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 {
  Category category;

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

  String capitalize(String s) {
    return "${s[0].toUpperCase()}${s.substring(1)}";
  }

  @override
  Widget build(BuildContext context) {
    var list = category.devices
        .map((device) => TableRow(children: [
              Text(
                  textAlign: TextAlign.center,
                  device.device_descriptor ?? device.device_id),
              DeviceLed(
                  device_id: device.device_id, led_state: device.led_state),
              DevicePower(
                  device_id: device.device_id,
                  power_state: device.power_state,
                  power_control: device.power_control),
              Text(textAlign: TextAlign.center, "${device.power_draw} W")
            ]))
        .toList();

    list.insert(
        0,
        const TableRow(
            decoration: BoxDecoration(
              color: Colors.blueGrey,
            ),
            children: [
              Text(
                  style: TextStyle(fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                  "Name"),
              Text(
                  style: TextStyle(fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                  "LED"),
              Text(
                  style: TextStyle(fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                  "Power"),
              Text(
                  style: TextStyle(fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                  "Power Draw"),
            ]));

    return Column(children: <Widget>[
      Text(
          style: const TextStyle(fontWeight: FontWeight.bold),
          textScaleFactor: 2.0,
          capitalize(category.name)),
      Table(
          border: TableBorder.all(),
          defaultVerticalAlignment: TableCellVerticalAlignment.middle,
          children: list)
    ]);
  }
}

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)));
}