#include "Sport.h"
#include <set>
#include <map>
#include <algorithm>
#include <regex>

#include <QJsonObject>
#include <QJsonArray>
#include <QJsonValueRef>
#include <QString>

// QJsonArray filter function, provide with input array and evaluation function
QJsonArray filter(QJsonArray input, function<bool (QJsonObject)> eval) {
    QJsonArray output;

    for (const QJsonValueRef &elemRef :input) {
        QJsonObject elem = elemRef.toObject();
        if(eval(elem)) {
            output.append(elem);
        }
    }

    return output;
}

// static compare function for specific attribute in competitors
function<bool (const QJsonValue &left, const QJsonValue &right)> genCompare(QString attribute) {
    return [attribute](const QJsonValue &left, const QJsonValue &right) {
        QString l = left.toObject()[attribute].toString();
        QString r = right.toObject()[attribute].toString();
        return l.compare(r) < 0;
    };
}

// static compare function for the results of a competitor in a specific competition (also called mark)
bool compareMark(const QJsonValue &left, const QJsonValue &right) {
    // check if one competitor has no mark
    QJsonObject l = left.toObject();
    if (!l.contains("results")) return true;
    QJsonObject r = right.toObject();
    if (!r.contains("results")) return false;

    QString lMark = l["results"].toObject()["mark"].toString();
    QString rMark = r["results"].toObject()["mark"].toString();

    // check if the marks are numerical values
    if (!lMark.contains(":") && !rMark.contains(":")) return lMark.toFloat() < rMark.toFloat();

    // compare time values if not numerical
    QString lTime(""), rTime("");

    for (QChar c : lMark) if (c.isDigit()) lTime.append(c);
    for (QChar c : rMark) if (c.isDigit()) rTime.append(c);

    return lTime.compare(rTime) < 0;
}

// static compare function for the amount of medals a competitor has gotten
bool compareMedals(const QJsonValue &left, const QJsonValue &right) {
    QJsonObject lMedals = left.toObject()["medals"].toObject();
    QJsonObject rMedals = right.toObject()["medals"].toObject();

    int gold = lMedals["ME_GOLD"].toInt() - rMedals["ME_GOLD"].toInt();
    int silver = lMedals["ME_SILVER"].toInt() - rMedals["ME_SILVER"].toInt();
    int bronze = lMedals["ME_BRONZE"].toInt() - rMedals["ME_BRONZE"].toInt();

    return gold < 0 || (gold == 0 && (silver < 0 || (silver == 0 && bronze < 0)));
}

/**
 * @brief Sport::lastName Reduce the full name to the part that is marked in capital letters (probably last name).
 * @param competitors The competitors of one category.
 */
void Sport::lastName(QJsonArray &competitors) {
    // validate competitors
    if (competitors.isEmpty() || !competitors[0].toObject().contains("name")) return;

    for (int i = 0; i < competitors.size(); ++i) {
        string fullName = competitors[i].toObject()["name"].toString().toUtf8().constData();

        // regex to identify names, written in CAPS
        regex r("[A-Z']{2,}");
        smatch m;

        regex_search(fullName, m, r);

        // combine found names again
        string lastName = "";
        for (string s : m) lastName = lastName + s + " ";

        // remove last space
        QJsonValue nameValue = QJsonValue(QString(lastName.substr(0, lastName.size() - 1).c_str()));

        // create new object with replaced name
        QJsonObject comp(competitors[i].toObject());
        comp.remove("name");
        comp.insert("name", nameValue);

        // replace competitor in array
        competitors.replace(i, comp);
    }
}

/**
 * @brief Sport::validateDiscipline Validates the discipline object. Checks for the units attribute.
 * @return True, if discipline contains units.
 */
bool Sport::validateDiscipline() {
    return this->discipline.contains("units");
}

/**
 * @brief Sport::getCategories Reads all possible categories (also called units).
 * @return A set of all category names.
 */
set<QString> Sport::getCategories() {
    set<QString> categoryNames;

    if (!validateDiscipline()) return categoryNames;

    // search in each unit for the category (named "eventUnitName")
    for (const QJsonValueRef &unitRef : this->discipline["units"].toArray()) {
        QJsonObject unit = unitRef.toObject();

        // validate unit
        if (!unit.contains("eventUnitName")) continue;

        categoryNames.insert(unit["eventUnitName"].toString());
    }

    return categoryNames;
}

/**
 * @brief Sport::getCompetitorsByCategory Searches for all competitors, who took part in the given category.
 * @param category The category to search in.
 * @return An QJsonArray with all competitors as QJsonValueRef, which can be casted to QJsonObject.
 */
QJsonArray Sport::getCompetitorsByCategory(QString category) {
    QJsonArray competitors;

    if (!validateDiscipline()) return competitors;

    for (const QJsonValueRef &unitRef : this->discipline["units"].toArray()) {
        QJsonObject unit = unitRef.toObject();

        // validate unit
        if (!unit.contains("eventUnitName") || !unit.contains("competitors")) continue;

        // search all units with the same category
        if (unit["eventUnitName"].toString().compare(category, Qt::CaseSensitive) != 0) continue;

        // add all competitors from one unit
        for (const QJsonValueRef &compRef : unit["competitors"].toArray()) {
            competitors.push_back(compRef.toObject());
        }
    }

    return QJsonArray(competitors);
}

/**
 * @brief Sport::getCompetitorsWithMedal Filters all competitors, who have at least one medal. These objects are different from getCompetitorsByCategory !!!
 * @return All competitors, who won at least one medal. Structure of one competitor: {code, name, noc, medals{ME_GOLD, ME_SILVER, ME_BRONZE}}
 */

QJsonArray Sport::getCompetitorsWithMedal() {
    map<QString, QJsonObject> competitors;

    if (!validateDiscipline()) return QJsonArray();

    // filter all units, which have medal events
    QJsonArray units = filter(this->discipline["units"].toArray(), [](QJsonObject unit){
        // search all units with Final, Gold or Bronze in their name, because these are the categories with the medal winners
        QString unitName = unit["eventUnitName"].toString();
        return unitName.contains("Bronze", Qt::CaseSensitive)
               || unitName.contains("Gold", Qt::CaseSensitive)
               || unitName.contains("Final", Qt::CaseSensitive);
    });

    for (const QJsonValueRef &unitRef : units) {
        QJsonObject unit = unitRef.toObject();

        // validate unit
        if (!unit.contains("competitors")) continue;

        // filter all competitors, who won medals
        QJsonArray medalComps = filter(unit["competitors"].toArray(), [](QJsonObject comp) {
            if (!comp.contains("results")) return false;

            QString medalType = comp["results"].toObject()["medalType"].toString();
            return !medalType.isEmpty();
        });

        for (const QJsonValueRef &medalCompRef : medalComps) {
            QJsonObject medalComp = medalCompRef.toObject();

            // validate competitor (with medal)
            if (!medalComp.contains("name")
                || !medalComp.contains("results")
                || !medalComp["results"].toObject().contains("medalType")) continue;

            QString name = medalComp["name"].toString();
            QString medalType = medalComp["results"].toObject()["medalType"].toString();

            // check if competitor has other medal(s)
            if (competitors.find(name) == competitors.end()) {
                competitors.insert({name, createCompetitorWithMedals(medalComp)});
            }

            // update the medal count
            QJsonObject updatedMedalCount = QJsonObject(competitors.find(name)->second["medals"].toObject());

            int amount = updatedMedalCount[medalType].toInt() + 1;
            updatedMedalCount.remove(medalType);
            updatedMedalCount.insert(medalType, amount);

            // create new medals QJsonObject and set it in the map
            competitors.find(name)->second["medals"] = updatedMedalCount;
        }
    }

    // convert map to QJsonArray
    QJsonArray output;
    for (const pair<QString, QJsonObject> &competitor : competitors) {
        output.append(competitor.second);
    }

    return output;
}

/**
 * @brief Sport::createCompetitorWithMedals Creates a competitor QJsonObject with the following attributes: code, name, noc, medals{ME_GOLD, ME_SILVER, ME_BRONZE}
 * @param comp The original competitor object.
 * @return A competitor object with medal counts.
 */
QJsonObject Sport::createCompetitorWithMedals(QJsonObject comp) {
    // repair competitor if something is missing
    if (!comp.contains("code")) comp.insert("code", "0");
    if (!comp.contains("name")) comp.insert("code", "");
    if (!comp.contains("noc")) comp.insert("code", "");

    // create new competitor QJsonObject and add it to the competitor map
    QJsonObject medals {
        {"ME_GOLD", 0},
        {"ME_SILVER", 0},
        {"ME_BRONZE", 0}
    };

    QJsonObject medalComp {
        {"code", comp["code"].toString()},
        {"name", comp["name"].toString()},
        {"noc", comp["noc"].toString()},
        {"medals", medals}
    };

    return medalComp;
}

/**
 * @brief Sport::filterByName Filter the competitors by name (case insensitive).
 * @param competitors The competitors of one category.
 * @param name The (part of the) name to search for.
 */
void Sport::filterByName(QJsonArray &competitors, QString name) {
    filterCompetitors(competitors, QString("name"), name);
}

/**
 * @brief Sport::filterByCountry Filter the competitors by their national olympics comittee (case insensitive, short form).
 * @param competitors The competitors of one category.
 * @param nocShort The (part of the) national olympics comittee short name to search for.
 */
void Sport::filterByCountry(QJsonArray &competitors, QString nocShort) {
    filterCompetitors(competitors, QString("noc"), nocShort);
}

/**
 * @brief Sport::filterCompetitors Filters the given QJsonArray by comparing the value of a certain attribute with the given filter string.
 * @param competitors The competitors of one category.
 * @param attribute The attribute to filter by.
 * @param filter The string, which should be contained.
 */
void Sport::filterCompetitors(QJsonArray &competitors, QString attribute, QString filter) {
    for (int i = 0; i < competitors.size(); i++) {
        QJsonObject comp = competitors[i].toObject();

        if (!comp.contains(attribute) || !comp[attribute].toString().contains(filter, Qt::CaseInsensitive)) {
            // remove the competitor, if the attribute does not fit the filter string
            competitors.removeAt(i);
            i--;
        }

    }
}

/**
 * @brief Sport::sortByName Sort the competitors by their name (alphabetical, ascending).
 * @param competitors The competitors of one category.
 */
void Sport::sortByName(QJsonArray &competitors) {
    sortCompetitors(competitors, genCompare( QString("name") ));
}

/**
 * @brief Sport::sortByCountry Sort the competitors by their national olympic comittee short name (alphabetical, ascending).
 * @param competitors The competitors of one category.
 */
void Sport::sortByCountry(QJsonArray &competitors) {
    sortCompetitors(competitors, genCompare( QString("noc") ));
}

/**
 * @brief Sport::sortByResult Sort the competitors by their results in one specific category (numerical, ascending).
 * @param competitors The competitors of one category.
 */
void Sport::sortByResult(QJsonArray &competitors) {
    if (competitors.isEmpty()) return;

    QJsonObject comp = competitors[0].toObject();

    if (comp.contains("results")) sortCompetitors(competitors, compareMark);
    else if (comp.contains("medals")) sortCompetitors(competitors, compareMedals);
}

/**
 * @brief Sport::sortCompetitors Sorts the given QJsonArray according to the compare function.
 * @param competitors The competitors of one category.
 * @param compare A function to compare two competitors with each other. This defines the order.
 */
void Sport::sortCompetitors(QJsonArray &competitors, function<bool (const QJsonValue &left, const QJsonValue &right)> compare) {
    make_heap(competitors.begin(), competitors.end(), compare);
    sort_heap(competitors.begin(), competitors.end(), compare);
}