import { makeArray } from "./general.js";

export const getNextCharacter = (charCode: number) => {
  if (charCode < 48) {
    return 48;
  }
  if (charCode < 57) {
    return charCode + 1;
  }
  if (charCode < 65) {
    return 65;
  }
  if (charCode < 90) {
    return charCode + 1;
  }
  if (charCode < 97) {
    return 97;
  }
  if (charCode < 122) {
    return charCode + 1;
  }
  // > 122
  return null;
};

export const charCodesToString = (charCodes: number[]) => {
  return charCodes.map((charCode) => String.fromCharCode(charCode)).join("");
};

/**
 * Function that finds the first next alphabetical available id in a list of ids
 * Needed for lmdb
 *
 * https://chat.openai.com/share/253a17ed-154b-4028-99bb-8769d2fa2f91
 */
export const findNextId = (ids: string[] | string) => {
  const sorted = makeArray(ids).sort();

  const lastId = sorted.pop() || "0";

  const charCodes = lastId.split("").map((letter) => letter.charCodeAt(0));
  const zeroCharcode = 48;
  const zCharCode = 122;

  if (charCodes.length < 6) {
    // Base case 1: always add a 0 if its shorter than 6
    const newCharcodes = charCodes.concat(zeroCharcode);
    return charCodesToString(newCharcodes);
  }

  const nonZIndex = charCodes.findLastIndex((c) => c < zCharCode);

  const newCharCodes =
    nonZIndex < 5 ? charCodes.slice(0, nonZIndex + 1) : charCodes;

  //console.log({ newCharCodes });
  if (charCodes.length === 6 && nonZIndex !== -1) {
    // Base case 2: if theres 6 and there's a nonZ index, just up that last one
    newCharCodes[nonZIndex] = getNextCharacter(
      newCharCodes[nonZIndex],
    ) as number;

    const newId = charCodesToString(newCharCodes);
    return newId;
  }

  // Rest case: not sure but it works :D

  const indexToIncrease = charCodes
    .map((charCode) => getNextCharacter(charCode))
    .findIndex((charCode) => charCode !== null);

  const otherCharCodes =
    indexToIncrease === -1
      ? charCodes.concat(zeroCharcode)
      : charCodes
          .slice(0, indexToIncrease + 1)
          .map((c, i) =>
            i === indexToIncrease ? (getNextCharacter(c) as number) : c,
          );

  const newId = charCodesToString(otherCharCodes);

  return newId;
};