81 lines
2.3 KiB
TypeScript
81 lines
2.3 KiB
TypeScript
/**
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* Magical Weapon — a Magical Object that deals fixed damage.
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*
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* Inherits health/status management from MagicalObject.
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* Invariants enforced at construction:
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* - Damage is non-negative
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*/
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import { Character } from '../characters/Character.ts';
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import { MagicalObject } from './MagicalObject.ts';
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import type { DamageDealer } from './magical-object-types.ts';
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export class MagicalWeapon extends MagicalObject implements DamageDealer {
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readonly #damage: number;
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readonly #owner: Character;
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private constructor(
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health: number,
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maxHealth: number,
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status: { readonly kind: 'alive' } | { readonly kind: 'destroyed' },
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damage: number,
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owner: Character,
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) {
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super(health, maxHealth, status);
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this.#damage = damage;
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this.#owner = owner;
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}
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static create({
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maxHealth,
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damage,
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owner,
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}: {
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maxHealth: number;
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damage: number;
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owner: Character;
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}): MagicalWeapon {
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if (maxHealth < 0) throw new Error('MaxHealth cannot be negative');
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if (damage < 0) throw new Error('Damage cannot be negative');
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return new MagicalWeapon(maxHealth, maxHealth, { kind: 'alive' }, damage, owner);
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}
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get damage(): number {
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return this.#damage;
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}
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get owner(): Character {
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return this.#owner;
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}
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/** Use this weapon to deal damage. Returns updated weapon and target. */
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use(target: Character): { weapon: MagicalWeapon; target: Character } {
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// Destroyed weapons can't be used
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if (this.status.kind === 'destroyed') {
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return { weapon: this, target };
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}
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// Deal fixed damage
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const newTargetHealth = Math.max(0, target.health.value - this.#damage);
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const newTargetStatus = newTargetHealth === 0 ? { kind: 'dead' as const } : target.status;
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const newTarget = Character.createWithHealthAndStatus({
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name: target.name,
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level: target.level,
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health: newTargetHealth,
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status: newTargetStatus,
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});
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// Reduce weapon health by 1
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const newWeaponHealth = this.health - 1;
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const newWeaponStatus =
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newWeaponHealth === 0 ? { kind: 'destroyed' as const } : { kind: 'alive' as const };
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return {
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weapon: new MagicalWeapon(
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newWeaponHealth,
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this.maxHealth,
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newWeaponStatus,
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this.#damage,
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this.#owner,
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),
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target: newTarget,
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};
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}
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}
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