Don't restore existing files

Author: ThatRendle

Add.cs

@@ -56,7 +56,7 @@ private static Task DownloadPackage(string package, string basePath, IEnumerable
             {
                 if (file.Type == "file")
                 {
-                    tasks.Add(Download.DistFile(package, $"{basePath}{file.Path}"));
+                    tasks.Add(DownloadFile(package, basePath, file));
                 }
                 else if (file.Files?.Count > 0)
                 {
@@ -66,5 +66,10 @@ private static Task DownloadPackage(string package, string basePath, IEnumerable
 
             return Task.WhenAll(tasks);
         }
+
+        private static async Task DownloadFile(string package, string basePath, DistFile file)
+        {
+            file.LocalPath = await Download.DistFile(package, $"{basePath}{file.Path}");
+        }
     }
 }

DistFile.cs

@@ -9,6 +9,7 @@ public class DistFile
         public DateTimeOffset LastModified { get; set; }
         public string ContentType { get; set; }
         public string Path { get; set; }
+        public string LocalPath { get; set; }
         public int Size { get; set; }
         public string Type { get; set; }
         public string Integrity { get; set; }

Download.cs

@@ -14,7 +14,7 @@ public static class Download
         };
         private static readonly string BaseDirectory = Path.Combine("wwwroot", "lib");
 
-        public static async Task DistFile(string package, string path)
+        public static async Task<string> DistFile(string package, string path)
         {
             var target = TargetFile(path);
             using (var response = await Client.GetAsync(path))
@@ -29,16 +29,19 @@ public static async Task DistFile(string package, string path)
                         Directory.CreateDirectory(directory);
                     }
 
-                    using (var fileStream = File.Create(Path.Combine(directory, file)))
+                    var localPath = Path.Combine(directory, file);
+                    using (var fileStream = File.Create(localPath))
                     {
                         await response.Content.CopyToAsync(fileStream);
                     }
 
-                    Console.WriteLine($"{Path.Combine(package, target)}... OK");
+                    Console.WriteLine($"{response.RequestMessage.RequestUri}... OK");
+                    return localPath;
                 }
                 else
                 {
-                    Console.WriteLine($"{Path.Combine(package, target)}... failed ({(int)response.StatusCode}");
+                    Console.WriteLine($"{response.RequestMessage.RequestUri}... failed ({(int)response.StatusCode})");
+                    return null;
                 }
             }
         }

Restore.cs

@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using System.Net.Http;
+using System.Security.Cryptography;
 using System.Threading.Tasks;
 using Newtonsoft.Json.Linq;
 
@@ -53,8 +54,50 @@ private static Task DownloadFiles(string package, JObject entry)
             var files = (JArray) entry["files"];
 
             return Task.WhenAll(files
-                .Select(f => f["file"].Value<string>())
-                .Select(f => Download.DistFile(package, $"{version}/{f}")));
+                .Select(f => DownloadFile(package, version, (JObject)f)));
+        }
+
+        private static Task DownloadFile(string package, string version, JObject file)
+        {
+            var local = file["local"].Value<string>();
+            if (File.Exists(local))
+            {
+                var integrity = file["integrity"].Value<string>();
+                var integrityBits = integrity.Split('-', 2);
+                if (integrityBits.Length == 2)
+                {
+                    var hashAlgorithm = GetAlgorithm(integrityBits[0]);
+                    if (hashAlgorithm != null)
+                    {
+                        using (var stream = File.OpenRead(local))
+                        {
+                            var hash = hashAlgorithm.ComputeHash(stream);
+                            if (integrityBits[1].Equals(Convert.ToBase64String(hash)))
+                            {
+                                Console.WriteLine($"{local} is up-to-date.");
+                                return Task.CompletedTask;
+                            }
+                        }
+                    }
+                }
+            }
+
+            return Download.DistFile(package, $"{version}/{file["file"].Value<string>()}");
+        }
+
+        private static HashAlgorithm GetAlgorithm(string name)
+        {
+            switch (name.ToLowerInvariant())
+            {
+                case "sha256":
+                    return SHA256.Create();
+                case "sha384":
+                    return SHA384.Create();
+                case "sha512":
+                    return SHA512.Create();
+                default:
+                    return null;
+            }
         }
     }
 }

UnpkgJson.cs

@@ -31,7 +31,8 @@ public static async Task Save(IEnumerable<UnpkgJsonEntry> entries)
                 var jEntry = new JObject
                 {
                     ["version"] = CleanVersion(entry.Version),
-                    ["files"] = JArray.FromObject(entry.Files.Select(f => new {file = f.Path, cdn = f.CdnUrl, integrity = f.Integrity}))
+                    ["files"] = JArray.FromObject(entry.Files.Select(f =>
+                        new {file = f.Path, cdn = f.CdnUrl, local = f.LocalPath, integrity = f.Integrity}))
                 };
                 file[CleanPackageName(entry.PackageName)] = jEntry;
             }

UnpkgJsonEntry.cs

@@ -26,7 +26,13 @@ private static void AddFiles(List<UnpkgJsonFile> files, string version, IEnumera
             {
                 if (distFile.Type == "file")
                 {
-                    files.Add(new UnpkgJsonFile { Path = distFile.Path, CdnUrl = $"https://unpkg.com/{version}{distFile.Path}", Integrity = distFile.Integrity});
+                    files.Add(new UnpkgJsonFile
+                    {
+                        Path = distFile.Path,
+                        LocalPath = distFile.LocalPath,
+                        CdnUrl = $"https://unpkg.com/{version}{distFile.Path}",
+                        Integrity = distFile.Integrity
+                    });
                 }
                 else if (distFile.Files?.Count > 0)
                 {

UnpkgJsonFile.cs

@@ -5,5 +5,6 @@ public class UnpkgJsonFile
         public string Path { get; set; }
         public string Integrity { get; set; }
         public string CdnUrl { get; set; }
+        public string LocalPath { get; set; }
     }
 }

dotnet-unpkg.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <Version>1.0.0-preview3</Version>
+    <Version>1.0.0</Version>
     <OutputType>Exe</OutputType>
     <TargetFramework>netcoreapp2.0</TargetFramework>
     <LangVersion>latest</LangVersion>