using ModelingToolkit, OrdinaryDiffEq
using GLMakie

@parameters R
@variables t v(t) i(t)
D = Differential(t)

eqs = [
   i ~ v/R
   D(v) ~ 0
]

@named circuit = ODESystem(eqs, t)

function solve_circuit(circuit)
    u0 = [
       v => 5.0,
    ]

    p = [
       R => 10,
    ]

    tspan = (0.0, 0.01)
    # convert the DAE problem to an ODE problem
    circuit = structural_simplify(circuit)
    prob = ODEProblem(circuit, u0, tspan, p)
    sol = solve(prob, Tsit5())

    # Interpolation can give the solution inside tspan and also further
    #sol(0.009)
    return sol
end


function show_sol(circuit)
    sol = solve_circuit(circuit)
    lines(sol.t, sol[i], color = :red)
    lines!(sol.t, sol[v], color = :blue)
    current_figure()
end