    void GetCmdLineArgument(const char *arg_name, T &val)
    {
        using namespace std;

        for (int i = 0; i < int(keys.size()); ++i)
        {
            if (keys[i] == string(arg_name))
            {
                istringstream str_stream(values[i]);
                str_stream >> val;
            }
        }
    }


    /**
     * Returns the values specified for a given commandline parameter --<flag>=<value>,<value>*
     */
    template <typename T>
    void GetCmdLineArguments(const char *arg_name, std::vector<T> &vals)
    {
        using namespace std;

        if (CheckCmdLineFlag(arg_name))
        {
            // Clear any default values
            vals.clear();

            // Recover from multi-value string
            for (int i = 0; i < keys.size(); ++i)
            {
                if (keys[i] == string(arg_name))
                {
                    string val_string(values[i]);
                    istringstream str_stream(val_string);
                    string::size_type old_pos = 0;
                    string::size_type new_pos = 0;

                    // Iterate comma-separated values
                    T val;
                    while ((new_pos = val_string.find(',', old_pos)) != string::npos)
                    {
                        if (new_pos != old_pos)
                        {
                            str_stream.width(new_pos - old_pos);
                            str_stream >> val;
                            vals.push_back(val);
                        }

                        // skip over comma
                        str_stream.ignore(1);
                        old_pos = new_pos + 1;
                    }

                    // Read last value
                    str_stream >> val;
                    vals.push_back(val);
                }
            }
        }
    }


    /**
     * The number of pairs parsed
     */
    int ParsedArgc()
    {
        return (int) keys.size();
    }
};