import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:provider/provider.dart';
import 'package:iperf3gui/domain/models/test_configuration.dart';
import 'package:iperf3gui/domain/services/iperf3_runner.dart';
import 'package:iperf3gui/ui/features/test_run/iperf3_event_formatter.dart';
import 'package:iperf3gui/ui/features/test_run/test_run_view_model.dart';

/// Main test run screen.
///
/// Takes an [Iperf3Runner] rather than constructing one, so this layer names no
/// transport: the Android app injects the JNI-backed implementation from
/// main(), and a test injects a fake.
class TestRunScreen extends StatelessWidget {
  const TestRunScreen({required this.runner, super.key});

  final Iperf3Runner runner;

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (_) => TestRunViewModel(iperf3Service: runner),
      child: const _TestRunContent(),
    );
  }
}

class _TestRunContent extends StatefulWidget {
  const _TestRunContent();

  @override
  State<_TestRunContent> createState() => _TestRunContentState();
}

class _TestRunContentState extends State<_TestRunContent> {
  static const _defaults = TestConfiguration();

  final _serverController =
      TextEditingController(text: _defaults.server);
  final _portController =
      TextEditingController(text: _defaults.port.toString());
  final _durationController =
      TextEditingController(text: _defaults.duration.inSeconds.toString());
  final _streamsController =
      TextEditingController(text: _defaults.parallelStreams.toString());
  final _outputScrollController = ScrollController();

  @override
  void dispose() {
    _serverController.dispose();
    _portController.dispose();
    _durationController.dispose();
    _streamsController.dispose();
    _outputScrollController.dispose();
    super.dispose();
  }

  TestConfiguration _readConfiguration() {
    return TestConfiguration(
      server: _serverController.text.trim(),
      port: int.tryParse(_portController.text) ?? _defaults.port,
      duration: Duration(
        seconds: int.tryParse(_durationController.text) ??
            _defaults.duration.inSeconds,
      ),
      parallelStreams:
          int.tryParse(_streamsController.text) ?? _defaults.parallelStreams,
    );
  }

  /// Keep the newest output in view, but only once the frame that added it has
  /// been laid out.
  void _scrollToBottom() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!_outputScrollController.hasClients) return;
      _outputScrollController
          .jumpTo(_outputScrollController.position.maxScrollExtent);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('iperf3-gui'),
        actions: [
          Consumer<TestRunViewModel>(
            builder: (context, vm, _) => IconButton(
              tooltip: 'Copy output',
              icon: const Icon(Icons.copy_all),
              onPressed: vm.output.isEmpty
                  ? null
                  : () {
                      Clipboard.setData(ClipboardData(text: vm.output));
                      ScaffoldMessenger.of(context).showSnackBar(
                        const SnackBar(content: Text('Output copied')),
                      );
                    },
            ),
          ),
        ],
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            TextField(
              controller: _serverController,
              autocorrect: false,
              decoration: const InputDecoration(
                labelText: 'Server',
                hintText: 'e.g. iperf.es.net or 192.168.1.1',
              ),
            ),
            const SizedBox(height: 12),

            Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _portController,
                    keyboardType: TextInputType.number,
                    decoration: const InputDecoration(labelText: 'Port'),
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: TextField(
                    controller: _durationController,
                    keyboardType: TextInputType.number,
                    decoration: const InputDecoration(labelText: 'Seconds'),
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: TextField(
                    controller: _streamsController,
                    keyboardType: TextInputType.number,
                    decoration: const InputDecoration(labelText: 'Streams'),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 16),

            Consumer<TestRunViewModel>(
              builder: (context, vm, _) {
                if (vm.isRunning) {
                  return OutlinedButton.icon(
                    onPressed: vm.stopTest,
                    icon: const Icon(Icons.stop),
                    label: const Text('STOP'),
                  );
                }
                return ElevatedButton(
                  onPressed: () => vm.runTest(_readConfiguration()),
                  child: const Text('GO'),
                );
              },
            ),
            const SizedBox(height: 12),

            // Status line
            Consumer<TestRunViewModel>(
              builder: (context, vm, _) {
                final scheme = Theme.of(context).colorScheme;
                final (String label, Color color) = switch (vm.state) {
                  TestRunState.idle => ('Ready', scheme.onSurfaceVariant),
                  TestRunState.running => ('Running…', scheme.primary),
                  TestRunState.completed => (
                      vm.wasStopped ? 'Stopped' : 'Test complete',
                      vm.wasStopped ? scheme.onSurfaceVariant : scheme.primary,
                    ),
                  TestRunState.error => (
                      'Error${vm.result != null ? ' (exit ${vm.result!.exitCode})' : ''}',
                      scheme.error,
                    ),
                };
                return Row(
                  children: [
                    if (vm.isRunning)
                      const Padding(
                        padding: EdgeInsets.only(right: 8),
                        child: SizedBox(
                          width: 14,
                          height: 14,
                          child: CircularProgressIndicator(strokeWidth: 2),
                        ),
                      ),
                    Text(label, style: TextStyle(color: color)),
                  ],
                );
              },
            ),
            const SizedBox(height: 12),

            // Live throughput figures. Every number here is read off the
            // session; none are computed in the widget tree.
            Consumer<TestRunViewModel>(
              builder: (context, vm, _) {
                final session = vm.session;
                final latest = session.latestBitsPerSecond;
                final mean = session.meanBitsPerSecond;
                final peak = session.peakBitsPerSecond;
                if (latest == null || mean == null || peak == null) {
                  return const SizedBox.shrink();
                }
                final total = session.summary?.sent;
                return Padding(
                  padding: const EdgeInsets.only(bottom: 12),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      _Stat(
                        label: total != null ? 'total' : 'now',
                        value: formatBitrate(total?.bitsPerSecond ?? latest),
                      ),
                      _Stat(label: 'avg', value: formatBitrate(mean)),
                      _Stat(label: 'peak', value: formatBitrate(peak)),
                      _Stat(
                          label: 'samples', value: '${session.sampleCount}'),
                    ],
                  ),
                );
              },
            ),

            // Live output
            Expanded(
              child: Container(
                width: double.infinity,
                padding: const EdgeInsets.all(8),
                decoration: BoxDecoration(
                  border: Border.all(
                    color: Theme.of(context).colorScheme.outlineVariant,
                  ),
                  borderRadius: BorderRadius.circular(4),
                ),
                child: Consumer<TestRunViewModel>(
                  builder: (context, vm, _) {
                    _scrollToBottom();
                    return SingleChildScrollView(
                      controller: _outputScrollController,
                      child: SelectableText(
                        vm.output.isEmpty
                            ? 'Output will appear here.'
                            : vm.output,
                        style: const TextStyle(
                          fontFamily: 'monospace',
                          fontSize: 12,
                        ),
                      ),
                    );
                  },
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}


/// One figure in the throughput row.
class _Stat extends StatelessWidget {
  const _Stat({required this.label, required this.value});

  final String label;
  final String value;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          label,
          style: theme.textTheme.labelSmall
              ?.copyWith(color: theme.colorScheme.onSurfaceVariant),
        ),
        Text(
          value,
          style: theme.textTheme.titleSmall
              ?.copyWith(fontFeatures: const [FontFeature.tabularFigures()]),
        ),
      ],
    );
  }
}