Structured parsing, folded repetitive initialization code

2 files changed, 135 insertions, 123 deletions

diff --git a/events/roommessageevent.cpp b/events/roommessageevent.cpp
index 0da35527..513534ad 100644
--- a/events/roommessageevent.cpp
+++ b/events/roommessageevent.cpp
@@ -70,6 +70,18 @@ MessageEventContent::Base* RoomMessageEvent::content() const
     return d->content;
 }
 
+template <class ContentT>
+MessageEventContent::Base* make(const QJsonObject& json)
+{
+    return new ContentT(json);
+}
+
+template <class ContentT>
+MessageEventContent::Base* make2(const QJsonObject& json)
+{
+    return new ContentT(json["url"].toString(), json["info"].toObject());
+};
+
 RoomMessageEvent* RoomMessageEvent::fromJson(const QJsonObject& obj)
 {
     RoomMessageEvent* e = new RoomMessageEvent();
@@ -82,104 +94,53 @@ RoomMessageEvent* RoomMessageEvent::fromJson(const QJsonObject& obj)
     }
     if( obj.contains("content") )
     {
-        using namespace MessageEventContent;
-
-        QJsonObject content = obj.value("content").toObject();
-        QString msgtype = content.value("msgtype").toString();
-
-        if( msgtype == "m.text" )
-        {
-            e->d->msgtype = MessageEventType::Text;
-            e->d->content = new TextContent(obj);
-        }
-        else if( msgtype == "m.emote" )
-        {
-            e->d->msgtype = MessageEventType::Emote;
-            e->d->content = new TextContent(obj);
-        }
-        else if( msgtype == "m.notice" )
-        {
-            e->d->msgtype = MessageEventType::Notice;
-            e->d->content = new TextContent(obj);
-        }
-        else if( msgtype == "m.image" )
-        {
-            e->d->msgtype = MessageEventType::Image;
-            ImageContent* c = new ImageContent;
-            c->url = QUrl(content.value("url").toString());
-            QJsonObject info = content.value("info").toObject();
-            c->height = info.value("h").toInt();
-            c->width = info.value("w").toInt();
-            c->size = info.value("size").toInt();
-            c->mimetype = info.value("mimetype").toString();
-            e->d->content = c;
-        }
-        else if( msgtype == "m.file" )
-        {
-            e->d->msgtype = MessageEventType::File;
-            FileContent* c = new FileContent;
-            c->filename = content.value("filename").toString();
-            c->url = QUrl(content.value("url").toString());
-            QJsonObject info = content.value("info").toObject();
-            c->size = info.value("size").toInt();
-            c->mimetype = info.value("mimetype").toString();
-            e->d->content = c;
-        }
-        else if( msgtype == "m.location" )
+        const QJsonObject content = obj["content"].toObject();
+        if ( content.contains("msgtype") && content.contains("body") )
         {
-            e->d->msgtype = MessageEventType::Location;
-            LocationContent* c = new LocationContent;
-            c->geoUri = content.value("geo_uri").toString();
-            c->thumbnailUrl = QUrl(content.value("thumbnail_url").toString());
-            QJsonObject info = content.value("thumbnail_info").toObject();
-            c->thumbnailHeight = info.value("h").toInt();
-            c->thumbnailWidth = info.value("w").toInt();
-            c->thumbnailSize = info.value("size").toInt();
-            c->thumbnailMimetype = info.value("mimetype").toString();
-            e->d->content = c;
-        }
-        else if( msgtype == "m.video" )
-        {
-            e->d->msgtype = MessageEventType::Video;
-            VideoContent* c = new VideoContent;
-            c->url = QUrl(content.value("url").toString());
-            QJsonObject info = content.value("info").toObject();
-            c->height = info.value("h").toInt();
-            c->width = info.value("w").toInt();
-            c->duration = info.value("duration").toInt();
-            c->size = info.value("size").toInt();
-            c->thumbnailUrl = QUrl(info.value("thumnail_url").toString());
-            QJsonObject thumbnailInfo = content.value("thumbnail_info").toObject();
-            c->thumbnailHeight = thumbnailInfo.value("h").toInt();
-            c->thumbnailWidth = thumbnailInfo.value("w").toInt();
-            c->thumbnailSize = thumbnailInfo.value("size").toInt();
-            c->thumbnailMimetype = thumbnailInfo.value("mimetype").toString();
-            e->d->content = c;
-        }
-        else if( msgtype == "m.audio" )
-        {
-            e->d->msgtype = MessageEventType::Audio;
-            AudioContent* c = new AudioContent;
-            c->url = QUrl(content.value("url").toString());
-            QJsonObject info = content.value("info").toObject();
-            c->duration = info.value("duration").toInt();
-            c->mimetype = info.value("mimetype").toString();
-            c->size = info.value("size").toInt();
-            e->d->content = c;
+            using namespace MessageEventContent;
+
+            e->d->plainBody = content["body"].toString();
+
+            struct Factory
+            {
+                QString jsonTag;
+                MessageEventType enumTag;
+                MessageEventContent::Base*(*make)(const QJsonObject& json);
+            };
+
+            const Factory factories[] {
+                { "m.text", MessageEventType::Text, make<TextContent> },
+                { "m.emote", MessageEventType::Emote, make<TextContent> },
+                { "m.notice", MessageEventType::Notice, make<TextContent> },
+                { "m.image", MessageEventType::Image, make<ImageContent> },
+                { "m.file", MessageEventType::File, make<FileContent> },
+                { "m.location", MessageEventType::Location, make<LocationContent> },
+                { "m.video", MessageEventType::Video, make2<VideoContent> },
+                { "m.audio", MessageEventType::Audio, make2<AudioContent> },
+                // Insert new message types before this line
+            };
+
+            QString msgtype = content.value("msgtype").toString();
+            for (auto f: factories)
+            {
+                if (msgtype == f.jsonTag)
+                {
+                    e->d->msgtype = f.enumTag;
+                    e->d->content = f.make(content);
+                    break;
+                }
+            }
+            if (e->d->msgtype == MessageEventType::Unknown)
+            {
+                qDebug() << "RoomMessageEvent: unknown msgtype: " << msgtype;
+                qDebug() << obj;
+                e->d->content = new Base;
+            }
         }
         else
         {
-            qDebug() << "RoomMessageEvent: unknown msgtype: " << msgtype;
+            qWarning() << "RoomMessageEvent(" << e->id() << "): no body or msgtype";
             qDebug() << obj;
-            e->d->msgtype = MessageEventType::Unknown;
-            e->d->content = new Base;
-        }
-
-        if( content.contains("body") )
-        {
-            e->d->plainBody = content.value("body").toString();
-        } else {
-            qDebug() << "RoomMessageEvent: body not found";
         }
     }
     return e;
@@ -203,3 +164,37 @@ TextContent::TextContent(const QJsonObject& json)
         mimeType = db.mimeTypeForData(body.toUtf8());
     }
 }
+
+FileInfo::FileInfo(QUrl u, const QJsonObject& infoJson, QString originalFilename)
+    : url(u)
+    , fileSize(infoJson["size"].toInt())
+    , mimetype(QMimeDatabase().mimeTypeForName(infoJson["mimetype"].toString()))
+    , originalName(originalFilename)
+{
+    if (!mimetype.isValid())
+        mimetype = QMimeDatabase().mimeTypeForData(QByteArray());
+}
+
+ImageInfo::ImageInfo(QUrl u, const QJsonObject& infoJson)
+    : FileInfo(u, infoJson)
+    , imageSize(infoJson["w"].toInt(), infoJson["h"].toInt())
+{ }
+
+LocationContent::LocationContent(const QJsonObject& json)
+    : geoUri(json["geo_uri"].toString())
+    , thumbnail(json["thumbnail_url"].toString(),
+                json["thumbnail_info"].toObject())
+{ }
+
+VideoContent::VideoContent(QUrl u, const QJsonObject& infoJson)
+    : FileInfo(u, infoJson)
+    , duration(infoJson["duration"].toInt())
+    , imageSize(infoJson["w"].toInt(), infoJson["h"].toInt())
+    , thumbnail(infoJson["thumbnail_url"].toString(),
+                infoJson["thumbnail_info"].toObject())
+{ }
+
+AudioContent::AudioContent(QUrl u, const QJsonObject& infoJson)
+    : FileInfo(u, infoJson)
+    , duration(infoJson["duration"].toInt())
+{ }
diff --git a/events/roommessageevent.h b/events/roommessageevent.h
index 7b6394ba..83022b4d 100644
--- a/events/roommessageevent.h
+++ b/events/roommessageevent.h
@@ -21,6 +21,7 @@
 
 #include <QtCore/QUrl>
 #include <QtCore/QMimeType>
+#include <QtCore/QSize>
 
 #include "event.h"
 
@@ -66,6 +67,10 @@ namespace QMatrixClient
 
     namespace MessageEventContent
     {
+        // The below structures fairly follow CS spec 11.2.1.6. The overall
+        // set of attributes for each content types is a superset of the spec
+        // but specific aggregation structure is altered.
+
         class TextContent: public Base
         {
             public:
@@ -75,59 +80,71 @@ namespace QMatrixClient
                 QString body;
         };
 
-        class ImageContent: public Base
+        class FileInfo: public Base
         {
             public:
+                FileInfo(QUrl u, const QJsonObject& infoJson,
+                         QString originalFilename = QString());
+
                 QUrl url;
-                int height;
-                int width;
-                int size;
-                QString mimetype;
+                int fileSize;
+                QMimeType mimetype;
+                QString originalName;
         };
 
-        class FileContent: public Base
+        class ImageInfo: public FileInfo
         {
             public:
-                QString filename;
-                QString mimetype;
-                int size;
-                QUrl url;
+                ImageInfo(QUrl u, const QJsonObject& infoJson);
+
+                QSize imageSize;
         };
 
+        template <class ContentInfoT>
+        class ThumbnailedContent: public ContentInfoT
+        {
+            public:
+                ThumbnailedContent(const QJsonObject& json)
+                    : ContentInfoT(json["url"].toString(), json["info"].toObject())
+                    , thumbnail(json["thumbnail_url"].toString(),
+                                json["thumbnail_info"].toObject())
+                { }
+
+                ImageInfo thumbnail;
+        };
+
+        using ImageContent = ThumbnailedContent<ImageInfo>;
+        using FileContent = ThumbnailedContent<FileInfo>;
+
         class LocationContent: public Base
         {
             public:
+                LocationContent(const QJsonObject& json);
+
                 QString geoUri;
-                int thumbnailHeight;
-                int thumbnailWidth;
-                QString thumbnailMimetype;
-                int thumbnailSize;
-                QUrl thumbnailUrl;
+                ImageInfo thumbnail;
         };
 
-        class VideoContent: public Base
+        // The spec structures m.video messages differently for some reason -
+        // instead of putting a thumbnail block on the top level, as with
+        // file and image, it puts it inside "info" key. So instead of
+        // using ThumbnailContent<> base, we add the thumbnail into VideoInfo explicitly.
+        class VideoContent: public FileInfo
         {
             public:
-                QUrl url;
+                VideoContent(QUrl u, const QJsonObject& infoJson);
+
                 int duration;
-                int width;
-                int height;
-                int size;
-                QString mimetype;
-                int thumbnailWidth;
-                int thumbnailHeight;
-                int thumbnailSize;
-                QString thumbnailMimetype;
-                QUrl thumbnailUrl;
+                QSize imageSize;
+                ImageInfo thumbnail;
         };
 
-        class AudioContent: public Base
+        class AudioContent: public FileInfo
         {
             public:
-                QUrl url;
-                int size;
+                AudioContent(QUrl u, const QJsonObject& infoJson);
+
                 int duration;
-                QString mimetype;
         };
     }
 }