Implement thread loading

lib/main.dart

@@ -3,6 +3,7 @@ import 'package:provider/provider.dart';
 import 'package:wind/newsgroup_list_view.dart';
 import 'package:wind/nntp_client.dart';
 import 'package:wind/thread_list_view.dart';
+import 'package:wind/thread_model.dart';
 import 'package:wind/thread_screen.dart';
 
 import 'thread_list_model.dart';
@@ -16,6 +17,12 @@ void main() {
           model!.client = client;
           return model;
         }),
+    ChangeNotifierProxyProvider<NNTPClient, ThreadModel>(
+        create: (context) => ThreadModel(),
+        update: (context, client, model) {
+          model!.client = client;
+          return model;
+        }),
   ], child: MyApp()));
 }
 

lib/message_item_view.dart

@@ -0,0 +1,80 @@
+import 'package:flutter/material.dart';
+
+class MessageItemView extends StatelessWidget {
+  const MessageItemView({Key? key, required this.item, required this.isOpPost})
+      : super(key: key);
+
+  final MessageItem item;
+  final bool isOpPost;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+        margin: this.isOpPost ? EdgeInsets.only(bottom: 10) : EdgeInsets.all(0),
+        child: Card(
+            elevation: 5,
+            child: InkWell(
+              splashColor: Colors.indigo.withAlpha(30),
+              onTap: () => {},
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  isOpPost
+                      ? Container(
+                          child: Text(
+                            item.subject!,
+                            style: TextStyle(
+                                fontWeight: FontWeight.bold, fontSize: 21),
+                          ),
+                          margin: EdgeInsets.only(top: 16, left: 16, right: 16),
+                        )
+                      : Container(),
+                  Container(
+                    child: Row(
+                      children: [
+                        Text(
+                          item.author,
+                          style: TextStyle(
+                              fontWeight: FontWeight.normal,
+                              color: Colors.blue,
+                              fontSize: 15),
+                        ),
+                        SizedBox(width: 5),
+                        Text(
+                          item.date,
+                          style: TextStyle(fontSize: 15),
+                        ),
+                        SizedBox(width: 5),
+                        Text(
+                          "#${item.number}",
+                          style: TextStyle(fontSize: 15, color: Colors.grey),
+                        )
+                      ],
+                    ),
+                    margin: isOpPost
+                        ? EdgeInsets.only(
+                            top: 5, bottom: 2, left: 16, right: 16)
+                        : EdgeInsets.only(top: 16, left: 16),
+                  ),
+                  Container(
+                    child: Text(item.body, style: TextStyle(fontSize: 17)),
+                    margin: EdgeInsets.all(16),
+                  )
+                ],
+              ),
+            )));
+  }
+}
+
+class MessageItem {
+  final String id;
+  final int number;
+  final String? subject;
+  final String author;
+  final String date;
+  final String body;
+
+  MessageItem(
+      this.id, this.number, this.subject, this.author, this.date, this.body);
+}

lib/nntp_client.dart

@@ -126,6 +126,31 @@ class NNTPClient {
 
     return threads;
   }
+
+  Future<List<Tuple2<int, MimeMessage>>> getThread(
+      int threadNumber) async {
+    if (currentGroup == null) throw new ArgumentError("current group is null");
+
+    List<Tuple2<int, MimeMessage>> threads = [];
+
+    var newThreadList = await _sendCommand(
+        "THREAD", [threadNumber.toString()]);
+
+    newThreadList.lines.removeAt(0);
+    newThreadList.lines.removeLast(); // remove dot
+
+    await Future.forEach<String>(newThreadList.lines, (element) async {
+      await _sendCommand("ARTICLE", [element]).then((response) {
+        response.lines.removeAt(0);
+        response.lines.removeLast();
+        var rawMsg = response.lines.join("\r\n");
+        threads
+            .add(Tuple2(int.parse(element), MimeMessage.parseFromText(rawMsg)));
+      });
+    });
+
+    return threads;
+  }
 }
 
 class _NNTPCommand {

lib/thread_list_view.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:wind/thread_list_model.dart';
+import 'package:wind/thread_screen.dart';
 
 class ThreadListView extends StatefulWidget {
   @override
@@ -96,7 +97,8 @@ class ThreadListItemView extends StatelessWidget {
         elevation: 5,
         child: InkWell(
           splashColor: Colors.indigo.withAlpha(30),
-          onTap: () => Navigator.pushNamed(context, "/thread"),
+          onTap: () => Navigator.pushNamed(context, "/thread",
+              arguments: ThreadScreenArguments(item)),
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             mainAxisSize: MainAxisSize.min,
@@ -123,6 +125,11 @@ class ThreadListItemView extends StatelessWidget {
                       item.date,
                       style: TextStyle(fontSize: 15),
                     ),
+                    SizedBox(width: 5),
+                    Text(
+                      "#${item.number}",
+                      style: TextStyle(fontSize: 15, color: Colors.grey),
+                    )
                   ],
                 ),
                 margin: EdgeInsets.only(top: 5, bottom: 2, left: 16, right: 16),

lib/thread_model.dart

@@ -0,0 +1,29 @@
+import 'package:flutter/cupertino.dart';
+import 'package:wind/message_item_view.dart';
+import 'package:wind/nntp_client.dart';
+
+class ThreadModel extends ChangeNotifier {
+  NNTPClient? client;
+
+  Future<List<MessageItem>> getThread(int threadNumber) async {
+    if (client!.currentGroup == "") return [];
+
+    List<MessageItem> items = [];
+
+    var thread = await client!.getThread(threadNumber);
+
+    thread.forEach((pair) {
+      var messageNum = pair.item1;
+      var message = pair.item2;
+      items.add(MessageItem(
+          message.getHeaderValue("Message-Id")!,
+          messageNum,
+          null,
+          message.getHeaderValue("From")!,
+          message.getHeaderValue("Date")!,
+          message.decodeTextPlainPart()!));
+    });
+
+    return items;
+  }
+}

lib/thread_screen.dart

@@ -1,4 +1,15 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:wind/message_item_view.dart';
+import 'package:wind/nntp_client.dart';
+import 'package:wind/thread_list_view.dart';
+import 'package:wind/thread_model.dart';
+
+class ThreadScreenArguments {
+  final ThreadItem item;
+
+  ThreadScreenArguments(this.item);
+}
 
 class ThreadScreen extends StatefulWidget {
   @override
@@ -6,12 +17,53 @@ class ThreadScreen extends StatefulWidget {
 }
 
 class ThreadScreenState extends State<ThreadScreen> {
+  late NNTPClient client;
+  late int threadNumber;
+
   @override
   Widget build(BuildContext context) {
+    var args =
+        ModalRoute.of(context)!.settings.arguments as ThreadScreenArguments;
+    client = context.read<NNTPClient>();
+    threadNumber = args.item.number;
+
     return Scaffold(
       appBar: AppBar(
-        title: Text("Thread"),
+        title: Text("Thread #${args.item.number}"),
       ),
+      body: Center(
+          child: Container(
+        width: 640,
+        child: FutureBuilder<List<MessageItem>>(
+          future: _fetch(context),
+          builder: (context, snapshot) {
+            if (snapshot.hasData) {
+              List<MessageItem> data = List.from(snapshot.data!);
+              data.insert(
+                  0,
+                  MessageItem(args.item.id, args.item.number, args.item.subject,
+                      args.item.author, args.item.date, args.item.body));
+              return _listView(data);
+            } else if (snapshot.hasError) {
+              return Text("${snapshot.error}");
+            }
+            return Center(child: CircularProgressIndicator());
+          },
+        ),
+      )),
     );
   }
+
+  Future<List<MessageItem>> _fetch(BuildContext context) async {
+    var model = context.read<ThreadModel>();
+    return await model.getThread(threadNumber);
+  }
+
+  Widget _listView(List<MessageItem> data) {
+    return ListView.builder(
+        itemCount: data.length,
+        itemBuilder: (context, index) {
+          return MessageItemView(item: data[index], isOpPost: index == 0);
+        });
+  }
 }