// Voice settings dialog (SDD-097). Surfaces a TransmitMode radio
// group, a bind-key button, and a release-tail slider.

import 'dart:io' show Platform;

import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';

import '../l10n/generated/app_localizations.dart';
import '../src/rust/api.dart' as rust;

/// True when the host is a touch-only mobile platform without a
/// hardware keyboard the user would bind a PTT key on. Mirrors the
/// helper in `voice_bar.dart`.
bool get _isTouchOnlyPttHost {
  if (kIsWeb) return false;
  return Platform.isIOS || Platform.isAndroid;
}

/// Result returned by [`VoiceSettingsDialog`]. `null` indicates a
/// cancelled dialog.
class VoiceSettingsResult {
  /// Construct a result snapshot.
  const VoiceSettingsResult({
    required this.mode,
    required this.releaseTailMs,
    required this.bindKeyRequested,
  });

  /// Selected transmit mode.
  final rust.BridgeTransmitMode mode;

  /// Chosen release-tail in milliseconds (0..=500, step 25).
  final int releaseTailMs;

  /// True when the user tapped the "bind key" button. The caller
  /// is expected to open the focus-scoped capture dialog
  /// afterwards.
  final bool bindKeyRequested;
}

/// Voice settings dialog widget.
class VoiceSettingsDialog extends StatefulWidget {
  /// Construct a dialog seeded with the current settings.
  const VoiceSettingsDialog({
    super.key,
    required this.initialMode,
    required this.initialReleaseTailMs,
  });

  /// Currently active transmit mode.
  final rust.BridgeTransmitMode initialMode;

  /// Currently configured release tail in milliseconds.
  final int initialReleaseTailMs;

  @override
  State<VoiceSettingsDialog> createState() => _VoiceSettingsDialogState();
}

class _VoiceSettingsDialogState extends State<VoiceSettingsDialog> {
  late rust.BridgeTransmitMode _mode;
  late double _releaseTail;

  @override
  void initState() {
    super.initState();
    _mode = widget.initialMode;
    _releaseTail = widget.initialReleaseTailMs.clamp(0, 500).toDouble();
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppL10n.of(context);
    final theme = Theme.of(context);
    return AlertDialog(
      title: Text(l10n.voiceSettingsTitle),
      content: SizedBox(
        width: 360,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              l10n.voiceModeLabel,
              style: theme.textTheme.titleSmall,
            ),
            const SizedBox(height: 4),
            RadioListTile<rust.BridgeTransmitMode>(
              dense: true,
              value: rust.BridgeTransmitMode.ptt,
              groupValue: _mode,
              title: Text(l10n.voiceModePtt),
              onChanged: (v) => setState(() => _mode = v!),
            ),
            RadioListTile<rust.BridgeTransmitMode>(
              dense: true,
              value: rust.BridgeTransmitMode.continuous,
              groupValue: _mode,
              title: Text(l10n.voiceModeContinuous),
              onChanged: (v) => setState(() => _mode = v!),
            ),
            RadioListTile<rust.BridgeTransmitMode>(
              dense: true,
              value: rust.BridgeTransmitMode.voiceActivity,
              groupValue: _mode,
              title: Text(l10n.voiceModeVoiceActivity),
              secondary: Text(
                l10n.voiceModeComingSoon,
                style: theme.textTheme.bodySmall,
              ),
              // VoiceActivity is reserved per DEC-030 — keep the
              // tile visible but disabled per SDD-095.
              onChanged: null,
            ),
            const Divider(),
            // Bind-key + release-tail are PTT-only concepts. Hide
            // them entirely when the user has switched to a
            // non-PTT mode so the dialog stays focused on what's
            // actually configurable for that mode.
            //
            // Additionally on touch-only mobile hosts (iOS / iPadOS
            // / Android) there is no hardware keyboard to bind a
            // key on — the VoiceBar renders an on-screen Push to
            // Talk button instead. Hide the Bind Key affordance
            // there but keep the release-tail slider since it
            // still applies to the on-screen button's behaviour.
            if (_mode == rust.BridgeTransmitMode.ptt) ...[
              if (!_isTouchOnlyPttHost) ...[
                OutlinedButton.icon(
                  icon: const Icon(Icons.keyboard),
                  label: Text(l10n.voiceBindKeyAction),
                  onPressed: () {
                    Navigator.of(context).pop(
                      VoiceSettingsResult(
                        mode: _mode,
                        releaseTailMs: _releaseTail.round(),
                        bindKeyRequested: true,
                      ),
                    );
                  },
                ),
                const SizedBox(height: 8),
              ],
              Text(
                l10n.voiceReleaseTailLabel,
                style: theme.textTheme.titleSmall,
              ),
              Row(
                children: [
                  Expanded(
                    child: Slider(
                      value: _releaseTail,
                      min: 0,
                      max: 500,
                      divisions: 20, // step 25 ms
                      label:
                          '${_releaseTail.round()}${l10n.voiceReleaseTailHint}',
                      onChanged: (v) => setState(() => _releaseTail = v),
                    ),
                  ),
                  SizedBox(
                    width: 64,
                    child: Text(
                      '${_releaseTail.round()}${l10n.voiceReleaseTailHint}',
                      style: theme.textTheme.bodySmall,
                      textAlign: TextAlign.end,
                    ),
                  ),
                ],
              ),
            ],
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: Text(l10n.closeAction),
        ),
        FilledButton(
          onPressed: () => Navigator.of(context).pop(
            VoiceSettingsResult(
              mode: _mode,
              releaseTailMs: _releaseTail.round(),
              bindKeyRequested: false,
            ),
          ),
          child: Text(l10n.pttConfigureSaveAction),
        ),
      ],
    );
  }
}