#include "./timespan.h"

#include "../conversion/stringconversion.h"

#include <cmath>
#include <iomanip>
#include <sstream>
#include <vector>

using namespace std;
using namespace ChronoUtilities;
using namespace ConversionUtilities;

/*!
 * \class ChronoUtilities::TimeSpan
 * \brief Represents a time interval.
 * \remarks Time values are measured in 100-nanosecond units called ticks.
 */

/*!
 * \brief Parses the given C-style string as TimeSpan.
 */
TimeSpan TimeSpan::fromString(const char *str, char separator)
{
    if (!*str) {
        return TimeSpan();
    }

    vector<double> parts;
    size_t partsSize = 1;
    for (const char *i = str; *i; ++i) {
        *i == separator && ++partsSize;
    }
    parts.reserve(partsSize);

    for (const char *i = str;;) {
        if (*i == separator) {
            parts.emplace_back(stringToNumber<double>(string(str, i)));
            str = ++i;
        } else if (*i == '\0') {
            parts.emplace_back(stringToNumber<double>(string(str, i)));
            break;
        } else {
            ++i;
        }
    }

    switch (parts.size()) {
    case 1:
        return TimeSpan::fromSeconds(parts.front());
    case 2:
        return TimeSpan::fromMinutes(parts.front()) + TimeSpan::fromSeconds(parts[1]);
    case 3:
        return TimeSpan::fromHours(parts.front()) + TimeSpan::fromMinutes(parts[1]) + TimeSpan::fromSeconds(parts[2]);
    default:
        return TimeSpan::fromDays(parts.front()) + TimeSpan::fromHours(parts[1]) + TimeSpan::fromMinutes(parts[2]) + TimeSpan::fromSeconds(parts[3]);
    }
}

/*!
 * \brief Converts the value of the current TimeSpan object to its equivalent std::string representation
 *        according the given \a format.
 *
 * If \a noMilliseconds is true the time interval will be rounded to full seconds.
 */
string TimeSpan::toString(TimeSpanOutputFormat format, bool noMilliseconds) const
{
    string result;
    toString(result, format, noMilliseconds);
    return result;
}

/*!
 * \brief Converts the value of the current TimeSpan object to its equivalent std::string representation
 *        according the given \a format.
 *
 * If \a noMilliseconds is true the time interval will be rounded to full seconds.
 *
 * The string representation will be stored in \a result.
 */
void TimeSpan::toString(string &result, TimeSpanOutputFormat format, bool noMilliseconds) const
{
    stringstream s(stringstream::in | stringstream::out);
    TimeSpan positive(m_ticks);
    if (positive.isNegative()) {
        s << '-';
        positive.m_ticks = -positive.m_ticks;
    }
    switch (format) {
    case TimeSpanOutputFormat::Normal:
        s << setfill('0') << setw(2) << floor(positive.totalHours()) << ":" << setw(2) << positive.minutes() << ":" << setw(2) << positive.seconds()
          << " ";
        break;
    case TimeSpanOutputFormat::WithMeasures:
        if (isNull()) {
            s << "0 s ";
        } else {
            if (positive.totalMilliseconds() < 1.0) {
                s << setprecision(2) << (m_ticks / 10.0) << " µs ";
            } else {
                if (const int days = positive.days()) {
                    s << days << " d ";
                }
                if (const int hours = positive.hours()) {
                    s << hours << " h ";
                }
                if (const int minutes = positive.minutes()) {
                    s << minutes << " min ";
                }
                if (const int seconds = positive.seconds()) {
                    s << seconds << " s ";
                }
                if (!noMilliseconds) {
                    if (const int milliseconds = positive.milliseconds()) {
                        s << milliseconds << " ms ";
                    }
                }
            }
        }
        break;
    }
    result = s.str().substr(0, static_cast<string::size_type>(s.tellp()) - 1);
}