feat: add Docker Cache cleaning category (#1)

PureMac/Models/Models.swift

@@ -13,6 +13,7 @@ enum CleaningCategory: String, CaseIterable, Identifiable, Codable {
     case xcodeJunk = "Xcode Junk"
     case brewCache = "Brew Cache"
     case nodeCache = "Node Cache"
+    case dockerCache = "Docker Cache"
 
     var id: String { rawValue }
 
@@ -28,6 +29,7 @@ enum CleaningCategory: String, CaseIterable, Identifiable, Codable {
         case .xcodeJunk: return "hammer.fill"
         case .brewCache: return "mug.fill"
         case .nodeCache: return "leaf.fill"
+        case .dockerCache: return "shippingbox.fill"
         }
     }
 
@@ -43,6 +45,7 @@ enum CleaningCategory: String, CaseIterable, Identifiable, Codable {
         case .xcodeJunk: return "Derived data, archives, and simulators"
         case .brewCache: return "Homebrew download cache"
         case .nodeCache: return "npm, yarn, and pnpm download caches"
+        case .dockerCache: return "Docker images, containers, and build cache"
         }
     }
 
@@ -58,6 +61,7 @@ enum CleaningCategory: String, CaseIterable, Identifiable, Codable {
         case .xcodeJunk: return .cyan
         case .brewCache: return .mint
         case .nodeCache: return .pink
+        case .dockerCache: return .indigo
         }
     }
 

PureMac/Services/ScanEngine.swift

@@ -33,6 +33,8 @@ actor ScanEngine {
             return scanBrewCache()
         case .nodeCache:
             return scanNodeCache()
+        case .dockerCache:
+            return scanDockerCache()
         }
     }
 
@@ -456,6 +458,119 @@ actor ScanEngine {
         return String(data: data, encoding: .utf8)
     }
 
+    private func scanDockerCache() -> CategoryResult {
+        var items: [CleanableItem] = []
+
+        // Docker Desktop on macOS keeps its VM disk + caches under
+        // ~/Library/Containers/com.docker.docker/Data. The caches we
+        // surface here are *recoverable* — they will be regenerated by
+        // Docker on next pull/build, and `docker system prune` is the
+        // CLI equivalent of cleaning them.
+        let dockerDataDirs = [
+            // Build cache (BuildKit), per-user
+            "\(home)/Library/Containers/com.docker.docker/Data/cache",
+            // Vmnetd / vpnkit log + telemetry caches
+            "\(home)/Library/Containers/com.docker.docker/Data/log",
+            "\(home)/Library/Containers/com.docker.docker/Data/tmp",
+            // Group containers caches (Docker Desktop helper apps)
+            "\(home)/Library/Group Containers/group.com.docker/Caches",
+            // CLI plugin download cache
+            "\(home)/.docker/cli-plugins/.cache",
+            // Buildx / containerd inline cache
+            "\(home)/.docker/buildx/cache",
+        ]
+
+        for path in dockerDataDirs {
+            guard fileManager.fileExists(atPath: path) else { continue }
+            let size = directorySize(path: path)
+            guard size > 0 else { continue }
+            items.append(CleanableItem(
+                name: URL(fileURLWithPath: path).lastPathComponent,
+                path: path,
+                size: size,
+                category: .dockerCache,
+                isSelected: true,
+                lastModified: nil
+            ))
+        }
+
+        // If the `docker` CLI is available, surface reclaimable space
+        // reported by `docker system df` as a single virtual entry.
+        // We don't try to delete it directly — the user runs
+        // `docker system prune` themselves, which is the safe path.
+        // We just show how much they can recover.
+        let dockerBinPaths = ["/usr/local/bin/docker", "/opt/homebrew/bin/docker"]
+        for dockerBin in dockerBinPaths where fileManager.fileExists(atPath: dockerBin) {
+            if let reclaimable = reclaimableDockerSpace(dockerBin: dockerBin), reclaimable > 0 {
+                items.append(CleanableItem(
+                    name: "Reclaimable (run `docker system prune -af`)",
+                    path: dockerBin,
+                    size: reclaimable,
+                    category: .dockerCache,
+                    isSelected: false,
+                    lastModified: nil
+                ))
+            }
+            break
+        }
+
+        let totalSize = items.reduce(0) { $0 + $1.size }
+        return CategoryResult(category: .dockerCache, items: items, totalSize: totalSize)
+    }
+
+    /// Sum the reclaimable bytes reported by `docker system df --format json`.
+    /// Returns nil when Docker isn't running or the command fails — callers
+    /// should treat that as "no reclaimable info available", not as an error.
+    private func reclaimableDockerSpace(dockerBin: String) -> Int64? {
+        let task = Process()
+        task.executableURL = URL(fileURLWithPath: dockerBin)
+        task.arguments = ["system", "df", "--format", "{{.Reclaimable}}"]
+        let stdoutPipe = Pipe()
+        task.standardOutput = stdoutPipe
+        task.standardError = Pipe()
+        do {
+            try task.run()
+            task.waitUntilExit()
+        } catch {
+            Logger.shared.log("docker system df failed: \(error.localizedDescription)", level: .warning)
+            return nil
+        }
+        guard task.terminationStatus == 0 else { return nil }
+        let data = stdoutPipe.fileHandleForReading.readDataToEndOfFile()
+        guard let output = String(data: data, encoding: .utf8) else { return nil }
+        // Each line looks like e.g. "1.234GB (45%)" — parse the leading number.
+        var total: Int64 = 0
+        for line in output.split(separator: "\n") {
+            let raw = line.split(separator: " ").first.map(String.init) ?? ""
+            if let bytes = parseHumanBytes(raw) {
+                total += bytes
+            }
+        }
+        return total
+    }
+
+    /// Parse Docker's compact size format ("1.23GB", "456MB", "789kB") into bytes.
+    private func parseHumanBytes(_ s: String) -> Int64? {
+        let trimmed = s.trimmingCharacters(in: .whitespaces)
+        guard !trimmed.isEmpty else { return nil }
+        let units: [(String, Double)] = [
+            ("TB", 1_000_000_000_000),
+            ("GB", 1_000_000_000),
+            ("MB", 1_000_000),
+            ("kB", 1_000),
+            ("KB", 1_000),
+            ("B", 1),
+        ]
+        for (suffix, multiplier) in units {
+            if trimmed.hasSuffix(suffix) {
+                let numberPart = String(trimmed.dropLast(suffix.count))
+                if let value = Double(numberPart) {
+                    return Int64(value * multiplier)
+                }
+            }
+        }
+        return nil
+    }
     // MARK: - Helpers
 
     private func scanDirectory(

PureMac/en.lproj/Localizable.strings

@@ -123,3 +123,8 @@
 "npm cache" = "npm cache";
 "yarn classic cache" = "yarn classic cache";
 "pnpm content-addressable store" = "pnpm content-addressable store";
+
+/* Docker Cache */
+"Docker Cache" = "Docker Cache";
+"Docker images, containers, and build cache" = "Docker images, containers, and build cache";
+"Reclaimable (run `docker system prune -af`)" = "Reclaimable (run `docker system prune -af`)";

PureMac/zh-Hans.lproj/Localizable.strings

@@ -123,3 +123,8 @@
 "npm cache" = "npm 缓存";
 "yarn classic cache" = "yarn 经典缓存";
 "pnpm content-addressable store" = "pnpm 内容寻址存储";
+
+/* Docker Cache */
+"Docker Cache" = "Docker 缓存";
+"Docker images, containers, and build cache" = "Docker 镜像、容器和构建缓存";
+"Reclaimable (run `docker system prune -af`)" = "可回收空间（运行 `docker system prune -af`）";