From 9d00e76901d247fa52154021bfa222ec781537ba Mon Sep 17 00:00:00 2001
From: Collin Barrett <collinbarrett@users.noreply.github.com>
Date: Thu, 23 Aug 2018 06:13:57 -0500
Subject: [PATCH] wip

---
 src/FilterLists.Services/Snapshot/Snapshot.cs | 14 ++------
 .../Snapshot/SnapshotBatch.cs                 | 34 +++++++++++++------
 2 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/src/FilterLists.Services/Snapshot/Snapshot.cs b/src/FilterLists.Services/Snapshot/Snapshot.cs
index 8b1f16923..4cca2b402 100644
--- a/src/FilterLists.Services/Snapshot/Snapshot.cs
+++ b/src/FilterLists.Services/Snapshot/Snapshot.cs
@@ -71,7 +71,7 @@ private async Task SaveAsync()
                 if (lines != null)
                 {
                     await SaveInBatches(lines);
-                    await DedupSnapshotRules();
+                    await AddRemovedSnapshotRules();
                     await SetSuccessful();
                 }
 
@@ -136,11 +136,10 @@ private static async Task SaveBatches(IEnumerable<SnapshotBatch> batches)
                 await batch.SaveAsync();
         }
 
-        private async Task DedupSnapshotRules()
+        private async Task AddRemovedSnapshotRules()
         {
             var existingSnapshotRules = GetExistingSnapshotRules();
             AddRemovedBySnapshots(existingSnapshotRules);
-            RemoveDuplicateSnapshotRules(existingSnapshotRules);
             await dbContext.SaveChangesAsync();
         }
 
@@ -157,15 +156,6 @@ private void AddRemovedBySnapshots(IQueryable<SnapshotRule> existingSnapshotRule
             removedSnapshotRules.ForEach(sr => sr.RemovedBySnapshot = snapEntity);
         }
 
-        private void RemoveDuplicateSnapshotRules(IQueryable<SnapshotRule> existingSnapshotRules)
-        {
-            var duplicateSnapshotRules = dbContext.SnapshotRules.Where(sr =>
-                sr.AddedBySnapshot == snapEntity &&
-                existingSnapshotRules.Any(e =>
-                    e.Rule == sr.Rule && e.RemovedBySnapshot == null));
-            dbContext.SnapshotRules.RemoveRange(duplicateSnapshotRules);
-        }
-
         private async Task SetSuccessful()
         {
             snapEntity.WasSuccessful = true;
diff --git a/src/FilterLists.Services/Snapshot/SnapshotBatch.cs b/src/FilterLists.Services/Snapshot/SnapshotBatch.cs
index a1af7099e..1385e54df 100644
--- a/src/FilterLists.Services/Snapshot/SnapshotBatch.cs
+++ b/src/FilterLists.Services/Snapshot/SnapshotBatch.cs
@@ -13,6 +13,7 @@ public class SnapshotBatch
         private readonly FilterListsDbContext dbContext;
         private readonly IEnumerable<string> lines;
         private readonly Data.Entities.Snapshot snapEntity;
+        private IQueryable<Rule> existingRules;
 
         public SnapshotBatch(FilterListsDbContext dbContext, IEnumerable<string> lines,
             Data.Entities.Snapshot snapEntity)
@@ -24,21 +25,32 @@ public SnapshotBatch(FilterListsDbContext dbContext, IEnumerable<string> lines,
 
         public async Task SaveAsync()
         {
-            var existingRules = GetExistingRules();
-            var newRules = CreateNewRules(existingRules);
-            dbContext.Rules.AddRange(newRules);
-            var rules = existingRules.Concat(newRules);
-            AddSnapshotRules(rules);
+            GetExistingRules();
+            AddAddedSnapshotRulesForExistingRules();
+            AddAddedSnapshotRulesForNewRules();
             await dbContext.SaveChangesAsync();
         }
 
-        private IQueryable<Rule> GetExistingRules() =>
-            dbContext.Rules.Join(lines, rule => rule.Raw, line => line, (rule, line) => rule);
+        private void GetExistingRules() =>
+            existingRules = dbContext.Rules.Join(lines, rule => rule.Raw, line => line, (rule, line) => rule);
 
-        private List<Rule> CreateNewRules(IQueryable<Rule> existingRules) =>
-            lines.Except(existingRules.Select(r => r.Raw)).Select(r => new Rule {Raw = r}).ToList();
+        private void AddAddedSnapshotRulesForExistingRules()
+        {
+            var existingSnapshotRules = dbContext.SnapshotRules
+                                                 .Where(sr =>
+                                                     existingRules.Contains(sr.Rule) &&
+                                                     sr.AddedBySnapshot.FilterListId == snapEntity.FilterListId &&
+                                                     sr.RemovedBySnapshot == null);
+            var newSnapshotRules = existingRules.Where(r => !existingSnapshotRules.Select(sr => sr.Rule).Contains(r))
+                                                .Select(r => new SnapshotRule {Rule = r});
+            snapEntity.AddedSnapshotRules.AddRange(newSnapshotRules);
+        }
 
-        private void AddSnapshotRules(IQueryable<Rule> rules) =>
-            snapEntity.AddedSnapshotRules.AddRange(rules.Select(r => new SnapshotRule {Rule = r}));
+        private void AddAddedSnapshotRulesForNewRules()
+        {
+            var rules = lines.Except(existingRules.Select(r => r.Raw)).Select(l => new Rule {Raw = l});
+            var snapshotRules = rules.Select(r => new SnapshotRule {Rule = r});
+            snapEntity.AddedSnapshotRules.AddRange(snapshotRules);
+        }
     }
 }
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