import 'dart:async';
import 'dart:convert';

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

import 'constants.dart';

class Category {
  Category(this.name) : devices = [];

  final String name;
  List<Device> devices;

  static Future<List<Category>> fetch() async {
    final response = await http.get(Uri.parse("${Constants.BASE_URL}/devices"));

    if (response.statusCode != 200) {
      throw Exception("Failed to fetch devices");
    }

    final List<Category> categories = [];

    final Map<String, List<dynamic>> json =
        Map.castFrom(jsonDecode(jsonDecode(response.body)));

    for (MapEntry<String, List<dynamic>> category_entry in json.entries) {
      final Category category = Category(category_entry.key);

      for (dynamic device_info_dyn in category_entry.value) {
        final Map<String, dynamic> device_info = device_info_dyn;

        final String device_id = device_info['id'];
        final String? device_descriptor = device_info['desc'];
        final bool power_control = device_info['toggle'];

        final response = await http
            .get(Uri.parse("${Constants.BASE_URL}/plug_state/$device_id"));

        if (response.statusCode != 200) {
          throw Exception("Failed to fetch plug_state for $device_id");
        }

        final Map<String, dynamic> device_state =
            Map.castFrom(jsonDecode(jsonDecode(response.body)));

        final Device device = Device(
          device_id,
          device_descriptor,
          device_state["led"],
          device_state["power"],
          device_state["power_draw"],
          power_control && device_state["power_draw"] < 15,
        );

        category.devices.add(device);
      }

      categories.add(category);
    }

    return categories;
  }
}

class CategoryWidget extends StatelessWidget {
  final Category category;

  CategoryWidget({super.key, required this.category});

  String Name() {
    var s = category.name;
    return "${s[0].toUpperCase()}${s.substring(1)}";
  }

  @override
  Widget build(BuildContext context) {
    final double header_height = 40;
    final double info_height = 30;

    return Wrap(
      spacing: 25,
      runSpacing: 25,
      children: category.devices.map((device) {
        return Table(
            border: TableBorder.all(),
            defaultVerticalAlignment: TableCellVerticalAlignment.middle,
            columnWidths: const {
              0: FixedColumnWidth(200.0),
              1: FixedColumnWidth(200.0),
            },
            children: [
              TableRow(
                  decoration: const BoxDecoration(
                    color: Colors.blueGrey,
                  ),
                  children: [
                    SizedBox(
                        height: header_height,
                        child: Stack(
                          children: [
                            Align(
                                child: Text(
                                    textAlign: TextAlign.center,
                                    device.device_descriptor ??
                                        device.device_id)),
                            Align(
                              alignment: Alignment.centerRight,
                              child: IconButton(
                                  onPressed: () {},
                                  icon: const Icon(Icons.settings)),
                            ),
                          ],
                        ))
                  ]),
              TableRow(children: [
                SizedBox(
                    height: info_height,
                    child: Stack(children: [
                      const Align(
                          alignment: Alignment(-0.9, 0.0),
                          child: Text(
                              style: TextStyle(fontWeight: FontWeight.bold),
                              textAlign: TextAlign.center,
                              "LED")),
                      Align(
                          alignment: const Alignment(0.5, 0.0),
                          child: DeviceLed(
                              device_id: device.device_id,
                              led_state: device.led_state)),
                    ]))
              ]),
              TableRow(children: [
                SizedBox(
                    height: info_height,
                    child: Stack(children: [
                      const Align(
                          alignment: Alignment(-0.9, 0.0),
                          child: Text(
                              style: TextStyle(fontWeight: FontWeight.bold),
                              textAlign: TextAlign.center,
                              "Power")),
                      Align(
                          alignment: const Alignment(0.4, 0.0),
                          child: DevicePower(
                              device_id: device.device_id,
                              power_state: device.power_state,
                              power_control: device.power_control)),
                    ]))
              ]),
              TableRow(children: [
                SizedBox(
                    height: info_height,
                    child: Stack(children: [
                      const Align(
                          alignment: Alignment(-0.9, 0.0),
                          child: Text(
                              style: TextStyle(fontWeight: FontWeight.bold),
                              textAlign: TextAlign.center,
                              "Power Draw")),
                      Align(
                          alignment: const Alignment(0.5, 0.0),
                          child: Text(
                              textAlign: TextAlign.center,
                              "${device.power_draw} W"))
                    ]))
              ])
            ]);
      }).toList(),
    );
  }
}

class Device {
  final String device_id;
  String? device_descriptor;
  bool led_state;
  bool power_state;
  double power_draw;
  bool power_control;

  Device(this.device_id, this.device_descriptor, this.led_state,
      this.power_state, this.power_draw, this.power_control);
}

class DeviceLed extends StatefulWidget {
  final String device_id;
  final bool led_state;

  DeviceLed({super.key, required this.device_id, required this.led_state});

  @override
  State<DeviceLed> createState() => DeviceLedState(device_id, led_state);
}

class DeviceLedState extends State<DeviceLed> {
  final String device_id;
  bool led_state;
  String _led_state_info;

  DeviceLedState(this.device_id, this.led_state)
      : this._led_state_info = led_state ? "On" : "Off";

  void _toggle_led_state() {
    String target_state;

    if (led_state) {
      target_state = "off";
    } else {
      target_state = "on";
    }

    change_plug_state(device_id, "led", target_state).then((device_state) {
      led_state = device_state["led"];

      setState(() {
        _led_state_info = led_state ? "On" : "Off";
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return TextButton(
        onPressed: _toggle_led_state,
        child: Text(textAlign: TextAlign.center, _led_state_info));
  }
}

class DevicePower extends StatefulWidget {
  final String device_id;
  final bool power_state;
  final bool power_control;

  DevicePower(
      {super.key,
      required this.device_id,
      required this.power_state,
      required this.power_control});

  @override
  State<DevicePower> createState() =>
      DevicePowerState(device_id, power_state, power_control);
}

class DevicePowerState extends State<DevicePower> {
  final String device_id;
  bool power_state;
  String _power_state_info;
  bool power_control;

  DevicePowerState(this.device_id, this.power_state, this.power_control)
      : this._power_state_info = power_state ? "On" : "Off";

  void _toggle_power_state() {
    String target_state;

    if (power_state) {
      target_state = "off";
    } else {
      target_state = "on";
    }

    change_plug_state(device_id, "power", target_state).then((device_state) {
      power_state = device_state["power"];

      power_control = device_state["power_draw"] < 15;

      setState(() {
        _power_state_info = power_state ? "On" : "Off";
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    if (power_control) {
      return TextButton(
          onPressed: _toggle_power_state,
          child: Text(textAlign: TextAlign.center, _power_state_info));
    } else {
      return Text(_power_state_info, textAlign: TextAlign.center);
    }
  }
}

Future<Map<String, dynamic>> change_plug_state(
    String device_id, String module, String state) async {
  var response = await http.post(
      Uri.parse("${Constants.BASE_URL}/plug/$device_id/${module}_$state"));

  if (response.statusCode != 200) {
    throw Exception("Failed to post new state");
  }

  response =
      await http.get(Uri.parse("${Constants.BASE_URL}/plug_state/$device_id"));

  if (response.statusCode != 200) {
    throw Exception("Failed to fetch plug_state for $device_id");
  }

  return Map.castFrom(jsonDecode(jsonDecode(response.body)));
}