From a7d83aa6f012fdac9d4d8b886b0f26b0b8d82e64 Mon Sep 17 00:00:00 2001
From: Yan Maniez <yanmaniez@hotmail.com>
Date: Mon, 22 Oct 2018 00:07:23 +0200
Subject: [PATCH] Versioning db Android

---
 .../AideDeJeu.Android.csproj                  |  3 +
 AideDeJeu/AideDeJeu.Android/NativeAPI.cs      | 77 ++++++++++++-------
 Data/library.ver                              |  1 +
 3 files changed, 54 insertions(+), 27 deletions(-)
 create mode 100644 Data/library.ver

diff --git a/AideDeJeu/AideDeJeu.Android/AideDeJeu.Android.csproj b/AideDeJeu/AideDeJeu.Android/AideDeJeu.Android.csproj
index 86fb8bf2..f05d2181 100644
--- a/AideDeJeu/AideDeJeu.Android/AideDeJeu.Android.csproj
+++ b/AideDeJeu/AideDeJeu.Android/AideDeJeu.Android.csproj
@@ -109,6 +109,9 @@
     <AndroidAsset Include="..\..\Data\library.db">
       <Link>Assets\library.db</Link>
     </AndroidAsset>
+    <AndroidAsset Include="..\..\Data\library.ver">
+      <Link>Assets\library.ver</Link>
+    </AndroidAsset>
     <None Include="Resources\AboutResources.txt" />
     <None Include="Assets\AboutAssets.txt" />
   </ItemGroup>
diff --git a/AideDeJeu/AideDeJeu.Android/NativeAPI.cs b/AideDeJeu/AideDeJeu.Android/NativeAPI.cs
index 5ad1c48a..cd68568d 100644
--- a/AideDeJeu/AideDeJeu.Android/NativeAPI.cs
+++ b/AideDeJeu/AideDeJeu.Android/NativeAPI.cs
@@ -1,6 +1,5 @@
 using AideDeJeu.Tools;
 using Android.Content.PM;
-using System;
 using System.IO;
 using System.Threading.Tasks;
 
@@ -30,36 +29,60 @@ namespace AideDeJeu.Droid
 
         public async Task<string> GetDatabasePathAsync(string databaseName)
         {
-            //string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
-            //string dbPath = Path.Combine(path, databaseName);
-            //return dbPath;
-            var documentsDirectoryPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
-            var path = Path.Combine(documentsDirectoryPath, $"{databaseName}.db");
+            if (await CheckDatabaseVersionAsync(databaseName))
+            {
+                await CopyOldToNewFileAsync(databaseName, "db");
+                await CopyOldToNewFileAsync(databaseName, "ver");
+            }
+            return GetNewFilePath(databaseName, "db");
+        }
 
-            // This is where we copy in our pre-created database
+        public Stream GetOldFileStream(string fileName, string extension)
+        {
+            return Android.App.Application.Context.Assets.Open($"{fileName}.{extension}");
+        }
+        public string GetNewFilePath(string fileName, string extension)
+        {
+            var documentsDirectoryPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
+            return Path.Combine(documentsDirectoryPath, $"{fileName}.{extension}");
+        }
+        public async Task CopyOldToNewFileAsync(string fileName, string extension)
+        {
+            using (var inStream = GetOldFileStream(fileName, extension))
+            {
+                using (var outStream = new FileStream(GetNewFilePath(fileName, extension), FileMode.Create))
+                {
+                    await inStream.CopyToAsync(outStream);
+                }
+            }
+        }
+
+        public async Task<bool> CheckDatabaseVersionAsync(string databaseName)
+        {
+            var path = GetNewFilePath(databaseName, "ver");
             if (!File.Exists(path))
             {
-                using (var inStream = Android.App.Application.Context.Assets.Open($"{databaseName}.db"))
-                {
-                    using (var outStream = new FileStream(path, FileMode.Create))
-                    {
-                        await inStream.CopyToAsync(outStream);
-                    }
-                }
-                //using (var binaryReader = new BinaryReader(Android.App.Application.Context.Assets.Open(databaseName)))
-                //{
-                //    using (var binaryWriter = new BinaryWriter(new FileStream(path, FileMode.Create)))
-                //    {
-                //        byte[] buffer = new byte[2048];
-                //        int length = 0;
-                //        while ((length = binaryReader.Read(buffer, 0, buffer.Length)) > 0)
-                //        {
-                //            binaryWriter.Write(buffer, 0, length);
-                //        }
-                //    }
-                //}
+                return true;
             }
-            return path;
+            int newVersion = 0;
+            int oldVersion = -1;
+            using (var newStream = GetOldFileStream(databaseName, "ver"))
+            {
+                using (var sr = new StreamReader(newStream))
+                {
+                    var str = await sr.ReadToEndAsync();
+                    int.TryParse(str, out newVersion);
+                }
+            }
+            using (var oldStream = new FileStream(path, FileMode.Open))
+            {
+                using (var sr = new StreamReader(oldStream))
+                {
+                    var str = await sr.ReadToEndAsync();
+                    int.TryParse(str, out oldVersion);
+                }
+            }
+            return newVersion > oldVersion;
         }
     }
 }
\ No newline at end of file
diff --git a/Data/library.ver b/Data/library.ver
new file mode 100644
index 00000000..bf0d87ab
--- /dev/null
+++ b/Data/library.ver
@@ -0,0 +1 @@
+4
\ No newline at end of file