fetch all posts instead of only the initial 50

lib/api/api.dart

@@ -103,6 +103,7 @@ class APIRequestBuilder {
     return this;
   }
 
+  /// Mark single item as read, unread, saved, unsaved
   APIRequestBuilder markItem(Item item, ItemMarkType markAs) {
     _addArg('mark=item');
     _addArg('as=${markAs.name}');
@@ -112,6 +113,22 @@ class APIRequestBuilder {
     return this;
   }
 
+  /// Use the `since_id` argument with the highest id of locally cached items to
+  /// request 50 additional items. Repeat until the items array in the response
+  /// is empty.
+  APIRequestBuilder sinceId(int id) {
+    _addArg('since_id=$id');
+    return this;
+  }
+
+  /// Use the `max_id` argument with the lowest id of locally cached items (or
+  /// 0 initially) to request 50 previous items. Repeat until the items array
+  /// in the response is empty.
+  APIRequestBuilder maxId(int id) {
+    _addArg('max_id=$id');
+    return this;
+  }
+
   /// Executes the API request and returns the JSON data
   Future<Map<String, dynamic>> fetch() async {
     if (api.apiKey == null || api.apiUrl == null) {
@@ -126,7 +143,7 @@ class APIRequestBuilder {
   }
 
   /// Executes the API request and populates the local cache with the response data
-  Future<void> execute() async {
+  Future<Map<String, dynamic>> execute() async {
     final data = await fetch();
 
     if (data.containsKey('groups')) {
@@ -185,6 +202,8 @@ class APIRequestBuilder {
       }
       api.cache.items.set(_markedItem!.id, _markedItem!);
     }
+
+    return data;
   }
 }
 

lib/api/cache.dart

@@ -42,6 +42,8 @@ class ObjectCache<K, T> {
   void set(K key, T value) {
     _items[key] = value;
   }
+
+  int get size => _items.length;
 }
 
 class ItemCache extends ObjectCache<int, Item> {

lib/main.dart

@@ -1,6 +1,5 @@
 import 'dart:async';
 
-import 'package:feet/pages/login.dart';
 import 'package:feet/widgets/centered_page_hint.dart';
 import 'package:feet/widgets/homepage_post.dart';
 import 'package:feet/widgets/login_prompt.dart';
@@ -10,6 +9,10 @@ import 'package:flutter/services.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'api/api.dart';
 
+// Limit the maximum amount of posts to fetch so we don't wait forever when
+// fetching a large list
+const FETCH_MAX_POSTS = 1000;
+
 void main() {
   runApp(MyApp());
 }
@@ -78,9 +81,47 @@ class MyHomePage extends StatefulWidget {
 class _MyHomePageState extends State<MyHomePage> {
   var _index = 0;
   var _fetched = false;
+  var _fetchedCount = 0;
+  var _knownPostsSize = -1;
 
-  Future<void> refresh() =>
-      widget.api.request().withFeeds().withGroups().withItems().execute();
+  Future<void> refresh() async {
+    widget.api.cache.clear();
+
+    print("Starting refresh");
+
+    var data = await widget.api
+        .request()
+        .withFeeds()
+        .withGroups()
+        .withItems()
+        .sinceId(0)
+        .execute();
+
+    while (
+      (data['items'] as List<dynamic>).isNotEmpty &&
+      _fetchedCount < FETCH_MAX_POSTS
+    ) {
+      print("Fetching more items");
+
+      var ids = widget.api.cache.items
+          .getAll()
+          .values
+          .map((value) => value.id)
+          .toList()
+        ..sort((a, b) => b - a);
+
+      setState(() {
+        _fetchedCount = ids.length;
+        _knownPostsSize = data['total_items'] ?? -1;
+      });
+
+      data =
+          await widget.api.request().withItems().sinceId(ids.first).execute();
+
+      print(
+          "Item cache size is now ${widget.api.cache.items.size} ${ids.first} ${ids.last}");
+    }
+  }
 
   @override
   void initState() {
@@ -233,8 +274,10 @@ class _MyHomePageState extends State<MyHomePage> {
       body: loggedIn
           ? (_fetched
               ? pages[_index]
-              : const CenteredPageHint(
-                  icon: Icons.downloading, text: "Fetching your feeds..."))
+              : CenteredPageHint(
+                  icon: Icons.downloading,
+                  text:
+                      "Fetching your feeds...\n${_fetchedCount > 0 && _knownPostsSize > -1 ? "$_fetchedCount / $_knownPostsSize" : ""}"))
           : Center(child: LoginPrompt(api: widget.api)),
     );
   }

lib/widgets/centered_page_hint.dart

@@ -15,7 +15,7 @@ class CenteredPageHint extends StatelessWidget {
             padding: const EdgeInsets.all(12.0),
             child: Icon(icon, size: 48),
           ),
-          Text(text),
+          Text(text, textAlign: TextAlign.center),
         ],
       ),
     );