import { isBigInt } from "./is.ts"

/**
 * @description Check whether a value is zero as a bigint.
 *
 * @example
 *   ```
 *   // Expect: true
 *   const example1 = bigintIsZero(0n)
 *   // Expect: false
 *   const example2 = bigintIsZero(2n)
 *   ```
 */
export const bigintIsZero = (value: unknown): value is 0n => {
  return isBigInt(value) && value === 0n
}

/**
 * @description Check whether a value is a positive bigint.
 *
 * @example
 *   ```
 *   // Expect: true
 *   const example1 = bigintIsPositive(3n)
 *   // Expect: false
 *   const example2 = bigintIsPositive(-1n)
 *   ```
 */
export const bigintIsPositive = (value: unknown): value is bigint => {
  return isBigInt(value) && value > 0n
}

/**
 * @description Check whether a value is a negative bigint.
 *
 * @example
 *   ```
 *   // Expect: true
 *   const example1 = bigintIsNegative(-3n)
 *   // Expect: false
 *   const example2 = bigintIsNegative(1n)
 *   ```
 */
export const bigintIsNegative = (value: unknown): value is bigint => {
  return isBigInt(value) && value < 0n
}

/**
 * @description Get the absolute value of a bigint.
 *
 * @example
 *   ```
 *   // Expect: 5n
 *   const example1 = bigintAbs(-5n)
 *   // Expect: 2n
 *   const example2 = bigintAbs(2n)
 *   ```
 */
export const bigintAbs = (value: bigint): bigint => {
  return value < 0n ? -value : value
}

/**
 * @description Get the smaller of two bigint values.
 *
 * @example
 *   ```
 *   // Expect: 2n
 *   const example1 = bigintMinOf(2n, 9n)
 *   // Expect: -1n
 *   const example2 = bigintMinOf(5n, -1n)
 *   ```
 */
export const bigintMinOf = (a: bigint, b: bigint): bigint => {
  return a < b ? a : b
}

/**
 * @description Get the larger of two bigint values.
 *
 * @example
 *   ```
 *   // Expect: 9n
 *   const example1 = bigintMaxOf(2n, 9n)
 *   // Expect: 5n
 *   const example2 = bigintMaxOf(5n, -1n)
 *   ```
 */
export const bigintMaxOf = (a: bigint, b: bigint): bigint => {
  return a > b ? a : b
}

/**
 * @description Clamp a bigint between two bounds.
 *
 * @example
 *   ```
 *   // Expect: 5n
 *   const example1 = bigintClamp(0n, 10n, 5n)
 *   // Expect: 0n
 *   const example2 = bigintClamp(0n, 10n, -3n)
 *   ```
 */
export const bigintClamp = (min: bigint, max: bigint, value: bigint): bigint => {
  const minValue = bigintMinOf(min, max)
  const maxValue = bigintMaxOf(min, max)
  if (value < minValue) {
    return minValue
  }
  if (value > maxValue) {
    return maxValue
  }
  return value
}