from functools import singledispatch, reduce
from operator import and_, or_

from bitarray import bitarray

import stl.ast
from stl.boolean_eval import eval_terms, op_lookup

def pointwise_sat(stl):
    f = pointwise_satf(stl)
    return lambda x, t: bool(int(f(x, [t]).to01()))

@singledispatch
def pointwise_satf(stl):
    raise NotImplementedError

def bool_op(stl, conjunction=False):
    binop = and_ if conjunction else or_
    fs = [pointwise_satf(arg) for arg in stl.args]
    return lambda x, t: reduce(binop, (f(x, t) for f in fs))


@pointwise_satf.register(stl.Or)
def _(stl):
    return bool_op(stl, conjunction=False)


@pointwise_satf.register(stl.And)
def _(stl):
    return bool_op(stl, conjunction=True)


def get_times(x, lo, hi, tau):
    return [min(tau + t2, x.index[-1]) for t2 in x[lo:hi].index]


def temporal_op(stl, lo, hi, conjunction=False):
    fold = bitarray.all if conjunction else bitarray.any
    f = pointwise_satf(stl.arg)
    def sat_comp(x,t):
        return bitarray([fold(f(x, get_times(x, lo, hi, tau))) for tau in t])
    return sat_comp


@pointwise_satf.register(stl.F)
def _(stl):
    lo, hi = stl.interval
    return temporal_op(stl, lo, hi, conjunction=False)


@pointwise_satf.register(stl.G)
def _(stl):
    lo, hi = stl.interval
    return temporal_op(stl, lo, hi, conjunction=True)


@pointwise_satf.register(stl.Neg)
def _(stl):
    return lambda x,t: ~pointwise_satf(stl.arg)(x, t) 


@pointwise_satf.register(stl.AtomicPred)
def _(stl):
    def sat_comp(x, t):
        sat = bitarray()
        [sat.append(x[str(stl.id)][tau]) for tau in t]
        return sat
    return sat_comp


@pointwise_satf.register(stl.LinEq)
def _(stl):
    op = op_lookup[stl.op]
    def sat_comp(x, t):
        sat = bitarray()
        [sat.append(op(eval_terms(stl, x, tau), stl.const)) for tau in t]
        return sat
    return sat_comp