Read from repository configs instead of hardcoding repos/arch for update

Sources/dpk-cli/RepositoriesConfig.swift

@@ -0,0 +1,47 @@
+/*
+ * darwin-apk © 2024 Gay Pizza Specifications
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import Foundation
+import ArgumentParser
+import darwin_apk
+
+struct RepositoriesConfig {
+  let repositories: [ApkIndexRepository]
+
+  init() async throws(ExitCode) {
+    let repositories: [String], architectures: [String]
+    do {
+      repositories = try await Self.read(name: "repositories")
+    } catch {
+      print("Failed to read repositories: \(error.localizedDescription)")
+      throw .failure
+    }
+    do {
+      architectures = try await Self.read(name: "arch")
+    } catch {
+      print("Failed to read arch: \(error.localizedDescription)")
+      throw .failure
+    }
+
+    self.repositories = repositories.flatMap { repo in
+      architectures.map { arch in
+        ApkIndexRepository(name: repo, arch: arch)
+      }
+    }
+  }
+
+  var localRepositories: [URL] {
+    self.repositories.map { repo in
+      URL(filePath: repo.localName, directoryHint: .notDirectory)
+    }
+  }
+
+  private static func read(name: String) async throws -> [String] {
+    try await URL(filePath: name, directoryHint: .notDirectory).lines
+      .map { $0.trimmingCharacters(in: .whitespaces) }
+      .filter { !$0.isEmpty && $0.first != "#" }  // Ignore empty & commented lines
+      .reduce(into: [String]()) { $0.append($1) }
+  }
+}