chore: move files around

src/Data - Android/Apk.swift

@@ -0,0 +1,130 @@
+import Foundation
+import AndroidXML
+
+/// Data structure for processing the content of `.apk` files.
+struct Apk {
+	let isApkm: Bool
+	let mainZip: ZipFile
+	
+	init(_ meta: MetaInfo) {
+		isApkm = meta.url.pathExtension.lowercased() == "apkm"
+		mainZip = meta.zipFile!
+	}
+	
+	/// Unzip `AndroidManifest.xml` (once). Data is cached until deconstructor.
+	lazy var manifest: Data? = { effectiveZip?.unzipFile("AndroidManifest.xml") }()
+	
+	/// Select zip-file depending on `.apk` or `.apkm` extension
+	private lazy var effectiveZip: ZipFile? = { isApkm ? nestedZip : mainZip }()
+	
+	/// `.apkm` may contain multiple `.apk` files. (plus "icon.png" and "info.json" files)
+	private lazy var nestedZip: ZipFile? = {
+		if isApkm, let pth = try? mainZip.unzipFileToTempDir("base.apk") {
+			return ZipFile(pth)
+		}
+		return nil
+	}()
+	
+	/// Shared instance for resolving resources
+	private lazy var resourceParser: Tbl_Parser? = {
+		guard let data = effectiveZip?.unzipFile("resources.arsc"),
+			  let xml = try? AndroidXML.init(data: data), xml.type == .Table else {
+			return nil
+		}
+		return xml.parseTable()
+	}()
+	
+	/// Lookup app bundle name / label
+	mutating func resolveName(_ name: inout String?) {
+		if let val = name, let ref = try? TblTableRef(val), let parser = resourceParser {
+			name = parser.getName(ref)
+		}
+	}
+	
+	/// Lookup image path and image data
+	mutating func resolveIcon(_ iconRef: inout String?) -> Data? {
+		if let val = iconRef, let ref = try? TblTableRef(val), let parser = resourceParser {
+			if let iconPath = parser.getIconDirect(ref) ?? parser.getIconIndirect(ref) {
+				iconRef = iconPath
+				return effectiveZip?.unzipFile(iconPath)
+			}
+		}
+		return nil
+	}
+}
+
+
+private extension Tbl_Parser {
+	func getName(_ ref: TblTableRef) -> String? {
+		// why the heck are these even allowed?
+		// apparently there can be references onto references
+		var ref = ref
+		while let res = try? self.getResource(ref) {
+			guard let val = res.entries.first?.entry.value else {
+				return nil
+			}
+			switch val.dataType {
+			case .Reference: ref = val.asTableRef // and continue
+			case .String: return val.resolve(self.stringPool)
+			default: return nil
+			}
+		}
+		return nil
+	}
+	
+	/// Lookup resource with matching id. Choose the icon with the highest density.
+	func getIconDirect(_ ref: TblTableRef) -> String? {
+		guard let res = try? self.getResource(ref) else {
+			return nil
+		}
+		var best: ResValue? = nil
+		var bestScore: UInt16 = 0
+		for e in res.entries {
+			switch e.config.screenType.density {
+			case .Default, .any, .None: continue
+			case let density:
+				if density.rawValue > bestScore, let val = e.entry.value {
+					bestScore = density.rawValue
+					best = val
+				}
+			}
+		}
+		return best?.resolve(self.stringPool)
+	}
+	
+	/// Iterate over all entries and choose best-rated icon file.
+	/// Rating prefers files which have an attribute name `"app_icon"` or `"ic_launcher"`.
+	func getIconIndirect(_ ref: TblTableRef) -> String? {
+		// sadly we cannot just `getResource()` because that can point to an app banner
+		guard let pkg = try? self.getPackage(ref.package),
+			  var pool = pkg.stringPool(for: .Keys),
+			  let (_, types) = try? pkg.getType(ref.type) else {
+			return nil
+		}
+		// density is 120-640
+		let rates: [String: UInt16] = [
+			"app_icon": 1000,
+			"ic_launcher": 800,
+			"ic_launcher_foreground": 200,
+		]
+		var best: ResValue? = nil
+		var bestScore: UInt16 = 0
+		for typ in types {
+			switch typ.config.screenType.density {
+			case .any, .None: continue
+			case let density:
+				try? typ.iterValues {
+					if let val = $1.value {
+						let attrName = pool.getStringCached($1.key)
+						let score = density.rawValue + (rates[attrName] ?? 0)
+						if score > bestScore {
+							bestScore = score
+							best = val
+						}
+					}
+				}
+			}
+		}
+		return best?.resolve(self.stringPool)
+	}
+}