import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../remote/discovery.dart';
import '../remote/remote_session.dart';
import '../state/remote_providers.dart';
import '../theme/tokens.dart';

/// Open the cross-device control sheet: pick a same-Wi-Fi Timbre device to
/// control, or detach back to local playback (updates-features.md #3).
Future<void> showDevicesSheet(BuildContext context) {
  return showModalBottomSheet<void>(
    context: context,
    backgroundColor: TimbreColors.background,
    isScrollControlled: true,
    builder: (_) => const _DevicesSheet(),
  );
}

class _DevicesSheet extends ConsumerStatefulWidget {
  const _DevicesSheet();

  @override
  ConsumerState<_DevicesSheet> createState() => _DevicesSheetState();
}

class _DevicesSheetState extends ConsumerState<_DevicesSheet> {
  @override
  void initState() {
    super.initState();
    // Browse only while the sheet is open — discovery is comparatively costly.
    Future.microtask(
        () => ref.read(remoteControlProvider.notifier).startBrowsing());
  }

  @override
  void dispose() {
    ref.read(remoteControlProvider.notifier).stopBrowsing();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final rc = ref.watch(remoteControlProvider);
    final accent = Theme.of(context).colorScheme.primary;

    return SafeArea(
      child: Padding(
        padding: const EdgeInsets.symmetric(vertical: TimbreSpacing.lg),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: TimbreSpacing.xl),
              child: Text('Devices',
                  style:
                      TextStyle(color: accent, fontWeight: FontWeight.w700)),
            ),
            const SizedBox(height: TimbreSpacing.md),
            if (!rc.supported)
              const _Note(
                  "Cross-device control isn't available on this platform.")
            else ...[
              // "Play here" row — active when currently controlling a remote.
              _LocalRow(
                active: !rc.isAttached,
                onTap: rc.isAttached
                    ? () => ref.read(remoteControlProvider.notifier).detach()
                    : null,
              ),
              const _Divider(),
              for (final d in rc.devices)
                _DeviceRow(
                  device: d,
                  active: rc.attachedDevice?.id == d.id,
                  connecting: rc.attachedDevice?.id == d.id &&
                      rc.status == RemoteConnStatus.connecting,
                  onTap: () =>
                      ref.read(remoteControlProvider.notifier).attach(d),
                ),
              if (rc.devices.isEmpty)
                const _Note('Searching for devices on your Wi-Fi…',
                    spinner: true),
              if (rc.status == RemoteConnStatus.denied)
                const _Note(
                    'That device refused the connection (different account?).'),
            ],
          ],
        ),
      ),
    );
  }
}

/// The "play on this device" (local) row, shown selected when not attached.
class _LocalRow extends StatelessWidget {
  const _LocalRow({required this.active, this.onTap});

  final bool active;
  final VoidCallback? onTap;

  @override
  Widget build(BuildContext context) {
    final accent = Theme.of(context).colorScheme.primary;
    return InkWell(
      onTap: onTap,
      child: Container(
        constraints:
            const BoxConstraints(minHeight: TimbreSpacing.minTouchTarget),
        padding: const EdgeInsets.symmetric(horizontal: TimbreSpacing.xl),
        child: Row(
          children: [
            Icon(Icons.smartphone,
                size: 16,
                color: active ? accent : TimbreColors.foreground),
            const SizedBox(width: TimbreSpacing.md),
            Expanded(
              child: Text('This device',
                  style: TextStyle(
                    color: TimbreColors.foreground,
                    fontWeight: active ? FontWeight.w700 : FontWeight.w400,
                  )),
            ),
            if (active)
              Text('●', style: TextStyle(color: accent)),
          ],
        ),
      ),
    );
  }
}

class _DeviceRow extends StatelessWidget {
  const _DeviceRow({
    required this.device,
    required this.active,
    required this.connecting,
    required this.onTap,
  });

  final DiscoveredDevice device;
  final bool active;
  final bool connecting;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final accent = Theme.of(context).colorScheme.primary;
    return InkWell(
      onTap: onTap,
      child: Container(
        constraints:
            const BoxConstraints(minHeight: TimbreSpacing.minTouchTarget),
        padding: const EdgeInsets.symmetric(horizontal: TimbreSpacing.xl),
        child: Row(
          children: [
            Icon(Icons.cast,
                size: 16,
                color: active ? accent : TimbreColors.foreground),
            const SizedBox(width: TimbreSpacing.md),
            Expanded(
              child: Text(
                device.name,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: TextStyle(
                  color: TimbreColors.foreground,
                  fontWeight: active ? FontWeight.w700 : FontWeight.w400,
                ),
              ),
            ),
            if (connecting)
              const SizedBox(
                height: 14,
                width: 14,
                child: CircularProgressIndicator(strokeWidth: 2),
              )
            else if (active)
              Text('●', style: TextStyle(color: accent)),
          ],
        ),
      ),
    );
  }
}

class _Divider extends StatelessWidget {
  const _Divider();

  @override
  Widget build(BuildContext context) => const Padding(
        padding: EdgeInsets.symmetric(
            horizontal: TimbreSpacing.xl, vertical: TimbreSpacing.sm),
        child: Divider(color: TimbreColors.border, height: 1),
      );
}

class _Note extends StatelessWidget {
  const _Note(this.text, {this.spinner = false});

  final String text;
  final bool spinner;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(
          horizontal: TimbreSpacing.xl, vertical: TimbreSpacing.md),
      child: Row(
        children: [
          if (spinner) ...[
            const SizedBox(
              height: 14,
              width: 14,
              child: CircularProgressIndicator(strokeWidth: 2),
            ),
            const SizedBox(width: TimbreSpacing.md),
          ],
          Flexible(
            child: Text(text,
                style: const TextStyle(color: TimbreColors.dimmed)),
          ),
        ],
      ),
    );
  }
}