require 'ffi'

module SketchupFFI

   extend FFI::Library

   ffi_lib "C:/Program Files/Sketchup/Sketchup 2017/SketchupAPI.dll"

   enum :SUResult, [
      :SU_ERROR_NONE,
      :SU_ERROR_NULL_POINTER_INPUT,
      :SU_ERROR_INVALID_INPUT,
      :SU_ERROR_NULL_POINTER_OUTPUT,
      :SU_ERROR_INVALID_OUTPUT,
      :SU_ERROR_OVERWRITE_VALID,
      :SU_ERROR_GENERIC,
      :SU_ERROR_SERIALIZATION,
      :SU_ERROR_OUT_OF_RANGE,
      :SU_ERROR_NO_DATA,
      :SU_ERROR_INSUFFICIENT_SIZE,
      :SU_ERROR_UNKNOWN_EXCEPTION,
      :SU_ERROR_MODEL_INVALID,
      :SU_ERROR_MODEL_VERSION,
      :SU_ERROR_LAYER_LOCKED,
      :SU_ERROR_DUPLICATE,
      :SU_ERROR_PARTIAL_SUCCESS,
      :SU_ERROR_UNSUPPORTED,
      :SU_ERROR_INVALID_ARGUMENT,
      :SU_ERROR_ENTITY_LOCKED,
      :SU_ERROR_INVALID_OPERATION
   ]

   enum :SUModelVersion, [
      :SUModelVersion_SU3,
      :SUModelVersion_SU4,
      :SUModelVersion_SU5,
      :SUModelVersion_SU6,
      :SUModelVersion_SU7,
      :SUModelVersion_SU8,
      :SUModelVersion_SU2013,
      :SUModelVersion_SU2014,
      :SUModelVersion_SU2015,
      :SUModelVersion_SU2016,
      :SUModelVersion_SU2017,
      :SUModelVersion_SU2018,
      :SUModelVersion_SU2019
   ]

   class SURef < FFI::Struct
      layout :ptr, :pointer
   end

   class SUPoint3d < FFI::Struct
      layout :x, :double,
         :y, :double,
         :z, :double
   end

   # SU_RESULT SUModelCreate(SUModelRef* model);
   attach_function(:create_model, :SUModelCreate, [:pointer], :SUResult)

   # SU_RESULT SUModelSaveToFileWithVersion(SUModelRef model, const char* file_path, enum SUModelVersion version);
   attach_function(:save_to_file_with_version, :SUModelSaveToFileWithVersion, [SURef, :string, :SUModelVersion], :SUResult)

   # SU_RESULT SUModelGetEntities(SUModelRef model, SUEntitiesRef* entities);
   attach_function(:get_entities, :SUModelGetEntities, [SURef, SURef], :SUResult)

   # SU_RESULT SUGuidePointCreate(SUGuidePointRef* guide_point, const struct SUPoint3D* position);
   attach_function(:create_guide_point, :SUGuidePointCreate, [:pointer, :pointer], :SUResult)

   # SU_RESULT SUEntitiesAddGuidePoints(SUEntitiesRef entities, size_t len, const SUGuidePointRef guide_points[]);
   attach_function(:add_guide_point, :SUEntitiesAddGuidePoints, [SURef, :size_t, :pointer], :SUResult)


end # module SketchupFFI


include SketchupFFI

# Create a Model
model = SURef.new
res = create_model model
if res != :SU_ERROR_NONE
   puts "Could not create model: #{res}"
   exit
end

# Get the Model's Entities
ents = SURef.new
res = get_entities(model, ents)
if res != :SU_ERROR_NONE
   puts "Could not get entities: #{res}"
   exit
end

# Need to create an array of SUGuidePointRef,
# or in this code just an array of SURef since it's the same thing.
len = 3
size = SURef.size
points = FFI::MemoryPointer.new(SURef, len)
len.times {|i|
   ptr = points + (i * size)
   pt3d = SUPoint3d.new
   pt3d[:x] = rand(10); pt3d[:y] = rand(10); pt3d[:z] = rand(10)
   res = create_guide_point(ptr, pt3d)
   if res != :SU_ERROR_NONE
      puts "Could not create GuidePoint: #{res}"
      exit
   end
}

# res == SU_ERROR_INVALID_INPUT: An API object input to the function was not created properly.
# or a SegFault
res = add_guide_point(ents[:ptr], len*SURef.size, points)
if res != :SU_ERROR_NONE
   puts "Could not add GuidePoint to Entities: #{res}"
   exit
end

save_to_file_with_version(model[:ptr], "model.skp", :SUModelVersion_SU2017)