mtso/task

// DateTime.cpp
// Task/Utilities
// CIS 22C F2016: Matthew Tso

#include "DateTime.h"

namespace task {

    uint64_t weekToMs(const int& weeks)
    {
        uint64_t ms_in_week = 604800000;
        return (uint64_t)weeks * ms_in_week;
    }
    
    uint64_t dayToMs(const int& days)
    {
        uint64_t ms_in_day = 86400000;
        return (uint64_t)days * ms_in_day;
    }

    uint64_t hourToMs(const int& hours)
    {
        uint64_t ms_in_hour = 3600000;
        return (uint64_t)hours * ms_in_hour;
    }

    uint64_t minuteToMs(const int& minutes)
    {
        uint64_t ms_in_minute = 60000;
        return (uint64_t)minutes * ms_in_minute;
    }

    uint64_t rawDateToMs(const string& raw_input)
    {
        // example date:                              11-14-2015
        string month_str = raw_input.substr(0, 2); // 11
        string day_str = raw_input.substr(3, 2);   //    14
        string year_str = raw_input.substr(6, 4);  //       2015

        // Convert strings into integers
        int month, day, year;
        try {
            month = stoi(month_str);
            day = stoi(day_str);
            year = stoi(year_str);
        }
        catch (std::invalid_argument error) {
            throw error;
        }

        // Build a time struct
        tm date = { 0 };
        date.tm_year = year - 1900; // since 1900
        date.tm_mon = month - 1;    // [0, 11] month since january
        date.tm_mday = day;         // [1, 31] day of month
        date.tm_hour = 12;          // Hardcode as noon

        // Convert into time value
        time_t time = mktime(&date);
        using namespace chrono;
        steady_clock::time_point point = steady_clock::from_time_t(time);
        milliseconds epoch_time = duration_cast<milliseconds>(point.time_since_epoch());

        // Return the raw integer
        return epoch_time.count();
    }

    string msToString(const uint64_t& raw_ms)
    {
        using namespace std::chrono;
        milliseconds ms = (milliseconds)raw_ms;
        time_t time_created_s = duration_cast<seconds>(ms).count();

        // Time string must have at least 26 char of space.
        const size_t TIME_BUFLEN = 26;
        char time_char[TIME_BUFLEN];
        ctime_s(time_char, TIME_BUFLEN, &time_created_s);

        // Convert to a string type in order to return 
        // its substr without the trailing newline character
        string raw_time_str = (string)time_char;
        return raw_time_str.substr(0, raw_time_str.length() - 1);
    }
}