using Roots, DelimitedFiles

include("../EC.jl")
include("../common.jl")
include("../p_space.jl")

μ = 0.5
V_system(c) = (p, q) -> c*(-5*g0(sqrt(3), p, q) + 2*g0(sqrt(10), p, q)) # ResonanceEC: Eq. (20)

# determining c0 with EC
temp_c = range(1.1, 0.9, 3)
p, w = get_mesh([0, 8], [256])
H0 = get_T_matrix(p, μ)
V = get_V_matrix(V_system(1), p, w)
EC = affine_EC(H0, V, w)
train!(EC, temp_c; ref_eval=-0.2, CAEC=false, verbose=false)
quick_extrapolate(c) = minimum(abs2, get_extrapolated_evals(EC.H0_EC, EC.H1_EC, EC.N_EC, c, 0))
c0 = find_zero(quick_extrapolate, 0.85)

training_c = range(1.2, 0.9, 9) # original: range(1.35, 0.9, 5)
extrapolating_c = range(0.78, 0.45, 7) # original: range(0.75, 0.40, 8)

data_c = vcat(training_c, extrapolating_c)
data_E = [quick_pole_E(V_system(c)) for c in data_c]

# export to CSV
file = "temp/2body_data.csv"
delim = ','
open(file, "w") do f
    writedlm(f, ["c" "re_E" "im_E"], delim)
    writedlm(f, [c0 0 0], delim) # first entry for the threshold
    writedlm(f, hcat(data_c, real.(data_E), imag.(data_E)), delim)
end