using System;

using Tensorflow.Functions;

using Tensorflow.Train;

namespace Tensorflow

{

public class Function: Trackable, IGenericFunction

{

#pragma warning disable CS0169 // The field 'Function._handle' is never used

private IntPtr _handle;

#pragma warning restore CS0169 // The field 'Function._handle' is never used

protected Func<Tensor[], Tensor[]> _csharp_function;

protected ConcreteFunction _concrete_variable_creation_fn;

protected bool _autograph;

protected TracingCompiler _variable_creation_fn;

public string Name { get; set; }

public Function(Func<Tensor[], Tensor[]> csharp_function,

string name, bool auto_graph = true)

{

_csharp_function = csharp_function;

Name = name;

_autograph = auto_graph;

}

public virtual Tensors Apply(Tensors inputs)

{

if (_run_functions_eagerly())

{

return _csharp_function(inputs);

}

var result = _call(inputs);

return result;

}

public ConcreteFunction get_concrete_function(params Tensor[] args)

{

return _get_concrete_function_garbage_collected(args);

}

protected virtual Tensors _call(Tensors inputs)

{

if(_variable_creation_fn is not null)

{

return _variable_creation_fn.Apply(inputs);

}

_initialize(inputs);

return _concrete_variable_creation_fn.CallFlat(inputs,

_concrete_variable_creation_fn.CapturedInputs);

}

protected TracingCompiler _compiler(Func<Tensor[], Tensor[]> fn)

{

var name = nameof(fn);

return new TracingCompiler(fn, name, autograph: _autograph);

}

protected virtual bool _run_functions_eagerly()

{

return false;

}

protected ConcreteFunction _get_concrete_function_garbage_collected(Tensor[] args)

{

if(_variable_creation_fn is null)

{

_initialize(args);

// TODO(Rinne): _initialize_uninitialized_variables

}

var concrete = _variable_creation_fn._get_concrete_function_internal_garbage_collected(args);

return concrete;

}

private void _initialize(Tensor[] args)

{

_variable_creation_fn = _compiler(_csharp_function);

_variable_creation_fn._name = this.Name;

_concrete_variable_creation_fn = _variable_creation_fn._get_concrete_function_internal_garbage_collected(args);

}

}

}