import 'dart:convert';

import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:flutter_spinkit/flutter_spinkit.dart';
import 'package:http/http.dart' as http;
import 'package:intl/intl.dart';

import '../constants.dart';
import '../devices/devices.dart';

class ChartData {
  ChartData(this.time, this.watts);

  int time;
  double watts;
}

class CheckBoxDevice {
  CheckBoxDevice(this.device);

  final DeviceIdOnly device;
  bool enabled = false;
  List<ChartData> data = List.empty();
}

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

  @override
  State<Graphs> createState() => _GraphsState();
}

class _GraphsState extends State<Graphs> {
  String? start_date;
  String? end_date;
  List<CheckBoxDevice> devices = List.empty();

  final TextEditingController categoryController = TextEditingController();
  final TextEditingController startDateController = TextEditingController();
  final TextEditingController endDateController = TextEditingController();

  @override
  void dispose() {
    // Clean up the controller when the widget is removed from the
    // widget tree.
    categoryController.dispose();
    startDateController.dispose();
    endDateController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<List<Category>>(
        future: Category.fetch_ids_only(),
        builder: (context, AsyncSnapshot<List<Category>> categories) {
          if (!categories.hasData) {
            return SpinKitWanderingCubes(
              color: Colors.deepPurple[100],
              size: 80.0,
            );
          }

          return Scaffold(
              appBar: AppBar(
                backgroundColor: Theme.of(context).colorScheme.inversePrimary,
                title: const Text('Graphs'),
                actions: [
                  IconButton(
                      icon: const Icon(Icons.arrow_back),
                      onPressed: () =>
                          Navigator.of(context).pushReplacementNamed(
                            '/',
                          ))
                ],
              ),
              body: Center(
                  child: Column(children: [
                const SizedBox(
                  height: 40,
                ),
                DropdownMenu<Category>(
                  label: const Text('Category'),
                  controller: categoryController,
                  width: 200,
                  onSelected: (Category? category) {
                    if (category != null) {
                      setState(() {
                        devices = category.devices
                            .map((dev) => CheckBoxDevice(dev as DeviceIdOnly))
                            .toList();
                      });
                    }
                  },
                  dropdownMenuEntries: categories.data!
                      .map((category) => DropdownMenuEntry<Category>(
                          label: category.Name(), value: category))
                      .toList(),
                ),
                Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: devices.map((device) {
                      return SizedBox(
                          width: 200,
                          height: 40,
                          child: CheckboxListTile(
                              title: Text(device.device.device_descriptor ??
                                  device.device.device_id),
                              controlAffinity: ListTileControlAffinity.leading,
                              splashRadius: 10.0,
                              value: device.enabled,
                              onChanged: (bool? value) {
                                setState(() {
                                  device.enabled = value!;
                                });
                              }));
                    }).toList()),
                Row(mainAxisAlignment: MainAxisAlignment.center, children: [
                  const Text('Start'),
                  SizedBox(
                      width: 200,
                      height: 40,
                      child: TextField(
                        controller: startDateController,
                        decoration: const InputDecoration(
                          icon: Icon(Icons.calendar_today),
                        ),
                        readOnly: true,
                        onTap: () async {
                          final DateTime? pickedDate = await showDatePicker(
                              context: context,
                              initialDate: DateTime.now(),
                              firstDate: DateTime(2023),
                              lastDate: DateTime(2101));

                          if (pickedDate != null) {
                            final String formattedDate =
                                DateFormat('dd.MM.yyyy').format(pickedDate);

                            startDateController.text = formattedDate;
                          }
                        },
                      ))
                ]),
                Row(mainAxisAlignment: MainAxisAlignment.center, children: [
                  const Text('End'),
                  SizedBox(
                      width: 200,
                      height: 40,
                      child: TextField(
                        controller: endDateController,
                        decoration: const InputDecoration(
                          icon: Icon(Icons.calendar_today),
                        ),
                        readOnly: true,
                        onTap: () async {
                          final DateTime? pickedDate = await showDatePicker(
                              context: context,
                              initialDate: DateTime.now(),
                              firstDate: DateTime(2023),
                              lastDate: DateTime(2101));

                          if (pickedDate != null) {
                            final String formattedDate =
                                DateFormat('dd.MM.yyyy').format(pickedDate);

                            endDateController.text = formattedDate;
                          }
                        },
                      ))
                ]),
                ElevatedButton(
                    onPressed: () {
                      setState(() {
                        for (var device in devices) {
                          if (!device.enabled) {
                            device.data = List.empty();
                            continue;
                          }

                          int start_date;
                          int end_date;

                          try {
                            start_date = (DateFormat('dd.MM.yyyy')
                                    .parse(startDateController.text)
                                    .millisecondsSinceEpoch /
                                1000) as int;
                          } on Exception catch (_) {
                            start_date = 0;
                            print('no start date set');
                          }

                          try {
                            end_date = (DateFormat('dd.MM.yyyy')
                                    .parse(endDateController.text)
                                    .millisecondsSinceEpoch /
                                1000) as int;
                          } on Exception catch (_) {
                            end_date = 0;
                            print('no end date set');
                          }

                          if (start_date == 0 || end_date == 0) {
                            device.data = List.empty();
                            continue;
                          }

                          const String filter_type = 'hourly';

                          http
                              .get(Uri.parse(
                                  "${Constants.BASE_URL}/plug_data/${device.device.device_id}/$start_date/$end_date/$filter_type"))
                              .then((response) {
                            if (response.statusCode != 200) {
                              throw Exception("Failed to fetch data");
                            }

                            final data = jsonDecode(jsonDecode(response.body))
                                as List<dynamic>;

                            final List<ChartData> chart_data = [];

                            for (final entry in data) {
                              final pair = entry as List<dynamic>;
                              chart_data.add(ChartData(pair[0], pair[1]));
                            }

                            device.data = chart_data;
                          });
                        }
                      });
                    },
                    child: const Text('Update')),
                if (devices.any((device) => device.data.isNotEmpty))
                  LineChart(
                    LineChartData(
                      lineBarsData: devices
                          .map((device) {
                            if (device.data.isNotEmpty) {
                              final data = device.data.map((data) {
                                return FlSpot(data.time as double, data.watts);
                              }).toList();

                              print('chart data: $data');

                              return LineChartBarData(
                                spots: data,
                              );
                            } else {
                              return null;
                            }
                          })
                          .where((element) => element != null)
                          .map((opt) => opt!)
                          .toList(),
                      // titlesData: FlTitlesData(bottomTitles: AxisTitles(sideTitles: ))
                    ),
                    duration: const Duration(milliseconds: 200),
                    curve: Curves.linear,
                  )
              ])));
        });
  }
}