update flow pages

lib/api.dart

@@ -490,3 +490,8 @@ class GlobalItemStat {
     total_price = json["total_price"];
   }
 }
+
+(String, String) itemVariant(String iv) {
+  var split = iv.split("::");
+  return (split[0], split[1]);
+}

lib/pages/expandable_list.dart

@@ -0,0 +1,52 @@
+import 'package:flutter/material.dart';
+
+class ExpandableListItem {
+  ExpandableListItem({
+    required this.body,
+    required this.header,
+    this.isExpanded = false,
+  });
+
+  Widget body;
+  Widget header;
+  bool isExpanded;
+}
+
+class ExpandableList extends StatefulWidget {
+  final List<ExpandableListItem> entries;
+
+  const ExpandableList(this.entries, {super.key});
+
+  @override
+  State<ExpandableList> createState() => _ExpandableListState();
+}
+
+class _ExpandableListState extends State<ExpandableList> {
+  @override
+  Widget build(BuildContext context) {
+    return SingleChildScrollView(
+      child: Container(
+        child: _buildPanel(),
+      ),
+    );
+  }
+
+  Widget _buildPanel() {
+    return ExpansionPanelList(
+      expansionCallback: (int index, bool isExpanded) {
+        setState(() {
+          widget.entries[index].isExpanded = isExpanded;
+        });
+      },
+      children: widget.entries.map<ExpansionPanel>((ExpandableListItem item) {
+        return ExpansionPanel(
+          headerBuilder: (BuildContext context, bool isExpanded) {
+            return item.header;
+          },
+          body: item.body,
+          isExpanded: item.isExpanded,
+        );
+      }).toList(),
+    );
+  }
+}

lib/pages/flow.dart

@@ -1,49 +1,136 @@
 import 'package:cdb_ui/api.dart' as API;
+import 'package:cdb_ui/pages/expandable_list.dart';
 import 'package:flutter/material.dart';
 
-class FlowsPage extends StatelessWidget {
+class FlowsPage extends StatefulWidget {
   const FlowsPage({super.key});
 
+  @override
+  State<FlowsPage> createState() => _FlowsPageState();
+}
+
+class _FlowsPageState extends State<FlowsPage> {
+  int tabSelection = 0;
+  Map<String, API.FlowInfo>? flowInfos;
+
+  @override
+  void initState() {
+    super.initState();
+    API.API().getFlows().then(
+      (value) {
+        setState(() {
+          flowInfos = value;
+        });
+      },
+    );
+  }
+
+  Widget flowTile(BuildContext context, API.FlowInfo x) {
+    return ListTile(
+      title: Text(x.name),
+      onTap: () {
+        Navigator.of(context).push(MaterialPageRoute(
+          builder: (context) => FlowInfoPage(x),
+        ));
+      },
+    );
+  }
+
   Widget listAllFlowInfos(
       BuildContext context, Map<String, API.FlowInfo> infos) {
     return ListView(
         children: infos.values.map((x) {
-      return ListTile(
+      return flowTile(context, x);
-        title: Text(x.name),
-        onTap: () {
-          Navigator.of(context).push(MaterialPageRoute(
-            builder: (context) => FlowPage(x),
-          ));
-        },
-      );
     }).toList());
   }
 
+  Widget listFlowInfoByProduced(
+      BuildContext context, Map<String, API.FlowInfo> infos) {
+    Map<String, List<API.FlowInfo>> producedMapping = {};
+
+    for (var f in infos.values) {
+      for (var produces in f.produces ?? []) {
+        var item = API.itemVariant(produces).$1;
+        producedMapping.putIfAbsent(item, () {
+          return [];
+        });
+        producedMapping[item]!.add(f);
+      }
+    }
+
+    List<ExpandableListItem> items = [];
+
+    for (var key in producedMapping.keys) {
+      var flows = Column(
+          children: producedMapping[key]!.map((x) {
+        return flowTile(context, x);
+      }).toList());
+      items.add(ExpandableListItem(body: flows, header: Text(key)));
+    }
+
+    return ExpandableList(items);
+  }
+
+  Widget listFlowInfoByDependant(
+      BuildContext context, Map<String, API.FlowInfo> infos) {
+    Map<String, List<API.FlowInfo>> dependsMapping = {};
+
+    for (var f in infos.values) {
+      for (var produces in f.depends) {
+        var item = API.itemVariant(produces).$1;
+        // todo : add only if item is in inventory
+        dependsMapping.putIfAbsent(item, () {
+          return [];
+        });
+        dependsMapping[item]!.add(f);
+      }
+    }
+
+    List<ExpandableListItem> items = [];
+
+    for (var key in dependsMapping.keys) {
+      var flows = Column(
+          children: dependsMapping[key]!.map((x) {
+        return flowTile(context, x);
+      }).toList());
+      items.add(ExpandableListItem(body: flows, header: Text(key)));
+    }
+
+    return ExpandableList(items);
+  }
+
   @override
   Widget build(BuildContext context) {
-    // todo : flows (info) by item produced
     // todo : list currently active
-    // todo : flows by item needed (show only avail)
+
+    if (flowInfos == null) {
+      return const CircularProgressIndicator();
+    }
+
     return Scaffold(
-        appBar: AppBar(title: const Text("Flows")),
+        appBar: AppBar(
-        body: FutureBuilder(
+            title: const Text("Flows"),
-            future: API.API().getFlows(),
+            bottom: TabBar(
-            builder: (ctx, snap) {
+              tabs: const [Text("All"), Text("Produces"), Text("Depends")],
-              if (!snap.hasData) {
+              onTap: (value) {
-                return const CircularProgressIndicator();
+                setState(() {
-              }
+                  tabSelection = value;
-
+                });
-              var data = snap.data!;
+              },
-
+            )),
-              return listAllFlowInfos(context, data);
+        body: switch (tabSelection) {
-            }));
+          0 => listAllFlowInfos(context, flowInfos!),
+          1 => listFlowInfoByProduced(context, flowInfos!),
+          2 => listFlowInfoByDependant(context, flowInfos!),
+          _ => const Text("..."),
+        });
   }
 }
 
-class FlowPage extends StatelessWidget {
+class FlowInfoPage extends StatelessWidget {
   final API.FlowInfo info;
 
-  const FlowPage(this.info, {super.key});
+  const FlowInfoPage(this.info, {super.key});
 
   @override
   Widget build(BuildContext context) {