import openbabel as ob
import sys

def clone(mol):
    obc = ob.OBConversion()
    obc.SetInAndOutFormats("mol", "mol")
    molstring = obc.WriteString(mol)
    new_mol = ob.OBMol()
    obc.ReadString(new_mol, molstring)
    return new_mol

def abs_h(mol):
    radicals = []
    mol.AddHydrogens()
    h_indexs = []
    hetero_indexs = []

    for atom in ob.OBMolAtomIter(mol):
        if atom.GetType() == 'H':
            h_indexs.append(atom.GetIdx())
        else:
            hetero_indexs.append(atom.GetIdx())

    hatoms = []
    non_redundant_hs = []
    for h_index in h_indexs:
        hetero = neighbor(mol, h_index, hetero_indexs)
        if hetero not in hatoms:
            hatoms.append(hetero)
            non_redundant_hs.append(h_index)

    for h_index in non_redundant_hs:
        new_mol = clone(mol)
        new_mol.DeleteAtom(new_mol.GetAtom(h_index))
        new_mol.SetTotalSpinMultiplicity(2)
        new_mol.SetTotalCharge(0)
        radicals.append(new_mol)
    return radicals

def neighbor(mol, index, hetero_indexs):
    q_atom = mol.GetAtom(index)
    for i in hetero_indexs:
        if mol.GetBond(index, i):
            #print "#%d is attached to atom #%d" % (index, i)
            return i

if __name__ == '__main__':
    input = sys.argv[1]

    obc = ob.OBConversion()
    obc.SetInAndOutFormats("smi", "mol")

    mol = ob.OBMol()
    next = obc.ReadString(mol, input)

    radicals = abs_h(mol)
    for r in radicals:
        print obc.WriteString(r)