import Users from '/imports/api/users';
import Auth from '/imports/ui/services/auth';
import WhiteboardMultiUser from '/imports/api/whiteboard-multi-user';
import addAnnotationQuery from '/imports/api/annotations/addAnnotation';
import { Slides } from '/imports/api/slides';
import { makeCall } from '/imports/ui/services/api';
import PresentationService from '/imports/ui/components/presentation/service';
import logger from '/imports/startup/client/logger';
import { isEqual } from 'lodash';

const Annotations = new Mongo.Collection(null);
const UnsentAnnotations = new Mongo.Collection(null);
const ANNOTATION_CONFIG = Meteor.settings.public.whiteboard.annotations;
const DRAW_START = ANNOTATION_CONFIG.status.start;
const DRAW_UPDATE = ANNOTATION_CONFIG.status.update;
const DRAW_END = ANNOTATION_CONFIG.status.end;

const ANNOTATION_TYPE_PENCIL = 'pencil';
const ANNOTATION_TYPE_TEXT = 'text';


let annotationsStreamListener = null;

const clearPreview = (annotation) => {
  UnsentAnnotations.remove({ id: annotation });
};

const clearFakeAnnotations = () => {
  UnsentAnnotations.remove({});
  Annotations.remove({ id: /-fake/g, annotationType: { $ne: 'text' } });
}

function handleAddedLiveSyncPreviewAnnotation({
  meetingId, whiteboardId, userId, annotation,
}) {
  const isOwn = Auth.meetingID === meetingId && Auth.userID === userId;
  const query = addAnnotationQuery(meetingId, whiteboardId, userId, annotation);

  if (!isOwn) {
    Annotations.upsert(query.selector, query.modifier);
    return;
  }

  const fakeAnnotation = Annotations.findOne({ id: `${annotation.id}-fake` });
  let fakePoints;

  if (fakeAnnotation) {
    fakePoints = fakeAnnotation.annotationInfo.points;
    const { points: lastPoints } = annotation.annotationInfo;

    if (annotation.annotationType !== 'pencil') {
      Annotations.update(fakeAnnotation._id, {
        $set: {
          position: annotation.position,
          'annotationInfo.color': isEqual(fakePoints, lastPoints) || annotation.status === DRAW_END
            ? annotation.annotationInfo.color : fakeAnnotation.annotationInfo.color,
        },
        $inc: { version: 1 }, // TODO: Remove all this version stuff
      });
      return;
    }
  }

  Annotations.upsert(query.selector, query.modifier, (err) => {
    if (err) {
      logger.error({
        logCode: 'whiteboard_annotation_upsert_error',
        extraInfo: { error: err },
      }, 'Error on adding an annotation');
      return;
    }

    // Remove fake annotation for pencil on draw end
    if (annotation.status === DRAW_END) {
      Annotations.remove({ id: `${annotation.id}-fake` });
      return;
    }

    if (annotation.status === DRAW_START) {
      Annotations.update(fakeAnnotation._id, {
        $set: {
          position: annotation.position - 1,
        },
        $inc: { version: 1 }, // TODO: Remove all this version stuff
      });
    }
  });
}

function handleAddedAnnotation({
  meetingId, whiteboardId, userId, annotation,
}) {
  const isOwn = Auth.meetingID === meetingId && Auth.userID === userId;
  const query = addAnnotationQuery(meetingId, whiteboardId, userId, annotation);

  Annotations.upsert(query.selector, query.modifier);

  if (isOwn) {
    UnsentAnnotations.remove({ id: `${annotation.id}` });
  }
}

function handleRemovedAnnotation({
  meetingId, whiteboardId, userId, shapeId,
}) {
  const query = { meetingId, whiteboardId };

  if (userId) {
    query.userId = userId;
  }

  if (shapeId) {
    query.id = shapeId;
  }
  const annotationIsFake = Annotations.remove(query) === 0;
  if (annotationIsFake) {
    query.id = { $in: [shapeId, `${shapeId}-fake`] };
    Annotations.remove(query);
  }
}

export function initAnnotationsStreamListener() {
  logger.info({ logCode: 'init_annotations_stream_listener' }, 'initAnnotationsStreamListener called');
  /**
   * We create a promise to add the handlers after a ddp subscription stop.
   * The problem was caused because we add handlers to stream before the onStop event happens,
   * which set the handlers to undefined.
   */
  annotationsStreamListener = new Meteor.Streamer(`annotations-${Auth.meetingID}`, { retransmit: false });

  const startStreamHandlersPromise = new Promise((resolve) => {
    const checkStreamHandlersInterval = setInterval(() => {
      const streamHandlersSize = Object.values(Meteor.StreamerCentral.instances[`annotations-${Auth.meetingID}`].handlers)
        .filter(el => el !== undefined)
        .length;

      if (!streamHandlersSize) {
        resolve(clearInterval(checkStreamHandlersInterval));
      }
    }, 250);
  });

  startStreamHandlersPromise.then(() => {
    logger.debug({ logCode: 'annotations_stream_handler_attach' }, 'Attaching handlers for annotations stream');

    annotationsStreamListener.on('removed', handleRemovedAnnotation);

    annotationsStreamListener.on('added', ({ annotations }) => {
      annotations.forEach((annotation) => {
        const tool = annotation.annotation.annotationType;
        if (tool === ANNOTATION_TYPE_TEXT) {
          handleAddedLiveSyncPreviewAnnotation(annotation);
        } else {
          handleAddedAnnotation(annotation);
        }
      });
    });
  });
}

function increaseBrightness(realHex, percent) {
  let hex = parseInt(realHex, 10).toString(16).padStart(6, 0);
  // strip the leading # if it's there
  hex = hex.replace(/^\s*#|\s*$/g, '');

  // convert 3 char codes --> 6, e.g. `E0F` --> `EE00FF`
  if (hex.length === 3) {
    hex = hex.replace(/(.)/g, '$1$1');
  }

  const r = parseInt(hex.substr(0, 2), 16);
  const g = parseInt(hex.substr(2, 2), 16);
  const b = parseInt(hex.substr(4, 2), 16);

  /* eslint-disable no-bitwise, no-mixed-operators */
  return parseInt(((0 | (1 << 8) + r + ((256 - r) * percent) / 100).toString(16)).substr(1)
     + ((0 | (1 << 8) + g + ((256 - g) * percent) / 100).toString(16)).substr(1)
     + ((0 | (1 << 8) + b + ((256 - b) * percent) / 100).toString(16)).substr(1), 16);
  /* eslint-enable no-bitwise, no-mixed-operators */
}

const annotationsQueue = [];
// How many packets we need to have to use annotationsBufferTimeMax
const annotationsMaxDelayQueueSize = 60;
// Minimum bufferTime
const annotationsBufferTimeMin = 30;
// Maximum bufferTime
const annotationsBufferTimeMax = 200;
// Time before running 'sendBulkAnnotations' again if user is offline
const annotationsRetryDelay = 1000;

let annotationsSenderIsRunning = false;

const proccessAnnotationsQueue = async () => {
  annotationsSenderIsRunning = true;
  const queueSize = annotationsQueue.length;

  if (!queueSize) {
    annotationsSenderIsRunning = false;
    return;
  }

  const annotations = annotationsQueue.splice(0, queueSize);

  const isAnnotationSent = await makeCall('sendBulkAnnotations', annotations);

  if (!isAnnotationSent) {
    // undo splice
    annotationsQueue.splice(0, 0, ...annotations);
    setTimeout(proccessAnnotationsQueue, annotationsRetryDelay);
  } else {
    // ask tiago
    const delayPerc = Math.min(annotationsMaxDelayQueueSize, queueSize) / annotationsMaxDelayQueueSize;
    const delayDelta = annotationsBufferTimeMax - annotationsBufferTimeMin;
    const delayTime = annotationsBufferTimeMin + (delayDelta * delayPerc);
    setTimeout(proccessAnnotationsQueue, delayTime);
  }
};

const sendAnnotation = (annotation) => {
  // Prevent sending annotations while disconnected
  // TODO: Change this to add the annotation, but delay the send until we're
  // reconnected. With this it will miss things
  if (!Meteor.status().connected) return;

  if (annotation.status === DRAW_END) {
    annotationsQueue.push(annotation);
    if (!annotationsSenderIsRunning) setTimeout(proccessAnnotationsQueue, annotationsBufferTimeMin);
  } else {
    const { position, ...relevantAnotation } = annotation;
    const queryFake = addAnnotationQuery(
      Auth.meetingID, annotation.wbId, Auth.userID,
      {
        ...relevantAnotation,
        id: `${annotation.id}`,
        position: Number.MAX_SAFE_INTEGER,
        annotationInfo: {
          ...annotation.annotationInfo,
          color: increaseBrightness(annotation.annotationInfo.color, 40),
        },
      },
    );

    // This is a really hacky solution, but because of the previous code reuse we need to edit
    // the pencil draw update modifier so that it sets the whole array instead of pushing to
    // the end
    const { status, annotationType } = relevantAnotation;
    if (status === DRAW_UPDATE && annotationType === ANNOTATION_TYPE_PENCIL) {
      delete queryFake.modifier.$push;
      queryFake.modifier.$set['annotationInfo.points'] = annotation.annotationInfo.points;
    }

    UnsentAnnotations.upsert(queryFake.selector, queryFake.modifier);
  }
};

const sendLiveSyncPreviewAnnotation = (annotation) => {
  // Prevent sending annotations while disconnected
  if (!Meteor.status().connected) return;

  annotationsQueue.push(annotation);
  if (!annotationsSenderIsRunning) setTimeout(proccessAnnotationsQueue, annotationsBufferTimeMin);

  // skip optimistic for draw end since the smoothing is done in akka
  if (annotation.status === DRAW_END) return;

  const { position, ...relevantAnotation } = annotation;
  const queryFake = addAnnotationQuery(
    Auth.meetingID, annotation.wbId, Auth.userID,
    {
      ...relevantAnotation,
      id: `${annotation.id}-fake`,
      position: Number.MAX_SAFE_INTEGER,
      annotationInfo: {
        ...annotation.annotationInfo,
        color: increaseBrightness(annotation.annotationInfo.color, 40),
      },
    },
  );

  Annotations.upsert(queryFake.selector, queryFake.modifier);
};

WhiteboardMultiUser.find({ meetingId: Auth.meetingID }).observeChanges({
  changed: clearFakeAnnotations,
});

Users.find({ userId: Auth.userID }, { fields: { presenter: 1 } }).observeChanges({
  changed(id, { presenter }) {
    if (presenter === false) clearFakeAnnotations();
  },
});

const getMultiUser = (whiteboardId) => {
  const data = WhiteboardMultiUser.findOne(
    {
      meetingId: Auth.meetingID,
      whiteboardId,
    }, { fields: { multiUser: 1 } },
  );

  if (!data || !data.multiUser || !Array.isArray(data.multiUser)) return [];

  return data.multiUser;
};

const getMultiUserSize = (whiteboardId) => {
  const multiUser = getMultiUser(whiteboardId);

  if (multiUser.length === 0) return 0;

  // Individual whiteboard access is controlled by an array of userIds.
  // When an user leaves the meeting or the presenter role moves from an
  // user to another we applying a filter at the whiteboard collection.
  // Ideally this should change to something more cohese but this would
  // require extra changes at multiple backend modules.
  const multiUserSize = Users.find(
    {
      meetingId: Auth.meetingID,
      userId: { $in: multiUser },
      presenter: false,
    }, { fields: { userId: 1 } },
  ).fetch();

  return multiUserSize.length;
};

const getCurrentWhiteboardId = () => {
  const podId = 'DEFAULT_PRESENTATION_POD';
  const currentPresentation = PresentationService.getCurrentPresentation(podId);

  if (!currentPresentation) return null;

  const currentSlide = Slides.findOne(
    {
      podId,
      presentationId: currentPresentation.id,
      current: true,
    }, { fields: { id: 1 } },
  );

  return currentSlide && currentSlide.id;
}

const isMultiUserActive = (whiteboardId) => {
  const multiUser = getMultiUser(whiteboardId);

  return multiUser.length !== 0;
};

const hasMultiUserAccess = (whiteboardId, userId) => {
  const multiUser = getMultiUser(whiteboardId);

  return multiUser.includes(userId);
};

const changeWhiteboardAccess = (userId, access) => {
  const whiteboardId = getCurrentWhiteboardId();

  if (!whiteboardId) return;

  if (access) {
    addIndividualAccess(whiteboardId, userId);
  } else {
    removeIndividualAccess(whiteboardId, userId);
  }
};

const addGlobalAccess = (whiteboardId) => {
  makeCall('addGlobalAccess', whiteboardId);
};

const addIndividualAccess = (whiteboardId, userId) => {
  makeCall('addIndividualAccess', whiteboardId, userId);
};

const removeGlobalAccess = (whiteboardId) => {
  makeCall('removeGlobalAccess', whiteboardId);
};

const removeIndividualAccess = (whiteboardId, userId) => {
  makeCall('removeIndividualAccess', whiteboardId, userId);
};

export {
  Annotations,
  UnsentAnnotations,
  sendAnnotation,
  sendLiveSyncPreviewAnnotation,
  clearPreview,
  getMultiUser,
  getMultiUserSize,
  getCurrentWhiteboardId,
  isMultiUserActive,
  hasMultiUserAccess,
  changeWhiteboardAccess,
  addGlobalAccess,
  addIndividualAccess,
  removeGlobalAccess,
  removeIndividualAccess,
  clearFakeAnnotations,
};