gghighlight | Highlight points and lines in ggplot2 | Data Visualization library

I would like to use ggplot to create multiple density plots that have the same data but that show a specific line highlighted. The table I have is extremely big but has the following columns:

I want to divide a column in a df into groups and run something like rollsum() for each 36 sequential rows in a column (Online_h) inside each group and select those rows, where the sum is the minimum inside the group (compared to the sum of the rest again inside the group). It means that for each group I should get 36 rows summing as minimum compared to others.

My dataframe includes three columns of "Date", "Online_h" and "week". Column "week" is used to group the data by. Rows summing to minimum for each 36 sequential row should be calculated on the values in "Online_h".

The df looks like this: Tha dataframe

My current code looks like this:

I have 2 tsibble objects, one being (atsibble) a time series plot:

Using the example in here, if I have a bunch of line, how can I randomly choose one of them if the data points connected to each other to form a line according to, say ID, column in the data table?

I'm trying to highlight (change the color) specific lines in a plot.

The input data looks like this:

I have come across a beautiful chart on this webpage: https://ourworldindata.org/coronavirus and interested to know if we can build the same chart in R with functionality of having highlighted series as well as selecting any line on hovering ?

I have build static highlighted charts using gghighlight but those are not interactive. Plotly can help in interaction but I think they don't work with gghighlight.

So how can we have the combination of both highlight and interactivity in charts as in the link shared on top ?

Is it possible to achieve same results in R ? It would be really helpful if someone could share an example or link that can help.

(UPDATE: May be I can manually highlight lines by creating a factor column instead of using gghighlight and then pass it to ggplotly but then can ggplotly or some other library provide similar results on hover ?)

(NOTE: Not looking for animation. Just need highlighted, hover over interactive chart)

Below is the snapshot of same chart hovered over US (This chart is also similar to the one shared in World Economic Forum many times.)

I am new in R and creating a function that highlight list of countries from the data set in the plot.

functionality issue If country names are not passed as arguments (which can vary) then it should be able to take from default list of countries.

I understand ... is used for variable arguments and then may be I can use list(...) but I am not able to put this together with default values.

Is there a way I can write: country_highlight_plot(Australia, Singapore, Norway) and if I don't mention any country then it takes default countries.

Below is the code (using gapminder data to reproduce):

I am creating a plot with a user defined function and passing color as an option. It's working fine by using as_label or quo_name with colors by name for example grey or pink.

But when I pass hex codes then it fails even if I pass just alpha numerical value without # still it doesn't make that as string.

small example:

I have a plot like this with the following code: