import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:logic_circuits_simulator/models/project.dart';
import 'package:logic_circuits_simulator/state/project.dart';
import 'package:logic_circuits_simulator/utils/provider_hook.dart';

class EditComponentPage extends HookWidget {
  final bool newComponent;
  final ComponentEntry component;

  const EditComponentPage({Key? key, this.newComponent = false, required this.component}) : super(key: key);

  static const String routeName = '/project/component/edit';

  @override
  Widget build(BuildContext context) {
    final anySave = useState(false);
    final projectState = useProvider<ProjectState>();
    final ce = projectState.index.components.where((c) => c.componentId == component.componentId).first;
    final componentNameEditingController = useTextEditingController(text: ce.componentName);
    useValueListenable(componentNameEditingController);
    final dirty = useMemoized(() {
      if (componentNameEditingController.text.isEmpty) {
        // Don't allow saving empty name
        return false;
      }
      if (componentNameEditingController.text != ce.componentName) {
        return true;
      }
      return false;
    }, [componentNameEditingController.text, ce.componentName]);

    return WillPopScope(
      onWillPop: () async {
        if (!dirty && !newComponent) {
          Navigator.of(context).pop(true);
        } else if (!dirty && anySave.value) {
          Navigator.of(context).pop(true);
        } else {
          final dialogResult = await showDialog(
            context: context,
            builder: (context) {
              return AlertDialog(
                actions: [
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(),
                    child: const Text('Cancel'),
                  ),
                  ElevatedButton(
                    onPressed: () {
                      Navigator.of(context).pop(true);
                    },
                    style: ButtonStyle(
                      backgroundColor: MaterialStateProperty.all(Colors.red),
                    ),
                    child: const Text('Discard'),
                  ),
                ],
                title: Text('Cancel ${newComponent ? 'Creation' : 'Editing'}'),
                content: Text(newComponent ? 'A new component will not be created.' : 'Are you sure you want to discard the changes?'),
              );
            }
          );
          if (dialogResult == true) {
            // ignore: use_build_context_synchronously
            Navigator.of(context).pop(!newComponent);
          }
        }
        return false;
      },
      child: Scaffold(
        appBar: AppBar(
          title: Text(newComponent ? 'New Component' : 'Edit Component'),
          centerTitle: true,
        ),
        body: CustomScrollView(
          slivers: [
            SliverPadding(
              padding: const EdgeInsets.all(8),
              sliver: SliverToBoxAdapter(
                child: TextField(
                  controller: componentNameEditingController,
                  decoration: const InputDecoration(
                    border: OutlineInputBorder(),
                    labelText: 'Component name',
                  ),
                ),
              ),
            ),
            SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  'Inputs',
                  style: Theme.of(context).textTheme.headline5,
                ),
              ),
            ),
            SliverList(
              delegate: SliverChildBuilderDelegate(
                (context, i) => ListTile(title: Text(ce.inputs[i]),),
                childCount: ce.inputs.length,
              ),
            ),
            SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  'Outputs',
                  style: Theme.of(context).textTheme.headline5,
                ),
              ),
            ),
            SliverList(
              delegate: SliverChildBuilderDelegate(
                (context, i) => ListTile(title: Text(ce.outputs[i]),),
                childCount: ce.outputs.length,
              ),
            ),
            if (ce.truthTable != null) ...[
              SliverToBoxAdapter(
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: Text(
                    'Truth Table',
                    style: Theme.of(context).textTheme.headline5,
                  ),
                ),
              ),
              SliverToBoxAdapter(
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: TruthTableEditor(
                    truthTable: ce.truthTable!,
                    inputs: ce.inputs,
                    outputs: ce.outputs,
                  ),
                ),
              )
            ],
          ],
        ),
        floatingActionButton: !dirty ? null : FloatingActionButton(
          onPressed: () async {
            if (componentNameEditingController.text.isNotEmpty) {
              await projectState.editComponent(component.copyWith(componentName: componentNameEditingController.text));
            }
            anySave.value = true;
            // TODO: Implement saving
          },
          tooltip: 'Save Component',
          child: const Icon(Icons.save),
        ),
      ),
    );
  }
}

class TruthTableEditor extends StatelessWidget {
  final List<String> inputs;
  final List<String> outputs;
  final List<String> truthTable;

  const TruthTableEditor({Key? key, required this.inputs, required this.outputs, required this.truthTable}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Table(
      defaultColumnWidth: const IntrinsicColumnWidth(),
      children: List.generate(
        truthTable.length + 1, 
        (index) {
          if (index == 0) {
            return TableRow(
              children: inputs.map((e) => Text(e)).followedBy(outputs.map((e) => Text(e))).toList(),
            );
          }
          final inputBinary = (index - 1).toRadixString(2).padLeft(inputs.length, '0');
          final outputBinary = truthTable[index - 1];

          return TableRow(
            children: inputBinary.runes.map((r) => Text(String.fromCharCodes([r])))
              .followedBy(outputBinary.runes.map((r) => Text(String.fromCharCodes([r]))))
              .toList(),
          );
        },
      ),
    );
  }
}