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import { assert, err, isNil, isNumber, isArray, reduce } from '../../util.js'
import { computeValue } from '../../internal.js'
export const arithmeticOperators = {
/**
* Returns the absolute value of a number.
* https://docs.mongodb.com/manual/reference/operator/aggregation/abs/#exp._S_abs
* @param obj
* @param expr
* @return {Number|null|NaN}
*/
$abs (obj, expr) {
let val = computeValue(obj, expr)
return (val === null || val === undefined) ? null : Math.abs(val)
},
/**
* Computes the sum of an array of numbers.
*
* @param obj
* @param expr
* @returns {Object}
*/
$add (obj, expr) {
let args = computeValue(obj, expr)
return reduce(args, (acc, num) => acc + num, 0)
},
/**
* Returns the smallest integer greater than or equal to the specified number.
*
* @param obj
* @param expr
* @returns {number}
*/
$ceil (obj, expr) {
let arg = computeValue(obj, expr)
if (isNaN(arg)) return NaN
if (isNil(arg)) return null
assert(isNumber(arg), '$ceil must be a valid expression that resolves to a number.')
return Math.ceil(arg)
},
/**
* Takes two numbers and divides the first number by the second.
*
* @param obj
* @param expr
* @returns {number}
*/
$divide (obj, expr) {
let args = computeValue(obj, expr)
return args[0] / args[1]
},
/**
* Raises Euler’s number (i.e. e ) to the specified exponent and returns the result.
*
* @param obj
* @param expr
* @returns {number}
*/
$exp (obj, expr) {
let arg = computeValue(obj, expr)
if (isNaN(arg)) return NaN
if (isNil(arg)) return null
assert(isNumber(arg), '$exp must be a valid expression that resolves to a number.')
return Math.exp(arg)
},
/**
* Returns the largest integer less than or equal to the specified number.
*
* @param obj
* @param expr
* @returns {number}
*/
$floor (obj, expr) {
let arg = computeValue(obj, expr)
if (isNaN(arg)) return NaN
if (isNil(arg)) return null
assert(isNumber(arg), '$floor must be a valid expression that resolves to a number.')
return Math.floor(arg)
},
/**
* Calculates the natural logarithm ln (i.e loge) of a number and returns the result as a double.
*
* @param obj
* @param expr
* @returns {number}
*/
$ln (obj, expr) {
let arg = computeValue(obj, expr)
if (isNaN(arg)) return NaN
if (isNil(arg)) return null
assert(isNumber(arg), '$ln must be a valid expression that resolves to a number.')
return Math.log(arg)
},
/**
* Calculates the log of a number in the specified base and returns the result as a double.
*
* @param obj
* @param expr
* @returns {number}
*/
$log (obj, expr) {
let args = computeValue(obj, expr)
assert(isArray(args) && args.length === 2, '$log must be a valid expression that resolves to an array of 2 items')
if (args.some(isNaN)) return NaN
if (args.some(isNil)) return null
assert(args.every(isNumber), '$log expression must resolve to array of 2 numbers')
return Math.log10(args[0]) / Math.log10(args[1])
},
/**
* Calculates the log base 10 of a number and returns the result as a double.
*
* @param obj
* @param expr
* @returns {number}
*/
$log10 (obj, expr) {
let arg = computeValue(obj, expr)
if (isNaN(arg)) return NaN
if (isNil(arg)) return null
assert(isNumber(arg), '$log10 must be a valid expression that resolves to a number.')
return Math.log10(arg)
},
/**
* Takes two numbers and calculates the modulo of the first number divided by the second.
*
* @param obj
* @param expr
* @returns {number}
*/
$mod (obj, expr) {
let args = computeValue(obj, expr)
return args[0] % args[1]
},
/**
* Computes the product of an array of numbers.
*
* @param obj
* @param expr
* @returns {Object}
*/
$multiply (obj, expr) {
let args = computeValue(obj, expr)
return reduce(args, (acc, num) => acc * num, 1)
},
/**
* Raises a number to the specified exponent and returns the result.
*
* @param obj
* @param expr
* @returns {Object}
*/
$pow (obj, expr) {
let args = computeValue(obj, expr)
assert(isArray(args) && args.length === 2 && args.every(isNumber), '$pow expression must resolve to an array of 2 numbers')
assert(!(args[0] === 0 && args[1] < 0), '$pow cannot raise 0 to a negative exponent')
return Math.pow(args[0], args[1])
},
/**
* Calculates the square root of a positive number and returns the result as a double.
*
* @param obj
* @param expr
* @returns {number}
*/
$sqrt (obj, expr) {
let n = computeValue(obj, expr)
if (isNaN(n)) return NaN
if (isNil(n)) return null
assert(isNumber(n) && n > 0, '$sqrt expression must resolve to non-negative number.')
return Math.sqrt(n)
},
/**
* Takes an array that contains two numbers or two dates and subtracts the second value from the first.
*
* @param obj
* @param expr
* @returns {number}
*/
$subtract (obj, expr) {
let args = computeValue(obj, expr)
return args[0] - args[1]
},
/**
* Truncates a number to its integer.
*
* @param obj
* @param expr
* @returns {number}
*/
$trunc (obj, expr) {
let n = computeValue(obj, expr)
if (isNaN(n)) return NaN
if (isNil(n)) return null
assert(isNumber(n) && n > 0, '$trunc must be a valid expression that resolves to a non-negative number.')
return Math.trunc(n)
}
}