// This source code file was last time modified by Arvo ES1JA on 20191202
// All changes are shown in the patch file coming together with the full JTDX source code.

#include "Radio.hpp"

#include <cmath>

#include <QString>
#include <QChar>
#include <QRegularExpression>

namespace Radio
{
  namespace
  {
    double constexpr MHz_factor {1.e6};
    int constexpr frequency_precsion {6};

    // very loose validation - callsign must contain a letter next to
    // a number
//    QRegularExpression valid_callsign_regexp {R"(\d[[:alpha:]]|[[:alpha:]]\d)"};
    QRegularExpression valid_callsign_regexp {R"([2,4-9]{1,1}[A-Z]{1,1}[0-9]{1,4}|[3]{1,1}[A-Z]{1,2}[0-9]{1,4}|[A-Z]{1,2}[0-9]{1,4})"};
    
    // Extracting prefix from callsign
    QRegularExpression prefix_re {R"(^(?:(?<prefix>[2-9]{0,1}[A-Z]{1,2}[0-9]{1,4})?)?)"};
  }


  Frequency frequency (QVariant const& v, int scale, QLocale const& locale)
  {
    double value {0};
    if (QVariant::String == v.type ())
      {
        value = locale.toDouble (v.value<QString> ());
      }
    else
      {
        value = v.toDouble ();
      }
    return std::llround (value * std::pow (10., scale));
  }

  FrequencyDelta frequency_delta (QVariant const& v, int scale, QLocale const& locale)
  {
    double value {0};
    if (QVariant::String == v.type ())
      {
        value = locale.toDouble (v.value<QString> ());
      }
    else
      {
        value = v.toDouble ();
      }
    return std::llround (value * std::pow (10., scale));
  }


  QString frequency_MHz_string (Frequency f, QLocale const& locale)
  {
    return locale.toString (f / MHz_factor, 'f', frequency_precsion);
  }

  QString frequency_MHz_string (FrequencyDelta d, QLocale const& locale)
  {
    return locale.toString (d / MHz_factor, 'f', frequency_precsion);
  }

  QString pretty_frequency_MHz_string (Frequency f, QLocale const& locale)
  {
    auto f_string = locale.toString (f / MHz_factor, 'f', frequency_precsion);
    return f_string.insert (f_string.size () - 3, QChar::Nbsp);
  }

  QString pretty_frequency_MHz_string (double f, int scale, QLocale const& locale)
  {
    auto f_string = locale.toString (f / std::pow (10., scale - 6), 'f', frequency_precsion);
    return f_string.insert (f_string.size () - 3, QChar::Nbsp);
  }

  QString pretty_frequency_MHz_string (FrequencyDelta d, QLocale const& locale)
  {
    auto d_string = locale.toString (d / MHz_factor, 'f', frequency_precsion);
    return d_string.insert (d_string.size () - 3, QChar::Nbsp);
  }

  bool is_callsign (QString const& callsign)
  {
    if ((!callsign.at(1).isDigit() && callsign.size () == 2) || callsign == "F" || callsign == "G" || callsign == "I" || callsign == "K" || callsign == "W") {
        auto call = callsign + "0";
        return call.contains (valid_callsign_regexp);
    }
    else
        return callsign.contains (valid_callsign_regexp);
  }

  bool is_compound_callsign (QString const& callsign)
  {
    return callsign.contains ('/');
  }

  // split on first '/' and return the larger portion or the whole if
  // there is no '/'
  QString base_callsign (QString callsign)
  {
    auto slash_pos = callsign.indexOf ('/');
    if (slash_pos >= 0)
      {
        auto right_size = callsign.size () - slash_pos - 1;
        if (right_size>= slash_pos)
          {
            callsign = callsign.mid (slash_pos + 1);
          }
        else
          {
            callsign = callsign.left (slash_pos);
          }
      }
    return callsign.toUpper ();
  }

  // analyze the callsign and determine the effective prefix, returns
  // the full call if no valid prefix (or prefix as a suffix) is specified
  QString effective_prefix (QString callsign)
  {
    auto parts = callsign.split('/');
    auto prefix = parts.at(0);
    int size = prefix.size();
    int region = -1;
    for (int i = 1; i < parts.size(); ++i) {
      if (parts.at(i) == "MM" || parts.at(i) == "AM") {
          prefix="1B1ABCD";
          size = prefix.size();
      } else if (is_callsign(parts.at(i)) && size > parts.at(i).size() && !((parts.at(i) == "LH" || parts.at(i) == "ND" || parts.at(i) == "AG" || parts.at(i) == "AE" || parts.at(i) == "KT") && i == (parts.size() -1))) {
          prefix = parts.at(i);
          size = prefix.size();
      } else {
        bool ok;
        auto reg = parts.at(i).toInt(&ok);
        if (ok) region = reg;
      }
    }
    auto const& match = prefix_re.match (prefix);  
    auto shorted = match.captured ("prefix");
    if (shorted.isEmpty() || region > -1) {
        if (shorted.isEmpty()) shorted = prefix+"0";
        if (region > -1) shorted = shorted.left(shorted.size()-1) + QString::number(region);
        return shorted.toUpper ();
    } else return prefix;
  }

  //  strip to prefix only
  QString striped_prefix (QString callsign)
  {
    auto const& match = prefix_re.match (callsign);  
    return match.captured ("prefix");
  }
}