From d6edd3f11dbdd93d88e41a57256b5cf434a4c702 Mon Sep 17 00:00:00 2001
From: Jonathan Bernard <jdbernard@gmail.com>
Date: Wed, 30 Mar 2016 01:12:41 -0500
Subject: [PATCH] Added core support for DB synchronization.

---
 .../com/jdbernard/wdiwtlt/MediaLibrary.groovy | 23 ++++++-
 .../com/jdbernard/wdiwtlt/db/DbApi.groovy     | 68 +++++++++++++++++++
 2 files changed, 89 insertions(+), 2 deletions(-)

diff --git a/core/src/main/groovy/com/jdbernard/wdiwtlt/MediaLibrary.groovy b/core/src/main/groovy/com/jdbernard/wdiwtlt/MediaLibrary.groovy
index 1be2f27..e7dca11 100644
--- a/core/src/main/groovy/com/jdbernard/wdiwtlt/MediaLibrary.groovy
+++ b/core/src/main/groovy/com/jdbernard/wdiwtlt/MediaLibrary.groovy
@@ -50,7 +50,10 @@ public class MediaLibrary {
             staleBookmarks.each { dbapi.delete(it) } } }
 
     public def rescanLibrary() {
-        def results = [ total: 0, ignored: 0, new: 0]
+        def results = [ total: 0, ignored: 0, new: 0, present: 0, absent: 0]
+
+        List<MediaFile> missingFiles = dbapi.getMediaFiles()
+        List<MediaFile> foundFiles = []
 
         Date startDate = new Date()
         libraryRoot.eachFileRecurse { file ->
@@ -60,7 +63,23 @@ public class MediaLibrary {
 
             results.total++
             if (!mf) results.ignored++
-            else if (mf.dateAdded > startDate) results.new++ }
+            else {
+                foundFiles << mf
+                if (missingFiles.contains(mf)) missingFiles.remove(mf)
+                if (mf.dateAdded > startDate) results.new++ } }
+
+        foundFiles.each { mf ->
+            if (!mf.presentLocally) {
+                mf.presentLocally = true
+                dbapi.update(mf) } }
+
+        missingFiles.each { mf ->
+            if (mf.presentLocally) {
+                mf.presentLocally = false
+                dbapi.update(mf) } }
+
+        results.present = foundFiles.size()
+        results.absent = missingFiles.size()
 
         return results }
 
diff --git a/core/src/main/groovy/com/jdbernard/wdiwtlt/db/DbApi.groovy b/core/src/main/groovy/com/jdbernard/wdiwtlt/db/DbApi.groovy
index 650e0d2..952df67 100644
--- a/core/src/main/groovy/com/jdbernard/wdiwtlt/db/DbApi.groovy
+++ b/core/src/main/groovy/com/jdbernard/wdiwtlt/db/DbApi.groovy
@@ -927,4 +927,72 @@ public class DbApi {
 
     static def getInstanceFields(Class modelClass) {
         return modelClass.fields.findAll { !Modifier.isStatic(it.modifiers) } }
+
+    /// ### DB Sync/Replication
+
+    public def diffWith(DbApi that) {
+
+        def results = [
+            ours: [ modelIds: [:], associations: [:] ],
+            theirs:[ modelIds: [:], associations: [:] ]  ]
+
+        [Album, Artist, Image, MediaFile, Playlist, Bookmark,
+         Tag].each { modelClass ->
+
+            List<UUID> ourIds = this.getAllIds(modelClass)
+            List<UUID> theirIds = that.getAllIds(modelClass)
+
+            results.ours.modelIds[modelClass] = ourIds - theirIds
+            results.theirs.modelIds[modelClass] = theirIds - ourIds }
+
+        ['albums_images', 'albums_media_files', 'artists_albums',
+         'artists_images', 'artists_media_files', 'media_files_tags',
+         'playlists_media_files'].each { tableName ->
+
+            def query = 'SELECT * FROM ' + tableName;
+            def allOurRows = this.sql.rows(query)
+            def allTheirRows = that.sql.rows(query)
+
+            def ourRows = allOurRows.clone()
+            def theirRows = allTheirRows.clone()
+
+            allOurRows.each { ourRow ->
+                allTheirRows.each { theirRow ->
+                    if (ourRow[0] == theirRow[0]) {
+                        ourRows.remove(ourRow)
+                        theirRows.remove(theirRow) } } }
+
+            results.ours.associations[tableName] = ourRows
+            results.theirs.associations[tableName] = theirRows }
+
+        return results }
+
+    public def ingestDiff(DbApi that, def diff) {
+
+        diff.modelIds.each { modelClass, ids ->
+            ids.each { id -> this.create(that.getById(modelClass, id)) } }
+
+        diff.associations.each { tableName, rows ->
+            String placeholders = null
+            String query = null
+            rows.each { row ->
+                if (!placeholders)
+                    placeholders = (1..row.size()).collect { '?' }.join(', ')
+
+                if (!query)
+                    query = "INSERT INTO ${tableName} VALUES (${placeholders})"
+
+                logger.debug("Adding association.\n\tSQL: {}\n\tPARAMS: {}",
+                    query, row.values() as List)
+                this.sql.executeInsert(query, row.values() as List) } } }
+
+    public def syncWith(DbApi that, boolean pull = true,
+    boolean push = false) {
+        def diff = this.diffWith(that)
+
+        if (pull) this.ingestDiff(that, diff.theirs)
+        if (push) that.ingestDiff(this, diff.ours)
+
+        return diff }
+
 }