import 'dart:io';

import 'package:flutter/material.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:file_picker/file_picker.dart';
import 'package:sense_the_rhythm/utils/esense_input.dart';
import 'package:sense_the_rhythm/utils/simfile.dart';
import 'package:sense_the_rhythm/widgets/connection_status_button.dart';
import 'package:sense_the_rhythm/widgets/level_list_entry.dart';

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

  @override
  State<LevelSelection> createState() => _LevelSelectionState();
}

class _LevelSelectionState extends State<LevelSelection> {
  String? _stepmaniaCoursesPath;
  List<Simfile> _stepmaniaCoursesFolders = [];
  List<Simfile> _stepmaniaCoursesFoldersFiltered = [];

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

  /// gets folder path from persistent storage and updates state with loaded simfiles
  Future<void> _loadFolderPath() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    final String? stepmaniaCoursesPathSetting =
        prefs.getString('stepmania_courses');

    if (stepmaniaCoursesPathSetting == null) return;
    List<Simfile> stepmaniaCoursesFoldersFuture =
        await _listFilesAndFolders(stepmaniaCoursesPathSetting);

    setState(() {
      _stepmaniaCoursesPath = stepmaniaCoursesPathSetting;
      _stepmaniaCoursesFolders = stepmaniaCoursesFoldersFuture;
      _stepmaniaCoursesFoldersFiltered = stepmaniaCoursesFoldersFuture;
    });
  }

  /// open folder selection dialog and save selected folder in persistent storage
  Future<void> _selectFolder() async {
    await Permission.manageExternalStorage.request();
    String? selectedFolder = await FilePicker.platform.getDirectoryPath();

    if (selectedFolder != null) {
      // Save the selected folder path
      SharedPreferences prefs = await SharedPreferences.getInstance();
      await prefs.setString('stepmania_courses', selectedFolder);

      _loadFolderPath();
    }
  }

  /// load all simfiles from a [directoryPath]
  Future<List<Simfile>> _listFilesAndFolders(String directoryPath) async {
    final directory = Directory(directoryPath);
    try {
      // List all files and folders in the directory
      List<Simfile> simfiles = directory
          .listSync(recursive: true)
          .where((entity) => entity.path.endsWith('.sm'))
          .map((entity) => Simfile(entity.path))
          .toList();

      List<bool> successfullLoads =
          await Future.wait(simfiles.map((simfile) => simfile.load()));
      List<Simfile> simfilesFiltered = [];
      for (int i = 0; i < simfiles.length; i++) {
        if (successfullLoads[i]) {
          simfilesFiltered.add(simfiles[i]);
        }
      }

      simfilesFiltered
          .sort((a, b) => a.tags['TITLE']!.compareTo(b.tags['TITLE']!));

      return simfilesFiltered;
    } catch (e) {
      print("Error reading directory: $e");
      return [];
    }
  }

  /// filter stepmaniaCoursesFolders based on [input]
  void _filterLevels(String input) {
    setState(() {
      _stepmaniaCoursesFoldersFiltered = _stepmaniaCoursesFolders
          .where((simfile) => simfile.tags["TITLE"]!
              .toLowerCase()
              .contains(input.toLowerCase()))
          .toList();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Sense the Rhythm'),
        actions: [
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 8.0),
            child: ValueListenableBuilder(
              valueListenable: ESenseInput.instance.deviceStatus,
              builder:
                  (BuildContext context, String deviceStatus, Widget? child) {
                return ConnectionStatusButton(deviceStatus);
              },
            ),
          )
        ],
      ),
      body: Builder(builder: (context) {
        if (_stepmaniaCoursesPath == null) {
          return Text('Add a Directory with Stepmania Songs on \'+\'');
        } else if (_stepmaniaCoursesFolders.isEmpty) {
          return Text(
              'Folder empty. Add Stepmania Songs to Folder or select a different folder on \'+\'');
        } else {
          return Column(
            children: [
              Padding(
                padding:
                    const EdgeInsets.symmetric(horizontal: 16.0, vertical: 0.0),
                child: TextField(
                  onChanged: _filterLevels,
                  decoration: InputDecoration(
                      // icon: Icon(Icons.search),
                      hintText: 'Search'),
                ),
              ),
              Expanded(
                child: ListView.separated(
                  itemCount: _stepmaniaCoursesFoldersFiltered.length,
                  separatorBuilder: (BuildContext context, int index) =>
                      const Divider(),
                  itemBuilder: (context, index) {
                    Simfile simfile = _stepmaniaCoursesFoldersFiltered[index];
                    return LevelListEntry(simfile: simfile);
                  },
                ),
              ),
            ],
          );
        }
      }),
      floatingActionButton: FloatingActionButton(
          onPressed: () {
            _selectFolder();
          },
          child: Icon(Icons.add)),
    );
  }
}