From ac6392ccbd133698d83fc8b76c0fb3744e7197d1 Mon Sep 17 00:00:00 2001
From: qnga <32197639+qnga@users.noreply.github.com>
Date: Tue, 21 May 2024 16:39:28 +0200
Subject: [PATCH] Add a retrieveLicenseDocument method to LcpService (#519)

---
 .../main/java/org/readium/r2/lcp/LcpService.kt   |  8 ++++++++
 .../readium/r2/lcp/service/LicensesService.kt    | 16 ++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/readium/lcp/src/main/java/org/readium/r2/lcp/LcpService.kt b/readium/lcp/src/main/java/org/readium/r2/lcp/LcpService.kt
index 51193da434..93e8d99b68 100644
--- a/readium/lcp/src/main/java/org/readium/r2/lcp/LcpService.kt
+++ b/readium/lcp/src/main/java/org/readium/r2/lcp/LcpService.kt
@@ -28,6 +28,7 @@ import org.readium.r2.shared.publication.protection.ContentProtection
 import org.readium.r2.shared.util.Try
 import org.readium.r2.shared.util.asset.Asset
 import org.readium.r2.shared.util.asset.AssetRetriever
+import org.readium.r2.shared.util.asset.ContainerAsset
 import org.readium.r2.shared.util.format.Format
 
 /**
@@ -118,6 +119,13 @@ public interface LcpService {
         allowUserInteraction: Boolean
     ): Try<LcpLicense, LcpError>
 
+    /**
+     * Retrieves the license document from a LCP-protected publication asset.
+     */
+    public suspend fun retrieveLicenseDocument(
+        asset: ContainerAsset
+    ): Try<LicenseDocument, LcpError>
+
     /**
      * Injects a [licenseDocument] into the given [publicationFile] package.
      *
diff --git a/readium/lcp/src/main/java/org/readium/r2/lcp/service/LicensesService.kt b/readium/lcp/src/main/java/org/readium/r2/lcp/service/LicensesService.kt
index f419a3d296..36ecd028fa 100644
--- a/readium/lcp/src/main/java/org/readium/r2/lcp/service/LicensesService.kt
+++ b/readium/lcp/src/main/java/org/readium/r2/lcp/service/LicensesService.kt
@@ -42,6 +42,7 @@ import org.readium.r2.shared.util.FileExtension
 import org.readium.r2.shared.util.Try
 import org.readium.r2.shared.util.asset.Asset
 import org.readium.r2.shared.util.asset.AssetRetriever
+import org.readium.r2.shared.util.asset.ContainerAsset
 import org.readium.r2.shared.util.format.Format
 import org.readium.r2.shared.util.format.FormatHints
 import org.readium.r2.shared.util.format.FormatSpecification
@@ -243,6 +244,21 @@ internal class LicensesService(
             Try.failure(LcpError.wrap(e))
         }
 
+    override suspend fun retrieveLicenseDocument(
+        asset: ContainerAsset
+    ): Try<LicenseDocument, LcpError> =
+        withContext(Dispatchers.IO) {
+            try {
+                val licenseContainer = createLicenseContainer(context, asset)
+                val licenseData = licenseContainer.read()
+                Try.success(LicenseDocument(licenseData))
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: Exception) {
+                Try.failure(LcpError.wrap(e))
+            }
+        }
+
     private suspend fun retrieveLicense(
         container: LicenseContainer,
         authentication: LcpAuthenticating,