import { defaultSettings } from "./constants";
import type { AppSettings } from "./types";

export function shuffleArray<T>(array: T[]) {
  const next = [...array];
  for (let i = next.length - 1; i > 0; i -= 1) {
    const j = Math.floor(Math.random() * (i + 1));
    [next[i], next[j]] = [next[j], next[i]];
  }
  return next;
}

export function mergeSettings(settings: Partial<AppSettings>): AppSettings {
  return {
    ttsVoice: settings.ttsVoice || defaultSettings.ttsVoice,
    ttsRate: settings.ttsRate || defaultSettings.ttsRate,
    scorePerCorrect: Number(settings.scorePerCorrect ?? defaultSettings.scorePerCorrect),
    scorePerWrong: Number(settings.scorePerWrong ?? defaultSettings.scorePerWrong),
    autoSpeak: settings.autoSpeak ?? defaultSettings.autoSpeak,
    wordDisplayMode:
      settings.wordDisplayMode === "capitalize" ||
      settings.wordDisplayMode === "input" ||
      settings.wordDisplayMode === "uppercase"
        ? settings.wordDisplayMode
        : defaultSettings.wordDisplayMode,
    pkWordCount: Math.max(0, Math.floor(Number(settings.pkWordCount ?? defaultSettings.pkWordCount))),
    pkOptionCount: normalizeOptionCount(Number(settings.pkOptionCount ?? defaultSettings.pkOptionCount)),
  };
}

export function getFairRoundCount(availableCount: number, limit: number) {
  const requestedCount = limit > 0 ? Math.min(limit, availableCount) : availableCount;
  if (requestedCount < 2) return requestedCount;
  return requestedCount % 2 === 0 ? requestedCount : requestedCount - 1;
}

export function formatWordDisplay(text: string, mode: AppSettings["wordDisplayMode"]) {
  if (mode === "input") return text;
  if (mode === "capitalize") {
    return text
      .split(/(\s+)/)
      .map((part) => {
        if (/^\s+$/.test(part) || !part) return part;
        return part.charAt(0).toUpperCase() + part.slice(1).toLowerCase();
      })
      .join("");
  }
  return text.toUpperCase();
}

export function normalizeOptionCount(value: number) {
  const count = Math.floor(value);
  if (!Number.isFinite(count)) return defaultSettings.pkOptionCount;
  if (count < 2) return 2;
  if (count > 8) return 8;
  return count % 2 === 0 ? count : count + 1;
}

export function isImageSource(value: string) {
  return /^(https?:\/\/|\/|data:image\/)/i.test(value);
}