import 'dart:async';
import 'package:flutter/material.dart';
import '../api/client.dart';
import '../api/models.dart';
import '../widgets/run_status_badge.dart';
import '../widgets/step_progress.dart';
import 'log_viewer.dart';

class RunScreen extends StatefulWidget {
  final Pipeline pipeline;
  final APIClient api;

  const RunScreen({super.key, required this.pipeline, required this.api});

  @override
  State<RunScreen> createState() => _RunScreenState();
}

class _RunScreenState extends State<RunScreen> {
  String? _runId;
  RunState? _runState;
  String? _error;
  bool _starting = true;
  Timer? _pollTimer;

  Future<void> _start() async {
    try {
      final data = await widget.api.startRun(widget.pipeline.id);
      setState(() {
        _runId = data['run_id'] as String;
        _runState = RunState(
          runId: data['run_id'] as String,
          pipelineId: data['pipeline_id'] as String? ?? '',
          status: parseRunStatus(data['status'] as String? ?? 'running'),
          currentStep: -1,
          steps: [],
        );
        _starting = false;
      });
      _startPolling();
    } catch (e) {
      setState(() {
        _error = e.toString();
        _starting = false;
      });
    }
  }

  void _startPolling() {
    _pollTimer = Timer.periodic(const Duration(seconds: 2), (_) => _poll());
  }

  Future<void> _poll() async {
    if (_runId == null) return;
    try {
      final state = await widget.api.getRunStatus(_runId!);
      setState(() {
        _runState = state;
      });
      if (state.isFinished) {
        _pollTimer?.cancel();
      }
    } catch (e) {
      // Silently ignore polling errors
    }
  }

  @override
  void dispose() {
    _pollTimer?.cancel();
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    _start();
  }

  void _viewLog() {
    if (_runId == null) return;
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => LogViewerScreen(
          runId: _runId!,
          api: widget.api,
          onStatusChanged: (finished) {
            if (finished) _pollTimer?.cancel();
          },
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    if (_starting) {
      return Scaffold(
        appBar: AppBar(title: Text('Run: ${widget.pipeline.name}')),
        body: const Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              CircularProgressIndicator(),
              SizedBox(height: 16),
              Text('Starting run...'),
            ],
          ),
        ),
      );
    }

    if (_error != null) {
      return Scaffold(
        appBar: AppBar(title: Text('Run: ${widget.pipeline.name}')),
        body: Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              const Icon(Icons.error_outline, size: 48, color: Colors.red),
              const SizedBox(height: 16),
              Text(_error!, textAlign: TextAlign.center),
              const SizedBox(height: 16),
              FilledButton(
                onPressed: () => Navigator.pop(context),
                child: const Text('Go Back'),
              ),
            ],
          ),
        ),
      );
    }

    if (_runId == null || _runState == null) {
      return Scaffold(
        appBar: AppBar(title: Text('Run: ${widget.pipeline.name}')),
        body: const Center(child: Text('Failed to start run')),
      );
    }

    final state = _runState!;

    return Scaffold(
      appBar: AppBar(
        title: Text('Run: ${widget.pipeline.name}'),
        actions: [RunStatusBadge(status: state.status)],
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text(
                      'Run ID',
                      style: TextStyle(color: Colors.grey, fontSize: 12),
                    ),
                    Text(
                      _runId!,
                      style: const TextStyle(fontFamily: 'monospace'),
                    ),
                    const SizedBox(height: 8),
                    Row(
                      children: [
                        const Text(
                          'Status: ',
                          style: TextStyle(fontWeight: FontWeight.bold),
                        ),
                        RunStatusBadge(status: state.status),
                        const SizedBox(width: 12),
                        if (state.currentStep >= 0)
                          Text(
                            'Step ${state.currentStep + 1}/${state.steps.length}',
                          ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 20),
            const Text(
              'Steps',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 12),
            StepProgress(steps: state.steps, totalSteps: state.steps.length),
            const SizedBox(height: 24),
            Row(
              children: [
                Expanded(
                  child: SizedBox(
                    height: 48,
                    child: FilledButton.icon(
                      onPressed: _viewLog,
                      icon: const Icon(Icons.article_outlined),
                      label: const Text('View Log'),
                    ),
                  ),
                ),
                if (state.isFinished) ...[
                  const SizedBox(width: 12),
                  Expanded(
                    child: SizedBox(
                      height: 48,
                      child: FilledButton.icon(
                        onPressed: () => Navigator.pop(context),
                        icon: const Icon(Icons.check),
                        label: const Text('Done'),
                      ),
                    ),
                  ),
                ],
              ],
            ),
            if (!state.isFinished)
              Padding(
                padding: const EdgeInsets.only(top: 16),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    const SizedBox(
                      width: 16,
                      height: 16,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    ),
                    const SizedBox(width: 12),
                    Text(
                      state.status == RunStatus.running
                          ? 'Running... (polling every 2s)'
                          : 'Waiting...',
                    ),
                  ],
                ),
              ),
          ],
        ),
      ),
    );
  }
}