import { FIGHTER } from "../../constants.js";
import { getFighterType } from "./fighterStats.js";

export function pickUniqueFighters(fighters, count) {
  if (count > fighters.length) {
    throw new Error(
      `Cannot pick ${count} fighters from ${fighters.length} entries.`,
    );
  }

  return shuffleFighters(fighters).slice(0, count);
}

export function pickFighters(fighters, count) {
  if (fighters.length === 0) {
    return [];
  }

  const picks = [];

  while (picks.length < count) {
    picks.push(...shuffleFighters(fighters).slice(0, count - picks.length));
  }

  return picks;
}

export function pickFightersForSetups(fighters, fighterSetups) {
  const eliteCount = fighterSetups.filter(
    (fighterSetup) => fighterSetup.isElite,
  ).length;
  const normalCount = fighterSetups.length - eliteCount;

  const eligibleEliteFighters = fighters.filter((fighter) =>
    FIGHTER.ELITE.TYPE.includes(getFighterType(fighter)),
  );

  if (eliteCount > 0 && eligibleEliteFighters.length === 0) {
    throw new Error(
      `Cannot create elite fighters without ${FIGHTER.ELITE.TYPE} fighter skins.`,
    );
  }

  const elitePicks = pickFighters(eligibleEliteFighters, eliteCount);
  const normalPicks = pickFighters(fighters, normalCount);
  let eliteIndex = 0;
  let normalIndex = 0;

  return fighterSetups.map((fighterSetup) =>
    fighterSetup.isElite
      ? elitePicks[eliteIndex++]
      : normalPicks[normalIndex++],
  );
}

function shuffleFighters(fighters) {
  const pool = [...fighters];

  for (let index = pool.length - 1; index > 0; index -= 1) {
    const randomIndex = Math.floor(Math.random() * (index + 1));
    [pool[index], pool[randomIndex]] = [pool[randomIndex], pool[index]];
  }

  return pool;
}