1 files changed, 42 insertions, 0 deletions
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/data/storage/GribFileManager.kt b/android-app/app/src/main/kotlin/org/terst/nav/data/storage/GribFileManager.kt
new file mode 100644
index 0000000..e17e5ca
--- /dev/null
+++ b/android-app/app/src/main/kotlin/org/terst/nav/data/storage/GribFileManager.kt
@@ -0,0 +1,42 @@
+package org.terst.nav.data.storage
+
+import org.terst.nav.data.model.GribFile
+import org.terst.nav.data.model.GribRegion
+import java.time.Instant
+
+interface GribFileManager {
+    /** Save metadata for a newly-downloaded GRIB file. */
+    fun saveMetadata(file: GribFile)
+    /** Return all stored GRIB files for [region], newest first. */
+    fun listFiles(region: GribRegion): List<GribFile>
+    /** Return the most-recently-downloaded GRIB file for [region], or null if none. */
+    fun latestFile(region: GribRegion): GribFile?
+    /** Delete a specific GRIB file's metadata and from disk. Returns true if deleted. */
+    fun delete(file: GribFile): Boolean
+    /** Delete all GRIB files older than [before]. Returns count of deleted files. */
+    fun purgeOlderThan(before: Instant): Int
+    /** Total size in bytes of all stored GRIB files. */
+    fun totalSizeBytes(): Long
+}
+
+class InMemoryGribFileManager : GribFileManager {
+    private val files = mutableListOf<GribFile>()
+
+    override fun saveMetadata(file: GribFile) { files.add(file) }
+
+    override fun listFiles(region: GribRegion): List<GribFile> =
+        files.filter { it.region.name == region.name }
+             .sortedByDescending { it.downloadedAt }
+
+    override fun latestFile(region: GribRegion): GribFile? = listFiles(region).firstOrNull()
+
+    override fun delete(file: GribFile): Boolean = files.remove(file)
+
+    override fun purgeOlderThan(before: Instant): Int {
+        val toRemove = files.filter { it.downloadedAt.isBefore(before) }
+        files.removeAll(toRemove)
+        return toRemove.size
+    }
+
+    override fun totalSizeBytes(): Long = files.sumOf { it.sizeBytes }
+}