[WOC] Implement Court of Locthwain

[Susucre]

So in this WIP, it is not possible to choose to cast for free. Commenting out "you may play" part:

CardUtil.makeCardPlayable(
        game, source, card, Duration.EndOfGame,
        true, controller.getId(), null
);

does unlock the ability to "you may cast without paying manacost". So I think there is an issue with two competing AsThoughEffect not letting the player choose the appropriate one.

[github-actions]

Unable to retrieve information for "Court of Lochtwain"

[github-actions]

Court of Locthwain - (Gatherer) (Scryfall) (EDHREC)

{2}{B}{B}
Enchantment
When Court of Locthwain enters the battlefield, you become the monarch.
At the beginning of your upkeep, exile the top card of target opponent's library. You may play that card for as long as it remains exiled, and mana of any type can be spent to cast it. If you're the monarch, until end of turn, you may cast a spell from among cards exiled with Court of Locthwain without paying its mana cost.

[Susucre]

Ok this PR is a mess, but in the end it works.
Will split the game engine improvement and make PR for them separatly.

[Susucre]

I consider Court of Locthwain working with the rework of AsThough effects (I did test it live, and with unit tests). I'll look into some of the known bugs of AsThough and see if I can also make them work from this point in other PRs.

[xenohedron]

Can you describe what you've changed about AsThoughEffect in this PR?

1. Is it all interdependent or are there separable refactor and logic change?
2. Does it help resolve [WIP] Allows player to choose which asThough ability to use #9268 at all?
3. Any impact to REFACTOR: AsThoughEffect need a refactor #9521 or [WIP] Refactor AsThoughEffect to split .applies into two functions #9559?

[Susucre]

Can you describe what you've changed about AsThoughEffect in this PR?

1. Is it all interdependent or are there separable refactor and logic change?
2. Does it help resolve [WIP] Allows player to choose which asThough ability to use #9268 at all?
3. Any impact to REFACTOR: AsThoughEffect need a refactor #9521 or [WIP] Refactor AsThoughEffect to split .applies into two functions #9559?

1. In short, yes. Aside from the Court of Locthwain code and the ConditionalOneShotEffect text generation all the changes should be done together. But since I did add unit tests on Court of Locthwain, I am not in favor of having a 26 file PR, then Court being added.
2. It should. I'll live test those and report back results, and can add further Unit Test covering those situations.
3. No progress on those. Applying AsThoughEffect does have side effects of setting info in the Player's state.

[Susucre]

So 2. let the user choose, but I need to add some MageIdentifier restriction from the alternative cost of Bolas's Citadel or else it does apply to Vivien's alternative cast too. I'll make another PR for that.

And I do have a way to make RisenExecutioneer cost reduction only apply for its own alternative cast, simply by introducing a specific MageIdentifier for it and setting the cost reduction to only apply on that MageIdentifier alternative cast.

[xenohedron]

Okay, I'm fine with the card and unit tests in this PR with the rework then, and the other PR #11114 to fix those old bugs can be rebased after this is merged. The other issue of the side effects in applies method can be revisited separately.

Please address all feedback from #11114, and update PR title and description to clearly explain what is being changed and why.

[Susucre]

Current plan is to rework the effects in #11114, then I'll rebase this PR with it.

[Susucre]

Rebased now that the AsThough rework has been merged. Everything works well.

[xenohedron]

(no need to null check source; indeed you've already called getControllerId() on it at this point)