/**
 * @file CountryDat.cpp
 * @brief Implementation of the CountryDat class for handling country data.
 */

/*
#Sov Mil Order of Malta:   15:  28:  EU:   41.90:   -12.43:    -1.0:  1A:
    #1A;
#Spratly Islands:          26:  50:  AS:    9.88:  -114.23:    -8.0:  1S:
    #1S,9M0,BV9S;
#Monaco:                   14:  27:  EU:   43.73:    -7.40:    -1.0:  3A:
    #3A;
#Heard Island:             39:  68:  AF:  -53.08:   -73.50:    -5.0:  VK0H:
    #=VK0IR;
#Macquarie Island:         30:  60:  OC:  -54.60:  -158.88:   -10.0:  VK0M:
    #=VK0KEV;
#Cocos-Keeling:            29:  54:  OC:  -12.15:   -96.82:    -6.5:  VK9C:
    #AX9C,AX9Y,VH9C,VH9Y,VI9C,VI9Y,VJ9C,VJ9Y,VK9C,VK9Y,VL9C,VL9Y,VM9C,VM9Y,
    #VN9C,VN9Y,VZ9C,VZ9Y,=VK9AA;
*/

#include "CountryDat.h"
#include "JS8_Main/Radio.h"

#include <QDebug>
#include <QFile>
#include <QTextStream>

/**
 * @brief Initialize the CountryDat instance with the specified filename.
 * @param filename The path to the country data file.
 */
void CountryDat::init(const QString filename) {
    _filename = filename;
    _data.clear();
}

/**
 * @brief Extract the country name from a line in the country data file.
 * @param line The line from which to extract the country name.
 * @return The extracted country name.
 */
QString CountryDat::_extractName(const QString line) const {
    int s1 = line.indexOf(':');
    if (s1 >= 0) {
        QString name = line.mid(0, s1);
        return name;
    }
    return "";
}

/**
 * @brief Remove substrings enclosed by specified brackets from a line.
 * @param line The line to process.
 * @param a The opening bracket.
 * @param b The closing bracket.
 */
void CountryDat::_removeBrackets(QString &line, const QString a,
                                 const QString b) const {
    int s1 = line.indexOf(a);
    while (s1 >= 0) {
        int s2 = line.indexOf(b);
        line = line.mid(0, s1) + line.mid(s2 + 1, -1);
        s1 = line.indexOf(a);
    }
}

/**
 * @brief Extract prefixes from a line in the country data file.
 * @param line The line from which to extract prefixes.
 * @param more Output parameter indicating if more prefixes are expected.
 * @return A list of extracted prefixes.
 */
QStringList CountryDat::_extractPrefix(QString &line, bool &more) const {
    line = line.remove(" \n");
    line = line.replace(" ", "");

    _removeBrackets(line, "(", ")");
    _removeBrackets(line, "[", "]");
    _removeBrackets(line, "<", ">");
    _removeBrackets(line, "~", "~");

    int s1 = line.indexOf(';');
    more = true;
    if (s1 >= 0) {
        line = line.mid(0, s1);
        more = false;
    }

    QStringList r = line.split(',');

    return r;
}

/**
 * @brief Load country data from the specified file.
 */
void CountryDat::load() {
    _data.clear();
    _countryNames.clear(); // used by countriesWorked

    QFile inputFile(_filename);
    if (inputFile.open(QIODevice::ReadOnly)) {
        QTextStream in(&inputFile);
        while (!in.atEnd()) {
            QString line1 = in.readLine();
            if (!in.atEnd()) {
                QString line2 = in.readLine();

                QString name = _extractName(line1);
                if (name.length() > 0) {
                    QString continent = line1.mid(36, 2);
                    QString principalPrefix = line1.mid(69, 4);
                    int i1 = principalPrefix.indexOf(":");
                    if (i1 > 0)
                        principalPrefix = principalPrefix.mid(0, i1);
                    name += "; " + principalPrefix + "; " + continent;
                    _countryNames << name;
                    bool more = true;
                    QStringList prefixs;
                    while (more) {
                        QStringList p = _extractPrefix(line2, more);
                        prefixs += p;
                        if (more)
                            line2 = in.readLine();
                    }

                    QString p;
                    foreach (p, prefixs) {
                        if (p.length() > 0)
                            _data.insert(p, name);
                    }
                }
            }
        }
        inputFile.close();
    }
}

/**
 * @brief Find the country name associated with a given callsign prefix.
 * @param call The callsign prefix to search for.
 * @return The corresponding country name, or an empty string if not found.
 */
QString CountryDat::find(QString call) const {
    call = call.toUpper();

    // check for exact match first
    if (_data.contains("=" + call)) {
        return fixup(_data.value("=" + call), call);
    }

    auto prefix = Radio::effective_prefix(call);
    auto match_candidate = prefix;
    while (match_candidate.size() >= 1) {
        if (_data.contains(match_candidate)) {
            return fixup(_data.value(match_candidate), prefix);
        }
        match_candidate = match_candidate.left(match_candidate.size() - 1);
    }
    return QString{};
}

/**
 * @brief Apply special rules to fix up country names based on callsigns.
 * @param country The initial country name.
 * @param call The callsign to check for special rules.
 * @return The potentially modified country name.
 */
QString CountryDat::fixup(QString country, QString const &call) const {
    //
    // deal with special rules that cty.dat does not cope with
    //

    // KG4 2x1 and 2x3 calls that map to Gitmo are mainland US not Gitmo
    if (call.startsWith("KG4") && call.size() != 5 && call.size() != 3) {
        country.replace("Guantanamo Bay; KG4; NA", "United States; K; NA");
    }
    return country;
}