#include "TimeChart.h"
#include "ChartScene.h"
#include "DataPoint.h"

const QList<int> TimeChart::TimeUnits = QList<int>() <<
    1 << 7 << 30 << 92 << 183;

TimeChart::TimeChart()
{
}

void TimeChart::setDates(const QList<QDateTime>& dates, int period,
    int dataDirection)
{
    this->dates = dates;
    scene->setDataDirection(dataDirection);
    TimeUnit timeUnit = findTimeUnit(period);
    QDate thisIntervalStart = getIntervalStart(QDate::currentDate(), timeUnit);
    QList<DataPoint> dataSet;
    int pointsNum = getDataPointsNum(period, timeUnit);
    for(int i = 0; i < pointsNum; i++)
        dataSet.append(createDataPoint(thisIntervalStart, timeUnit, i));
    scene->setDataSet(dataSet, getTicksInterval(pointsNum));
}

int TimeChart::getDataPointsNum(int period, TimeUnit timeUnit)
{
    return period / TimeUnits.at(timeUnit);
}

int TimeChart::getTicksInterval(int pointsNum)
{
    int ticksInterval = 1;
    while(pointsNum / ticksInterval > MaxXTicks)
        ticksInterval *= 2;
    return ticksInterval;
}

TimeChart::TimeUnit TimeChart::findTimeUnit(int period)
{
    for(int unit = Day; unit < (int)TimeUnitsNum; unit++)
        if(getDataPointsNum(period, (TimeUnit)unit) <= MaxDataPoints)
            return (TimeUnit)unit;
    return HalfYear;
}

QDate TimeChart::getIntervalStart(const QDate& date, TimeUnit timeUnit)
{
    switch(timeUnit)
    {
    case Day:
        return date;
    case Week:
        return date.addDays(-date.dayOfWeek() + 1);
    case Month:
        return QDate(date.year(), date.month(), 1);
    case Quarter:
        return getQuarterStart(date);
    case HalfYear:
        return getHalfYearStart(date);
    default:
        return date;
    }
}

QDate TimeChart::getQuarterStart(const QDate& date)
{
    const int quarterLen = 3;
    int quarter = (date.month() - 1) / quarterLen;
    int startMonth = quarter * quarterLen + 1;
    return QDate(date.year(), startMonth, 1);
}

QDate TimeChart::getHalfYearStart(const QDate& date)
{
    const int secondHalfStart = 7;
    int startMonth = date.month() < secondHalfStart ? 1 : secondHalfStart;
    return QDate(date.year(), startMonth, 1);
}

QDate TimeChart::getInterval(const QDate& start, TimeUnit timeUnit,
    int num)
{
    switch(timeUnit)
    {
    case Day:
        return start.addDays(num);
    case Week:
        return start.addDays(7 * num);
    case Month:
        return start.addMonths(num);
    case Quarter:
        return start.addMonths(3 * num);
    case HalfYear:
        return start.addMonths(6 * num);
    default:
        return start;
    }
}

QDate TimeChart::getIntervalEnd(const QDate& start, TimeUnit timeUnit)
{
    return getInterval(start, timeUnit, 1).addDays(-1);
}

DataPoint TimeChart::createDataPoint(const QDate& thisIntervalStart, TimeUnit timeUnit,
    int intervalIndex)
{
    QDate startDate = getInterval(thisIntervalStart, timeUnit,
        scene->getDataDirection() * intervalIndex);
    QDate endDate = getIntervalEnd(startDate, timeUnit);
    QString xLabel = getDateLabel(startDate, timeUnit);
    int value = getCardsNumForDate(startDate, endDate);
    QString toolTipLabel = getIntervalLabel(startDate, endDate, timeUnit);
    return DataPoint(xLabel, value, toolTipLabel);
}

QString TimeChart::getDateLabel(const QDate& date, TimeUnit timeUnit)
{
    return date.toString(getIntervalFormat(timeUnit));
}

QString TimeChart::getIntervalFormat(TimeUnit timeUnit)
{
    switch(timeUnit)
    {
    case Day:
    case Week:
        return "dd.MM";
    case Month:
    case Quarter:
    case HalfYear:
        return "MM/yy";
    default:
        return "dd.MM";
    }
}

QString TimeChart::getIntervalLabel(const QDate& startDate,
    const QDate& endDate, TimeUnit timeUnit)
{
    QString startLabel = getDateLabel(startDate, timeUnit);
    if(timeUnit == Day || timeUnit == Month)
        return startLabel;
    return startLabel + " - " + getDateLabel(endDate, timeUnit);
}

int TimeChart::getCardsNumForDate(const QDate& startDate, const QDate& endDate)
{
    int cardsNum = 0;
    foreach(QDateTime date, dates)
        if(date.date() >= startDate && date.date() <= endDate)
            cardsNum++;
    return cardsNum;
}