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manabrew_engine/ability/effects/
explore_effect.rs

1use forge_foundation::ZoneType;
2
3use super::{emit_zone_trigger, EffectContext};
4use crate::ability::ability_ir::DefinedRef;
5use crate::card::CounterType;
6use crate::event::RunParams;
7use crate::parsing::keys;
8use crate::replacement::replacement_handler::{apply_replacements, ReplacementEvent};
9use crate::replacement::ReplacementResult;
10use crate::trigger::TriggerType;
11
12/// `SP$ Explore` — target creature explores.
13///
14/// Mirrors Java's `ExploreEffect.java`.
15/// Explore: Reveal the top card of your library. If it's a land, put it into your hand.
16/// Otherwise, put a +1/+1 counter on this creature, then you may put the card into
17/// your graveyard.
18///
19/// # Card script examples
20/// ```text
21/// A:SP$ Explore | Defined$ Self
22/// A:SP$ Explore | Defined$ Targeted | Num$ 2
23/// ```
24/// Struct form of this effect so it can participate in the
25/// `SpellAbilityEffect` trait hierarchy — mirrors Java's
26/// `ExploreEffect` class extending `SpellAbilityEffect`.
27#[manabrew_engine_macros::spell_effect(ExploreEffect)]
28fn resolve(ctx: &mut EffectContext, sa: &crate::spellability::SpellAbility) {
29    let controller = sa.activating_player;
30
31    // Determine the exploring creature
32    let explorer = sa
33        .target_chosen
34        .target_card
35        .or_else(|| match sa.defined_ref() {
36            Some(DefinedRef::SelfCard) => sa.source,
37            Some(DefinedRef::ParentTarget) => ctx.parent_target_card,
38            _ => sa.source,
39        });
40
41    let explorer_id = match explorer {
42        Some(id) if ctx.game.card(id).zone == ZoneType::Battlefield => id,
43        _ => return,
44    };
45
46    // Run Explore replacement effects before exploring.
47    let mut event = ReplacementEvent::Explore { card: explorer_id };
48    let result = apply_replacements(ctx.game, &mut event);
49    if result == ReplacementResult::Skipped || result == ReplacementResult::Replaced {
50        return;
51    }
52
53    // Parse Num parameter for multiple explores (e.g. Jadelight Ranger explores twice).
54    // Mirrors Java's `AbilityUtils.calculateAmount(host, sa.getParamOrDefault("Num", "1"), sa)`.
55    let amount = super::resolve_numeric_svar(ctx.game, sa, keys::NUM, 1).max(1);
56
57    for _ in 0..amount {
58        // Re-check explorer is still on battlefield (may have been removed by a trigger)
59        if ctx.game.card(explorer_id).zone != ZoneType::Battlefield {
60            return;
61        }
62        ctx.game.player_record_explore(controller, 1);
63
64        // Check if library has cards
65        let lib = ctx.game.cards_in_zone(ZoneType::Library, controller);
66        if lib.is_empty() {
67            // Explorer still gets the +1/+1 counter per rules
68            if !crate::staticability::static_ability_cant_put_counter::any_cant_put_counter_on_card(
69                &ctx.game.cards,
70                ctx.game.card(explorer_id),
71                &CounterType::P1P1,
72            ) {
73                ctx.add_counter(explorer_id, &CounterType::P1P1, 1, sa, RunParams::default());
74            }
75            continue;
76        }
77
78        // Reveal top card
79        let top_card = *lib.last().unwrap();
80
81        let is_land = ctx.game.card(top_card).is_land();
82
83        if is_land {
84            // Land → put into hand
85            let owner = ctx.game.card(top_card).owner;
86            ctx.move_card(top_card, ZoneType::Hand, owner);
87            emit_zone_trigger(
88                ctx.trigger_handler,
89                top_card,
90                ZoneType::Library,
91                ZoneType::Hand,
92            );
93        } else {
94            // Nonland → put +1/+1 counter on explorer
95            if !crate::staticability::static_ability_cant_put_counter::any_cant_put_counter_on_card(
96                &ctx.game.cards,
97                ctx.game.card(explorer_id),
98                &CounterType::P1P1,
99            ) {
100                ctx.add_counter(explorer_id, &CounterType::P1P1, 1, sa, RunParams::default());
101            }
102
103            // Player may put revealed card into graveyard (otherwise it stays on top).
104            // Java's ExploreEffect calls controller.confirmAction() which in the
105            // harness DeterministicController uses a random boolean (pickBool).
106            // Use confirm_action here to match that RNG-consuming path.
107            let card_name = ctx.game.card(top_card).card_name.clone();
108            let explorer_name = ctx.game.card(explorer_id).card_name.clone();
109            let msg = format!("Put {} into your graveyard?", card_name);
110            let put_in_gy = ctx.agents[controller.index()].confirm_action(
111                controller,
112                None,
113                &msg,
114                &[],
115                sa.source,
116                Some(crate::ability::api_type::ApiType::Explore),
117            );
118
119            if put_in_gy {
120                let owner = ctx.game.card(top_card).owner;
121                ctx.move_card(top_card, ZoneType::Graveyard, owner);
122                emit_zone_trigger(
123                    ctx.trigger_handler,
124                    top_card,
125                    ZoneType::Library,
126                    ZoneType::Graveyard,
127                );
128            }
129        }
130        ctx.trigger_handler.run_trigger(
131            TriggerType::Explored,
132            RunParams {
133                card: Some(explorer_id),
134                explored: Some(top_card),
135                ..Default::default()
136            },
137            false,
138        );
139    }
140}