local identifierGeneratorFunction = function (suffix)
    local nextIndex = 0
    return function (specification)
        nextIndex = nextIndex + 1
        return specification.Identifier or
            (specification.Parent .. suffix .. nextIndex)
    end
end

local generateGridIdentifier = identifierGeneratorFunction("Grid")

local addGrid = function (specification)
    local identifier = specification.Identifier or
        generateGridIdentifier(specification)

    local name = specification.Name
    local color = specification.Color
    local parent = specification.Parent
    local scale = specification.Scale
    local position = specification.Position
    local rotation = specification.Rotation

    local grid = {
        Identifier = identifier,
        Parent = parent,
        Transform = {
            Scale = {
                Type = "StaticScale",
                Scale = scale;
            },
            Translation = {
                Type = "StaticTranslation",
                Position = position
            },
            Rotation = {
                Type = "StaticRotation",
                Rotation = rotation
            }
        },
        Renderable = {
            Type = "RenderableSphericalGrid",
            Enabled = true,
            LineWidth = 2.0,
            GridColor = color
        },
        GUI = {
            Name = name,
            Path = "/Other/Grids"
        }
    }
    openspace.addSceneGraphNode(grid)
    return identifier;
end

local generateAxesIdentifier = identifierGeneratorFunction("Axes")

local addCartesianAxes = function (specification)
    local identifier = specification.Identifier or
        generateAxesIdentifier(specification)

    local name = specification.Name or specification.Identifier
    local parent = specification.Parent or "Root"
    local scale = specification.Scale or 1.0
    local position = specification.Position or {0.0, 0.0, 0.0}
    local rotation = specification.Rotation or {0.0, 0.0, 0.0}

    local axes = {
        Identifier = identifier,
        Parent = parent,
        Transform = {
            Scale = {
                Type = "StaticScale",
                Scale = scale;
            },
            Translation = {
                Type = "StaticTranslation",
                Position = position
            },
            Rotation = {
                Type = "StaticRotation",
                Rotation = rotation
            }
        },
        Renderable = {
            Type = "RenderableCartesianAxes",
            Enabled = true,
            XColor = {1.0, 0.0, 0.0, 1.0},
            YColor = {0.0, 1.0, 0.0, 1.0},
            ZColor = {0.0, 0.0, 1.0, 1.0}
        },
        GUI = {
            Name = name,
            Path = "/Other/Coordinate Systems"
        }
    }
    openspace.addSceneGraphNode(axes)
    return identifier;
end


local registerNode = function(
    containerAsset,
    nodeCreationFunction,
    identifierGeneratorFunction,
    specification
)
    local identifier = specification.Identifier or
        identifierGeneratorFunction(specification)

    specification.Identifier = identifier

    containerAsset.onInitialize(function ()
        nodeCreationFunction(specification)
    end)
    containerAsset.onDeinitialize(function ()
        openspace.removeSceneGraphNode(identifier)
    end)
end

local registerGrid = function(gridAsset, specification)
    registerNode(gridAsset, addGrid, generateGridIdentifier, specification)
end

local registerCartesianAxes = function(axesAsset, specification)
    registerNode(axesAsset, addCartesianAxes, generateAxesIdentifier, specification)
end

asset.export("addGrid", addGrid)
asset.export("registerGrid", registerGrid)

asset.export("addCartesianAxes", addGrid)
asset.export("registerCartesianAxes", registerCartesianAxes)