Add Konverter: a local-only menu bar file converter

Drag files in Finder, hold a modifier, and drop on a wheel of outputs. Conversions run entirely on-device through ImageIO, PDFKit, AVFoundation, the bundled CLI tools, and optional ffmpeg/LibreOffice. Includes a --self-test suite (41 checks) and a --convert CLI mode so the conversion matrix can be verified without the UI.
2026-10-20 00:36:40 +08:00
commit 2d031e58a4
47 changed files with 9149 additions and 0 deletions
@@ -0,0 +1,176 @@
+import Foundation
+import PDFKit
+
+/// Whether an output format can actually be produced on this Mac, and why not
+/// when it cannot. The wheel uses this to mark options as unavailable instead
+/// of failing after the user has already committed to a drop.
+struct Availability {
+    let isAvailable: Bool
+    let reason: String?
+
+    static let ok = Availability(isAvailable: true, reason: nil)
+
+    static func unavailable(_ reason: String) -> Availability {
+        Availability(isAvailable: false, reason: reason)
+    }
+}
+
+/// Front door for format conversions: picks the engine, handles formats that
+/// produce more than one file, and reports a useful reason when nothing can.
+enum Converter {
+    @discardableResult
+    static func convert(
+        source: URL,
+        to format: Format,
+        at destination: URL,
+        quality: Double = 0.9,
+        mediaQuality: String = "Medium",
+        audioBitrate: String = "192",
+        cancellation: Cancellation? = nil,
+        progress: ((Double) -> Void)? = nil
+    ) throws -> [URL] {
+        try cancellation?.check()
+        let category = FileKind.category(of: source)
+
+        switch category {
+        case .image:
+            try ImageConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                quality: quality,
+                cancellation: cancellation
+            )
+            progress?(1)
+            return [destination]
+
+        case .video, .audio:
+            try AVConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                quality: mediaQuality,
+                bitrate: audioBitrate,
+                cancellation: cancellation,
+                progress: progress
+            )
+            return [destination]
+
+        case .pdf:
+            switch format {
+            case .jpg, .png:
+                let directory = OutputNaming.artifactDirectory(for: source, suffix: " \(format.displayName)")
+                return try PDFConverter.renderPages(
+                    source,
+                    to: format,
+                    into: directory,
+                    dpi: 300,
+                    cancellation: cancellation,
+                    progress: progress
+                )
+            case .pptx, .xlsx:
+                try Office.convert(source, to: format, at: destination, cancellation: cancellation)
+                progress?(1)
+                return [destination]
+            case .pdf:
+                guard let document = PDFDocument(url: source) else {
+                    throw ConversionError.unreadable(source.lastPathComponent)
+                }
+                guard document.write(to: destination) else {
+                    throw ConversionError.failed("Could not rewrite the PDF.")
+                }
+                progress?(1)
+                return [destination]
+            default:
+                try DocumentConverter.convert(
+                    source: source,
+                    to: format,
+                    at: destination,
+                    cancellation: cancellation,
+                    progress: progress
+                )
+                return [destination]
+            }
+
+        case .document, .spreadsheet:
+            try DocumentConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                cancellation: cancellation,
+                progress: progress
+            )
+            return [destination]
+
+        case .slides:
+            try SlidesConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                cancellation: cancellation,
+                progress: progress
+            )
+            if format == .png || format == .jpg {
+                let directory = OutputNaming.artifactDirectory(for: source, suffix: " \(format.displayName)")
+                let files = (try? FileManager.default.contentsOfDirectory(at: directory, includingPropertiesForKeys: nil)) ?? []
+                return files.sorted { $0.lastPathComponent < $1.lastPathComponent }
+            }
+            return [destination]
+
+        case .ebook:
+            try EbookConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                cancellation: cancellation,
+                progress: progress
+            )
+            return [destination]
+
+        case .subtitle:
+            try SubtitleConverter.convert(source: source, to: format, at: destination, cancellation: cancellation)
+            progress?(1)
+            return [destination]
+
+        case .archive:
+            try ArchiveConverter.convert(
+                source: source,
+                to: format,
+                at: destination,
+                cancellation: cancellation,
+                progress: progress
+            )
+            return [destination]
+
+        case .folder, .unknown:
+            throw ConversionError.unsupported("\(source.lastPathComponent) has no conversion options.")
+        }
+    }
+
+    // MARK: - Availability
+
+    static func availability(target: Format, source: FileCategory) -> Availability {
+        if let offered = ConversionCatalog.targets[source], !offered.contains(target) {
+            return .unavailable("\(source.title) cannot become \(target.displayName).")
+        }
+        if target.requiresFFmpeg, !Toolchain.hasFFmpeg {
+            return .unavailable("Needs ffmpeg — brew install ffmpeg")
+        }
+        if target.requiresLibreOffice, !Toolchain.hasLibreOffice {
+            return .unavailable("Needs LibreOffice — brew install --cask libreoffice")
+        }
+        if !Settings.shared.useExternalTools, target.requiresFFmpeg || target.requiresLibreOffice {
+            return .unavailable("External tools are turned off in Settings.")
+        }
+        if target.category == .image, !Raster.canEncode(target) {
+            if target == .webp, WebPEncoder.isAvailable {
+                return .ok
+            }
+            return .unavailable("This Mac cannot write \(target.displayName) files.")
+        }
+        if source == .spreadsheet, !["xlsx", "ods", "csv", "tsv"].contains(target.ext), target != .pdf {
+            return .unavailable("Spreadsheets cannot become \(target.displayName).")
+        }
+        return .ok
+    }
+}