import { Config } from '../core/Config.js'
import type { FnComplexBinary } from '../Complex/type.js'
import { FnAdd, FnConj, FnSubtract, FnUnaryMinus, FnMultiply, FnAbsSquare, FnReciprocal, FnDivide, FnConservativeSqrt, FnSqrt } from '../interfaces/arithmetic.js'

export const add: FnAdd<number> = (a, b) => a + b
export const addReal = add
export const unaryMinus: FnUnaryMinus<number> = (a) => -a
export const conj: FnConj<number> = (a) => a
export const subtract: FnSubtract<number> = (a, b) => a - b
export const multiply: FnMultiply<number> = (a, b) => a * b
export const absquare: FnAbsSquare<number, number> = (a) => a * a
export const reciprocal: FnReciprocal<number> = (a) => 1 / a
export const divide: FnDivide<number> = (a, b) => a / b
export const divideByReal = divide

export const conservativeSqrt: FnConservativeSqrt<number> = (a) => isNaN(a) ? NaN : Math.sqrt(a)

export const sqrt =
   (dep: {
      config: Config,
      complex: FnComplexBinary<number>
   }): FnSqrt<number> => {
      if (dep.config.predictable || !dep.complex) return conservativeSqrt
      return a => {
         if (isNaN(a)) return NaN
         if (a >= 0) return Math.sqrt(a)
         return dep.complex(0, Math.sqrt(unaryMinus(a)))
      }
   }