import { factory } from '../../utils/factory.js'

import { isMatrix } from '../../utils/is.js'

import { createRng } from './util/seededRNG.js'

import { randomMatrix } from './util/randomMatrix.js'

const name = 'random'

const dependencies = ['typed', 'config', '?on']

export const createRandom = /* #__PURE__ */ factory(name, dependencies, ({ typed, config, on }) => {

// seeded pseudo random number generator

let rng = createRng(config.randomSeed)

if (on) {

on('config', function (curr, prev) {

if (curr.randomSeed !== prev.randomSeed) {

rng = createRng(curr.randomSeed)

}

})

}

/**

* Return a random number larger or equal to `min` and smaller than `max`

* using a uniform distribution.

*

* Syntax:

*

* math.random() // generate a random number between 0 and 1

* math.random(max) // generate a random number between 0 and max

* math.random(min, max) // generate a random number between min and max

* math.random(size) // generate a matrix with random numbers between 0 and 1

* math.random(size, max) // generate a matrix with random numbers between 0 and max

* math.random(size, min, max) // generate a matrix with random numbers between min and max

*

* Examples:

*

* math.random() // returns a random number between 0 and 1

* math.random(100) // returns a random number between 0 and 100

* math.random(30, 40) // returns a random number between 30 and 40

* math.random([2, 3]) // returns a 2x3 matrix with random numbers between 0 and 1

*

* See also:

*

* randomInt, pickRandom

*

* @param {Array | Matrix} [size] If provided, an array or matrix with given

* size and filled with random values is returned

* @param {number} [min] Minimum boundary for the random value, included

* @param {number} [max] Maximum boundary for the random value, excluded

* @return {number | Array | Matrix} A random number

*/

return typed(name, {

'': () => _random(0, 1),

number: (max) => _random(0, max),

'number, number': (min, max) => _random(min, max),

'Array | Matrix': (size) => _randomMatrix(size, 0, 1),

'Array | Matrix, number': (size, max) => _randomMatrix(size, 0, max),

'Array | Matrix, number, number': (size, min, max) => _randomMatrix(size, min, max)

})

function _randomMatrix (size, min, max) {

const res = randomMatrix(size.valueOf(), () => _random(min, max))

return isMatrix(size) ? size.create(res, 'number') : res

}

function _random (min, max) {

return min + rng() * (max - min)

}

})

// number only implementation of random, no matrix support

// TODO: there is quite some duplicate code in both createRandom and createRandomNumber, can we improve that?

export const createRandomNumber = /* #__PURE__ */ factory(name, ['typed', 'config', '?on'], ({ typed, config, on, matrix }) => {

// seeded pseudo random number generator1

let rng = createRng(config.randomSeed)

if (on) {

on('config', function (curr, prev) {

if (curr.randomSeed !== prev.randomSeed) {

rng = createRng(curr.randomSeed)

}

})

}

return typed(name, {

'': () => _random(0, 1),

number: (max) => _random(0, max),

'number, number': (min, max) => _random(min, max)

})

function _random (min, max) {

return min + rng() * (max - min)

}

})