Utils = {
  // XXX We should remove these two methods
  goBoardId(_id) {
    const board = Boards.findOne(_id);
    return board && FlowRouter.go('board', {
      id: board._id,
      slug: board.slug,
    });
  },

  goCardId(_id) {
    const card = Cards.findOne(_id);
    const board = Boards.findOne(card.boardId);
    return board && FlowRouter.go('card', {
      cardId: card._id,
      boardId: board._id,
      slug: board.slug,
    });
  },

  capitalize(string) {
    return string.charAt(0).toUpperCase() + string.slice(1);
  },

  windowResizeDep: new Tracker.Dependency(),

  // in fact, what we really care is screen size
  // large mobile device like iPad or android Pad has a big screen, it should also behave like a desktop
  // in a small window (even on desktop), Wekan run in compact mode.
  // we can easily debug with a small window of desktop browser. :-)
  isMiniScreen() {
    this.windowResizeDep.depend();
    return $(window).width() <= 800;
  },

  calculateIndexData(prevData, nextData, nItems = 1) {
    let base, increment;
    // If we drop the card to an empty column
    if (!prevData && !nextData) {
      base = 0;
      increment = 1;
    // If we drop the card in the first position
    } else if (!prevData) {
      base = nextData.sort - 1;
      increment = -1;
    // If we drop the card in the last position
    } else if (!nextData) {
      base = prevData.sort + 1;
      increment = 1;
    }
    // In the general case take the average of the previous and next element
    // sort indexes.
    else {
      const prevSortIndex = prevData.sort;
      const nextSortIndex = nextData.sort;
      increment = (nextSortIndex - prevSortIndex) / (nItems + 1);
      base = prevSortIndex + increment;
    }
    // XXX Return a generator that yield values instead of a base with a
    // increment number.
    return {
      base,
      increment,
    };
  },

  // Determine the new sort index
  calculateIndex(prevCardDomElement, nextCardDomElement, nCards = 1) {
    let base, increment;
    // If we drop the card to an empty column
    if (!prevCardDomElement && !nextCardDomElement) {
      base = 0;
      increment = 1;
    // If we drop the card in the first position
    } else if (!prevCardDomElement) {
      base = Blaze.getData(nextCardDomElement).sort - 1;
      increment = -1;
    // If we drop the card in the last position
    } else if (!nextCardDomElement) {
      base = Blaze.getData(prevCardDomElement).sort + 1;
      increment = 1;
    }
    // In the general case take the average of the previous and next element
    // sort indexes.
    else {
      const prevSortIndex = Blaze.getData(prevCardDomElement).sort;
      const nextSortIndex = Blaze.getData(nextCardDomElement).sort;
      increment = (nextSortIndex - prevSortIndex) / (nCards + 1);
      base = prevSortIndex + increment;
    }
    // XXX Return a generator that yield values instead of a base with a
    // increment number.
    return {
      base,
      increment,
    };
  },
};

// A simple tracker dependency that we invalidate every time the window is
// resized. This is used to reactively re-calculate the popup position in case
// of a window resize. This is the equivalent of a "Signal" in some other
// programming environments (eg, elm).
$(window).on('resize', () => Utils.windowResizeDep.changed());