fix: Support images on Linux

.gitignore

@@ -1,6 +1,7 @@
 /.build
 /.local
 /.swiftpm
+/.vscode
 /_site
 /archives
 /build

Package.swift

@@ -3,6 +3,44 @@
 
 import PackageDescription
 
+#if os(macOS)
+
+let coreDependencies: [Target.Dependency] = [
+    "PlatformSupport",
+    "Hoedown",
+    .product(name: "Crypto", package: "swift-crypto"),
+    .product(name: "FSEventsWrapper", package: "FSEventsWrapper"),
+    .product(name: "Hummingbird", package: "hummingbird"),
+    .product(name: "HummingbirdFoundation", package: "hummingbird"),
+    .product(name: "Licensable", package: "licensable"),
+    .product(name: "Logging", package: "swift-log"),
+    .product(name: "SQLite", package: "SQLite.swift"),
+    .product(name: "SwiftSoup", package: "SwiftSoup"),
+    .product(name: "Tilt", package: "Tilt"),
+    .product(name: "Titlecaser", package: "Titlecaser"),
+    .product(name: "Yams", package: "Yams"),
+]
+
+#else
+
+let coreDependencies: [Target.Dependency] = [
+    "PlatformSupport",
+    "Hoedown",
+    .product(name: "Crypto", package: "swift-crypto"),
+    .product(name: "Hummingbird", package: "hummingbird"),
+    .product(name: "HummingbirdFoundation", package: "hummingbird"),
+    .product(name: "Licensable", package: "licensable"),
+    .product(name: "Logging", package: "swift-log"),
+    .product(name: "SQLite", package: "SQLite.swift"),
+    .product(name: "SwiftExif", package: "SwiftExif"),
+    .product(name: "SwiftSoup", package: "SwiftSoup"),
+    .product(name: "Tilt", package: "Tilt"),
+    .product(name: "Titlecaser", package: "Titlecaser"),
+    .product(name: "Yams", package: "Yams"),
+]
+
+#endif
+
 let package = Package(
     name: "incontext",
     platforms: [
@@ -33,6 +71,7 @@ let package = Package(
         .package(url: "https://github.com/jwells89/Titlecaser.git", from: "1.0.0"),
         .package(url: "https://github.com/scinfu/SwiftSoup.git", from: "2.6.0"),
         .package(url: "https://github.com/stephencelis/SQLite.swift.git", from: "0.14.1"),
+        .package(url: "https://github.com/kradalby/SwiftExif.git", from: "0.0.7"),
     ],
     targets: [
        .executableTarget(
@@ -51,22 +90,7 @@ let package = Package(
            ]),
         .target(
             name: "InContextCore",
-            dependencies: [
-                "PlatformSupport",
-                "Hoedown",
-                .product(name: "Crypto", package: "swift-crypto"),
-                .product(name: "FSEventsWrapper", package: "FSEventsWrapper", condition:
-                    .when(platforms: [.macOS])),
-                .product(name: "Hummingbird", package: "hummingbird"),
-                .product(name: "HummingbirdFoundation", package: "hummingbird"),
-                .product(name: "Licensable", package: "licensable"),
-                .product(name: "Logging", package: "swift-log"),
-                .product(name: "SQLite", package: "SQLite.swift"),
-                .product(name: "SwiftSoup", package: "SwiftSoup"),
-                .product(name: "Tilt", package: "Tilt"),
-                .product(name: "Titlecaser", package: "Titlecaser"),
-                .product(name: "Yams", package: "Yams"),
-            ],
+            dependencies: coreDependencies,
             resources: [
                 .process("Licenses"),
             ],

README.md

@@ -16,6 +16,16 @@ brew install inseven/incontext/incontext
 
 See [https://incontext.app/docs](https://incontext.app/docs).
 
+## Development
+
+### Linux
+
+Install third-party dependencies:
+
+```bash
+sudo dnf install libexif-devel libiptcdata-devel 
+```` 
+
 ## Frontmatter
 
 Frontmatter is supported in Markdown files and image and video descriptions. InContext will pass through all unknown markdown fields, but puts type constraints on fields that have specific meaning:

Sources/InContextCore/Extensions/Dictionary.swift

@@ -22,6 +22,33 @@
 
 import Foundation
 
+protocol Transformable {
+
+    // TODO: I think this might actually be returning an Any?
+    // TODO: ASK TOM WTF
+    static func transform(from value: Any) -> Self?
+
+}
+
+extension Int: Transformable {
+
+    static func transform(from value: Any) -> Int? {
+        if let stringValue = value as? String {
+            return Int(stringValue)
+        }
+        return nil
+    }
+
+}
+
+extension String {
+
+    func convert<T>(type: T.Type) -> T? {
+        return nil
+    }
+
+}
+
 extension Dictionary {
 
     func value<T>(for key: Key, default defaultValue: T) throws -> T {
@@ -51,10 +78,14 @@ extension Dictionary {
         guard let value = self[key] else {
             return nil
         }
-        guard let value = value as? T else {
-            throw InContextError.incorrectType(expected: T.Type.self, received: value)
+        if let value = value as? T {
+            return value
         }
-        return value
+        if let transformable = T.self as? Transformable.Type,
+           let value = transformable.transform(from: value) as? T {
+            return value
+        }
+        throw InContextError.incorrectType(expected: T.Type.self, received: value)
     }
 
     func requiredValue<T>(for key: Key) throws -> T {

Sources/InContextCore/Importers/ImageImporter.swift

@@ -32,8 +32,6 @@ import ImageIO
 
 import PlatformSupport
 
-#if !os(Linux)
-
 protocol _Test {
     // TODO: This needs to pass in the metadata
     func evaluate(fileURL: URL) -> Bool
@@ -135,8 +133,8 @@ struct _Or<A: _Test, B: _Test>: _Test {
 struct TransformContext {
 
     let fileURL: URL
-    let imageSource: CGImageSource
-    let exif: EXIF
+    let image: PlatformImage
+    let exif: EXIF  // TODO: This is encapsulated in `PlatformImage`
 
     let assetsURL: URL
 
@@ -178,19 +176,23 @@ struct _Resize: _Transform {
         let targetSize = size.fit(width: self.width)
         let maxPixelSize = max(targetSize.width, targetSize.height)
 
-        let options = [kCGImageSourceCreateThumbnailWithTransform: kCFBooleanTrue,
-                     kCGImageSourceCreateThumbnailFromImageAlways: kCFBooleanTrue,
-                              kCGImageSourceThumbnailMaxPixelSize: maxPixelSize as NSNumber] as CFDictionary
-
+        // TODO: Honour the input format if we don't have one.
         guard let format = self.format ?? context.fileURL.type else {
             throw InContextError.internalInconsistency("Failed to detect output type for '\(context.fileURL.relativePath)'.")
         }
-
-        let frameCount = CGImageSourceGetCount(context.imageSource)
-
-        // TODO: Honour the input format if we don't have one.
         let destinationFilename = basename + "." + (format.preferredFilenameExtension ?? "")
         let destinationURL = context.assetsURL.appending(component: destinationFilename)
+
+#if os(Linux)
+
+#else
+
+        let options = [kCGImageSourceCreateThumbnailWithTransform: kCFBooleanTrue,
+                     kCGImageSourceCreateThumbnailFromImageAlways: kCFBooleanTrue,
+                              kCGImageSourceThumbnailMaxPixelSize: maxPixelSize as NSNumber] as CFDictionary
+
+        let frameCount = CGImageSourceGetCount(context.image.source)
+
         guard let destination = CGImageDestinationCreateWithURL(destinationURL as CFURL,
                                                                 format.identifier as CFString,
                                                                 frameCount,
@@ -200,7 +202,7 @@ struct _Resize: _Transform {
 
         // Cherry-pick relevant image properties.
         var destinationProperties: [String: Any] = [:]
-        if let sourceProperties = CGImageSourceCopyProperties(context.imageSource, nil) as? [String: Any] {
+        if let sourceProperties = CGImageSourceCopyProperties(context.image.source, nil) as? [String: Any] {
             if let gifProperties = sourceProperties[kCGImagePropertyGIFDictionary as String] {
                 destinationProperties[kCGImagePropertyGIFDictionary as String] = gifProperties
             }
@@ -209,8 +211,8 @@ struct _Resize: _Transform {
 
         // Resize the frames.
         for i in 0..<frameCount {
-            let thumbnail = CGImageSourceCreateThumbnailAtIndex(context.imageSource, i, options)!
-            if let properties = CGImageSourceCopyPropertiesAtIndex(context.imageSource, i, nil) as? [String: Any] {
+            let thumbnail = CGImageSourceCreateThumbnailAtIndex(context.image.source, i, options)!
+            if let properties = CGImageSourceCopyPropertiesAtIndex(context.image.source, i, nil) as? [String: Any] {
                 var frameProperties: [String: Any] = [:]
                 if let gifProperties = properties[kCGImagePropertyGIFDictionary as String] {
                     frameProperties[kCGImagePropertyGIFDictionary as String] = gifProperties
@@ -220,7 +222,10 @@ struct _Resize: _Transform {
         }
 
         CGImageDestinationFinalize(destination)  // TODO: Handle error here?
-        context.assets.append(Asset(fileURL: destinationURL as URL))
+
+#endif
+
+        // context.assets.append(Asset(fileURL: destinationURL as URL))  // TODO: Why `as URL`?
 
         let details = [
             "width": targetSize.width,
@@ -316,8 +321,6 @@ let configuration = _Configuration {
 
 }
 
-#endif
-
 class ImageImporter {
 
     struct Settings: ImporterSettings {
@@ -346,22 +349,6 @@ class ImageImporter {
 
 }
 
-#if os(Linux)
-
-extension ImageImporter: Importer {
-
-    func process(file: File,
-                 settings: Settings,
-                 outputURL: URL) async throws -> ImporterResult {
-
-        throw InContextError.internalInconsistency("Unsupported")
-
-    }
-
-}
-
-#else
-
 extension ImageImporter: Importer {
 
     func process(file: File,
@@ -374,14 +361,8 @@ extension ImageImporter: Importer {
         let assetsURL = URL(filePath: fileURL.relevantRelativePath, relativeTo: outputURL)  // TODO: Make this a utiltiy and test it
         try FileManager.default.createDirectory(at: assetsURL, withIntermediateDirectories: true)
 
-        // Load the original image.
-        guard let image = CGImageSourceCreateWithURL(fileURL as CFURL, nil) else {
-            throw InContextError.internalInconsistency("Failed to open image file at '\(fileURL.relativePath)'.")
-        }
-
-        guard let exif = try EXIF(image, 0) else {
-            throw InContextError.internalInconsistency("Failed to load properties for image at '\(fileURL.relativePath)'.")
-        }
+        // Load the image.
+        let image = try PlatformImage(url: fileURL)
 
         let details = fileURL.basenameDetails()
 
@@ -392,13 +373,13 @@ extension ImageImporter: Importer {
             metadata["scale"] = scale
         }
 
-        if let projectionType = try exif.projectionType {
+        if let projectionType = try image.exif.projectionType {
             metadata["projection"] = projectionType
         }
 
         // Content.
         var content: FrontmatterDocument? = nil
-        if let imageDescription = try exif.imageDescription {
+        if let imageDescription = try image.exif.imageDescription {
             let frontmatter = try FrontmatterDocument(contents: imageDescription, generateHTML: true)
             guard let contentMetadata = frontmatter.metadata as? [String: Any] else {
                 throw InContextError.internalInconsistency("Unexpected key type for metadata")
@@ -408,8 +389,8 @@ extension ImageImporter: Importer {
         }
 
         // Location.
-        if let latitude = try exif.signedLatitude,
-           let longitude = try exif.signedLongitude {
+        if let latitude = try image.exif.signedLatitude,
+           let longitude = try image.exif.signedLongitude {
             metadata["location"] = [
                 "latitude": latitude,
                 "longitude": longitude,
@@ -418,8 +399,8 @@ extension ImageImporter: Importer {
 
         // Perform the transforms.
         var context = TransformContext(fileURL: fileURL,
-                                       imageSource: image,
-                                       exif: exif,
+                                       image: image,
+                                       exif: image.exif,
                                        assetsURL: assetsURL,
                                        metadata: metadata,
                                        assets: [])
@@ -438,8 +419,8 @@ extension ImageImporter: Importer {
 
         // N.B. The EXIF 'DateTimeOriginal' field sometimes appears to be invalid so we fall back on DateTimeDigitized.
 
-        let date = try (try? exif.dateTimeOriginal) ?? (try exif.dateTimeDigitized) ?? details.date
-        let title = try exif.firstTitle ?? content?.title ?? filenameTitle
+        let date = try (try? image.exif.dateTimeOriginal) ?? (try image.exif.dateTimeDigitized) ?? details.date
+        let title = try image.exif.firstTitle ?? content?.title ?? filenameTitle
 
         let document = try Document(url: fileURL.siteURL,
                                     parent: fileURL.parentURL,
@@ -457,5 +438,3 @@ extension ImageImporter: Importer {
     }
 
 }
-
-#endif