feat: first working version

LICENSE

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (c) 2022 cnixbtc 
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

Package.resolved

@@ -0,0 +1,41 @@
+{
+  "pins" : [
+    {
+      "identity" : "secp256k1.swift",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/GigaBitcoin/secp256k1.swift.git",
+      "state" : {
+        "revision" : "b80388789a8058fc99202436225f8f15d35dfbea",
+        "version" : "0.8.1"
+      }
+    },
+    {
+      "identity" : "starscream",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/daltoniam/Starscream",
+      "state" : {
+        "revision" : "e6b65c6d9077ea48b4a7bdda8994a1d3c6969c8d",
+        "version" : "3.1.1"
+      }
+    },
+    {
+      "identity" : "swift-crypto",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-crypto.git",
+      "state" : {
+        "revision" : "d9825fa541df64b1a7b182178d61b9a82730d01f",
+        "version" : "2.1.0"
+      }
+    },
+    {
+      "identity" : "swift-nio-zlib-support",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-nio-zlib-support.git",
+      "state" : {
+        "revision" : "37760e9a52030bb9011972c5213c3350fa9d41fd",
+        "version" : "1.0.0"
+      }
+    }
+  ],
+  "version" : 2
+}

Package.swift

@@ -4,14 +4,35 @@ import PackageDescription
 
 let package = Package(
     name: "NostrKit",
+    platforms: [
+        .macOS(.v11),
+    ],
     products: [
         .library(name: "NostrKit", targets: ["NostrKit"]),
-        .executable(name: "example", targets: ["Example"]),
+        .executable(name: "example-reader", targets: ["ExampleReader"]),
+        .executable(name: "example-writer", targets: ["ExampleWriter"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/GigaBitcoin/secp256k1.swift", exact: .init(stringLiteral: "0.8.1")),
+        .package(url: "https://github.com/apple/swift-crypto.git", exact: .init(stringLiteral: "2.1.0")),
+        .package(url: "https://github.com/daltoniam/Starscream", exact: .init(stringLiteral: "3.1.1")),
     ],
-    dependencies: [],
     targets: [
-        .target(name: "NostrKit", dependencies: []),
-        .testTarget(name: "NostrKitTests", dependencies: ["NostrKit"]),
-        .executableTarget(name: "Example", dependencies: ["NostrKit"]),
+        .target(name: "NostrKit", dependencies: [
+            .product(name: "secp256k1", package: "secp256k1.swift"),
+            .product(name: "Crypto", package: "swift-crypto"),
+            .product(name: "Starscream", package: "Starscream"),
+        ]),
+        .testTarget(name: "NostrKitTests", dependencies: [
+            .target(name: "NostrKit"),
+        ]),
+        .executableTarget(name: "ExampleReader", dependencies: [
+            .target(name: "NostrKit"),
+            .product(name: "Starscream", package: "Starscream"),
+        ]),
+        .executableTarget(name: "ExampleWriter", dependencies: [
+            .target(name: "NostrKit"),
+            .product(name: "Starscream", package: "Starscream"),
+        ]),
     ]
 )

README.md

@@ -1 +1,49 @@
-# NostrKit
+# NostrKit 
+
+A Swift library for interacting with a [Nostr](https://github.com/nostr-protocol/nostr) relay.
+
+## Installation
+
+NostrKit is available as a [Swift Package Manager](https://swift.org/package-manager/) package.
+To use it, add the following dependency to your `Package.swift` file:
+
+``` swift
+.package(url: "https://github.com/cnixbtc/NostrKit.git", from: "0.1.0"),
+```
+
+## Functionality
+
+NostrKit can be used to publish events on a Nostr relay as well as request events and subscribe to new updates.
+
+### Subscribing to Events
+
+``` swift
+let keyPair = try KeyPair(privateKey: "<hex>")
+let relay = Relay(url: URL("<url>")!, onEvent: { print($0) })
+
+let subscription = Subscription(filters: [
+    .init(authors: [keyPair.publicKey])
+])
+
+try await relay.connect()
+try await relay.subscribe(to: subscription)
+
+// later on...
+
+try await relay.unsubscribe(from: subscription.id)
+```
+
+### Publishing Events
+
+``` swift
+let keyPair = try KeyPair(privateKey: "<hex>")
+let relay = Relay(url: URL("<url>")!)
+
+let event = try Event(keyPair: keyPair, content: "Hello NostrKit.")
+
+try await relay.connect()
+try await relay.send(event: event)
+```
+
+Fully functional code examples can be found in `Sources/ExampleReader` as well as `Sources/ExampleWriter`.
+Run `swift run example-reader` and `swift run example-writer` to see them in action.

Sources/ExampleReader/main.swift

@@ -0,0 +1,30 @@
+import Foundation
+import Starscream
+import NostrKit
+
+// See the `docker/` directory in the project root for a local relay to use in development and testing.
+let relayUrl = URL(string: "http://localhost:8080")!
+
+// This is just a dummy key pair. Don't use it like this in production.
+let keyPair = try KeyPair(privateKey: "df9aae2ac8233ffa210a086c54059d02ba3247dab1130dad968f28f036326a83")
+
+let relay = Relay(url: relayUrl, onEvent: { message in
+    print(message)
+})
+
+let subscription = Subscription(filters: [
+    .init(authors: [keyPair.publicKey])
+])
+
+Task {
+    do {
+        try await relay.connect()
+        try await relay.subscribe(to: subscription)
+    } catch {
+        print("Something went wrong: \(error)")
+
+        exit(EXIT_FAILURE)
+    }
+}
+
+RunLoop.current.run()

Sources/ExampleWriter/main.swift

@@ -0,0 +1,28 @@
+import Foundation
+import Starscream
+import NostrKit
+
+// See the `docker/` directory in the project root for a local relay to use in development and testing.
+let relayUrl = URL(string: "http://localhost:8080")!
+
+// This is just a dummy key pair. Don't use it like this in production.
+let keyPair = try KeyPair(privateKey: "df9aae2ac8233ffa210a086c54059d02ba3247dab1130dad968f28f036326a83")
+
+let relay = Relay(url: relayUrl)
+
+let event = try Event(keyPair: keyPair, content: "Hello NostrKit.")
+
+Task {
+    do {
+        try await relay.connect()
+        try await relay.send(event: event)
+
+        exit(EXIT_SUCCESS)
+    } catch {
+        print("Something went wrong: \(error)")
+
+        exit(EXIT_FAILURE)
+    }
+}
+
+RunLoop.current.run()

Sources/NostrKit/ClientMessage.swift

@@ -0,0 +1,29 @@
+import Foundation
+
+enum ClientMessage: Encodable {
+    case event(Event)
+    case subscribe(Subscription)
+    case unsubscribe(SubscriptionId)
+
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.unkeyedContainer()
+
+        switch self {
+        case .event(let event):
+            try container.encode("EVENT")
+            try container.encode(event)
+        case .subscribe(let subscription):
+            try container.encode("REQ")
+            try container.encode(subscription.id)
+            try subscription.filters.forEach { try container.encode($0) }
+        case .unsubscribe(let subscriptionId):
+            try container.encode("CLOSE")
+            try container.encode(subscriptionId)
+        }
+    }
+
+    func string() throws -> String {
+        return String(data: try JSONEncoder().encode(self), encoding: .utf8)!
+    }
+}
+

Sources/NostrKit/DataExtensions.swift

@@ -0,0 +1,40 @@
+import Foundation
+
+private extension Collection {
+    func unfoldSubSequences(ofMaxLength maxSequenceLength: Int) -> UnfoldSequence<SubSequence, Index> {
+        sequence(state: startIndex) { current in
+            guard current < endIndex else { return nil }
+
+            let upperBound = index(current, offsetBy: maxSequenceLength, limitedBy: endIndex) ?? endIndex
+            defer { current = upperBound }
+
+            return self[current..<upperBound]
+        }
+    }
+}
+
+extension Data {
+    enum DecodingError: Error {
+        case oddNumberOfCharacters
+        case invalidHexCharacters([Character])
+    }
+
+    func hex() -> String {
+        return self.map { String(format: "%02hhx", $0) }.joined()
+    }
+
+    init(hex: String) throws {
+        guard hex.count.isMultiple(of: 2) else { throw DecodingError.oddNumberOfCharacters }
+
+        self = .init(capacity: hex.utf8.count / 2)
+
+        for pair in hex.unfoldSubSequences(ofMaxLength: 2) {
+            guard let byte = UInt8(pair, radix: 16) else {
+                let invalidCharacters = Array(pair.filter({ !$0.isHexDigit }))
+                throw DecodingError.invalidHexCharacters(invalidCharacters)
+            }
+
+            append(byte)
+        }
+    }
+}