manabrew-engine 0.6.2

Magic: The Gathering rules engine — a Rust port of Forge
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

//! ControlSpell effect — gain control of a spell on the stack.
//!
//! Ported from Java's `ControlSpellEffect.java`.
//! Gain control of target spell. You may choose new targets for it.

use super::EffectContext;
use crate::spellability::SpellAbility;

/// Configure the spell ability during construction.
/// Mirrors Java `ControlSpellEffect.buildSpellAbility` — sets the target zone
/// to Stack so the ability targets spells on the stack.
pub fn build_spell_ability(sa: &mut SpellAbility) {
    if sa.uses_targeting() {
        if let Some(ref mut tr) = sa.target_restrictions {
            tr.tgt_zone = vec![forge_foundation::ZoneType::Stack];
        }
    }
}

/// Struct form of this effect so it can participate in the
/// `SpellAbilityEffect` trait hierarchy — mirrors Java's
/// `ControlSpellEffect` class extending `SpellAbilityEffect`.
#[manabrew_engine_macros::spell_effect(ControlSpellEffect)]
fn resolve(ctx: &mut EffectContext, sa: &crate::spellability::SpellAbility) {
    let controller = sa.activating_player;

    // Find the targeted spell on the stack and change its controller
    if let Some(target_card) = sa.target_chosen.target_card {
        if ctx.game.card(target_card).zone == forge_foundation::ZoneType::Stack {
            ctx.game.card_mut(target_card).set_controller(controller);
            // The stack entry's activating_player should also change
            // but MagicStack doesn't expose mutable entries easily.
            // The controller change on the card handles most game mechanics.
        }
    }
}