using Microsoft.VisualStudio.TestTools.UnitTesting;
using Tensorflow.Eager;
using static Tensorflow.Binding;

namespace Tensorflow.Native.UnitTest.Eager
{
    public partial class CApiEagerTest
    {
        /// <summary>
        /// TEST(CAPI, Variables)
        /// </summary>
        [TestMethod]
        public unsafe void Variables()
        {
            using var status = c_api.TF_NewStatus();

            static SafeContextHandle NewContext(SafeStatusHandle status)
            {
                using var opts = c_api.TFE_NewContextOptions();
                return c_api.TFE_NewContext(opts, status);
            }

            using var ctx = NewContext(status);
            ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));

            using (var var_handle = CreateVariable(ctx, 12.0f, status))
            {
                ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));

                int num_retvals = 1;
                var value_handle = new SafeEagerTensorHandle[1];
                using (var op = TFE_NewOp(ctx, "ReadVariableOp", status))
                {
                    ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
                    TFE_OpSetAttrType(op, "dtype", TF_FLOAT);
                    TFE_OpAddInput(op, var_handle, status);
                    ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
                    TFE_Execute(op, value_handle, out num_retvals, status);
                    ASSERT_EQ(1, num_retvals);
                }

                try
                {
                    ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
                    ASSERT_EQ(1, num_retvals);
                    EXPECT_EQ(TF_FLOAT, TFE_TensorHandleDataType(value_handle[0]));
                    EXPECT_EQ(0, TFE_TensorHandleNumDims(value_handle[0], status));
                    ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
                    var value = 0f; // new float[1];
                    var t = TFE_TensorHandleResolve(value_handle[0], status);
                    ASSERT_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
                    ASSERT_EQ(sizeof(float), (int)TF_TensorByteSize(t));
                    tf.memcpy(&value, TF_TensorData(t).ToPointer(), sizeof(float));
                    t.Dispose();
                    EXPECT_EQ(12.0f, value);
                }
                finally
                {
                    value_handle[0].Dispose();
                }
            }

            CHECK_EQ(TF_OK, TF_GetCode(status), TF_Message(status));
        }
    }
}