open Jest
open Expect

let params: GenericDist_GenericOperation.params = {
  sampleCount: 100,
  xyPointLength: 100,
}

let normalDist: GenericDist_Types.genericDist = #Symbolic(#Normal({mean: 5.0, stdev: 2.0}))
let normalDist10: GenericDist_Types.genericDist = #Symbolic(#Normal({mean: 10.0, stdev: 2.0}))
let normalDist20: GenericDist_Types.genericDist = #Symbolic(#Normal({mean: 20.0, stdev: 2.0}))
let uniformDist: GenericDist_Types.genericDist = #Symbolic(#Uniform({low: 9.0, high: 10.0}))

let {toFloat, toDist, toString, toError} = module(GenericDist_GenericOperation.Output)
let {run, fmap} = module(GenericDist_GenericOperation)
let run = run(params)
let fmap = fmap(params)
let toExt: option<'a> => 'a = E.O.toExt(
  "Should be impossible to reach (This error is in test file)",
)

describe("normalize", () => {
  test("has no impact on normal dist", () => {
    let result = run(#fromDist(#toDist(#normalize), normalDist))
    expect(result)->toEqual(#Dist(normalDist))
  })
})

describe("mean", () => {
  test("for a normal distribution", () => {
    let result = GenericDist_GenericOperation.run(params, #fromDist(#toFloat(#Mean), normalDist))
    expect(result)->toEqual(#Float(5.0))
  })
})

describe("mixture", () => {
  test("on two normal distributions", () => {
    let result =
      run(#mixture([(normalDist10, 0.5), (normalDist20, 0.5)]))
      |> fmap(#fromDist(#toFloat(#Mean)))
      |> toFloat
      |> toExt
    expect(result)->toBeCloseTo(15.28)
  })
})

describe("toPointSet", () => {
  test("on symbolic normal distribution", () => {
    let result =
      run(#fromDist(#toDist(#toPointSet), normalDist))
      |> fmap(#fromDist(#toFloat(#Mean)))
      |> toFloat
      |> toExt
    expect(result)->toBeCloseTo(5.09)
  })

  test("on sample set distribution with under 4 points", () => {
    let result =
      run(#fromDist(#toDist(#toPointSet), #SampleSet([0.0, 1.0, 2.0, 3.0]))) |> fmap(
        #fromDist(#toFloat(#Mean)),
      )
    expect(result)->toEqual(#Error(Other("Converting sampleSet to pointSet failed")))
  })

  test("back and forth", () => {
    let result =
      run(#fromDist(#toDist(#toPointSet), normalDist))
      |> fmap(#fromDist(#toDist(#toSampleSet(1000))))
      |> fmap(#fromDist(#toDist(#consoleLog)))
      |> fmap(#fromDist(#toDist(#toPointSet)))
      |> fmap(#fromDist(#toDist(#consoleLog)))
      |> fmap(#fromDist(#toFloat(#Mean)))
      |> toFloat
      |> toExt
    expect(result)->toBeCloseTo(5.09)
  })

  test("on sample set distribution", () => {
    let result =
      run(
        #fromDist(
          #toDist(#toPointSet),
          #SampleSet([
            0.0,
            1.0,
            2.0,
            3.0,
            4.0,
            5.0,
            6.0,
            7.0,
            8.0,
            9.0,
            10.0,
          ]),
        ),
      )
      |> fmap(#fromDist(#toFloat(#Mean)))
      |> toFloat
      |> toExt
    Js.log(result)
    expect(result)->toBeCloseTo(5.09)
  })
})