Slightly expand documentation and fix ChannelManager dependency within the PeerManager.

Author: arik-so

Documentation/ChannelManager.md

@@ -39,14 +39,36 @@ let feeEstimator = LDKFeeEstimator(
 
 ### ManyChannelMonitor ([Rust](https://docs.rs/lightning/0.0.11/lightning/ln/channelmonitor/trait.ManyChannelMonitor.html))
 
-The channel monitor is responsible for registering monitors for relevant on-chain events. For the
-sake of simplicity, however, we will initially rely on a placeholder instantiation using
+The channel monitor is responsible for registering monitors for relevant on-chain events. For now,
+in the interest of simplicity, we will simply stub out all the methods it supports without
+putting in actual processing. The following snippet of Swift could should give you an idea
+of what such a stub would look like:
 
 ```swift
-let channelMonitor = LDKManyChannelMonitor()
+func addMonitor(this_arg: UnsafeRawPointer?, funding_txo: LDKOutPoint, monitor: LDKChannelMonitor) -> LDKCResult_NoneChannelMonitorUpdateErrZ {
+    print("adding monitor")
+    return LDKCResult_NoneChannelMonitorUpdateErrZ()
+}
+
+func updateMonitor(this_arg: UnsafeRawPointer?, funding_txo: LDKOutPoint, update: LDKChannelMonitorUpdate) -> LDKCResult_NoneChannelMonitorUpdateErrZ {
+    print("updating monitor")
+    return LDKCResult_NoneChannelMonitorUpdateErrZ()
+}
+
+func clearPendingHTLCs(this_arg: UnsafeRawPointer?) -> LDKCVec_HTLCUpdateZ {
+    print("clearing pending HTLCs")
+    return LDKCVec_HTLCUpdateZ()
+}
+
+let manyChannelMonitor = LDKManyChannelMonitor(
+        this_arg: instance,
+        add_monitor: addMonitor,
+        update_monitor: updateMonitor,
+        get_and_clear_pending_htlcs_updated: clearPendingHTLCs
+)
 ``` 
 
-This will, however, be a **critical** component to update later on.
+The above example is, as of yet, stubbed out, but it will be a **critical** component to update later on.
 
 ### Broadcaster Interface ([Rust](https://docs.rs/lightning/0.0.11/lightning/chain/chaininterface/trait.BroadcasterInterface.html))
 

Documentation/Coordination.md

@@ -23,10 +23,22 @@ message handler, is responsible for peer-to-peer-communication. Even though it h
 involved prerequisites, it is the first Rust Lightning component most developers integrating
 the bindings will interact and experiment with.
 
+## Reference
+
+Should you feel the need for further, in-depth guidance, you might find a referential C++
+demo implementation to be very useful. As pointed out [earlier](GettingStarted.md#header-files),
+the demo file located in `lightning-c-bindings/demo.cpp` should be a very focused, 
+distilled no-nonsense example of getting the bindings working with the bare minimum of
+external dependencies.
+
 ## Next
 
 There are still aspects of the bindings this guide doesn't touch on yet, such as the proper
 instantiation of a [ManyChannelMonitor](https://docs.rs/lightning/0.0.11/lightning/ln/channelmonitor/trait.ManyChannelMonitor.html),
-custom key management and external signing, as well as user-triggered channel state updates.
+custom key management and external signing.
+
+We would like to touch on some user-triggered actions, such as showing a payment invoice 
+or calculating a payment route (likely based on the input of such an invoice), in this next
+section about [User Actions](UserActions.md).
 
-We hope to add those very soon!
+As to the other missing parts, we hope to add those very soon!

Documentation/GettingStarted.md

@@ -19,10 +19,18 @@ either C or C++ header files. The header files don't vary between architectures,
 convenience, they are already provided in the `include` subdirectory. (The full path from 
 the project root is thus `lightning-c-bindings/include`.)
 
-As we're primarily focused on the application in Swift, we cannot use C++ header files, so the
-only two files from that directory we need are `lightning.h` and `rust_types.h`.
-
-If you're working with C++, you will instead only need `lightning.hpp`.
+As we're primarily focused on the application in Swift, we cannot use C++ header files due to
+the environment constraints set by Apple, so the only two files from that directory that
+we will need are `lightning.h` and `rust_types.h`.
+
+Nonetheless, we do strongly encourage working with the C++ bindings if your environment supports
+it, given the plethora of "free" benefits that provides, such as memory deallocation, as well
+as the convenience of instance methods. If you do end up working with C++, 
+you will only need `lightning.hpp` for the header reference.
+
+One additional benefit of C++ is the reference demo file, located at 
+`lightning-c-bindings/demo.cpp`, which should prove a handy guide as you navigate your way
+through building support in a new environment.
 
 ## Compilation
 

Documentation/README.md

@@ -4,6 +4,10 @@ This guide aims to give the reader an overview of the structure of Rust Lightnin
 as well as a reference for integrating the exported bindings in an object-oriented language using
 Swift as the example.
 
+If you are here, we sincerely wish to thank you for working on expanding the Lightning
+Development Kit's scope to yet another, new, environment. We hope that this guide makes that
+task easier, and removes unnecessary roadblocks.
+
 ## Architecture
 
 To run a Lightning node, there are several fundamental components that need setting up.
@@ -37,7 +41,7 @@ implementing the [ChainWatchInterface](https://docs.rs/lightning/0.0.11/lightnin
 trait, which would allow Rust Lightning to tell us when new transactions or outpoints become
 relevant and should be watched for on-chain.
 
-An alternatively, for the developer slightly more naïve approach, is relying on the 
+An alternative approach, one that is slightly more naïve from a developer's perspective, is relying on the 
 [BlockNotifier](https://docs.rs/lightning/0.0.11/lightning/chain/chaininterface/struct.BlockNotifier.html)
 struct, which will let us feed raw block data to it and simply keep track of reorgs to deregister
 or unconfirm blocks if need be.
@@ -74,4 +78,5 @@ in this document.
     * [PeerManager](PeerManager.md)
     * [ChannelManager](ChannelManager.md)
     * [BlockNotifier](BlockNotifier.md)
-* [Coordination](Coordination.md)
+* [Coordination](Coordination.md)
+* [User Actions](UserActions.md)

Documentation/UserActions.md

@@ -0,0 +1,13 @@
+# User Actions
+
+## Invoices
+
+// TODO
+
+### Generate a payment invoice
+
+### Parse a payment invoice
+
+## Route Calculation
+
+// In progress; Arik is experimenting with the freshly exposed code.

Swift Rust FFI.xcodeproj/project.pbxproj

@@ -43,6 +43,7 @@
 		2DD11E177CCCC9E9C4D3E949 /* Coordination.md in Sources */ = {isa = PBXBuildFile; fileRef = 2DD11896B49A9872990F4B75 /* Coordination.md */; };
 		2DD11E554B923CFD2ACC66B5 /* BlockListener.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2DD1114BCCB63083A0C97DB6 /* BlockListener.swift */; };
 		2DD11E689A19E6FE3660C28D /* CustomPeer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2DD11A892D5A07AE47006E98 /* CustomPeer.swift */; };
+		2DD11F50EF7D9C09EF5A869B /* UserActions.md in Sources */ = {isa = PBXBuildFile; fileRef = 2DD112313DB3181E0851EE46 /* UserActions.md */; };
 		2DD11FD9D863B2994D8DF3CB /* ChannelManager.md in Sources */ = {isa = PBXBuildFile; fileRef = 2DD11A364D265C16AF639C21 /* ChannelManager.md */; };
 		9CC87346C07A1FC6013EC06F /* Pods_Swift_Rust_FFI.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 769F94D0AF02F1B815B4006B /* Pods_Swift_Rust_FFI.framework */; };
 		EC130784C3A8F72C6D855FA3 /* Pods_Swift_Rust_FFI_Swift_Rust_FFITests.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 691A071346B646857399E1A1 /* Pods_Swift_Rust_FFI_Swift_Rust_FFITests.framework */; };
@@ -84,6 +85,7 @@
 		2DD11071A3A772E151D7B6A1 /* BlockNotifier.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = BlockNotifier.md; sourceTree = "<group>"; };
 		2DD110AA3B0A133662005BE6 /* rust_types.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = rust_types.h; sourceTree = "<group>"; };
 		2DD1114BCCB63083A0C97DB6 /* BlockListener.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BlockListener.swift; sourceTree = "<group>"; };
+		2DD112313DB3181E0851EE46 /* UserActions.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = UserActions.md; sourceTree = "<group>"; };
 		2DD112BDA8EA0262BDA4744C /* BlockchainMonitor.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BlockchainMonitor.swift; sourceTree = "<group>"; };
 		2DD1133AED83E5E97DBC455F /* Primitives.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = Primitives.md; sourceTree = "<group>"; };
 		2DD11372CB28789C64A0F55F /* BlockNotifierBasedBlockListener.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BlockNotifierBasedBlockListener.swift; sourceTree = "<group>"; };
@@ -242,6 +244,7 @@
 				2DD11A364D265C16AF639C21 /* ChannelManager.md */,
 				2DD11896B49A9872990F4B75 /* Coordination.md */,
 				2DD11071A3A772E151D7B6A1 /* BlockNotifier.md */,
+				2DD112313DB3181E0851EE46 /* UserActions.md */,
 			);
 			path = Documentation;
 			sourceTree = "<group>";
@@ -470,6 +473,7 @@
 				2DD11FD9D863B2994D8DF3CB /* ChannelManager.md in Sources */,
 				2DD11E177CCCC9E9C4D3E949 /* Coordination.md in Sources */,
 				2DD110E9D0F00206FA1686B4 /* BlockNotifier.md in Sources */,
+				2DD11F50EF7D9C09EF5A869B /* UserActions.md in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Swift Rust FFI/Demonstration.swift

@@ -17,58 +17,65 @@ class Demonstration {
     public static var peer: Peer?
     static var channelManager: ChannelManager?
 
-    static func setupPeerManager() {
+    static func setupPeerManager() -> Promise<Void> {
 
         let privateKey = Data.init(base64Encoded: "ERERERERERERERERERERERERERERERERERERERERERE=")!;
         let ephemeralPrivateKey = Data.init(base64Encoded: "EhISEhISEhISEhISEhISEhISEhISEhISEhISEhISEhI=")!;
         let remotePublicKey = Data.init(base64Encoded: "Ao11AN1MEmhdH1aLTCtQSOhTS4czGfOo2qYStGkTLsf3")!;
         let alexPublicKey = Data.init(base64Encoded: "AnRVrvhFPZL0cGtWC2FSfMIX3fFNpBdw6O1mBxkKGFG4")!;
         let localPublicKey = Data.init(base64Encoded: "Ai/bcTpKVRYmMWTmDDLOvG9MrW5v7xRNY5vXzcsLIPZZ")!;
 
-        let peerManager = PeerManager(privateKey: privateKey, ephemeralSeed: ephemeralPrivateKey)
+        return self.setupChannelManager().done { manager in
+            let peerManager = PeerManager(privateKey: privateKey, ephemeralSeed: ephemeralPrivateKey, channelManager: manager.cChannelManager!)
 
 
-        // set up block listener
-        let chainWatchInterface = peerManager.routingMessageHandler!.cChainWatchInterface
-        let blockListener = BlockNotifierBasedBlockListener(chainWatchInterface: chainWatchInterface)
+            // set up block listener
+            let chainWatchInterface = peerManager.routingMessageHandler!.cChainWatchInterface
+            let blockListener = BlockNotifierBasedBlockListener(chainWatchInterface: chainWatchInterface)
 
-        // set up chain monitor
-        let chainMonitor = BlockchainMonitor()
-        chainMonitor.listener = blockListener // connect the two
-        chainMonitor.monitor() // off we go
+            // set up chain monitor
+            let chainMonitor = BlockchainMonitor()
+            chainMonitor.listener = blockListener // connect the two
+            chainMonitor.monitor() // off we go
 
-        /*
-        // a connection to be discarded
-        peerManager.initiateOutboundConnection(remotePublicKey: remotePublicKey)
+            /*
+            // a connection to be discarded
+            peerManager.initiateOutboundConnection(remotePublicKey: remotePublicKey)
 
-        // a custom peer to be discarded
-        print("Creating Google Peer")
-        let googleClient = TCPClient(address: "google.com", port: 443)
-        let fakePeer = CustomPeer(tcpClient: googleClient)
-        fakePeer.name = "Google"
-        */
+            // a custom peer to be discarded
+            print("Creating Google Peer")
+            let googleClient = TCPClient(address: "google.com", port: 443)
+            let fakePeer = CustomPeer(tcpClient: googleClient)
+            fakePeer.name = "Google"
+            */
 
 
-        print("Creating Alex Bosworth peer")
-        let tcpClient = TCPClient(address: "testnet-lnd.yalls.org", port: 9735)
-        let peer = CustomPeer(tcpClient: tcpClient)
-        peer.name = "Alex"
-        peer.publicKey = alexPublicKey
+            print("Creating Alex Bosworth peer")
+            let tcpClient = TCPClient(address: "testnet-lnd.yalls.org", port: 9735)
+            let peer = CustomPeer(tcpClient: tcpClient)
+            peer.name = "Alex"
+            peer.publicKey = alexPublicKey
 
-        // print("Creating local peer")
-        // let tcpClient = TCPClient(address: "127.0.0.1", port: 1337)
-        // let peer = CustomPeer(tcpClient: tcpClient)
-        // peer.name = "Local"
+            // print("Creating local peer")
+            // let tcpClient = TCPClient(address: "127.0.0.1", port: 1337)
+            // let peer = CustomPeer(tcpClient: tcpClient)
+            // peer.name = "Local"
 
-        self.peer = peer;
-        peerManager.initiateOutboundConnection(remotePublicKey: alexPublicKey, peer: peer)
+            self.peer = peer;
+            peerManager.initiateOutboundConnection(remotePublicKey: alexPublicKey, peer: peer)
+
+        }
     }
 
     enum BlockchainFetchError: Error {
         case didntWork
     }
 
     static func setupChannelManager() -> Promise<ChannelManager> {
+        if let channelManager = self.channelManager {
+            return Promise.value(channelManager)
+        }
+
         let heightPromise = Promise { (resolver: Resolver<UInt>) in
             let latestBlockUrl = "https://test.bitgo.com/api/v2/tbtc/public/block/latest"
             AF.request(latestBlockUrl).responseJSON { response in
@@ -96,6 +103,7 @@ class Demonstration {
             let logger = Logger()
             print("Instantiating Swift ChannelManager")
             let manager = ChannelManager(privateKey: privateKey, logger: logger, currentBlockchainHeight: height)
+            self.channelManager = manager
             return manager
         }
     }

Swift Rust FFI/LDK/ChannelManager.swift

@@ -8,7 +8,7 @@ import PromiseKit
 
 class ChannelManager {
 
-    private var cChannelManager: LDKChannelManager?
+    var cChannelManager: LDKChannelManager?
     // private var inMemoryChannelKeys: LDKInMemoryChannelKeys?
 
     private var keyDerivationParamA: UInt64 = 0

Swift Rust FFI/LDK/PeerManager.swift

@@ -19,9 +19,11 @@ class PeerManager {
 
     private var tickPromise: Guarantee<Void>?
 
+    private var peerCount: UInt = 0
+
     // private var cSecretKey: LDKSecretKey;
 
-    init(privateKey: Data, ephemeralSeed: Data) {
+    init(privateKey: Data, ephemeralSeed: Data, channelManager: LDKChannelManager) {
         // let privateKeyPointer = RawLDKTypes.dataToPointer(data: privateKey)
         // let ephemeralSeedPointer = RawLDKTypes.dataToPointer(data: ephemeralSeed)
         // self.cPeerManager = peer_manager_create(privateKeyPointer, ephemeralSeedPointer)
@@ -33,6 +35,10 @@ class PeerManager {
         self.logger = Logger()
 
         self.channelMessageHandler = ChannelMessageHandler()
+        let channelManagerPointer = withUnsafePointer(to: channelManager) { (pointer: UnsafePointer<LDKChannelManager>) in
+            pointer
+        }
+        let channelMessageHandler = ChannelManager_as_ChannelMessageHandler(channelManagerPointer)
         self.routingMessageHandler = RoutingMessageHandler(logger: self.logger!)
 
         // let chainWatchInterface = ChainWatchInterfaceUtil_new(LDKNetwork_Testnet)
@@ -42,7 +48,8 @@ class PeerManager {
         // let blockNotifier = BlockNotifier_new(ChainWatchInterfaceUtil_as_ChainWatchInterface(chainWatchInterfacePointer))
 
 
-        let messageHandler = MessageHandler_new(self.channelMessageHandler!.cMessageHandler!, routingMessageHandler!.cRoutingMessageHandler!)
+        let messageHandler = MessageHandler_new(channelMessageHandler, routingMessageHandler!.cRoutingMessageHandler!)
+        // let messageHandler = MessageHandler_new(self.channelMessageHandler!.cMessageHandler!, routingMessageHandler!.cRoutingMessageHandler!)
 
 
         let ourNodeSecret = LDKSecretKey(bytes: privateKeyBytes);
@@ -57,13 +64,44 @@ class PeerManager {
         // DispatchQueue.global(qos: .background).async {
         //     self.forceTick()
         // }
+
+        self.monitorPeerCount();
+
     }
 
     public func singleTick() {
         // TODO: fix
         // peer_force_tick(self.cPeerManager);
     }
 
+    private func monitorPeerCount() {
+        let peerManagerPointer = withUnsafePointer(to: self.cPeerManager) { pointer in
+            pointer
+        }
+        let peers: LDKCVecTempl_PublicKey = PeerManager_get_peer_node_ids(peerManagerPointer);
+        let peerCount = peers.datalen;
+        if (peerCount > self.peerCount) {
+            self.peerConnected()
+        }
+
+        let backgroundQueue = DispatchQueue.global(qos: .background);
+
+        Promise<Void> { seal in
+            self.peerCount = peerCount;
+            seal.fulfill(())
+        }.then(on: backgroundQueue) {
+            after(seconds: 1) // wait five seconds
+        }.done {
+            self.monitorPeerCount()
+        }
+    }
+
+    private func peerConnected() {
+        Demonstration.contentView?.isConnecting = false
+        Demonstration.contentView?.isConnected = true
+        Demonstration.logInUI(message: "Peer connected")
+    }
+
     private func forceTick() -> Guarantee<Void> {
 
         guard let promise = self.tickPromise else {