import 'package:cdb_ui/api.dart' as API;
import 'package:cdb_ui/pages/expandable_list.dart';
import 'package:cdb_ui/pages/transaction.dart';
import 'package:flutter/material.dart';

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 listFlowInfoByActive(
      BuildContext context, Map<String, API.FlowInfo> infos) {
    return FutureBuilder(future: () async {
      var included = [];

      for (var key in infos.keys) {
        var active = await API.API().getActiveFlowsOf(key);
        if (active.isNotEmpty) {
          included.add(infos[key]);
        }
      }

      return included;
    }(), builder: (context, snapshot) {
      if (!snapshot.hasData) {
        return const CircularProgressIndicator();
      }

      var included = snapshot.data!;

      return ListView(
          children: included.map((x) => flowTile(context, x)).toList());
    });
  }

  Widget listAllFlowInfos(
      BuildContext context, Map<String, API.FlowInfo> infos) {
    return ListView(
        children: infos.values.map((x) {
      return flowTile(context, 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) {
    if (flowInfos == null) {
      return const CircularProgressIndicator();
    }

    return DefaultTabController(
        length: 4,
        child: Scaffold(
            appBar: AppBar(
                title: const Text("Flows"),
                bottom: TabBar(
                  tabs: const [
                    Tab(text: "All"),
                    Tab(text: "Produces"),
                    Tab(text: "Depends"),
                    Tab(text: "Active")
                  ],
                  onTap: (value) {
                    setState(() {
                      tabSelection = value;
                    });
                  },
                )),
            body: switch (tabSelection) {
              0 => listAllFlowInfos(context, flowInfos!),
              1 => listFlowInfoByProduced(context, flowInfos!),
              2 => listFlowInfoByDependant(context, flowInfos!),
              3 => listFlowInfoByActive(context, flowInfos!),
              _ => const Text("..."),
            }));
  }
}

class FlowInfoPage extends StatefulWidget {
  final API.FlowInfo info;

  const FlowInfoPage(this.info, {super.key});

  @override
  State<FlowInfoPage> createState() => _FlowInfoPageState();
}

class _FlowInfoPageState extends State<FlowInfoPage> {
  void refresh() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(widget.info.name)),
      body: Column(
        children: [
          // todo : ui improve
          if (widget.info.next != null) Text("Next: ${widget.info.next}"),
          if (widget.info.depends.isNotEmpty)
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                const Text("Flow can use: "),
                ...widget.info.depends.map((x) => Text(x)).toList(),
              ],
            ),
          if (widget.info.produces?.isNotEmpty ?? false)
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                const Text("Flow can produce: "),
                ...widget.info.produces!.map((x) => Text(x)).toList(),
              ],
            ),
          const Divider(),
          FutureBuilder(
            future: API.API().getActiveFlowsOf(widget.info.id),
            builder: (context, snapshot) {
              if (!snapshot.hasData) {
                return const CircularProgressIndicator();
              }

              var data = snapshot.data!;

              return Expanded(
                child: ListView(
                    children: data
                        .map((x) => ListTile(
                            title: Text(x.id),
                            onTap: () =>
                                Navigator.of(context).push(MaterialPageRoute(
                                  builder: (context) =>
                                      ActiveFlowPage(x, widget.info),
                                ))))
                        .toList()),
              );
            },
          )
        ],
      ),
      floatingActionButton: FloatingActionButton(
          onPressed: () {
            Navigator.of(context).push(MaterialPageRoute(
                builder: (context) => CreateFlowPage(widget.info, refresh)));
          },
          child: const Icon(Icons.add)),
    );
  }
}

class CreateFlowPage extends StatefulWidget {
  final API.FlowInfo info;
  final Function refresh;
  final API.Flow? previousFlow;

  const CreateFlowPage(this.info, this.refresh, {this.previousFlow, super.key});

  @override
  State<CreateFlowPage> createState() => _CreateFlowPageState();
}

class _CreateFlowPageState extends State<CreateFlowPage> {
  List<API.Transaction> depends = [];

  void _create(BuildContext context) {
    if (widget.previousFlow != null) {
      API
          .API()
          .continueFlow(widget.previousFlow!.id,
              input: depends.map((x) => x.uuid).toList())
          .then((x) {
        API.API().getFlow(x).then((flow) {
          API.API().getFlowInfo(flow.kind).then((info) {
            Navigator.of(context).pushReplacement(MaterialPageRoute(
              builder: (context) => ActiveFlowPage(flow, info),
            ));
          });
        });
      });
      return;
    }

    API
        .API()
        .startFlow(widget.info.id, input: depends.map((x) => x.uuid).toList())
        .then((flowID) {
      widget.refresh();
      API.API().getFlow(flowID).then((flow) {
        Navigator.of(context).pushReplacement(MaterialPageRoute(
            builder: (context) => ActiveFlowPage(flow, widget.info)));
      });
    });
  }

  void selectDependItems(BuildContext context, String itemVariant) {
    var (item, variant) = API.itemVariant(itemVariant);

    API.API().getInventoryOfVariant(item, variant).then((transactions) {
      Navigator.of(context).push(MaterialPageRoute(
        builder: (context) {
          return TransactionSelectPage(transactions, onSelect: (t) {
            if (!depends.contains(t)) {
              setState(() {
                depends.add(t);
              });
            }
          }, exclude: depends);
        },
      ));
    });
  }

  Widget buildInputSelection(BuildContext context) {
    return Column(
        children: widget.info.depends.map((x) {
      return ElevatedButton(
          onPressed: () {
            selectDependItems(context, x);
          },
          child: Text("Add $x"));
    }).toList());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Create new ${widget.info.name} Flow")),
      body: Column(
        children: [
          // todo : flow continuation overview
          buildInputSelection(context),
          const Divider(),
          Card(
              child: Column(
                  children: depends
                      .map((x) => TransactionCard(x, () {},
                          onTap: (x) {}, onLongPress: (x) {}))
                      .toList())),
          ElevatedButton(
              onPressed: () => _create(context),
              child: const Text("Create Flow"))
        ],
      ),
    );
  }
}

class TransactionSelectPage extends StatelessWidget {
  final Function(API.Transaction) onSelect;
  final List<API.Transaction> selections;
  final List<API.Transaction>? exclude;

  const TransactionSelectPage(this.selections,
      {super.key, required this.onSelect, this.exclude});

  @override
  Widget build(BuildContext context) {
    var selectionList = [];

    for (var s in selections) {
      if (exclude?.any((x) => x.uuid == s.uuid) ?? false) {
        continue;
      }

      selectionList.add(s);
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text("Select a Transaction"),
      ),
      body: ListView(
          children: selections
              .map((x) => TransactionCard(
                    x,
                    () {},
                    onLongPress: (x) {},
                    onTap: (t) {
                      onSelect(t);
                      Navigator.of(context).pop();
                    },
                  ))
              .toList()),
    );
  }
}

class ActiveFlowPage extends StatelessWidget {
  final API.Flow flow;
  final API.FlowInfo info;

  const ActiveFlowPage(this.flow, this.info, {super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(info.name),
          actions: [
            // todo : end flow
            IconButton(
                onPressed: () async {
                  if (info.produces?.isNotEmpty ?? false) {
                    // todo : show end screen with produce

                    return;
                  }

                  // simple dialog
                  var confirm = await showDialog(
                    context: context,
                    builder: (context) => AlertDialog(
                      title: const Text('Are you sure?'),
                      content: const Text('This will delete the flow.'),
                      actions: [
                        TextButton(
                          onPressed: () => Navigator.of(context).pop(false),
                          child: const Text('Cancel'),
                        ),
                        ElevatedButton(
                          onPressed: () => Navigator.of(context).pop(true),
                          child: const Text('Delete'),
                        ),
                      ],
                    ),
                  );

                  if (confirm) {
                    await API
                        .API()
                        .endFlow(flow.id)
                        .then((x) => Navigator.of(context).pop());
                  }
                },
                icon: const Icon(Icons.stop)),
            // todo : continue next flow
            if (info.next != null)
              IconButton(
                  onPressed: () {
                    API.API().getFlowInfo(info.next!).then((newInfo) {
                      Navigator.of(context).push(MaterialPageRoute(
                        builder: (context) {
                          return CreateFlowPage(
                            newInfo,
                            () {},
                            previousFlow: flow,
                          );
                        },
                      ));
                    });
                  },
                  icon: const Icon(Icons.arrow_forward)),

            // todo : add notes to flow
            IconButton(onPressed: () {}, icon: const Icon(Icons.note))
          ],
        ),
        body: Column(
          children: [
            Text("ID: ${flow.id}"),
            Text("Started since: ${tsFormat(flow.started)}"),
            ...flow.input!.map((x) => Text("Input: $x")).toList(),
            if (flow.done != null) ...[
              Text("Ended: ${tsFormat(flow.done!.ended)}"),
              if (flow.done!.next != null) Text("Next: ${flow.done!.next!}"),
              ...flow.done!.produced!.map((x) => Text("Produced: $x")).toList(),
            ],

            const Divider(),
            // todo : show notes
          ],
        ));
  }
}