#= TupleDuplicator
This is used to create a tuple of size n with deepcopies of any object x
=#
struct TupleDuplicator
        n::Int
end
#make tuples consisting of copies of whatever was provided
function (f::TupleDuplicator)(s::State)
	st = state_to_tuple(s)
    return f(st)
	#BROKEN: Fails in test, but works in REPL.
end

(f::TupleDuplicator)(x) = tuple([deepcopy(x) for i=1:f.n]...)



struct BranchGenerator
        n::UInt
end
function (b::BranchGenerator)(branch::Flux.Parallel,join_fn::Function) 
        # used to deepcopy the branches and duplicate the inputs in the returned chain
        f = TupleDuplicator(b.n)
        
        return Flux.Chain(state_to_tuple,f,Flux.Parallel(join_fn,f(branch)...))
        #note that it destructures the state to a tuple, duplicates,
		# and then passes to the parallelized functions.
end


# Neural Network Generators

function value_function_generator(number_params=32)
	return Flux.Chain(
	    Flux.Parallel(vcat
		        #parallel joins together stocks and debris, after a little bit of preprocessing
		        ,Flux.Chain(
					Flux.Dense(N_constellations, number_params*2,Flux.relu)
		            ,Flux.Dense(number_params*2, number_params*2,Flux.σ)
		        )
		        ,Flux.Chain(
					Flux.Dense(N_debris, number_params,Flux.relu)
		            ,Flux.Dense(number_params, number_params,Flux.σ)
				)
			)
		    #Apply some transformations to the preprocessed data.
			,Flux.Dense(number_params*3,number_params,Flux.σ)
			,Flux.Dense(number_params,number_params,Flux.σ)
			,Flux.Dense(number_params,1)
		)

end

function cross_linked_planner_policy_function_generator(number_params=32)
	return Flux.Chain(
	    Flux.Parallel(vcat
		        #parallel joins together stocks and debris
		        ,Flux.Chain(
					Flux.Dense(N_constellations, number_params*2,Flux.relu)
		            ,Flux.Dense(number_params*2, number_params*2,Flux.σ)
		        )
		        ,Flux.Chain(
					Flux.Dense(N_debris, number_params,Flux.relu)
		            ,Flux.Dense(number_params, number_params)
				)
			)
		    #Apply some transformations
			,Flux.Dense(number_params*3,number_params,Flux.σ)
			,Flux.Dense(number_params,number_params,Flux.σ)
			,Flux.Dense(number_params,N_constellations,Flux.relu)
		)

end

function operator_policy_function_generator(
	N_constellations::Int
	,N_debris
	,number_params=32
	)
	return Flux.Chain(
	    Flux.Parallel(vcat
		        #parallel joins together stocks and debris
		        ,Flux.Chain(
					Flux.Dense(N_constellations, number_params*2,Flux.relu)
		            ,Flux.Dense(number_params*2, number_params*2,Flux.tanh)
		        )
		        ,Flux.Chain(
					Flux.Dense(N_debris, number_params,Flux.relu)
		            ,Flux.Dense(number_params, number_params)
				)
			)
		    #Apply some transformations
			,Flux.Dense(number_params*3,number_params,Flux.tanh)
			,Flux.Dense(number_params,number_params,Flux.tanh)
			,Flux.Dense(number_params,1,x -> Flux.relu.(sinh.(x)))
		)

end