//! What happened, in order. The engine records an event each time it changes the game.
//! The world also keeps the nesting depth each event was recorded at (`World::log_depths`).

use super::card::TriggerOn;
use super::world::{EntityId, PlayerId};

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Event {
    /// `id` entered the board. `by` is the minion whose triggered ability put it there (the
    /// trigger resolving when it entered), or `None` for a spell, a play or a summon from
    /// outside a Sequence. Module 10: SpellGrid puts it on `by`'s grid tile. The course's log
    /// doesn't show `by`.
    Summoned {
        id: EntityId,
        by: Option<EntityId>,
    },
    Damaged {
        target: EntityId,
        amount: i32,
    },
    Triggered {
        source: EntityId,
        on: TriggerOn,
    },
    Drew {
        player: PlayerId,
        id: EntityId,
    },
    Fatigue {
        player: PlayerId,
    },
    ArmorGained {
        player: PlayerId,
        amount: i32,
    },
    /// Armor absorbed `amount` of a Damage to `player`'s hero. The `Damaged` that follows
    /// shows the full amount.
    ArmorLost {
        player: PlayerId,
        amount: i32,
    },
    StatsChanged {
        id: EntityId,
        attack: i32,
        health: i32,
    },
    SpellCast {
        card: String,
    },
    /// A Death Event: the Death Creation Step moved `id` from play to the graveyard.
    /// `before` is the nearest minion to its right that did not die in the same step, if any:
    /// its Deathrattle summons immediately left of that minion, or at the right end. It is a
    /// handle because a board index goes stale when a minion further left dies in the same step.
    Destroyed {
        id: EntityId,
        before: Option<EntityId>,
    },
    DeathPhase {
        round: u32,
    },
    /// A minion was played from hand (it has just entered the board). Its Battlecry answers this.
    Played {
        id: EntityId,
    },
    /// Module 12: `player`'s turn ended. Their minions' end of turn triggers answer this.
    TurnEnded {
        player: PlayerId,
    },
    /// Module 10: `source`'s effect asked for `word` to be written on its grid tile.
    /// Part I has no grid: it only records the request. SpellGrid reads it when the
    /// Sequence ends.
    TextSpawned {
        source: EntityId,
        word: String,
    },
}