From 710f0970c51037799b5bb51dc1ed7d07aa38c695 Mon Sep 17 00:00:00 2001
From: a dinosaur <dino@a-dinosaur.com>
Date: Sun, 6 Jul 2025 18:32:15 +1000
Subject: [PATCH] Add requirement-based resolution to index

---
 Sources/apk/Index/ApkIndex.swift              | 13 ++++++
 .../apk/Version/ApkVersionRequirement.swift   |  4 +-
 .../apk/Version/ApkVersionSpecification.swift | 45 +++++++++++++++++++
 Tests/darwin-apk-tests/ApkVersionTests.swift  | 13 ++++++
 4 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/Sources/apk/Index/ApkIndex.swift b/Sources/apk/Index/ApkIndex.swift
index f7e9a19..d3ad40f 100644
--- a/Sources/apk/Index/ApkIndex.swift
+++ b/Sources/apk/Index/ApkIndex.swift
@@ -7,6 +7,7 @@ import Foundation
 
 public struct ApkIndex: Sendable {
   public let packages: [ApkIndexPackage]
+  public typealias Index = Array<ApkIndexPackage>.Index
 }
 
 public extension ApkIndex {
@@ -21,6 +22,18 @@ public extension ApkIndex {
       $0.name == name
     }
   }
+
+  func resolve(requirement: ApkVersionRequirement) -> ApkIndexPackage? {
+    self.packages.first {
+      $0.name == requirement.name && requirement.versionSpec.satisfied(by: $0.version)
+    }
+  }
+
+  func resolveIndex(requirement: ApkVersionRequirement) -> Index? {
+    self.packages.firstIndex {
+      $0.name == requirement.name && requirement.versionSpec.satisfied(by: $0.version)
+    }
+  }
 }
 
 public extension ApkIndex {
diff --git a/Sources/apk/Version/ApkVersionRequirement.swift b/Sources/apk/Version/ApkVersionRequirement.swift
index aaab99b..bc411f7 100644
--- a/Sources/apk/Version/ApkVersionRequirement.swift
+++ b/Sources/apk/Version/ApkVersionRequirement.swift
@@ -5,7 +5,7 @@
 
 import Foundation
 
-internal struct ApkVersionRequirement: Sendable, Hashable {
+public struct ApkVersionRequirement: Sendable, Hashable {
   let name: String
   let versionSpec: ApkVersionSpecification
 
@@ -49,7 +49,7 @@ internal struct ApkVersionRequirement: Sendable, Hashable {
 }
 
 extension ApkVersionRequirement: CustomStringConvertible {
-  var description: String {
+  public var description: String {
     switch self.versionSpec {
     case .any(let invert):
       "\(invert ? "!" : "")\(self.name)"
diff --git a/Sources/apk/Version/ApkVersionSpecification.swift b/Sources/apk/Version/ApkVersionSpecification.swift
index eae3b55..bac67cd 100644
--- a/Sources/apk/Version/ApkVersionSpecification.swift
+++ b/Sources/apk/Version/ApkVersionSpecification.swift
@@ -30,6 +30,51 @@ internal extension ApkVersionSpecification {
       return false
     }
   }
+
+  func satisfied(by version: String) -> Bool {
+    switch self {
+    case .any:
+      //return true
+      return ApkVersionCompare.validate(version)
+    case .constraint(_ , let op, let requiredVersion):
+      switch ApkVersionCompare.compare(version, requiredVersion, mode: op.isFuzzy ? .fuzzy : .normal) {
+      case .equal:   return op.isEqual
+      case .greater: return op.isGreater
+      case .less:    return op.isLess
+      default: return false
+      }
+    }
+  }
+}
+
+internal extension ApkVersionSpecification.Operator {
+  @inlinable var isFuzzy: Bool {
+    switch self {
+    case .fuzzyEquals, .lessFuzzy, .greaterFuzzy: return true
+    default: return false
+    }
+  }
+
+  @inlinable var isEqual: Bool {
+    switch self {
+    case .equals, .fuzzyEquals, .greaterEqual, .lessEqual, .greaterFuzzy, .lessFuzzy: true
+    default: false
+    }
+  }
+
+  @inlinable var isGreater: Bool {
+    switch self {
+    case .greater, .greaterEqual, .greaterFuzzy: true
+    default: false
+    }
+  }
+
+  @inlinable var isLess: Bool {
+    switch self {
+    case .less, .lessEqual, .lessFuzzy: true
+    default: false
+    }
+  }
 }
 
 extension ApkVersionSpecification.Operator: CustomStringConvertible {
diff --git a/Tests/darwin-apk-tests/ApkVersionTests.swift b/Tests/darwin-apk-tests/ApkVersionTests.swift
index ae82a82..b11876a 100644
--- a/Tests/darwin-apk-tests/ApkVersionTests.swift
+++ b/Tests/darwin-apk-tests/ApkVersionTests.swift
@@ -57,3 +57,16 @@ import Testing
     #expect(!ApkVersionCompare.validate(invalid), "Should be invalid: \(invalid)")
   }
 }
+
+@Test func testVersionComparion() {
+  func test(_ spec: ApkVersionSpecification, _ version: String) -> Bool { spec.satisfied(by: version) }
+  #expect(test(.any(), "15.6-r0"))
+  #expect(test(.constraint(op: .equals,       version: "15.6"),   "15.6"))
+  #expect(test(.constraint(op: .fuzzyEquals,  version: "15.6"),   "15.6b"))
+  #expect(test(.constraint(op: .greaterEqual, version: "15.6"),   "15.6"))
+  #expect(test(.constraint(op: .lessEqual,    version: "15.6"),   "15.6"))
+  #expect(!test(.constraint(op: .greater,     version: "15.6"),   "15.6"))
+  #expect(!test(.constraint(op: .less,        version: "15.6"),   "15.6"))
+  #expect(test(.constraint(op: .less,         version: "15.6"),   "14.7.6"))
+  #expect(test(.constraint(op: .greaterEqual, version: "13.7.6"), "15.6"))
+}