# compile using
# gfortran -shared -fPIC osbrac.f90 -o osbrac.so
# gfortran -shared -fPIC allosbrac.f90 -o allosbrac.so

println("OSBRACKETS test against Brody et al.")

Emax = 3
Λ = 1
l1 = 1
l2 = 2

ϵ = (Emax - Λ) % 2
N = (l1 - l2 + Λ - ϵ) ÷ 2
M = (l1 + l2 - Λ - ϵ) ÷ 2
L = Λ
NQMAX = Emax
CO = 1/sqrt(2)
SI = 1/sqrt(2)
FIRSTCALL = true
# from source: BRAC(NP,N1P,MP,N1,N2) with dimensions BRAC(0:L,0:(NQMAX-L)/2,0:(NQMAX-L)/2,0:(NQMAX-L)/2,0:(NQMAX-L)/2)
BRAC = zeros(Float64, L + 1, (NQMAX - L) ÷ 2 + 1,(NQMAX - L) ÷ 2 + 1,(NQMAX - L) ÷ 2 + 1,(NQMAX - L) ÷ 2 + 1)

@ccall "./OSBRACKETS/osbrac.so".osbrac_(N::Ref{Int32},M::Ref{Int32},L::Ref{Int32},NQMAX::Ref{Int32},CO::Ref{Float64},SI::Ref{Float64},FIRSTCALL::Ref{UInt8},BRAC::Ptr{Array{Float64}})::Cvoid

function get_bracket(n1′, l1′, n2′, l2′, n1, n2)
    Nq = l1 + l2 + 2 * (n1 + n2)
    Nq′ = l1′ + l2′ + 2 * (n1′ + n2′)
    if Nq ≠ Nq′; return 0; end
    N′ = (l1′ - l2′ + Λ - ϵ) ÷ 2
    N1′ = n1′
    M′ = (l1′ + l2′ - Λ - ϵ) ÷ 2
    N1 = n1
    N2 = n2
    return BRAC[N′ + 1, N1′ + 1, M′ + 1, N1 + 1, N2 + 1]
end

test_n = [0 0 0 0 1 1]
test_l = [0 1 1 2 0 1]
test_N = [1 0 1 0 0 0]
test_L = [1 2 0 1 1 0]

bracs = get_bracket.(test_n, test_l, test_N, test_L, 0, 0)
display(bracs)