From 0ac28bca0dd32b4f2ae20f340074591191b53fa4 Mon Sep 17 00:00:00 2001
From: Kabir Oberai <oberai.kabir@gmail.com>
Date: Thu, 12 Dec 2024 23:19:02 +0530
Subject: [PATCH] SDK commands

---
 Package.swift                                 |   4 +-
 Sources/SupersignCLISupport/DevCommand.swift  |  19 +-
 .../SupersignCLISupport/DevSDKCommand.swift   | 239 ++++++++++++++++++
 3 files changed, 243 insertions(+), 19 deletions(-)
 create mode 100644 Sources/SupersignCLISupport/DevSDKCommand.swift

diff --git a/Package.swift b/Package.swift
index dbe6bd5..6f8e7ed 100644
--- a/Package.swift
+++ b/Package.swift
@@ -46,6 +46,7 @@ let package = Package(
         .package(url: "https://github.com/pointfreeco/swift-concurrency-extras", from: "1.3.0"),
 
         .package(url: "https://github.com/attaswift/BigInt", from: "5.5.0"),
+        .package(url: "https://github.com/mxcl/Version", from: "2.1.0"),
     ],
     targets: [
         .systemLibrary(name: "CSupersette"),
@@ -118,7 +119,8 @@ let package = Package(
                 "SwiftyMobileDevice",
                 "Supersign",
                 .product(name: "PackLib", package: "swiftpack"),
-                .product(name: "ArgumentParser", package: "swift-argument-parser")
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+                .product(name: "Version", package: "Version"),
             ],
             cSettings: cSettings
         ),
diff --git a/Sources/SupersignCLISupport/DevCommand.swift b/Sources/SupersignCLISupport/DevCommand.swift
index 8e3f427..e6a50b1 100644
--- a/Sources/SupersignCLISupport/DevCommand.swift
+++ b/Sources/SupersignCLISupport/DevCommand.swift
@@ -3,12 +3,6 @@ import ArgumentParser
 import PackLib
 import Supersign
 
-struct AddSDKOperation {
-    func run() async throws {
-        print("TODO: install Swift SDK for iOS")
-    }
-}
-
 struct DevSetupCommand: AsyncParsableCommand {
     static let configuration = CommandConfiguration(
         commandName: "setup",
@@ -22,18 +16,7 @@ struct DevSetupCommand: AsyncParsableCommand {
 
     func run() async throws {
         try await AuthOperation(logoutFromExisting: false).run()
-        try await AddSDKOperation().run()
-    }
-}
-
-struct DevSDKCommand: AsyncParsableCommand {
-    static let configuration = CommandConfiguration(
-        commandName: "sdk",
-        abstract: "Manages the Swift SDK for iOS"
-    )
-
-    func run() async throws {
-        try await AddSDKOperation().run()
+        try await InstallSDKOperation().run()
     }
 }
 
diff --git a/Sources/SupersignCLISupport/DevSDKCommand.swift b/Sources/SupersignCLISupport/DevSDKCommand.swift
new file mode 100644
index 0000000..53378c6
--- /dev/null
+++ b/Sources/SupersignCLISupport/DevSDKCommand.swift
@@ -0,0 +1,239 @@
+import Foundation
+import Supersign
+import Version
+import ArgumentParser
+#if os(Linux)
+import FoundationNetworking
+#endif
+
+struct DevSDKCommand: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "sdk",
+        abstract: "Manages the Darwin Swift SDK",
+        subcommands: [
+            DevSDKInstallCommand.self,
+            DevSDKRemoveCommand.self,
+        ],
+        defaultSubcommand: DevSDKInstallCommand.self
+    )
+}
+
+struct DevSDKInstallCommand: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "install",
+        abstract: "Install the Darwin Swift SDK"
+    )
+
+    func run() async throws {
+        try await InstallSDKOperation().run()
+    }
+}
+
+struct DevSDKRemoveCommand: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "remove",
+        abstract: "Remove the Darwin Swift SDK"
+    )
+
+    func run() async throws {
+        guard let sdk = try DarwinSDK.current() else {
+            throw Console.Error("Cannot remove SDK: no Darwin SDK installed")
+        }
+        try FileManager.default.removeItem(at: sdk.bundle)
+        print("Uninstalled SDK")
+    }
+}
+
+struct DarwinSDKVersions: Decodable {
+    private static let url = URL(string: """
+    https://raw.githubusercontent.com/kabiroberai/swift-sdk-darwin/refs/heads/main/versions.json
+    """)!
+
+    private static let decoder = JSONDecoder()
+
+    struct Metadata: Decodable {
+        var arm64Checksum: String
+        var x64Checksum: String
+        var compilerRange: [String]
+
+        func checksum(for arch: SDKArch) -> String {
+            switch arch {
+            case .arm64: return arm64Checksum
+            case .x86_64: return x64Checksum
+            }
+        }
+
+        var versionRange: Range<Version> {
+            get throws {
+                guard compilerRange.count == 2,
+                      let lower = Version(tolerant: compilerRange[0]),
+                      let upper = Version(tolerant: compilerRange[1]) else {
+                    throw Console.Error("Could not parse SDK metadata list. You may need to update Supersign.")
+                }
+                return lower..<upper
+            }
+        }
+    }
+    var current: String
+    var metadata: [String: Metadata]
+
+    static func all(
+        httpFactory: HTTPClientFactory = defaultHTTPClientFactory
+    ) async throws -> DarwinSDKVersions {
+        let data = try await httpFactory.makeClient().makeRequest(HTTPRequest(url: url)).body ?? Data()
+        return try decoder.decode(self, from: data)
+    }
+}
+
+struct DarwinSDK {
+    private static let sdksDir = URL(fileURLWithPath: NSHomeDirectory())
+        .appendingPathComponent(".swiftpm/swift-sdks")
+        .resolvingSymlinksInPath()
+
+    let bundle: URL
+    let version: String
+
+    init?(bundle: URL) {
+        self.bundle = bundle
+        if let version = try? Data(contentsOf: bundle.appendingPathComponent("darwin-sdk-version.txt")) {
+            self.version = String(decoding: version, as: UTF8.self)
+                .trimmingCharacters(in: .whitespacesAndNewlines)
+        } else if bundle.lastPathComponent == "darwin.artifactbundle" {
+            self.version = "unknown"
+        } else {
+            return nil
+        }
+    }
+
+    static func current() throws -> DarwinSDK? {
+        let sdks = (try? FileManager.default.contentsOfDirectory(at: sdksDir, includingPropertiesForKeys: nil)) ?? []
+        let darwinSDKs = sdks.compactMap { DarwinSDK(bundle: $0) }
+        switch darwinSDKs.count {
+        case 0:
+            return nil
+        case 1:
+            return darwinSDKs[0]
+        default:
+            throw Console.Error("""
+            You have multiple copies of the Darwin SDK installed. Please delete all but one to continue.
+            \(darwinSDKs.map { "- \($0.bundle.path) (version '\($0.version)')" }.joined(separator: "\n"))
+            """)
+        }
+    }
+}
+
+enum SDKArch {
+    case arm64
+    case x86_64
+
+    var releaseName: String {
+        switch self {
+        case .arm64: "aarch64"
+        case .x86_64: "x86_64"
+        }
+    }
+
+    static var current: SDKArch {
+        get throws {
+            #if arch(arm64)
+            return .arm64
+            #elseif arch(x86_64)
+            return .x86_64
+            #else
+            throw Console.Error("Unsupported architecture: the Swift SDK supports aarch64 and x86_64.")
+            #endif
+        }
+    }
+}
+
+private enum SwiftVersion {}
+extension SwiftVersion {
+    static func current() async throws -> Version {
+        let outPipe = Pipe()
+        let errPipe = Pipe()
+        let swift = Process()
+        swift.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+        swift.arguments = ["swift", "--version"]
+        swift.standardOutput = outPipe
+        swift.standardError = errPipe
+        try swift.run()
+        async let outputTask = outPipe.fileHandleForReading.readToEnd()
+        await swift.waitForExit()
+        guard swift.terminationStatus == 0 else {
+            throw Console.Error("Failed to obtain Swift version")
+        }
+        let outputData = try await outputTask
+        var output = String(decoding: outputData ?? Data(), as: UTF8.self)[...]
+        if output.hasPrefix("Apple ") {
+            output = output.dropFirst("Apple ".count)
+        }
+        guard output.hasPrefix("Swift version ") else {
+            throw Console.Error("Could not parse Swift version: '\(output)'")
+        }
+        output = output.dropFirst("Swift version ".count)
+        guard let space = output.firstIndex(of: " ") else {
+            throw Console.Error("Could not parse Swift version: '\(output)'")
+        }
+        output = output[..<space]
+        guard let version = Version(tolerant: output) else {
+            throw Console.Error("Could not parse Swift version: '\(output)'")
+        }
+        return version
+    }
+}
+
+struct InstallSDKOperation {
+    func run() async throws {
+        #if os(macOS) && false
+        print("Skipping SDK install; the iOS SDK ships with Xcode on macOS")
+        #else
+        let arch = try SDKArch.current
+
+        let list = try await DarwinSDKVersions.all()
+        guard let item = list.metadata[list.current] else {
+            throw Console.Error("""
+            Couldn't find SDK metadata for '\(list.current)'. You may need to update Supersign.
+            """)
+        }
+        let acceptedRange = try item.versionRange
+        let swiftVersion = try await SwiftVersion.current()
+
+        guard acceptedRange.contains(swiftVersion) else {
+            throw Console.Error("""
+            You currently have Swift version \(swiftVersion) installed. \
+            The Darwin Swift SDK currently requires Swift ≥\(acceptedRange.lowerBound), \
+            <\(acceptedRange.upperBound).
+            """)
+        }
+
+        if let sdk = try DarwinSDK.current() {
+            let installed = sdk.version
+            if list.current != installed {
+                print("Installed Darwin SDK version is '\(installed)' but latest is '\(list.current)'. Updating...")
+                try FileManager.default.removeItem(at: sdk.bundle)
+            } else {
+                print("Darwin SDK is up to date.")
+                return
+            }
+        } else {
+            print("Darwin Swift SDK not found on disk. Installing...")
+        }
+
+        let install = Process()
+        install.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+        install.arguments = [
+            "swift", "sdk", "install",
+            """
+            https://github.com/kabiroberai/swift-sdk-darwin/releases/download/\(list.current)/\
+            darwin-linux-\(arch.releaseName).artifactbundle.zip
+            """,
+            "--checksum", item.checksum(for: arch)
+        ]
+        try install.run()
+        await install.waitForExit()
+        guard install.terminationStatus == 0 else {
+            throw Console.Error("Failed to install SDK")
+        }
+        #endif
+    }
+}