added dns discovery

widget/form/addfriendform.cpp

@@ -1,9 +1,14 @@
 #include "addfriendform.h"
-#include "ui_widget.h"
+
 #include <QFont>
+#include <QMessageBox>
+
+#define TOX_ID_SIZE 76
 
-AddFriendForm::AddFriendForm()
+AddFriendForm::AddFriendForm() : dns(this)
 {
+    dns.setType(QDnsLookup::TXT);
+
     main = new QWidget(), head = new QWidget();
     QFont bold;
     bold.setBold(true);
@@ -25,6 +30,13 @@ AddFriendForm::AddFriendForm()
     headLayout.addWidget(&headLabel);
 
     connect(&sendButton, SIGNAL(clicked()), this, SLOT(onSendTriggered()));
+    connect(&dns, SIGNAL(finished()), this, SLOT(handleDnsLookup()));
+}
+
+AddFriendForm::~AddFriendForm()
+{
+    head->deleteLater();
+    main->deleteLater();
 }
 
 void AddFriendForm::show(Ui::Widget &ui)
@@ -35,13 +47,80 @@ void AddFriendForm::show(Ui::Widget &ui)
     head->show();
 }
 
+bool AddFriendForm::isToxId(const QString &value) const
+{
+    const QRegularExpression hexRegExp("^[A-Fa-f0-9]+$");
+    return value.length() == TOX_ID_SIZE && value.contains(hexRegExp);
+}
+
+void AddFriendForm::showWarning(const QString &message) const
+{
+    QMessageBox warning(main);
+    warning.setText(message);
+    warning.setIcon(QMessageBox::Warning);
+    warning.exec();
+}
+
+QString AddFriendForm::getMessage() const
+{
+    const QString msg = message.toPlainText();
+    return !msg.isEmpty() ? msg : "Tox me maybe?";
+}
+
 void AddFriendForm::onSendTriggered()
 {
-    QString id = toxId.text(), msg = message.toPlainText();
-    if (id.isEmpty())
+    const QString id  = toxId.text().trimmed();
+
+    if (id.isEmpty()) {
+        showWarning("Please fill in a valid Tox ID");
+    } else if (isToxId(id)) {
+        emit friendRequested(id, getMessage());
+    } else {
+        dns.setName(id);
+        dns.lookup();
+    }
+}
+
+void AddFriendForm::handleDnsLookup()
+{
+    const QString idKeyWord("id=");
+
+    if (dns.error() != QDnsLookup::NoError) {
+        showWarning("Error while looking up DNS");
+        return;
+    }
+
+    const QList<QDnsTextRecord> textRecords = dns.textRecords();
+    if (textRecords.length() != 1) {
+        showWarning("Unexpected number of text records");
+        return;
+    }
+
+    const QList<QByteArray> textRecordValues = textRecords.first().values();
+    if (textRecordValues.length() != 1) {
+        showWarning("Unexpected number of values in text record");
+        return;
+    }
+
+    const QString entry(textRecordValues.first());
+    int idx = entry.indexOf(idKeyWord);
+    if (idx < 0) {
+        showWarning("The DNS lookup does not contain any Tox ID");
+        return;
+    }
+
+    idx += idKeyWord.length();
+    if (entry.length() < idx + static_cast<int>(TOX_ID_SIZE)) {
+        showWarning("The DNS lookup does not contain a valid Tox ID");
+        return;
+    }
+
+    const QString friendAdress = entry.mid(idx, TOX_ID_SIZE);
+    if (!isToxId(friendAdress)) {
+        showWarning("The DNS lookup does not contain a valid Tox ID");
         return;
-    if (msg.isEmpty())
-        msg = "Tox me maybe?";
+    }
 
-    emit friendRequested(id, msg);
+    // finally we got it
+    emit friendRequested(friendAdress, getMessage());
 }

widget/form/addfriendform.h

@@ -1,27 +1,33 @@
 #ifndef ADDFRIENDFORM_H
 #define ADDFRIENDFORM_H
 
+#include "ui_widget.h"
+
 #include <QVBoxLayout>
 #include <QLabel>
 #include <QLineEdit>
 #include <QTextEdit>
 #include <QPushButton>
-
-#include "ui_widget.h"
+#include <QDnsLookup>
 
 class AddFriendForm : public QObject
 {
     Q_OBJECT
 public:
     AddFriendForm();
+    ~AddFriendForm();
 
     void show(Ui::Widget& ui);
+    bool isToxId(const QString& value) const;
+    void showWarning(const QString& message) const;
+    QString getMessage() const;
 
 signals:
     void friendRequested(const QString& friendAddress, const QString& message);
 
 private slots:
      void onSendTriggered();
+     void handleDnsLookup();
 
 private:
     QLabel headLabel, toxIdLabel, messageLabel;
@@ -30,6 +36,9 @@ private:
     QTextEdit message;
     QVBoxLayout layout, headLayout;
     QWidget *head, *main;
+
+    /** will be used for dns discovery if necessary */
+    QDnsLookup dns;
 };
 
 #endif // ADDFRIENDFORM_H