import { Constant } from "./const";
import { makeBigInt, type Integer, type IntegerLike } from "./integer";

type FloatLike = Float | IntegerLike;

export class Float extends Constant {
  public readonly man: bigint;
  public readonly exp: bigint;

  constructor(man: IntegerLike, exp: IntegerLike = 0) {
    super();

    man = makeBigInt(man);
    exp = makeBigInt(exp);

    while (man % 10n === 0n) {
      man /= 10n;
      exp += 1n;
    }

    this.man = man;
    this.exp = exp;
  }

  public add(other: FloatLike) {
    const otherDec = makeFloat(other);

    if (otherDec.exp === this.exp) return new Float(this.man + otherDec.man, this.exp);

  }

  public equals(other: FloatLike) {
    const otherDec = makeFloat(other);
    return otherDec.exp === this.exp && otherDec.man === this.man;
  }

  public gt(other: FloatLike) {
    const otherDec = makeFloat(other);
    if (otherDec.exp > this.exp) return true;
    if (otherDec.exp < this.exp) return false;
    return otherDec.man > this.man;
  }

  public toString(): string {
    let str = this.man.toString();

    if (this.exp < 0) {
      const arr = str.split('');
      arr.splice(str.length + Number(this.exp), 0, '.');
      str = arr.join('');
    } else if (this.exp > 0) {
      for (let i = 0n; i < this.exp; i++) {
        str += '0';
      }
    }

    return str;
  }
}

function makeFloat(value: FloatLike) {
  if (value instanceof Float) return value;

  if (typeof value === 'number') value = value.toString();

  if (typeof value === 'string') {
    if (!value.includes('.')) value += '.0';

  }

  return new Float(value);
}