import { timeToGain } from '@domain/services/GaugeCalculator';
import { xpForLevel } from '@domain/value-objects/XpTable';
import type { GaugeType } from '@domain/value-objects/GaugeType';

export interface XpEtaInput {
  currentLevel: number;
  target: number | null;
  gaugeLevels: Readonly<Record<string, number>>;
  activeGauges: readonly string[];
}

export interface XpEtaResult {
  done: boolean;
  seconds: number;
  needsGauge?: GaugeType;
}

export class XpCalculator {
  computeEta(input: XpEtaInput): XpEtaResult {
    const { currentLevel, target, gaugeLevels, activeGauges } = input;
    if (target === null || target === undefined) return { done: false, seconds: 0 };
    if (currentLevel >= target) return { done: true, seconds: 0 };
    if (!activeGauges.includes('mangeoire')) return { done: false, seconds: Infinity, needsGauge: 'mangeoire' };

    const gl = gaugeLevels['mangeoire'] ?? 0;
    const xpNeeded = Math.max(0, xpForLevel(target) - xpForLevel(currentLevel));
    if (xpNeeded <= 0) return { done: true, seconds: 0 };

    const sec = timeToGain(gl, xpNeeded);
    return { done: false, seconds: sec };
  }
}