Add a command line option to decompress a subset of images matching a glob

plugin/src/main/kotlin/xyz/block/microfilm/decompression/DecompressTask.kt

@@ -19,13 +19,25 @@ import okio.FileSystem
 import okio.Path.Companion.toOkioPath
 import org.gradle.api.DefaultTask
 import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.provider.ListProperty
 import org.gradle.api.tasks.Internal
 import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.options.Option
 import org.gradle.work.DisableCachingByDefault
+import xyz.block.microfilm.Manifest
 import xyz.block.microfilm.scanning.RealScanner
+import xyz.block.microfilm.writeManifest
 
 @DisableCachingByDefault(because = "This task modifies the source tree in place")
 internal abstract class DecompressTask : DefaultTask() {
+  @get:Internal
+  @get:Option(
+    option = "images",
+    description =
+      "Decompress the images matching these glob patterns, relative to the res directory.",
+  )
+  abstract val imagePatterns: ListProperty<String>
+
   @get:Internal abstract val microfilmDirectory: DirectoryProperty
 
   @get:Internal abstract val resourcesDirectory: DirectoryProperty
@@ -54,11 +66,18 @@ internal abstract class DecompressTask : DefaultTask() {
       )
 
     // Decompress the images
-    scanner.scan().forEach { imageGroup ->
-      decompressor.decompress(imageGroup = imageGroup)
-    }
+    val manifestEntries =
+      decompressor.decompress(
+        scanner = scanner,
+        imagePatterns = imagePatterns.get().ifEmpty { listOf("**") },
+        resourcesDirectory = resourcesDirectoryPath,
+        microfilmDirectory = microfilmDirectoryPath,
+      )
+
+    // Create the manifest from remaining images
+    val manifest = Manifest(entries = manifestEntries.sortedBy { entry -> entry.sourcePath })
 
-    // Delete the manifest
-    fileSystem.delete(path = microfilmManifestPath)
+    // Write the manifest to disk
+    fileSystem.writeManifest(path = microfilmManifestPath, manifest = manifest)
   }
 }

plugin/src/main/kotlin/xyz/block/microfilm/decompression/Decompressor.kt

@@ -15,7 +15,12 @@
  */
 package xyz.block.microfilm.decompression
 
+import okio.Path
+import okio.Path.Companion.toPath
+import xyz.block.microfilm.Manifest
+import xyz.block.microfilm.matchesGlobs
 import xyz.block.microfilm.scanning.ImageGroup
+import xyz.block.microfilm.scanning.Scanner
 
 /**
  * A decompressor that removes compressed images and restores their original uncompressed
@@ -25,3 +30,25 @@ internal interface Decompressor {
   /** Removes the given compressed image and restores its original uncompressed counterpart. */
   fun decompress(imageGroup: ImageGroup)
 }
+
+/** Scans for images and decompresses them. */
+internal fun Decompressor.decompress(
+  scanner: Scanner,
+  imagePatterns: List<String>,
+  resourcesDirectory: Path,
+  microfilmDirectory: Path,
+): List<Manifest.Entry> {
+  return scanner.scan().mapNotNull { imageGroup ->
+    val pngPath =
+      imageGroup.microfilmManifestEntry?.sourcePath?.toPath()
+        ?: imageGroup.microfilmPng?.relativeTo(other = microfilmDirectory)
+        ?: imageGroup.resourcesPng?.relativeTo(other = resourcesDirectory)
+    val webpPath = imageGroup.resourcesWebp?.relativeTo(other = resourcesDirectory)
+    if (listOfNotNull(pngPath, webpPath).matchesGlobs(patterns = imagePatterns)) {
+      decompress(imageGroup = imageGroup)
+      null
+    } else {
+      imageGroup.microfilmManifestEntry
+    }
+  }
+}

plugin/src/test/kotlin/xyz/block/microfilm/decompression/DecompressorTest.kt

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2026 Block, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package xyz.block.microfilm.decompression
+
+import assertk.assertThat
+import assertk.assertions.containsExactly
+import assertk.assertions.isEmpty
+import org.junit.jupiter.api.Test
+import xyz.block.microfilm.scanning.FakeScanner
+import xyz.block.microfilm.scanning.ImageGroup
+import xyz.block.microfilm.scanning.ImageGroupFixtures.LOSSY_IMAGE_GROUP
+import xyz.block.microfilm.scanning.ImageGroupFixtures.MICROFILM_DIRECTORY
+import xyz.block.microfilm.scanning.ImageGroupFixtures.RELATIVE_PNG
+import xyz.block.microfilm.scanning.ImageGroupFixtures.RELATIVE_WEBP
+import xyz.block.microfilm.scanning.ImageGroupFixtures.RESOURCES_DIRECTORY
+
+class DecompressorTest {
+  @Test
+  fun `decompress respects image patterns`() {
+    assertDecompress(
+      imageGroup = LOSSY_IMAGE_GROUP,
+      imagePattern = RELATIVE_PNG,
+      expected = true,
+    )
+
+    assertDecompress(
+      imageGroup = LOSSY_IMAGE_GROUP,
+      imagePattern = "other.png",
+      expected = false,
+    )
+
+    assertDecompress(
+      imageGroup = LOSSY_IMAGE_GROUP,
+      imagePattern = RELATIVE_WEBP,
+      expected = true,
+    )
+
+    assertDecompress(
+      imageGroup = LOSSY_IMAGE_GROUP,
+      imagePattern = "other.webp",
+      expected = false,
+    )
+  }
+
+  private fun assertDecompress(
+    imageGroup: ImageGroup,
+    imagePattern: String = "**",
+    expected: Boolean,
+  ) {
+    val decompressor = FakeDecompressor()
+    val scanner = FakeScanner().apply { scanResponses.add(listOf(imageGroup)) }
+
+    val manifestEntries =
+      decompressor.decompress(
+        scanner = scanner,
+        imagePatterns = listOf(imagePattern),
+        resourcesDirectory = RESOURCES_DIRECTORY,
+        microfilmDirectory = MICROFILM_DIRECTORY,
+      )
+
+    if (expected) {
+      assertThat(decompressor.decompressRequests).containsExactly(imageGroup)
+      assertThat(manifestEntries).isEmpty()
+    } else {
+      assertThat(decompressor.decompressRequests).isEmpty()
+      assertThat(manifestEntries).containsExactly(imageGroup.microfilmManifestEntry)
+    }
+  }
+}

plugin/src/test/kotlin/xyz/block/microfilm/decompression/FakeDecompressor.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2026 Block, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package xyz.block.microfilm.decompression
+
+import xyz.block.microfilm.scanning.ImageGroup
+
+internal class FakeDecompressor : Decompressor {
+  val decompressRequests = ArrayDeque<ImageGroup>()
+
+  override fun decompress(imageGroup: ImageGroup) {
+    decompressRequests.add(imageGroup)
+  }
+}