import "package:flutter/material.dart";
import "package:file_picker/file_picker.dart";
import "package:go_router/go_router.dart";
import "../models/trip.dart";
import "../parsers/arriva_schedule_parser.dart";
import "../parsers/stagecoach_schedule_parser.dart";
import "../services/brr_export_service.dart";
import "../services/storage_service.dart";

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  static GoRoute route = GoRoute(
    path: "/",
    builder: (context, state) => const HomePage(),
  );

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  bool _isUploading = false;
  String? _errorMessage;
  BRROperator _selectedOperator = BRROperator.arriva;

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

  Future<void> _restoreSession() async {
    final state = await StorageService().loadState();
    if (state != null && state.trips.isNotEmpty && mounted) {
      context.go("/trips", extra: {
        "trips": state.trips,
        "fileName": state.scheduleFileName ?? "",
        "operator": _selectedOperator,
      });
    }
  }

  String get _fileExtension {
    switch (_selectedOperator) {
      case BRROperator.arriva:
        return "docx";
      case BRROperator.stagecoach:
        return "pdf";
    }
  }

  String get _formatLabel {
    switch (_selectedOperator) {
      case BRROperator.arriva:
        return "Arriva schedule format (.docx)";
      case BRROperator.stagecoach:
        return "Stagecoach schedule format (.pdf)";
    }
  }

  Future<void> _uploadSchedule() async {
    print("Upload button pressed");
    setState(() {
      _isUploading = true;
      _errorMessage = null;
    });

    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: [_fileExtension],
        allowMultiple: false,
        withData: true,
      );

      if (result == null || result.files.isEmpty) {
        setState(() { _isUploading = false; });
        return;
      }

      final file = result.files.first;
      if (file.bytes == null) throw Exception("Could not read file bytes");

      String? routeName;
      final List<Trip> trips;
      if (_selectedOperator == BRROperator.stagecoach) {
        final parser = StagecoachScheduleParser();
        trips = await parser.parseBytes(file.bytes!);
        routeName = parser.parsedRouteName;
      } else {
        trips = await ArrivaScheduleParser().parseBytes(file.bytes!);
      }

      if (trips.isEmpty) throw Exception("No trips found in schedule");

      if (mounted) {
        context.go("/station-selection", extra: {
          "trips": trips,
          "fileName": file.name,
          "operator": _selectedOperator,
          if (routeName != null) "routeName": routeName,
        });
      }
    } catch (e) {
      print("Error: $e");
      setState(() {
        _errorMessage = e.toString();
      });
    } finally {
      setState(() { _isUploading = false; });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(20),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [

              const SizedBox(height: 40),

              const Text(
                "BUS\nRUNNING\nRECORD",
                style: TextStyle(
                  fontSize: 40,
                  fontWeight: FontWeight.w900,
                  height: 1.0,
                  letterSpacing: -1,
                  color: Color(0xFFEEEEEE),
                ),
              ),

              const SizedBox(height: 8),

              Container(
                width: 40,
                height: 3,
                color: const Color(0xFF00A9CE),
              ),

              const Spacer(),

              // operator selector
              const Text(
                "OPERATOR",
                style: TextStyle(
                  fontSize: 11,
                  fontWeight: FontWeight.w700,
                  color: Color(0xFF777777),
                  letterSpacing: 1.5,
                ),
              ),
              const SizedBox(height: 8),

              Row(
                children: [
                  _OperatorChip(
                    label: "ARRIVA",
                    selected: _selectedOperator == BRROperator.arriva,
                    onTap: () => setState(() => _selectedOperator = BRROperator.arriva),
                  ),
                  const SizedBox(width: 8),
                  _OperatorChip(
                    label: "STAGECOACH",
                    selected: _selectedOperator == BRROperator.stagecoach,
                    onTap: () => setState(() => _selectedOperator = BRROperator.stagecoach),
                  ),
                ],
              ),

              const SizedBox(height: 16),

              // format info
              Container(
                padding: const EdgeInsets.all(14),
                decoration: BoxDecoration(
                  border: Border.all(color: const Color(0xFF2E2E2E)),
                  borderRadius: BorderRadius.circular(3),
                ),
                child: Row(
                  children: [
                    const Icon(Icons.info_outline, size: 16, color: Color(0xFF777777)),
                    const SizedBox(width: 10),
                    Text(
                      _formatLabel,
                      style: const TextStyle(fontSize: 13, color: Color(0xFF777777)),
                    ),
                  ],
                ),
              ),

              const SizedBox(height: 12),

              if (_errorMessage != null) ...[
                Container(
                  width: double.infinity,
                  padding: const EdgeInsets.all(14),
                  decoration: BoxDecoration(
                    color: const Color(0xFF2A1515),
                    border: Border.all(color: const Color(0xFF7A2020)),
                    borderRadius: BorderRadius.circular(3),
                  ),
                  child: Text(
                    _errorMessage!,
                    style: const TextStyle(
                      color: Color(0xFFCF6679),
                      fontSize: 13,
                    ),
                  ),
                ),
                const SizedBox(height: 12),
              ],

              SizedBox(
                width: double.infinity,
                height: 54,
                child: ElevatedButton(
                  onPressed: _isUploading ? null : _uploadSchedule,
                  child: _isUploading
                      ? const SizedBox(
                          width: 18,
                          height: 18,
                          child: CircularProgressIndicator(
                            strokeWidth: 2,
                            color: Colors.black,
                          ),
                        )
                      : const Text("LOAD SCHEDULE"),
                ),
              ),

            ],
          ),
        ),
      ),
    );
  }
}

class _OperatorChip extends StatelessWidget {
  final String label;
  final bool selected;
  final VoidCallback onTap;

  const _OperatorChip({
    required this.label,
    required this.selected,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: GestureDetector(
        onTap: onTap,
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 150),
          padding: const EdgeInsets.symmetric(vertical: 14),
          decoration: BoxDecoration(
            color: selected ? const Color(0xFF002A33) : const Color(0xFF1E1E1E),
            border: Border.all(
              color: selected ? const Color(0xFF00A9CE) : const Color(0xFF2E2E2E),
              width: selected ? 1.5 : 1,
            ),
            borderRadius: BorderRadius.circular(3),
          ),
          child: Center(
            child: Text(
              label,
              style: TextStyle(
                fontSize: 13,
                fontWeight: FontWeight.w700,
                color: selected ? const Color(0xFF00A9CE) : const Color(0xFF777777),
                letterSpacing: 1,
              ),
            ),
          ),
        ),
      ),
    );
  }
}