import 'package:flutter/material.dart';

import '../../Entities/dialog_type_enum.dart';
import '../../Services/navigation_service.dart';
import '../../Services/theme_service.dart';
import 'dialog_action.dart';
import 'dialog_input_field.dart';

/// Erstellt einen neuen dynamischen Dialog
class DynamicDialog {
  /// Erstellt eine neue Instanz dieser Klasse
  DynamicDialog({
    this.title,
    this.icon,
    this.content,
    final List<DialogInputField>? inputFields,
    final List<DialogAction>? actions,
    this.backgroundColor,
    this.borderRadius = 16,
    this.barrierDismissible = true,
    this.dialogType = DialogTypeEnum.info,
    this.hiddenValues
  }) : inputFields = inputFields ?? const [],
       actions = actions ?? [DialogAction(label: 'Schließen')];

  /// Der Titel des Dialogs
  final String? title;

  /// Der Icon des Dialogs
  final IconData? icon;

  /// Der Inhalt des Dialogs
  final Widget? content;

  /// Die Hintergrundfarbe des Dialogs, Standard wenn nicht gesetzt
  final Color? backgroundColor;

  /// Der BorderRadius des Dialogs
  final double borderRadius;

  /// Ob der Dialog bei einem Klick auf die Barriere geschlossen werden kann
  final bool barrierDismissible;

  /// Die InputFelder des Dialogs
  final List<DialogInputField> inputFields;

  /// Die Aktionen des Dialogs
  final List<DialogAction> actions;

  /// Der Typ des Dialogs
  final DialogTypeEnum dialogType;

  /// Versteckte Werte, die beim Abschicken mit zurückgegeben werden
  final Map<String, dynamic>? hiddenValues;

  Map<String, TextEditingController>? _controllers;
  Map<String, FocusNode>? _focusNodes;

  BuildContext? _dialogContext;

  void _prepareControllers() {
    _controllers = {
      for (final field in inputFields)
        field.id: TextEditingController(text: field.initialValue ?? ''),
    };
  }

  void _prepareFocusNodes() {
    _focusNodes = {for (final field in inputFields) field.id: FocusNode()};
  }

  void _disposeControllers() {
    for (final TextEditingController controller in _controllers!.values) {
      controller.dispose();
    }
    _controllers = null;
  }

  void _disposeFocusNodes() {
    for (final FocusNode node in _focusNodes!.values) {
      node.dispose();
    }
    _focusNodes = null;
  }

  /// Zeigt den vorher zusammengebauten Dialog an
  Future<void> show() async {
    final BuildContext? context = NavigationService.getCurrentBuildContext();

    if (context != null) {
      final ThemeData theme = Theme.of(context);

      _prepareControllers();
      _prepareFocusNodes();

      await showDialog(
        context: context,
        barrierDismissible: barrierDismissible,
        builder: (final BuildContext ctx) {
          _dialogContext = ctx;
          WidgetsBinding.instance.addPostFrameCallback((_) {
            final DialogInputField? autoFocusField = inputFields
                .where((final DialogInputField f) => f.autoFocus)
                .cast<DialogInputField?>()
                .firstWhere(
                  (final DialogInputField? f) => f != null,
              orElse: () => null,
            );

            if (autoFocusField != null) {
              _focusNodes![autoFocusField.id]!.requestFocus();
            }
          });

          final DialogAction primaryAction = actions.firstWhere(
                (final a) => a.isPrimary,
            orElse: () => actions.first,
          );

          Color backgroundColor =
              this.backgroundColor ?? theme.colorScheme.surface;

          if (dialogType == DialogTypeEnum.error) {
            backgroundColor = theme.colorScheme.errorContainer;
          } else if (dialogType == DialogTypeEnum.success) {
            backgroundColor = ThemeService.getSuccessColor(
              brightness: theme.brightness,
            );
          }

          return AlertDialog(
            backgroundColor: backgroundColor,
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(borderRadius),
            ),
            title: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                if (icon != null)
                  Icon(icon, size: 48, color: theme.colorScheme.primary),
                if (title != null)
                  Padding(
                    padding: const EdgeInsets.only(top: 8),
                    child: Text(
                      title!,
                      style: theme.textTheme.titleLarge,
                      textAlign: TextAlign.center,
                    ),
                  ),
              ],
            ),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                if (content != null) content!,
                ...inputFields.map(
                      (final DialogInputField field) =>
                      Padding(
                        padding: const EdgeInsets.symmetric(vertical: 6),
                        child: TextField(
                          controller: _controllers![field.id],
                          focusNode: _focusNodes![field.id],
                          keyboardType: field.keyboardType,
                          obscureText: field.obscureText,
                          onChanged: field.onChanged,
                          decoration: InputDecoration(
                            labelText: field.label,
                            border: const OutlineInputBorder(),
                            isDense: true,
                          ),
                          onSubmitted: (_) {
                            final Map<String, dynamic> values = {
                              for (final entry in _controllers!.entries)
                                entry.key: entry.value.text,
                            };

                            hiddenValues?.forEach((final key, final value) {
                              values[key] = value;
                            });

                            close();
                            primaryAction.onPressed?.call(values);
                          },
                        ),
                      ),
                ),
              ],
            ),
            actions: actions
                .map(
                  (final action) =>
                  TextButton(
                    onPressed: () {
                      final Map<String, dynamic> values = {
                        for (final entry in _controllers!.entries)
                          entry.key: entry.value.text,
                      };

                      hiddenValues?.forEach((final key, final value) {
                        values[key] = value;
                      });

                      close();
                      action.onPressed?.call(values);
                    },
                    child: Text(action.label),
                  ),
            )
                .toList(),
          );
        },
      );
    }
  }

  /// Schließt den dynamischen Dialog
  void close() {
    if (_dialogContext != null) {
      Navigator.of(_dialogContext!).pop();
    }

    _disposeControllers();
    _disposeFocusNodes();
  }
}