import type { AttemptResult } from '@flashcard/shared';

export const MAX_BOX = 5;
// index 1..5; index 0 unused
export const BOX_INTERVALS_SEC: Record<number, number> = {
  1: 0,
  2: 1 * 24 * 60 * 60,
  3: 3 * 24 * 60 * 60,
  4: 7 * 24 * 60 * 60,
  5: 14 * 24 * 60 * 60,
};

export interface ProgressLike {
  box: number;
  correctCount: number;
  incorrectCount: number;
}

export interface ProgressDelta {
  box: number;
  correctCount: number;
  incorrectCount: number;
  nextDueAt: number;
  lastShownAt: number;
}

export function applyResult(
  current: ProgressLike,
  result: AttemptResult,
  nowSec: number
): ProgressDelta {
  let box = current.box;
  let correctCount = current.correctCount;
  let incorrectCount = current.incorrectCount;
  if (result === 'correct') {
    box = Math.min(MAX_BOX, current.box + 1);
    correctCount += 1;
  } else {
    box = 1;
    incorrectCount += 1;
  }
  return {
    box,
    correctCount,
    incorrectCount,
    nextDueAt: nowSec + BOX_INTERVALS_SEC[box]!,
    lastShownAt: nowSec,
  };
}