From d60d57ee435a3f6efbe6d7e06c096dd641c4137a Mon Sep 17 00:00:00 2001
From: Zlatin Balevsky <zlatinb@gmail.com>
Date: Sun, 8 Mar 2020 17:04:11 +0000
Subject: [PATCH] wip on server side feed handling

---
 .../core/connection/ConnectionAcceptor.groovy | 51 +++++++++++++++++++
 .../muwire/core/filefeeds/FeedItems.groovy    | 28 ++++++++++
 .../com/muwire/core/files/FileManager.groovy  | 12 +++++
 3 files changed, 91 insertions(+)
 create mode 100644 core/src/main/groovy/com/muwire/core/filefeeds/FeedItems.groovy

diff --git a/core/src/main/groovy/com/muwire/core/connection/ConnectionAcceptor.groovy b/core/src/main/groovy/com/muwire/core/connection/ConnectionAcceptor.groovy
index b1fcbaf3..16c67c1c 100644
--- a/core/src/main/groovy/com/muwire/core/connection/ConnectionAcceptor.groovy
+++ b/core/src/main/groovy/com/muwire/core/connection/ConnectionAcceptor.groovy
@@ -15,9 +15,11 @@ import com.muwire.core.EventBus
 import com.muwire.core.InfoHash
 import com.muwire.core.MuWireSettings
 import com.muwire.core.Persona
+import com.muwire.core.SharedFile
 import com.muwire.core.chat.ChatServer
 import com.muwire.core.filecert.Certificate
 import com.muwire.core.filecert.CertificateManager
+import com.muwire.core.filefeeds.FeedItems
 import com.muwire.core.files.FileManager
 import com.muwire.core.hostcache.HostCache
 import com.muwire.core.trust.TrustLevel
@@ -161,6 +163,9 @@ class ConnectionAcceptor {
                 case (byte)'I':
                     processIRC(e)
                     break
+                case (byte)'F':
+                    processFEED(e)
+                    break
                 default:
                     throw new Exception("Invalid read $read")
             }
@@ -524,5 +529,51 @@ class ConnectionAcceptor {
             throw new Exception("Invalid IRC connection")
         chatServer.handle(e)
     }
+    
+    private void processFEED(Endpoint e) {
+        try {
+            byte[] EED = new byte[5];
+            DataInputStream dis = new DataInputStream(e.getInputStream())
+            dis.readFully(EED);
+            if (EED != "EED\r\n".getBytes(StandardCharsets.US_ASCII))
+                throw new Exception("Invalid FEED connection")
+
+
+            Map<String, String> headers = DataUtil.readAllHeaders(dis)
+            if (!headers.containsKey("Persona"))
+                throw new Exception("Persona header missing")
+            Persona requestor = new Persona(new ByteArrayInputStream(Base64.decode(headers['Persona'])))
+            if (requestor.destination != e.destination)
+                throw new Exception("Requestor persona mismatch")
+
+            // TODO: check settings if feed is permitted at all
+
+            long timestamp = 0
+            if (headers.containsKey("Timestamp")) {
+                timestamp = Long.parseLong(headers['Timestamp'])
+            }
+
+            List<SharedFile> published = fileManager.getPublishedSince(timestamp)
+
+            OutputStream os = e.getOutputStream()
+            os.write("200 OK\r\n".getBytes(StandardCharsets.US_ASCII))
+            os.write("Count: ${published.size()}\r\n".getBytes(StandardCharsets.US_ASCII));
+            os.write("\r\n".getBytes(StandardCharsets.US_ASCII))
+
+            DataOutputStream dos = new DataOutputStream(new GZIPOutputStream(os))
+            JsonOutput jsonOutput = new JsonOutput()
+            published.each {
+                int certificates = certificateManager.getByInfoHash(new InfoHash(it.getRoot())).size()
+                def obj = FeedItems.sharedFileToObj(it, certificates)
+                def json = jsonOutput.toJson(obj)
+                dos.writeShort((short)json.length())
+                dos.write(json.getBytes(StandardCharsets.US_ASCII))
+            }
+            dos.flush()
+            dos.close()
+        } finally {
+            e.close()
+        }
+    }
 
 }
diff --git a/core/src/main/groovy/com/muwire/core/filefeeds/FeedItems.groovy b/core/src/main/groovy/com/muwire/core/filefeeds/FeedItems.groovy
new file mode 100644
index 00000000..c2519aa6
--- /dev/null
+++ b/core/src/main/groovy/com/muwire/core/filefeeds/FeedItems.groovy
@@ -0,0 +1,28 @@
+package com.muwire.core.filefeeds
+
+import com.muwire.core.SharedFile
+import com.muwire.core.util.DataUtil
+
+import net.i2p.data.Base64
+
+class FeedItems {
+    
+    public static def sharedFileToObj(SharedFile sf, int certificates) {
+        def json = [:]
+        json.type = "FeedItem"
+        json.version = 1
+        json.name = Base64.encode(DataUtil.encodei18nString(sf.getFile().getName()))
+        json.infoHash = Base64.encode(sf.getRoot())
+        json.size = sf.getCachedLength()
+        json.pieceSize = sf.getPieceSize()
+        
+        if (sf.getComment() != null)
+            json.comment = sf.getComment()
+        
+        json.certificates = certificates
+        
+        json.timestamp = sf.getPublishedTimestamp()
+        
+        json
+    } 
+}
diff --git a/core/src/main/groovy/com/muwire/core/files/FileManager.groovy b/core/src/main/groovy/com/muwire/core/files/FileManager.groovy
index 16864be7..a130d336 100644
--- a/core/src/main/groovy/com/muwire/core/files/FileManager.groovy
+++ b/core/src/main/groovy/com/muwire/core/files/FileManager.groovy
@@ -1,5 +1,8 @@
 package com.muwire.core.files
 
+import java.util.stream.Collectors
+import java.util.stream.Stream
+
 import com.muwire.core.EventBus
 import com.muwire.core.InfoHash
 import com.muwire.core.MuWireSettings
@@ -254,4 +257,13 @@ class FileManager {
         settings.negativeFileTree.clear()
         settings.negativeFileTree.addAll(negativeTree.fileToNode.keySet().collect { it.getAbsolutePath() })
     }
+    
+    public List<SharedFile> getPublishedSince(long timestamp) {
+        synchronized(fileToSharedFile) {
+            fileToSharedFile.values().stream().
+                    filter({sf -> sf.isPublished()}).
+                    filter({sf -> sf.getPublishedTimestamp() >= timestamp}).
+                    collect(Collectors.toList())
+        }
+    }
 }