import 'package:flutter/material.dart';

import '../model/callback_models/create_task_request.dart';
import '../model/extensions/controller_context.dart';
import '../model/task.dart';
import '../service/task_controller.dart';
import '../service/tools.dart';
import '../service/validators.dart';

class TaskEditPage extends StatefulWidget {
  static const routeName = '/edit';
  const TaskEditPage({super.key});

  @override
  State<TaskEditPage> createState() => _TaskEditPageState();
}

class _TaskEditPageState extends State<TaskEditPage> {
  Task? task;
  bool isInitialized = false;
  final titleController = TextEditingController();
  final descriptionController = TextEditingController();
  final categoryController = TextEditingController();
  final urlController = TextEditingController();
  final dueDateController = TextEditingController();
  final dueTimeController = TextEditingController();
  String pageTitle = 'Create Task';
  final dueDateFocusNode = FocusNode();
  final dueTimeFocusNode = FocusNode();
  final categoryFocusNode = FocusNode();
  final formKey = GlobalKey<FormState>(debugLabel: 'taskEditFormKey');
  bool didFormChange = false;
  bool isDueTimeEnabled = false;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    task = ModalRoute.of(context)!.settings.arguments as Task?;
    if (task != null && !isInitialized) {
      titleController.text = task!.title;
      descriptionController.text = task!.description;
      categoryController.text = task!.category;
      urlController.text = task!.url;
      if (task!.due != null) {
        dueDateController.text = getIsoDateString(task!.due!);
        dueTimeController.text = TimeOfDay.fromDateTime(
          task!.due!,
        ).format(context);
        isDueTimeEnabled = true;
      }
      isInitialized = true;
      pageTitle = task!.title;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(pageTitle),
        actions: [
          if (task != null)
            IconButton(
              onPressed: () {
                context.controller<TaskController>().deleteTask(task!);
                Navigator.of(context).pop();
              },
              icon: Icon(Icons.delete),
            ),
        ],
      ),
      body: Form(
        canPop: !didFormChange,
        onChanged: () => didFormChange = true,
        onPopInvokedWithResult: onPopInvoked,
        autovalidateMode: AutovalidateMode.onUnfocus,
        key: formKey,
        child: Padding(
          padding: EdgeInsets.symmetric(
            horizontal: MediaQuery.of(context).size.width * 0.05,
          ),
          child: Column(
            children: [
              TextFormField(
                autofocus: true,
                controller: titleController,
                decoration: InputDecoration(label: Text('Title')),
                keyboardType: TextInputType.text,
                textInputAction: TextInputAction.next,
              ),
              TextFormField(
                controller: descriptionController,
                decoration: InputDecoration(label: Text('Description')),
                keyboardType: TextInputType.multiline,
                textInputAction: TextInputAction.newline,
                minLines: 3,
                maxLines: 10,
              ),
              TextFormField(
                focusNode: dueDateFocusNode,
                controller: dueDateController,
                onChanged: maybeEnableDueTime,
                onFieldSubmitted: (_) {
                  isDueTimeEnabled
                      ? dueDateFocusNode.nextFocus()
                      : categoryFocusNode.requestFocus();
                },
                decoration: InputDecoration(
                  label: Text('Due Date'),
                  suffix: IconButton(
                    onPressed: () async {
                      final result = await onOpenCalendarPickerPressed();
                      if (result != null) {
                        final dateString = getIsoDateString(result);
                        dueDateController.text = dateString;
                        maybeEnableDueTime(dateString);
                        formKey.currentState?.validate();
                        dueTimeFocusNode.requestFocus();
                      }
                    },
                    icon: Icon(Icons.calendar_month),
                  ),
                ),
                validator: dateTimeValidator,
                keyboardType: TextInputType.datetime,
                textInputAction: TextInputAction.next,
              ),
              TextFormField(
                focusNode: dueTimeFocusNode,
                onFieldSubmitted: (_) => dueTimeFocusNode.nextFocus(),
                controller: dueTimeController,
                enabled: isDueTimeEnabled,
                decoration: InputDecoration(
                  label: Text('Due Time'),
                  suffix: IconButton(
                    onPressed: () async {
                      final result = await onOpenTimePickerPressed();
                      if (result != null && context.mounted) {
                        dueTimeController.text = result.format(context);
                        categoryFocusNode.requestFocus();
                      }
                    },
                    icon: Icon(Icons.schedule),
                  ),
                ),
                validator: timeValidator,
                keyboardType: TextInputType.text,
                textInputAction: TextInputAction.next,
              ),
              TextFormField(
                focusNode: categoryFocusNode,
                controller: categoryController,
                decoration: InputDecoration(label: Text('Category')),
                keyboardType: TextInputType.text,
                textInputAction: TextInputAction.next,
              ),
              TextFormField(
                controller: urlController,
                decoration: InputDecoration(label: Text('Url')),
                keyboardType: TextInputType.text,
                textInputAction: TextInputAction.next,
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: onSavePressed,
        child: Icon(Icons.save),
      ),
    );
  }

  Future<DateTime?> onOpenCalendarPickerPressed() {
    return showDialog<DateTime?>(
      context: context,
      builder: (context) => DatePickerDialog(
        firstDate: DateTime(DateTime.now().year - 100),
        lastDate: DateTime(DateTime.now().year + 100),
        initialDate:
            DateTime.tryParse(dueDateController.text) ?? DateTime.now(),
      ),
    );
  }

  Future<TimeOfDay?> onOpenTimePickerPressed() {
    return showDialog<TimeOfDay?>(
      context: context,
      builder: (context) => TimePickerDialog(
        initialTime: TimeOfDay.fromDateTime(task?.due ?? DateTime.now()),
      ),
    );
  }

  void onSavePressed() {
    Navigator.of(context).pop(
      CreateTaskRequest(
        title: titleController.text,
        description: descriptionController.text,
        start: null,
        due: null,
        isCompleted: false,
        category: categoryController.text,
        subtasks: [],
        alarms: [],
        location: null,
        url: urlController.text,
      ),
    );
  }

  void onPopInvoked(bool didPop, Object? result) {
    if (!didPop) {
      showDialog<bool>(
        context: context,
        builder: (context) => AlertDialog(
          title: Text('Unsaved Changes'),
          content: Text(
            'Are you sure you want to cancel editing? Unsaved changes will be lost.',
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(context).pop(false),
              child: Text('No'),
            ),
            TextButton(
              onPressed: () => Navigator.of(context).pop(true),
              child: Text('Yes'),
            ),
          ],
        ),
      ).then((result) {
        if (result != null && result && context.mounted) {
          Navigator.of(context).pop();
        }
      });
    }
  }

  void maybeEnableDueTime(String value) {
    if (value.isNotEmpty &&
        dateTimeValidator(value) == null &&
        !isDueTimeEnabled) {
      setState(() {
        isDueTimeEnabled = true;
      });
    } else if (isDueTimeEnabled) {
      setState(() {
        isDueTimeEnabled = false;
      });
    }
  }
}