# example.py
import nmodl.dsl as nmodl


def run_conductance_visitor_and_return_breakpoint(mod_string):
    # parse NMDOL file (supplied as a string) into AST
    driver = nmodl.NmodlDriver()
    AST = driver.parse_string(mod_string)
    # run SymtabVisitor to generate Symbol Table
    nmodl.symtab.SymtabVisitor().visit_program(AST)
    # constant folding, inlining & local variable renaming passes
    nmodl.visitor.ConstantFolderVisitor().visit_program(AST)
    nmodl.visitor.InlineVisitor().visit_program(AST)
    nmodl.visitor.LocalVarRenameVisitor().visit_program(AST)
    # run CONDUCTANCE visitor
    nmodl.visitor.SympyConductanceVisitor().visit_program(AST)
    # return new BREAKPOINT block
    return nmodl.to_nmodl(
        nmodl.visitor.AstLookupVisitor().lookup(
            AST, nmodl.ast.AstNodeType.BREAKPOINT_BLOCK
        )[0]
    )


ex1 = """
NEURON {
    USEION na READ ena WRITE ina
    RANGE gna
}
BREAKPOINT {
    ina = gna*(v - ena)
}"""
print(run_conductance_visitor_and_return_breakpoint(ex1))