import {randId} from "./random";
import {nullish} from "./null";
import {fetchGet, fetchPatch} from "./fetcher";

const localData = {};
const callbacks = [];

export function subscribeToLight(lightId, callback) {
  const callbackId = randId();

  callbacks.push({callbackId, lightId, callback});

  if (lightId >= 0) {
    dispatch();

    fetchOne(lightId);
  } else {
    dispatch();

    fetchAll();
  }
}

export function unsubscribeFromLight(callbackId) {
  const callback = callbacks.find(c => c !== null && c.callbackId === callbackId);
  const index = callbacks.indexOf(callback);
  callbacks[index] = null;
}

export function changeColor(lightId, newColor, newBrightness, newPower) {
  const light = localData[lightId];
  if (nullish(light)) {
    return;
  }

  const oldBrightness = light.brightness;
  const oldPower = light.on;
  const oldColor = light.color;
  light.color = newColor;
  light.brightness = newBrightness;
  light.on = newPower;
  dispatch();

  fetchPatch(`/light/${lightId}`, {
    color: newColor,
    brightness: newBrightness,
    on: newPower,
  }).then(({data, error}) => {
    if (error !== null) {
      light.color = oldColor;
      light.brightness = oldBrightness;
      light.on = oldPower;
      dispatch();
      return;
    }

    localData[lightId] = data;
    dispatch();
  });
}

export function changeLight(lightId, name, groupId) {
  const light = localData[lightId];
  if (nullish(light)) {
    return;
  }

  const oldName = light.name;
  const oldGroupId = light.groupId;
  light.name = name;
  light.groupId = groupId;
  dispatch();
  console.log({name,groupId});

  fetchPatch(`/light/${lightId}`, {
    name: name,
    groupId: groupId,
  }).then(({data, error}) => {
    if (error !== null) {
      light.name = oldName;
      light.groupId = oldGroupId;
      dispatch();
      return;
    }

    localData[lightId] = data;
    dispatch();
  });
}

function fetchAll() {
  fetchGet(`/light/`).then(({data, error}) => {
    if (error === null) {
      handleLights(data);
    }
  });
}

function fetchOne(id) {
  fetchGet(`/light/${id}`).then(({data, error}) => {
    if (error === null) {
      handleLight(data);
    }
  });
}

function handleLights(lights) {
  lights.forEach(l => handleLight(l));

  for (let key in localData) {
    if (localData.hasOwnProperty(key) && nullish(lights.find(l => l.id === parseInt(key, 10)))) {
      delete localData[key];
    }
  }

  dispatch(lights);
}

function handleLight(light) {
  localData[light.id] = light;

  dispatch(light);
}

function dispatch(data = null) {
  if (data === null) {
    data = Object.values(localData);
  }

  if (Array.isArray(data)) {
    callbacks
      .filter(c => c !== null)
      .filter(c => c.lightId === -1)
      .forEach(c => c.callback(data));
  } else {
    callbacks
      .filter(c => c !== null)
      .filter(c => c.lightId === data.id)
      .forEach(c => c.callback(data));
  }
}