Add injectLicense to LCPService

Author: qnga

Sources/LCP/LCPService.swift

@@ -80,6 +80,18 @@ public final class LCPService: Loggable {
         }
     }
 
+    /// Injects a `licenseDocument` into a publication package at `url`.
+    ///
+    /// This is useful if you downloaded the publication yourself instead of using `acquirePublication`.
+    public func injectLicense(
+        _ license: LicenseDocument,
+        in url : FileURL
+    ) async -> Result<Void, LCPError> {
+        await wrap {
+            try await licenses.injectLicense(license, in: url)
+        }
+    }
+
     /// Opens the LCP license of a protected publication, to access its DRM
     /// metadata and decipher its content.
     ///

Sources/LCP/Services/LicensesService.swift

@@ -120,28 +120,49 @@ final class LicensesService: Loggable {
             onProgress: { onProgress(.percent(Float($0))) }
         ).get()
 
-        var hints = FormatHints()
-        if let type = license.link(for: .publication)?.mediaType {
-            hints.mediaTypes.append(type)
-        }
-        if let type = download.mediaType {
-            hints.mediaTypes.append(type)
-        }
-
-        let asset = try await assetRetriever.retrieve(url: download.location, hints: hints)
-            .mapError { LCPError.licenseContainer(ContainerError.openFailed($0)) }
-            .get()
-
-        try await injectLicense(license, in: asset)
+        let format = try await injectLicenseAndGetFormat(
+            license,
+            in: download.location,
+            mediaTypeHint: download.mediaType
+        )
 
         return LCPAcquiredPublication(
             localURL: download.location,
-            format: asset.format,
-            suggestedFilename: asset.format.fileExtension.appendedToFilename(license.id),
+            format: format,
+            suggestedFilename: format.fileExtension.appendedToFilename(license.id),
             licenseDocument: license
         )
     }
 
+    func injectLicense(
+        _ license: LicenseDocument,
+        in url: FileURL
+    ) async throws {
+        let _ = try await injectLicenseAndGetFormat(license, in: url, mediaTypeHint: nil)
+    }
+
+    private func injectLicenseAndGetFormat(
+        _ license: LicenseDocument,
+        in url: FileURL,
+        mediaTypeHint: MediaType? = nil
+    ) async throws -> Format {
+        var formatHints = FormatHints()
+        if let type = license.publicationLink.mediaType {
+            formatHints.mediaTypes.append(type)
+        }
+        if let type = mediaTypeHint {
+            formatHints.mediaTypes.append(type)
+        }
+    
+        let asset = try await assetRetriever.retrieve(url: url, hints: formatHints)
+            .mapError { LCPError.licenseContainer(ContainerError.openFailed($0)) }
+            .get()
+    
+        try await injectLicense(license, in: asset)
+    
+        return asset.format
+    }
+
     private func readLicense(from lcpl: LicenseDocumentSource) async throws -> LicenseDocument? {
         switch lcpl {
         case let .data(data):