#    This file is part of EAP.
#
#    EAP is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Lesser General Public License as
#    published by the Free Software Foundation, either version 3 of
#    the License, or (at your option) any later version.
#
#    EAP is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
#    GNU Lesser General Public License for more details.
#
#    You should have received a copy of the GNU Lesser General Public
#    License along with EAP. If not, see <http://www.gnu.org/licenses/>.

import random
import operator

from deap import algorithms
from deap import base
from deap import creator
from deap import tools
from deap import gp

# Initialize Parity problem input and output matrices
PARITY_FANIN_M = 6
PARITY_SIZE_M = 2**PARITY_FANIN_M

inputs = [None] * PARITY_SIZE_M
outputs = [None] * PARITY_SIZE_M

for i in range(PARITY_SIZE_M):
    inputs[i] = [None] * PARITY_FANIN_M
    value = i
    dividor = PARITY_SIZE_M
    parity = 1
    for j in range(PARITY_FANIN_M):
        dividor /= 2
        if value >= dividor:
            inputs[i][j] = 1
            parity = int(not parity)
            value -= dividor
        else:
            inputs[i][j] = 0
    outputs[i] = parity

pset = gp.PrimitiveSet("MAIN", PARITY_FANIN_M, "IN")
pset.addPrimitive(operator.and_, 2)
pset.addPrimitive(operator.or_, 2)
pset.addPrimitive(operator.xor, 2)
pset.addPrimitive(operator.not_, 1)
pset.addTerminal(1)
pset.addTerminal(0)

creator.create("FitnessMax", base.Fitness, weights=(1.0,))
creator.create("Individual", gp.PrimitiveTree, fitness=creator.FitnessMax, pset=pset)

toolbox = base.Toolbox()
toolbox.register("expr", gp.genFull, pset=pset, min_=3, max_=5)
toolbox.register("individual", tools.initIterate, creator.Individual, toolbox.expr)
toolbox.register("population", tools.initRepeat, list, toolbox.individual)
toolbox.register("lambdify", gp.lambdify, pset=pset)

def evalParity(individual):
    func = toolbox.lambdify(expr=individual)
    return sum(func(*in_) == out for in_, out in zip(inputs, outputs)),

toolbox.register("evaluate", evalParity)
toolbox.register("select", tools.selTournament, tournsize=3)
toolbox.register("mate", gp.cxOnePoint)
toolbox.register("expr_mut", gp.genGrow, min_=0, max_=2)
toolbox.register("mutate", gp.mutUniform, expr=toolbox.expr_mut)

def main():
    random.seed(21)
    pop = toolbox.population(n=300)
    hof = tools.HallOfFame(1)
    stats = tools.Statistics(lambda ind: ind.fitness.values)
    stats.register("avg", tools.mean)
    stats.register("std", tools.std)
    stats.register("min", min)
    stats.register("max", max)
    
    algorithms.eaSimple(pop, toolbox, 0.5, 0.2, 40, stats, halloffame=hof)
    
    return pop, stats, hof

if __name__ == "__main__":
    main()