using Test

using TOML
using Sbplib.SbpOperators

import Sbplib.SbpOperators.Stencil


@testset "parse_rational" begin
    @test SbpOperators.parse_rational("1") isa Rational
    @test SbpOperators.parse_rational("1") == 1//1
    @test SbpOperators.parse_rational("1/2") isa Rational
    @test SbpOperators.parse_rational("1/2") == 1//2
    @test SbpOperators.parse_rational("37/13") isa Rational
    @test SbpOperators.parse_rational("37/13") == 37//13
end

@testset "readoperator" begin
    toml_str = """
        [meta]
        authors = "Ken Mattson"
        description = "Standard operators for equidistant grids"
        type = "equidistant"
        cite = "A paper a long time ago in a galaxy far far away."

        [[stencil_set]]

        order = 2
        test = 2

        H.inner = ["1"]
        H.closure = ["1/2"]

        D1.inner_stencil = ["-1/2", "0", "1/2"]
        D1.closure_stencils = [
            {s = ["-1", "1"], c = 1},
        ]

        D2.inner_stencil = ["1", "-2", "1"]
        D2.closure_stencils = [
            {s = ["1", "-2", "1"], c = 1},
        ]

        e.closure = ["1"]
        d1.closure = {s = ["-3/2", "2", "-1/2"], c = 1}

        [[stencil_set]]

        order = 4
        test = 1
        H.inner = ["1"]
        H.closure = ["17/48", "59/48", "43/48", "49/48"]

        D2.inner_stencil = ["-1/12","4/3","-5/2","4/3","-1/12"]
        D2.closure_stencils = [
            {s = [     "2",    "-5",      "4",       "-1",     "0",     "0"], c = 1},
            {s = [     "1",    "-2",      "1",        "0",     "0",     "0"], c = 2},
            {s = [ "-4/43", "59/43", "-110/43",   "59/43", "-4/43",     "0"], c = 3},
            {s = [ "-1/49",     "0",   "59/49", "-118/49", "64/49", "-4/49"], c = 4},
        ]

        e.closure = ["1"]
        d1.closure = {s = ["-11/6", "3", "-3/2", "1/3"], c = 1}

        [[stencil_set]]
        order = 4
        test = 2

        H.closure = ["-1/49", "0", "59/49", "-118/49", "64/49", "-4/49"]
    """

    parsed_toml = TOML.parse(toml_str)

    @testset "get_stencil_set" begin
        @test get_stencil_set(parsed_toml; order = 2) isa Dict
        @test get_stencil_set(parsed_toml; order = 2) == parsed_toml["stencil_set"][1]
        @test get_stencil_set(parsed_toml; test = 1) == parsed_toml["stencil_set"][2]
        @test get_stencil_set(parsed_toml; order = 4, test = 2) == parsed_toml["stencil_set"][3]

        @test_throws ArgumentError get_stencil_set(parsed_toml; test = 2)
        @test_throws ArgumentError get_stencil_set(parsed_toml; order = 4)
    end

    @testset "parse_stencil" begin
        toml = """
            s1 = ["-1/12","4/3","-5/2","4/3","-1/12"]
            s2 = {s = ["2", "-5", "4", "-1", "0", "0"], c = 1}
            s3 = {s = ["1", "-2", "1", "0", "0", "0"], c = 2}
            s4 = "not a stencil"
            s5 = [-1, 4, 3]
            s6 = {k = ["1", "-2", "1", "0", "0", "0"], c = 2}
            s7 = {s = [-1, 4, 3], c = 2}
            s8 = {s = ["1", "-2", "1", "0", "0", "0"], c = [2,2]}
        """

        @test parse_stencil(TOML.parse(toml)["s1"]) == CenteredStencil(-1/12, 4/3, -5/2, 4/3, -1/12)
        @test parse_stencil(TOML.parse(toml)["s2"]) == Stencil(2., -5., 4., -1., 0., 0.; center=1)
        @test parse_stencil(TOML.parse(toml)["s3"]) == Stencil(1., -2., 1., 0., 0., 0.; center=2)

        @test_throws ArgumentError parse_stencil(TOML.parse(toml)["s4"])
        @test_throws ArgumentError parse_stencil(TOML.parse(toml)["s5"])
        @test_throws ArgumentError parse_stencil(TOML.parse(toml)["s6"])
        @test_throws ArgumentError parse_stencil(TOML.parse(toml)["s7"])
        @test_throws ArgumentError parse_stencil(TOML.parse(toml)["s8"])

        stencil_set = get_stencil_set(parsed_toml; order = 4, test = 1)

        @test parse_stencil.(stencil_set["D2"]["closure_stencils"]) == [
            Stencil(    2.,    -5.,      4.,       -1.,     0.,     0.; center=1),
            Stencil(    1.,    -2.,      1.,        0.,     0.,     0.; center=2),
            Stencil(-4/43, 59/43, -110/43,   59/43, -4/43,     0.; center=3),
            Stencil(-1/49,     0.,   59/49, -118/49, 64/49, -4/49; center=4),
        ]
    end
end