package org.openrndr.extra.noise

import org.openrndr.extra.noise.*
import org.openrndr.extra.noise.fbm as orxFbm
import org.openrndr.math.Vector2
import org.openrndr.math.Vector3
import org.openrndr.math.Vector4
import kotlin.math.ln
import kotlin.math.max
import kotlin.math.sqrt
import kotlin.math.pow
import kotlin.random.Random as DefaultRandom


object Random {
    var rnd: DefaultRandom

    private var seedTracking: Int = 0
    private var nextGaussian: Double = 0.0
    private var hasNextGaussian = false

    enum class Fractal {
        FBM, BILLOW, RIGID
    }

    enum class Noise {
        LINEAR, QUINTIC, HERMIT
    }

    var seed: String = "OPENRNDR"
        set(value) {
            field = value
            rnd = newRandomGenerator(value)
        }

    init {
        rnd = newRandomGenerator(seed)
    }

    private fun newRandomGenerator(newSeed: String): DefaultRandom {
        return DefaultRandom(stringToInt(newSeed))
    }

    private fun stringToInt(str: String): Int = str.toCharArray().fold(0) { i: Int, c: Char ->
        i + c.toInt()
    }

    fun resetState() {
        rnd = newRandomGenerator(seed)
    }

    fun randomizeSeed() {
        val seedBase = seed.replace(Regex("""-\d+"""), "")
        seedTracking = int0(999999)
        seed = "${seedBase}-${seedTracking}"
    }

    fun double(min: Double = -1.0, max: Double = 1.0): Double {
        return Double.uniform(min, max, rnd)
    }

    fun double0(max: Double = 1.0): Double {
        return rnd.nextDouble(max)
    }

    fun int0(max: Int = Int.MAX_VALUE): Int {
        return rnd.nextInt(max)
    }

    fun int(min: Int = 0, max: Int = Int.MAX_VALUE): Int {
        return rnd.nextInt(min, max)
    }

    fun bool(): Boolean {
        return rnd.nextBoolean()
    }

    fun <T> pick(coll: Collection<T>): T {
        return pick(coll, count = 1).first()
    }

    fun <T> pick(coll: Collection<T>, compareAgainst: Collection<T>): T {
        return pick(coll, compareAgainst, 1).first()
    }

    fun <T> pick(coll: Collection<T>, compareAgainst: Collection<T> = listOf(), count: Int): MutableList<T> {
        var list = coll.toMutableList()
        val picked = mutableListOf<T>()

        while(picked.size < count) {
            if (list.isEmpty()) {
                list = coll.toMutableList()
            }

            var index = int0(list.size)
            var newElem = list.elementAt(index)

            while(compareAgainst.contains(newElem)) {
                index = int0(list.size)
                newElem = list.elementAt(index)
            }

            picked.add(list[index])
            list.removeAt(index)
        }

        return picked
    }

    fun gaussian(mean: Double = 0.0, standardDeviation: Double = 1.0): Double {
        if (hasNextGaussian) {
            val result = nextGaussian
            nextGaussian = 0.0
            hasNextGaussian = false

            return mean + standardDeviation * result
        } else {
            var v1 = 0.0
            var v2 = 0.0
            var s = 0.0

            while (s >= 1.0 || s == 0.0) {
                v1 = double() // between -1 and 1
                v2 = double() // between -1 and 1
                s = v1 * v1 + v2 * v2
            }
            val multiplier = sqrt(-2.0 * ln(s) / s)

            nextGaussian = (v2 * multiplier)
            hasNextGaussian = true
            return mean + standardDeviation * (v1 * multiplier)
        }
    }

    /**
     * https://en.wikipedia.org/wiki/Pareto_distribution
     */
    fun pareto(alpha: Double = 1.0): () -> Double {
        val invAlpha = 1.0 / max(alpha, 0.0)

        return {
            1.0 / (1.0 - double0()).pow(invAlpha)
        }
    }

    fun Vector2(min: Double = -1.0, max: Double = 1.0): Vector2 {
        return Vector2.uniform(min, max, rnd)
    }

    fun Vector3(min: Double = -1.0, max: Double = 1.0): Vector3 {
        return Vector3.uniform(min, max, rnd)
    }

    fun Vector4(min: Double = -1.0, max: Double = 1.0): Vector4 {
        return Vector4.uniform(min, max, rnd)
    }

    fun perlin(x: Double, y: Double, type: Noise = Noise.LINEAR): Double {
        val sd = stringToInt(seed)

        return when (type) {
            Noise.LINEAR -> perlinLinear(sd, x, y)
            Noise.QUINTIC -> perlinQuintic(sd, x, y)
            Noise.HERMIT -> perlinHermite(sd, x, y)
        }
    }

    fun perlin(x: Double, y: Double, z: Double, type: Noise = Noise.LINEAR): Double {
        val sd = stringToInt(seed)

        return when (type) {
            Noise.LINEAR -> perlinLinear(sd, x, y, z)
            Noise.QUINTIC -> perlinQuintic(sd, x, y, z)
            Noise.HERMIT -> perlinHermite(sd, x, y, z)
        }
    }

    fun value(x: Double, y: Double, type: Noise = Noise.LINEAR): Double {
        val sd = stringToInt(seed)

        return when (type) {
            Noise.LINEAR -> valueLinear(sd, x, y)
            Noise.QUINTIC -> valueQuintic(sd, x, y)
            Noise.HERMIT -> valueHermite(sd, x, y)
        }
    }

    fun value(x: Double, y: Double, z: Double, type: Noise = Noise.LINEAR): Double {
        val sd = stringToInt(seed)

        return when (type) {
            Noise.LINEAR -> valueLinear(sd, x, y, z)
            Noise.QUINTIC -> valueQuintic(sd, x, y, z)
            Noise.HERMIT -> valueHermite(sd, x, y, z)
        }
    }

    fun simplex(x: Double, y: Double): Double {
        return simplex(stringToInt(seed), x, y)
    }

    fun simplex(x: Double, y: Double, z: Double): Double {
        return simplex(stringToInt(seed), x, y, z)
    }
    
    fun simplex(x: Double, y: Double, z: Double, w: Double): Double {
        return simplex(stringToInt(seed), x, y, z, w)
    }

    fun fbm(x: Double, y: Double, noiseFun: (Int, Double, Double) -> Double, type: Fractal = Fractal.FBM,
            octaves: Int = 8, lacunarity: Double = 0.5, gain: Double = 0.5): Double {
        val s = stringToInt(seed)

        return when (type) {
            Fractal.FBM -> orxFbm(s, x, y, noiseFun, octaves, lacunarity, gain)
            Fractal.RIGID -> rigid(s, x, y, noiseFun, octaves, lacunarity, gain)
            Fractal.BILLOW -> billow(s, x, y, noiseFun, octaves, lacunarity, gain)
        }
    }

    fun fbm(x: Double, y: Double, z: Double, noiseFun: (Int, Double, Double, Double) -> Double, type: Fractal = Fractal.FBM,
            octaves: Int = 8, lacunarity: Double = 0.5, gain: Double = 0.5): Double {
        val s = stringToInt(seed)

        return when (type) {
            Fractal.FBM -> orxFbm(s, x, y, z, noiseFun, octaves, lacunarity, gain)
            Fractal.RIGID -> rigid(s, x, y, z, noiseFun, octaves, lacunarity, gain)
            Fractal.BILLOW -> billow(s, x, y, z, noiseFun, octaves, lacunarity, gain)
        }
    }

    fun cubic(x: Double, y: Double): Double {
        return cubic(stringToInt(seed), x, y)
    }

    fun cubic(x: Double, y: Double, z: Double): Double {
        return cubic(stringToInt(seed), x, y, z)
    }

    fun ring2d(innerRadius: Double = 0.0, outerRadius: Double = 1.0, count: Int = 1): Any {
        return when(count) {
            1 -> Vector2.uniformRing(innerRadius, outerRadius, rnd)
            else -> Vector2.uniformsRing(count, innerRadius, outerRadius, rnd)
        }
    }

    fun ring3d(innerRadius: Double = 0.0, outerRadius: Double = 1.0, count: Int = 1): Any {
        return when(count) {
            1 -> Vector3.uniformRing(innerRadius, outerRadius, rnd)
            else -> Vector3.uniformsRing(count, innerRadius, outerRadius, rnd)
        }
    }

    fun <T> roll(elements: Collection<T>, distribution: (Int) -> List<Double>): T {
        val result = double0()
        val probabilities = distribution(elements.size)
        val index = probabilities.indexOfFirst { result <= it }

        return elements.elementAtOrNull(index) ?: elements.last()
    }
}