Tricoder/frontend/lib/features/observation/presentation/pages/observation_page.dart

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

import '../../../../data/models/analysis_models.dart';
import '../../../../services/analysis_providers.dart';
import '../../../shared/presentation/widgets/async_value_view.dart';
import '../../../shared/presentation/widgets/lab_section_scaffold.dart';

class ObservationPage extends ConsumerWidget {
  const ObservationPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final snapshot = ref.watch(selectedSessionSnapshotProvider);
    final observation = ref.watch(selectedObservationProvider);

    return LabSectionScaffold(
      eyebrow: 'Observation',
      title: 'Inspect sample metadata and probe evidence.',
      description:
          'This page will show the captured audio summary, waveform slices, probe output, and sample tags before deeper analysis begins.',
      children: [
        AsyncValueView(
          value: snapshot,
          loadingMessage: 'Loading observation snapshot...',
          data: (session) {
            if (session != null) {
              return _ObservationSessionView(session: session);
            }
            return AsyncValueView(
              value: observation,
              loadingMessage: 'Loading observation details...',
              data: (selectedObservation) {
                if (selectedObservation == null) {
                  return const _EmptySelectionCard();
                }
                return _ObservationOnlyView(observation: selectedObservation);
              },
            );
          },
        ),
      ],
    );
  }
}

class _ObservationSessionView extends StatelessWidget {
  const _ObservationSessionView({required this.session});

  final AnalysisSessionSnapshot session;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        _ObservationDetailView(
          observation: session.observation,
          headerLine: 'Mode: ${session.mode} | Status: ${session.status}',
        ),
        const SizedBox(height: 16),
        Card(
          child: Padding(
            padding: const EdgeInsets.all(20),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  'Probe Evidence',
                  style: Theme.of(context).textTheme.titleLarge,
                ),
                const SizedBox(height: 12),
                ...session.probeEvidence.map(
                  (evidence) => ListTile(
                    contentPadding: EdgeInsets.zero,
                    title: Text(
                      '${evidence.category} | ${evidence.producerModuleId ?? 'unknown'}',
                    ),
                    subtitle: Text(
                      evidence.values.entries
                          .map((entry) => '${entry.key}: ${entry.value}')
                          .join(' | '),
                    ),
                    trailing: Text(evidence.confidence.toStringAsFixed(2)),
                  ),
                ),
              ],
            ),
          ),
        ),
        const SizedBox(height: 16),
        FilledButton(
          onPressed: () => context.goNamed('experiment'),
          child: const Text('Open Experiment Timeline'),
        ),
      ],
    );
  }
}

class _ObservationDetailView extends StatelessWidget {
  const _ObservationDetailView({
    required this.observation,
    this.headerLine,
  });

  final ObservationSummary observation;
  final String? headerLine;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Observation ${observation.id}',
              style: theme.textTheme.titleLarge,
            ),
            if (headerLine != null) ...[
              const SizedBox(height: 10),
              Text(headerLine!, style: theme.textTheme.bodyMedium),
            ],
            const SizedBox(height: 14),
            Text(
              'Duration ${observation.durationMs} ms | ${observation.sampleRate} Hz | ${observation.channels} channel',
              style: theme.textTheme.bodyLarge,
            ),
            const SizedBox(height: 12),
            if (observation.tags.isEmpty)
              Text('No tags attached yet.', style: theme.textTheme.bodyMedium)
            else
              Wrap(
                spacing: 8,
                runSpacing: 8,
                children: observation.tags
                    .map((tag) => Chip(label: Text(tag)))
                    .toList(),
              ),
            if (observation.captureMetadata.isNotEmpty) ...[
              const SizedBox(height: 14),
              ...observation.captureMetadata.entries.map(
                (entry) => Padding(
                  padding: const EdgeInsets.only(bottom: 4),
                  child: Text('${entry.key}: ${entry.value}'),
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }
}

class _ObservationOnlyView extends ConsumerStatefulWidget {
  const _ObservationOnlyView({required this.observation});

  final ObservationSummary observation;

  @override
  ConsumerState<_ObservationOnlyView> createState() =>
      _ObservationOnlyViewState();
}

class _ObservationOnlyViewState extends ConsumerState<_ObservationOnlyView> {
  bool _creatingSession = false;
  String? _errorMessage;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        _ObservationDetailView(observation: widget.observation),
        const SizedBox(height: 16),
        if (_errorMessage != null)
          Card(
            child: Padding(
              padding: const EdgeInsets.all(20),
              child: Text(_errorMessage!),
            ),
          ),
        if (_errorMessage != null) const SizedBox(height: 16),
        FilledButton(
          onPressed: _creatingSession ? null : _createSession,
          child: Text(
            _creatingSession ? 'Creating Analysis Session...' : 'Analyze This Observation',
          ),
        ),
      ],
    );
  }

  Future<void> _createSession() async {
    setState(() {
      _creatingSession = true;
      _errorMessage = null;
    });

    try {
      await ref
          .read(sessionActionsProvider)
          .createSessionForObservation(widget.observation.id);
      if (!mounted) return;
      context.goNamed('experiment');
    } catch (error) {
      if (!mounted) return;
      setState(() {
        _errorMessage = 'Failed to create analysis session: $error';
      });
    } finally {
      if (mounted) {
        setState(() {
          _creatingSession = false;
        });
      }
    }
  }
}

class _EmptySelectionCard extends StatelessWidget {
  const _EmptySelectionCard();

  @override
  Widget build(BuildContext context) {
    return const Card(
      child: Padding(
        padding: EdgeInsets.all(20),
        child: Text(
          'No observation selected yet. Open one from History or create a new capture.',
        ),
      ),
    );
  }
}