import 'package:flutter/material.dart';
import '../core/app_controller.dart';
import '../core/failure.dart';
import '../l10n/strings.dart';
import '../services/ssh_service.dart';
import 'password_fields.dart';

/// Asks for the current password, then the new one twice, and changes the
/// master password. The Vault stays open and unchanged on any failure.
class ChangePasswordPage extends StatefulWidget {
  final AppController controller;
  const ChangePasswordPage(this.controller, {super.key});
  @override
  State<ChangePasswordPage> createState() => _ChangePasswordPageState();
}

class _ChangePasswordPageState extends State<ChangePasswordPage> {
  final current = TextEditingController();
  final next = TextEditingController();
  final repeated = TextEditingController();
  bool busy = false;
  String? error;

  @override
  void dispose() {
    for (final c in [current, next, repeated]) {
      c.clear();
      c.dispose();
    }
    super.dispose();
  }

  Future<void> submit() async {
    FocusManager.instance.primaryFocus?.unfocus();
    setState(() {
      busy = true;
      error = null;
    });
    try {
      if (next.text != repeated.text) throw const Failure('passwordMismatch');
      if (next.text == current.text) throw const Failure('samePassword');
      await widget.controller.changePassword(
        current.text,
        next.text,
        context.tr('biometricReason'),
      );
      if (!mounted) return;
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(SnackBar(content: Text(context.tr('passwordChanged'))));
      Navigator.pop(context, true);
    } catch (e) {
      if (!mounted) return;
      final code = failureCode(e);
      if (code == 'passwordChangedBiometricOff') {
        // The password itself was changed.
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(context.tr(code)),
            duration: const Duration(seconds: 10),
          ),
        );
        Navigator.pop(context, true);
        return;
      }
      setState(
        () => error = code == 'unlockFailed' ? 'wrongCurrentPassword' : code,
      );
    } finally {
      if (mounted) setState(() => busy = false);
    }
  }

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(title: Text(context.tr('changePassword'))),
    body: SafeArea(
      child: Center(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 450),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                PasswordField(
                  controller: current,
                  label: context.tr('currentPassword'),
                  autofocus: true,
                  action: TextInputAction.next,
                ),
                const SizedBox(height: 16),
                PasswordField(
                  controller: next,
                  label: context.tr('newPassword'),
                  action: TextInputAction.next,
                  onChanged: (_) => setState(() {}),
                ),
                const SizedBox(height: 8),
                PasswordAdvice(next.text),
                const SizedBox(height: 16),
                PasswordField(
                  controller: repeated,
                  label: context.tr('confirmNewPassword'),
                  action: TextInputAction.done,
                  onSubmitted: (_) {
                    if (!busy) submit();
                  },
                ),
                if (error != null) ...[
                  const SizedBox(height: 12),
                  Text(
                    context.tr(error!),
                    style: TextStyle(
                      color: Theme.of(context).colorScheme.error,
                    ),
                  ),
                ],
                const SizedBox(height: 20),
                FilledButton(
                  onPressed: busy ? null : submit,
                  child: Text(context.tr('changePassword')),
                ),
                if (busy) const LinearProgressIndicator(),
              ],
            ),
          ),
        ),
      ),
    ),
  );
}