Add support for Plex Watchlist

[Spacetech]

Addresses: #1828. Explanation below for how this works:

You can check your Plex Watchlist by going to https://metadata.provider.plex.tv/library/sections/watchlist/all?X-Plex-Token={token} (fill out the token param). Here's an example result:

<?xml version="1.0"?>
<MediaContainer librarySectionID="watchlist" librarySectionTitle="Watchlist" offset="0"
    totalSize="32" identifier="tv.plex.provider.metadata" size="20">
    <Video art="https://metadata-static.plex.tv/5/gracenote/5d3ffdbcdf1e8c07cffff3aad36ac0ce.jpg"
        banner="http://assets.fanart.tv/fanart/movies/46838/moviebanner/tucker--dale-vs-evil-51ab23d9dab5e.jpg"
        guid="plex://movie/5d776883ebdf2200209c104e"
        key="/library/metadata/5d776883ebdf2200209c104e" rating="8.5"
        ratingKey="5d776883ebdf2200209c104e" studio="Eden Rock Media"
        tagline="Evil just messed with the wrong hillbillies." type="movie"
        thumb="https://metadata-static.plex.tv/c/gracenote/ce5e380d9209dc7fa5fbb8fb3cff9d48.jpg"
        addedAt="1291852800" duration="5340000"
        publicPagesURL="https://watch.plex.tv/movie/tucker-and-dale-vs-evil"
        slug="tucker-and-dale-vs-evil" expiresAt="1713941940" userState="0"
        title="Tucker and Dale vs Evil" contentRating="R" originallyAvailableAt="2010-12-09"
        year="2010" availabilityId="62cf3270700e44e58631846c"
        streamingMediaId="62cf3270700e44e5863182d6" audienceRating="8.5"
        audienceRatingImage="rottentomatoes://image.rating.upright"
        ratingImage="rottentomatoes://image.rating.ripe" imdbRatingCount="192418"
        playableKey="provider://tv.plex.provider.vod/library/metadata/5d776883ebdf2200209c104e">
        ...
    </Video>
    <Video art="https://metadata-static.plex.tv/9/gracenote/91e174f0c46ea20c58192bfef5aa6f1e.jpg"
        guid="plex://movie/6310ea4493df84910ae108a2"
        key="/library/metadata/6310ea4493df84910ae108a2" rating="9.1"
        ratingKey="6310ea4493df84910ae108a2" studio="A24" tagline="Meet the man of your dreams."
        type="movie"
        thumb="https://metadata-static.plex.tv/6/gracenote/6b1ab0cb7db6d33b6de803e22d1db37b.jpg"
        addedAt="1699574400" duration="6120000"
        publicPagesURL="https://watch.plex.tv/movie/dream-scenario-2" slug="dream-scenario-2"
        expiresAt="1709942340" userState="0" title="Dream Scenario" contentRating="R"
        originallyAvailableAt="2023-11-10" year="2023" audienceRating="6.8"
        audienceRatingImage="rottentomatoes://image.rating.upright"
        ratingImage="rottentomatoes://image.rating.ripe" imdbRatingCount="39881">
        ...
    </Video>
    ...

Each Video element includes a guid. This is also known as a 'plex media key' in wiki land and every movie, TV show, TV season, & TV episode will have a unique guid assigned to it.

It's important to note that there is no id in the Video element and the key/ratingKey do not point to a key on your server (e.g. it's not like /library/metadata/123). This means that you cannot directly map the items in this response into your local server without changing the lookup strategy. My understanding is that lookups should use the guid instead.

Based on that, when we want to view the Watchlist in Kodi, we need to map the items from that Watchlist response into items that were synced into Kodi. We can do that by looking up items in the plex db based on that guid. The flow would be:
Watchlist Video.guid -> Plex DB lookup by guid -> Kodi item

This requires the addition of a new guid column in the plex db, which requires a database reset/recreation. I also added new indexes for that column to enable quick lookups.

The end result is that the Watchlist will sync correctly and show items that are available in Kodi.

Some pictures:

My watchlist on plex web:

Me, about to add the watchlist to my home page in arctic fuse skin. It shows up alongside search, channels, watch later:

The watchlist items showing up on my home screen. Each item correctly points to the kodi item and is playable

[croneter]

Love this!

[AvAars]

You read my mind! Was looking for this yesterday

Would it be possible to separate the watchlist per library as well?

[Spacetech]

You read my mind! Was looking for this yesterday

Would it be possible to separate the watchlist per library as well?

I added that

[croneter]

Thanks so much!! ❤️

[bokkoman]

I think this came in 3.9.1 of PKC? Cause I'm getting an error with that version that plex-guid is missing?
I had to revert back to 3.9.0.

[croneter]

Could you please share a debug log (see https://github.com/croneter/PlexKodiConnect/wiki/How-to-Report-A-Bug) and open a new issue? Thanks @bokkoman

[bokkoman]

Could you please share a debug log (see https://github.com/croneter/PlexKodiConnect/wiki/How-to-Report-A-Bug) and open a new issue? Thanks @bokkoman

Here's the log.
If you search for plex_guid you should find it.
kodi.log

I only had 1 item in Watchlist.

[AvAars]

Did you do a db reset @bokkoman ?

This requires the addition of a new guid column in the plex db, which requires a database reset/recreation.

[bokkoman]

Did you do a db reset @bokkoman ?

This requires the addition of a new guid column in the plex db, which requires a database reset/recreation.

No? But you don't get this info when you update automatically.
In fact, imo, it should automatically reset your db if there's breaking changes like this.
Perhaps give a warning first that it is going to reset db because there's an update which requires a new DB.

Also, where does it say this? I know it was necessary with 3.8.8 (iirc) cause of the missing movies.
I know it is on this PR, but not in the update info on the Releases page.