From 5c4e6fd82a3ef656bee5fae53bff16a41394d06e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BB=BB=E5=A4=A9=E5=A4=A9?= <ruattqwq@gmail.com>
Date: Thu, 8 Jan 2026 11:43:29 +0800
Subject: [PATCH 1/4] init

---
 Net/NDownload/NDlConnection.cs    | 5 +++++
 Net/NDownload/NDlFactory.cs       | 5 +++++
 Net/NDownload/NDlScheduler.cs     | 5 +++++
 Net/NDownload/NDlSource.cs        | 5 +++++
 Net/NDownload/NDlSourceManager.cs | 5 +++++
 Net/NDownload/NDlTask.cs          | 5 +++++
 Net/NDownload/NDlTaskSegment.cs   | 5 +++++
 7 files changed, 35 insertions(+)
 create mode 100644 Net/NDownload/NDlConnection.cs
 create mode 100644 Net/NDownload/NDlFactory.cs
 create mode 100644 Net/NDownload/NDlScheduler.cs
 create mode 100644 Net/NDownload/NDlSource.cs
 create mode 100644 Net/NDownload/NDlSourceManager.cs
 create mode 100644 Net/NDownload/NDlTask.cs
 create mode 100644 Net/NDownload/NDlTaskSegment.cs

diff --git a/Net/NDownload/NDlConnection.cs b/Net/NDownload/NDlConnection.cs
new file mode 100644
index 00000000..6c020a4d
--- /dev/null
+++ b/Net/NDownload/NDlConnection.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlConnection
+{
+}
\ No newline at end of file
diff --git a/Net/NDownload/NDlFactory.cs b/Net/NDownload/NDlFactory.cs
new file mode 100644
index 00000000..c41be5cf
--- /dev/null
+++ b/Net/NDownload/NDlFactory.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public static class NDlFactory
+{
+}
diff --git a/Net/NDownload/NDlScheduler.cs b/Net/NDownload/NDlScheduler.cs
new file mode 100644
index 00000000..03e46b2a
--- /dev/null
+++ b/Net/NDownload/NDlScheduler.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlScheduler
+{
+}
\ No newline at end of file
diff --git a/Net/NDownload/NDlSource.cs b/Net/NDownload/NDlSource.cs
new file mode 100644
index 00000000..9b1e4a47
--- /dev/null
+++ b/Net/NDownload/NDlSource.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlSource
+{
+}
\ No newline at end of file
diff --git a/Net/NDownload/NDlSourceManager.cs b/Net/NDownload/NDlSourceManager.cs
new file mode 100644
index 00000000..4cc41185
--- /dev/null
+++ b/Net/NDownload/NDlSourceManager.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlSourceManager
+{
+}
\ No newline at end of file
diff --git a/Net/NDownload/NDlTask.cs b/Net/NDownload/NDlTask.cs
new file mode 100644
index 00000000..20c6a88b
--- /dev/null
+++ b/Net/NDownload/NDlTask.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlTask
+{
+}
\ No newline at end of file
diff --git a/Net/NDownload/NDlTaskSegment.cs b/Net/NDownload/NDlTaskSegment.cs
new file mode 100644
index 00000000..9b02bc29
--- /dev/null
+++ b/Net/NDownload/NDlTaskSegment.cs
@@ -0,0 +1,5 @@
+namespace PCL.Core.Net.NDownload;
+
+public class NDlTaskSegment
+{
+}
\ No newline at end of file

From ae1ae3d4ac8b510aaa446602b8877980ac452e2f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BB=BB=E5=A4=A9=E5=A4=A9?= <ruattqwq@outlook.com>
Date: Thu, 8 Jan 2026 19:49:48 +0800
Subject: [PATCH 2/4] =?UTF-8?q?=F0=9F=A5=9A?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Net/NDownload/IDlConnection.cs      | 29 ++++++++++++++
 Net/NDownload/IDlResourceMapping.cs | 10 +++++
 Net/NDownload/IDlWriter.cs          | 31 +++++++++++++++
 Net/NDownload/NDlConnection.cs      |  5 ---
 Net/NDownload/NDlConnectionInfo.cs  | 15 +++++++
 Net/NDownload/NDlFactory.cs         | 61 ++++++++++++++++++++++++++++-
 Net/NDownload/NDlScheduler.cs       |  2 +-
 Net/NDownload/NDlSource.cs          |  5 ---
 Net/NDownload/NDlSourceManager.cs   |  4 +-
 Net/NDownload/NDlTask.cs            |  2 +-
 Net/NDownload/NDlTaskSegment.cs     |  2 +-
 11 files changed, 150 insertions(+), 16 deletions(-)
 create mode 100644 Net/NDownload/IDlConnection.cs
 create mode 100644 Net/NDownload/IDlResourceMapping.cs
 create mode 100644 Net/NDownload/IDlWriter.cs
 delete mode 100644 Net/NDownload/NDlConnection.cs
 create mode 100644 Net/NDownload/NDlConnectionInfo.cs
 delete mode 100644 Net/NDownload/NDlSource.cs

diff --git a/Net/NDownload/IDlConnection.cs b/Net/NDownload/IDlConnection.cs
new file mode 100644
index 00000000..533b9919
--- /dev/null
+++ b/Net/NDownload/IDlConnection.cs
@@ -0,0 +1,29 @@
+using System.Threading.Tasks;
+
+namespace PCL.Core.Net.NDownload;
+
+/// <summary>
+/// 下载连接，负责与服务器进行通信。
+/// </summary>
+public interface IDlConnection
+{
+    /// <summary>
+    /// 开始连接，发起与服务器的通信。
+    /// </summary>
+    /// <param name="beginOffset">起始偏移，为 <c>0</c> 表示不使用分块</param>
+    /// <returns>连接信息</returns>
+    public Task<NDlConnectionInfo> StartAsync(long beginOffset);
+
+    /// <summary>
+    /// 停止连接，同时停止服务器通信并释放资源。
+    /// </summary>
+    /// <returns></returns>
+    public Task StopAsync();
+
+    /// <summary>
+    /// 读取指定长度的数据，若无法继续读取则返回空数组。
+    /// </summary>
+    /// <param name="length">读取长度</param>
+    /// <returns>字节数组形式的数据</returns>
+    public Task<byte[]> ReadAsync(int length);
+}
diff --git a/Net/NDownload/IDlResourceMapping.cs b/Net/NDownload/IDlResourceMapping.cs
new file mode 100644
index 00000000..db7f9db8
--- /dev/null
+++ b/Net/NDownload/IDlResourceMapping.cs
@@ -0,0 +1,10 @@
+namespace PCL.Core.Net.NDownload;
+
+/// <summary>
+/// 资源 ID 映射。
+/// </summary>
+/// <typeparam name="TMappingValue">映射目标类型</typeparam>
+public interface IDlResourceMapping<out TMappingValue>
+{
+    public TMappingValue? Parse(string resId);
+}
diff --git a/Net/NDownload/IDlWriter.cs b/Net/NDownload/IDlWriter.cs
new file mode 100644
index 00000000..80c66b38
--- /dev/null
+++ b/Net/NDownload/IDlWriter.cs
@@ -0,0 +1,31 @@
+using System.IO;
+using System.Threading.Tasks;
+
+namespace PCL.Core.Net.NDownload;
+
+/// <summary>
+/// 下载写入器。
+/// </summary>
+public interface IDlWriter
+{
+    /// <summary>
+    /// 是否支持并行写入，即是否支持多次调用 <see cref="CreateStreamAsync"/>。
+    /// </summary>
+    public bool IsSupportParallel { get; }
+
+    /// <summary>
+    /// 创建写入流。
+    /// </summary>
+    /// <returns>写入流</returns>
+    public Task<Stream> CreateStreamAsync();
+
+    /// <summary>
+    /// 停止写入并释放资源。
+    /// </summary>
+    public Task StopAsync();
+
+    /// <summary>
+    /// 完成写入，用于执行某些并行操作的收尾工作 (例如合并文件)。
+    /// </summary>
+    public Task FinishAsync();
+}
diff --git a/Net/NDownload/NDlConnection.cs b/Net/NDownload/NDlConnection.cs
deleted file mode 100644
index 6c020a4d..00000000
--- a/Net/NDownload/NDlConnection.cs
+++ /dev/null
@@ -1,5 +0,0 @@
-namespace PCL.Core.Net.NDownload;
-
-public class NDlConnection
-{
-}
\ No newline at end of file
diff --git a/Net/NDownload/NDlConnectionInfo.cs b/Net/NDownload/NDlConnectionInfo.cs
new file mode 100644
index 00000000..5d9ab2fe
--- /dev/null
+++ b/Net/NDownload/NDlConnectionInfo.cs
@@ -0,0 +1,15 @@
+namespace PCL.Core.Net.NDownload;
+
+/// <summary>
+/// 下载连接信息。
+/// </summary>
+/// <param name="Length">内容长度，单位为字节</param>
+/// <param name="BeginOffset">起始偏移</param>
+/// <param name="EndOffset">结束偏移</param>
+/// <param name="IsSupportSegment">是否支持分块</param>
+public record NDlConnectionInfo(
+    long Length,
+    long BeginOffset,
+    long EndOffset,
+    bool IsSupportSegment
+);
diff --git a/Net/NDownload/NDlFactory.cs b/Net/NDownload/NDlFactory.cs
index c41be5cf..55a01c76 100644
--- a/Net/NDownload/NDlFactory.cs
+++ b/Net/NDownload/NDlFactory.cs
@@ -1,5 +1,64 @@
 namespace PCL.Core.Net.NDownload;
 
-public static class NDlFactory
+/// <summary>
+/// 无泛型的下载器构建工厂。
+/// </summary>
+public abstract class NDlFactory
 {
+    /// <summary>
+    /// 新建连接。
+    /// </summary>
+    /// <param name="resId">资源 ID</param>
+    /// <param name="retry">重试计数，用于自动换源</param>
+    /// <returns>下载连接</returns>
+    public abstract IDlConnection CreateConnection(string resId, int retry = 0);
+
+    /// <summary>
+    /// 新建写入器。
+    /// </summary>
+    /// <param name="resId">资源 ID</param>
+    /// <returns>下载写入器</returns>
+    public abstract IDlWriter CreateWriter(string resId);
+}
+
+/// <summary>
+/// 下载器构建工厂。
+/// </summary>
+/// <typeparam name="TSourceArgument">下载源参数类型</typeparam>
+/// <typeparam name="TTargetArgument">写入目标参数类型</typeparam>
+public abstract class NDlFactory<TSourceArgument, TTargetArgument> : NDlFactory
+{
+    /// <summary>
+    /// 下载源管理器。
+    /// </summary>
+    protected abstract NDlSourceManager<TSourceArgument> SourceManager { get; }
+
+    /// <summary>
+    /// 写入目标。
+    /// </summary>
+    protected abstract IDlResourceMapping<TTargetArgument> TargetMapping { get; }
+
+    /// <summary>
+    /// 新建连接。
+    /// </summary>
+    /// <param name="source">下载源参数</param>
+    /// <returns>下载连接</returns>
+    protected abstract IDlConnection CreateConnection(TSourceArgument source);
+
+    public override IDlConnection CreateConnection(string resId, int retry = 0)
+    {
+        throw new System.NotImplementedException();
+    }
+
+    /// <summary>
+    /// 新建写入器。
+    /// </summary>
+    /// <param name="target">写入目标</param>
+    /// <returns>下载写入器</returns>
+    protected abstract IDlWriter CreateWriter(TTargetArgument target);
+
+    public override IDlWriter CreateWriter(string resId)
+    {
+        throw new System.NotImplementedException();
+    }
 }
diff --git a/Net/NDownload/NDlScheduler.cs b/Net/NDownload/NDlScheduler.cs
index 03e46b2a..99d4f16d 100644
--- a/Net/NDownload/NDlScheduler.cs
+++ b/Net/NDownload/NDlScheduler.cs
@@ -2,4 +2,4 @@ namespace PCL.Core.Net.NDownload;
 
 public class NDlScheduler
 {
-}
\ No newline at end of file
+}
diff --git a/Net/NDownload/NDlSource.cs b/Net/NDownload/NDlSource.cs
deleted file mode 100644
index 9b1e4a47..00000000
--- a/Net/NDownload/NDlSource.cs
+++ /dev/null
@@ -1,5 +0,0 @@
-namespace PCL.Core.Net.NDownload;
-
-public class NDlSource
-{
-}
\ No newline at end of file
diff --git a/Net/NDownload/NDlSourceManager.cs b/Net/NDownload/NDlSourceManager.cs
index 4cc41185..a8eaa8c2 100644
--- a/Net/NDownload/NDlSourceManager.cs
+++ b/Net/NDownload/NDlSourceManager.cs
@@ -1,5 +1,5 @@
 namespace PCL.Core.Net.NDownload;
 
-public class NDlSourceManager
+public class NDlSourceManager<TSourceArgument>
 {
-}
\ No newline at end of file
+}
diff --git a/Net/NDownload/NDlTask.cs b/Net/NDownload/NDlTask.cs
index 20c6a88b..134f7b64 100644
--- a/Net/NDownload/NDlTask.cs
+++ b/Net/NDownload/NDlTask.cs
@@ -2,4 +2,4 @@ namespace PCL.Core.Net.NDownload;
 
 public class NDlTask
 {
-}
\ No newline at end of file
+}
diff --git a/Net/NDownload/NDlTaskSegment.cs b/Net/NDownload/NDlTaskSegment.cs
index 9b02bc29..f855e0c7 100644
--- a/Net/NDownload/NDlTaskSegment.cs
+++ b/Net/NDownload/NDlTaskSegment.cs
@@ -2,4 +2,4 @@ namespace PCL.Core.Net.NDownload;
 
 public class NDlTaskSegment
 {
-}
\ No newline at end of file
+}

From 5316dcd397587d8d53e9f8260dbeb1a83d3c2895 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BB=BB=E5=A4=A9=E5=A4=A9?= <ruattqwq@gmail.com>
Date: Mon, 12 Jan 2026 18:00:32 +0800
Subject: [PATCH 3/4] =?UTF-8?q?=E5=86=8D=E6=8C=A4=E4=B8=80=E7=82=B9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Net/NDownload/NDlFactory.cs       | 21 +++++++++++----------
 Net/NDownload/NDlSourceManager.cs | 11 ++++++++++-
 Net/NDownload/NDlSourceReport.cs  |  7 +++++++
 3 files changed, 28 insertions(+), 11 deletions(-)
 create mode 100644 Net/NDownload/NDlSourceReport.cs

diff --git a/Net/NDownload/NDlFactory.cs b/Net/NDownload/NDlFactory.cs
index 55a01c76..df099b6c 100644
--- a/Net/NDownload/NDlFactory.cs
+++ b/Net/NDownload/NDlFactory.cs
@@ -9,16 +9,15 @@ public abstract class NDlFactory
     /// 新建连接。
     /// </summary>
     /// <param name="resId">资源 ID</param>
-    /// <param name="retry">重试计数，用于自动换源</param>
     /// <returns>下载连接</returns>
-    public abstract IDlConnection CreateConnection(string resId, int retry = 0);
+    public abstract IDlConnection? CreateConnection(string resId);
 
     /// <summary>
     /// 新建写入器。
     /// </summary>
     /// <param name="resId">资源 ID</param>
     /// <returns>下载写入器</returns>
-    public abstract IDlWriter CreateWriter(string resId);
+    public abstract IDlWriter? CreateWriter(string resId);
 }
 
 /// <summary>
@@ -29,12 +28,12 @@ public abstract class NDlFactory
 public abstract class NDlFactory<TSourceArgument, TTargetArgument> : NDlFactory
 {
     /// <summary>
-    /// 下载源管理器。
+    /// 下载源映射。
     /// </summary>
-    protected abstract NDlSourceManager<TSourceArgument> SourceManager { get; }
+    protected abstract IDlResourceMapping<TSourceArgument> SourceMapping { get; }
 
     /// <summary>
-    /// 写入目标。
+    /// 写入目标映射。
     /// </summary>
     protected abstract IDlResourceMapping<TTargetArgument> TargetMapping { get; }
 
@@ -45,9 +44,10 @@ public abstract class NDlFactory<TSourceArgument, TTargetArgument> : NDlFactory
     /// <returns>下载连接</returns>
     protected abstract IDlConnection CreateConnection(TSourceArgument source);
 
-    public override IDlConnection CreateConnection(string resId, int retry = 0)
+    public override IDlConnection? CreateConnection(string resId)
     {
-        throw new System.NotImplementedException();
+        var source = SourceMapping.Parse(resId);
+        return (source == null) ? null : CreateConnection(source);
     }
 
     /// <summary>
@@ -57,8 +57,9 @@ public override IDlConnection CreateConnection(string resId, int retry = 0)
     /// <returns>下载写入器</returns>
     protected abstract IDlWriter CreateWriter(TTargetArgument target);
 
-    public override IDlWriter CreateWriter(string resId)
+    public override IDlWriter? CreateWriter(string resId)
     {
-        throw new System.NotImplementedException();
+        var target = TargetMapping.Parse(resId);
+        return (target == null) ? null : CreateWriter(target);
     }
 }
diff --git a/Net/NDownload/NDlSourceManager.cs b/Net/NDownload/NDlSourceManager.cs
index a8eaa8c2..08240d81 100644
--- a/Net/NDownload/NDlSourceManager.cs
+++ b/Net/NDownload/NDlSourceManager.cs
@@ -1,5 +1,14 @@
+using System.Collections.Generic;
+
 namespace PCL.Core.Net.NDownload;
 
-public class NDlSourceManager<TSourceArgument>
+public class NDlSourceManager<TSourceArgument>(IList<IDlResourceMapping<TSourceArgument>> sources)
+    : IDlResourceMapping<TSourceArgument>
 {
+    public IList<IDlResourceMapping<TSourceArgument>> Sources { get; } = sources;
+
+    public TSourceArgument? Parse(string resId)
+    {
+        throw new System.NotImplementedException();
+    }
 }
diff --git a/Net/NDownload/NDlSourceReport.cs b/Net/NDownload/NDlSourceReport.cs
new file mode 100644
index 00000000..656e78fb
--- /dev/null
+++ b/Net/NDownload/NDlSourceReport.cs
@@ -0,0 +1,7 @@
+namespace PCL.Core.Net.NDownload;
+
+public record NDlSourceReport(
+    bool IsSupportSegment = true,
+    int RetryCount = 0,
+    long AverageSpeed = -1
+);

From 199d23005955044f0e5440b23d7ddcaa2823bf55 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BB=BB=E5=A4=A9=E5=A4=A9?= <ruattqwq@gmail.com>
Date: Sun, 18 Jan 2026 10:11:57 +0800
Subject: [PATCH 4/4] =?UTF-8?q?imp:=20=E5=BE=AE=E8=B0=83=20source=20report?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Net/NDownload/NDlSourceReport.cs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Net/NDownload/NDlSourceReport.cs b/Net/NDownload/NDlSourceReport.cs
index 656e78fb..f19cbb82 100644
--- a/Net/NDownload/NDlSourceReport.cs
+++ b/Net/NDownload/NDlSourceReport.cs
@@ -1,7 +1,13 @@
 namespace PCL.Core.Net.NDownload;
 
+/// <summary>
+/// 下载源质量报告
+/// </summary>
+/// <param name="MaxSegmentCount">支持最大分块数量</param>
+/// <param name="RetryCount">重试计数</param>
+/// <param name="AverageSpeed">总体平均速度</param>
 public record NDlSourceReport(
-    bool IsSupportSegment = true,
+    int MaxSegmentCount = 1,
     int RetryCount = 0,
     long AverageSpeed = -1
 );