using DelimitedFiles, Plots
include("../3body_resonance.jl")

current_E = 5.9673 - 0.0006im

training_c = 2.0 : -0.2 : 1.2
extrapolating_c = 1.05 .- [0.0 : 0.1 : 0.4; 0.45 : 0.05 : 0.60]

@time "H0" H0 = T1 + T2

# free memory
Es = n1s = l1s = n2s = l2s = mask1 = mask2 = T1 = T2 = V1_cache = V_relative_cache = V1 = V_relative = U = V2 = nothing
GC.gc()

exact = ComplexF64[]
training = ComplexF64[]
extrapolated = ComplexF64[]
training_vecs = Vector{ComplexF64}[]

for c in training_c
    println("Training for c = $c")
    local H = H0 + c .* V
    local evals, evecs = eigs(H, nev=3, ncv=24, which=:LI, maxiter=5000, tol=1e-5, ritzvec=true, check=1)

    global current_E = nearest(evals, current_E)
    push!(training, current_E)
    push!(training_vecs, evecs[:, nearestIndex(evals, current_E)])
end

EC_basis = hcat(training_vecs...)
N_EC = transpose(EC_basis) * EC_basis
H0_EC = transpose(EC_basis) * H0 * EC_basis
V_EC = transpose(EC_basis) * V * EC_basis

for c in extrapolating_c
    println("Extrapolating for c = $c")
    local H = H0 + c .* V
    local evals, evecs = eigs(H, nev=3, ncv=24, which=:LI, maxiter=5000, tol=1e-5, ritzvec=true, check=1)

    global current_E = nearest(evals, current_E)
    push!(exact, current_E)

    # extrapolation
    H_EC = H0_EC + c .* V_EC
    evals = eigvals(H_EC, N_EC)
    push!(extrapolated, nearest(evals, current_E))
end

open("temp/NCSM.training.csv", "w") do f; writedlm(f, hcat(reim(training)...)); end
open("temp/NCSM.exact.csv", "w") do f; writedlm(f, hcat(reim(exact)...)); end
open("temp/NCSM.extrapolated.csv", "w") do f; writedlm(f, hcat(reim(extrapolated)...)); end

scatter(real.(training),imag.(training), label="training")
scatter!(real.(exact),imag.(exact), label="exact")
scatter!(real.(extrapolated),imag.(extrapolated), label="extrapolated")
savefig("temp/NCSM.pdf")