/**
 * This module provides utility functions and type class instances for working with the `number` type in TypeScript.
 * It includes functions for basic arithmetic operations, as well as type class instances for
 * `Equivalence`, `Order`, `Semigroup`, and `Monoid`.
 *
 * @since 1.0.0
 */
import * as equivalence from "@effect/data/Equivalence"
import { dual } from "@effect/data/Function"
import * as order from "@effect/data/Order"
import type { Ordering } from "@effect/data/Ordering"
import * as predicate from "@effect/data/Predicate"

/**
 * Tests if a value is a `number`.
 *
 * @param input - The value to test.
 *
 * @example
 * import { isNumber } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(isNumber(2), true)
 * assert.deepStrictEqual(isNumber("2"), false)
 *
 * @category guards
 * @since 1.0.0
 */
export const isNumber: (input: unknown) => input is number = predicate.isNumber

/**
 * Provides an addition operation on `number`s.
 *
 * @param self - The first operand.
 * @param that - The second operand.
 *
 * @example
 * import { sum } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(sum(2, 3), 5)
 *
 * @category math
 * @since 1.0.0
 */
export const sum: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = dual(2, (self: number, that: number): number => self + that)

/**
 * Provides a multiplication operation on `number`s.
 *
 * @param self - The first operand.
 * @param that - The second operand.
 *
 * @example
 * import { multiply } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(multiply(2, 3), 6)
 *
 * @category math
 * @since 1.0.0
 */
export const multiply: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = dual(2, (self: number, that: number): number => self * that)

/**
 * Provides a subtraction operation on `number`s.
 *
 * @param self - The first operand.
 * @param that - The second operand.
 *
 * @example
 * import { subtract } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(subtract(2, 3), -1)
 *
 * @category math
 * @since 1.0.0
 */
export const subtract: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = dual(2, (self: number, that: number): number => self - that)

/**
 * Provides a division operation on `number`s.
 *
 * @param self - The dividend operand.
 * @param that - The divisor operand.
 *
 * @example
 * import { divide } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(divide(6, 3), 2)
 *
 * @category math
 * @since 1.0.0
 */
export const divide: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = dual(2, (self: number, that: number): number => self / that)

/**
 * Returns the result of adding `1` to a given number.
 *
 * @param n - A `number` to be incremented.
 *
 * @example
 * import { increment } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(increment(2), 3)
 *
 * @category math
 * @since 1.0.0
 */
export const increment = (n: number): number => n + 1

/**
 * Decrements a number by `1`.
 *
 * @param n - A `number` to be decremented.
 *
 * @example
 * import { decrement } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(decrement(3), 2)
 *
 * @category math
 * @since 1.0.0
 */
export const decrement = (n: number): number => n - 1

/**
 * @category instances
 * @since 1.0.0
 */
export const Equivalence: equivalence.Equivalence<number> = equivalence.number

/**
 * @category instances
 * @since 1.0.0
 */
export const Order: order.Order<number> = order.number

/**
 * Returns `true` if the first argument is less than the second, otherwise `false`.
 *
 * @param self - The first argument.
 * @param that - The second argument.
 *
 * @example
 * import { lessThan } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(lessThan(2, 3), true)
 * assert.deepStrictEqual(lessThan(3, 3), false)
 * assert.deepStrictEqual(lessThan(4, 3), false)
 *
 * @category predicates
 * @since 1.0.0
 */
export const lessThan: {
  (that: number): (self: number) => boolean
  (self: number, that: number): boolean
} = order.lessThan(Order)

/**
 * Returns a function that checks if a given `number` is less than or equal to the provided one.
 *
 * @param self - The first `number` to compare with.
 * @param that - The second `number` to compare with.
 *
 * @example
 * import { lessThanOrEqualTo } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(lessThanOrEqualTo(2, 3), true)
 * assert.deepStrictEqual(lessThanOrEqualTo(3, 3), true)
 * assert.deepStrictEqual(lessThanOrEqualTo(4, 3), false)
 *
 * @category predicates
 * @since 1.0.0
 */
export const lessThanOrEqualTo: {
  (that: number): (self: number) => boolean
  (self: number, that: number): boolean
} = order.lessThanOrEqualTo(Order)

/**
 * Returns `true` if the first argument is greater than the second, otherwise `false`.
 *
 * @param self - The first argument.
 * @param that - The second argument.
 *
 * @example
 * import { greaterThan } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(greaterThan(2, 3), false)
 * assert.deepStrictEqual(greaterThan(3, 3), false)
 * assert.deepStrictEqual(greaterThan(4, 3), true)
 *
 * @category predicates
 * @since 1.0.0
 */
export const greaterThan: {
  (that: number): (self: number) => boolean
  (self: number, that: number): boolean
} = order.greaterThan(Order)

/**
 * Returns a function that checks if a given `number` is greater than or equal to the provided one.
 *
 * @param self - The first `number` to compare with.
 * @param that - The second `number` to compare with.
 *
 * @example
 * import { greaterThanOrEqualTo } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(greaterThanOrEqualTo(2, 3), false)
 * assert.deepStrictEqual(greaterThanOrEqualTo(3, 3), true)
 * assert.deepStrictEqual(greaterThanOrEqualTo(4, 3), true)
 *
 * @category predicates
 * @since 1.0.0
 */
export const greaterThanOrEqualTo: {
  (that: number): (self: number) => boolean
  (self: number, that: number): boolean
} = order.greaterThanOrEqualTo(Order)

/**
 * Checks if a `number` is between a `minimum` and `maximum` value (inclusive).
 *
 * @param self - The `number` to check.
 * @param minimum - The `minimum` value to check.
 * @param maximum - The `maximum` value to check.
 *
 * @example
 * import { between } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(between(0, 5)(3), true)
 * assert.deepStrictEqual(between(0, 5)(-1), false)
 * assert.deepStrictEqual(between(0, 5)(6), false)
 *
 * @category predicates
 * @since 1.0.0
 */
export const between: {
  (minimum: number, maximum: number): (self: number) => boolean
  (self: number, minimum: number, maximum: number): boolean
} = order.between(Order)

/**
 * Restricts the given `number` to be within the range specified by the `minimum` and `maximum` values.
 *
 * - If the `number` is less than the `minimum` value, the function returns the `minimum` value.
 * - If the `number` is greater than the `maximum` value, the function returns the `maximum` value.
 * - Otherwise, it returns the original `number`.
 *
 * @param self - The `number` to be clamped.
 * @param minimum - The lower end of the range.
 * @param maximum - The upper end of the range.
 *
 * @example
 * import { clamp } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(clamp(0, 5)(3), 3)
 * assert.deepStrictEqual(clamp(0, 5)(-1), 0)
 * assert.deepStrictEqual(clamp(0, 5)(6), 5)
 *
 * @since 1.0.0
 */
export const clamp: {
  (minimum: number, maximum: number): (self: number) => number
  (self: number, minimum: number, maximum: number): number
} = order.clamp(Order)

/**
 * Returns the minimum between two `number`s.
 *
 * @param self - The first `number`.
 * @param that - The second `number`.
 *
 * @example
 * import { min } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(min(2, 3), 2)
 *
 * @since 1.0.0
 */
export const min: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = order.min(Order)

/**
 * Returns the maximum between two `number`s.
 *
 * @param self - The first `number`.
 * @param that - The second `number`.
 *
 * @example
 * import { max } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(max(2, 3), 3)
 *
 * @since 1.0.0
 */
export const max: {
  (that: number): (self: number) => number
  (self: number, that: number): number
} = order.max(Order)

/**
 * Determines the sign of a given `number`.
 *
 * @param n - The `number` to determine the sign of.
 *
 * @example
 * import { sign } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(sign(-5), -1)
 * assert.deepStrictEqual(sign(0), 0)
 * assert.deepStrictEqual(sign(5), 1)
 *
 * @category math
 * @since 1.0.0
 */
export const sign = (n: number): Ordering => Order(n, 0)

/**
 * Takes an `Iterable` of `number`s and returns their sum as a single `number`.
 *
 * @param collection - The collection of `number`s to sum.
 *
 * @example
 * import { sumAll } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(sumAll([2, 3, 4]), 9)
 *
 * @category math
 * @since 1.0.0
 */
export const sumAll = (collection: Iterable<number>): number => {
  let out = 0
  for (const n of collection) {
    out += n
  }
  return out
}

/**
 * Takes an `Iterable` of `number`s and returns their multiplication as a single `number`.
 *
 * @param collection - The collection of `number`s to multiply.
 *
 * @example
 * import { multiplyAll } from '@effect/data/Number'
 *
 * assert.deepStrictEqual(multiplyAll([2, 3, 4]), 24)
 *
 * @category math
 * @since 1.0.0
 */
export const multiplyAll = (collection: Iterable<number>): number => {
  let out = 1
  for (const n of collection) {
    if (n === 0) {
      return 0
    }
    out *= n
  }
  return out
}

/**
 * Returns the remainder left over when one operand is divided by a second operand.
 *
 * It always takes the sign of the dividend.
 *
 * @param self - The dividend.
 * @param divisor - The divisor.
 *
 * @example
 * import { remainder } from "@effect/data/Number"
 *
 * assert.deepStrictEqual(remainder(2, 2), 0)
 * assert.deepStrictEqual(remainder(3, 2), 1)
 * assert.deepStrictEqual(remainder(-4, 2), -0)
 *
 * @category math
 * @since 1.0.0
 */
export const remainder: {
  (divisor: number): (self: number) => number
  (self: number, divisor: number): number
} = dual(2, (self: number, divisor: number): number => {
  // https://stackoverflow.com/questions/3966484/why-does-modulus-operator-return-fractional-number-in-javascript/31711034#31711034
  const selfDecCount = (self.toString().split(".")[1] || "").length
  const divisorDecCount = (divisor.toString().split(".")[1] || "").length
  const decCount = selfDecCount > divisorDecCount ? selfDecCount : divisorDecCount
  const selfInt = parseInt(self.toFixed(decCount).replace(".", ""))
  const divisorInt = parseInt(divisor.toFixed(decCount).replace(".", ""))
  return (selfInt % divisorInt) / Math.pow(10, decCount)
})