# This file is part of project Sverchok. It's copyrighted by the contributors
# recorded in the version control history of the file, available from
# its original location https://github.com/nortikin/sverchok/commit/master
#  
# SPDX-License-Identifier: GPL3
# License-Filename: LICENSE


import ast
import random
import time
from collections import namedtuple
from typing import NamedTuple
import numpy as np

import bpy
from mathutils.noise import seed_set, random
from bpy.props import (
    BoolProperty, StringProperty, EnumProperty, IntProperty, FloatProperty)

from sverchok.node_tree import SverchCustomTreeNode
from sverchok.data_structure import updateNode
from sverchok.core.update_system import make_tree_from_nodes, do_update
from sverchok.utils.sv_operator_mixins import SvGenericNodeLocator
from sverchok.utils.listutils import (
    listinput_getI,
    listinput_getF,
    listinput_setI,
    listinput_setF
    )

def check_memory_prop(tx):
    if len(tx) > 1:
        gene_split = tx.find('#')
        return [tx[:gene_split], ast.literal_eval(tx[gene_split+1:])]
    else:
        return []

def write_memory_prop(genes, p, node):
    '''write values to string property'''
    full = str(genes) + '#' +''.join(str(p))
    node.memory = full


Gene = namedtuple('Gene', 'name, g_type, min_n, max_n, range, init_val')
# ListInputGene = namedtuple('ListInputGene', 'name, g_type, num_length, init_val')

class NumberGene(NamedTuple):
    name: str
    g_type: str
    min_n: float
    max_n: float
    range: float
    init_val: float

    @classmethod
    def init_from_node(cls, node):
        num_type = node.selected_mode
        if node.selected_mode == "float":
            min_n = node.float_min
            max_n = node.float_max
            initial_value = node.float_
        else:
            min_n = node.int_min
            max_n = node.int_max
            initial_value = node.int_
        gene = cls(name=node.name, g_type=num_type, min_n=min_n, max_n=max_n, range=max_n-min_n, init_val=initial_value)
        return gene

    def set_node_with_gene(self, tree, agent_gene):
        if self.g_type == 'float':
            tree.nodes[self.name].float_ = agent_gene
        else:
            tree.nodes[self.name].int_ = agent_gene

    def random_variation(self):
        agent_gene = self.min_n + random() * self.range
        if self.g_type == 'int':
            agent_gene = int(agent_gene)
        return agent_gene

    def cross(self, ancestor1, ancestor2):

        mixing_factor = random()
        new_gene = ancestor1 * mixing_factor + ancestor2 * (1 - mixing_factor)
        if self.g_type == 'int':
            new_gene = int(new_gene)
        return new_gene

    def small_mutation(self, gene, mutation_factor):
        small_mutation = (random() - 0.5) * self.range * mutation_factor
        gene += small_mutation
        gene = max(min(gene, self.max_n), self.min_n)
        if self.g_type == 'int':
            gene = int(gene)
        return gene

class ListInputGene(NamedTuple):
    name: str
    g_type: str
    num_length: int
    init_val: list
    values: list

    @classmethod
    def init_from_node(cls, node):
        num_type = node.mode

        if num_type == 'int_list':
            num_length = node.int_
            init_val = list(range(num_length))
            values = listinput_getI(node, num_length)[:num_length]
        elif num_type == 'float_list':
            num_length = node.int_
            init_val = list(range(num_length))
            values = listinput_getF(node, num_length)[:num_length]
        else:
            num_length = node.v_int
            init_val = list(range(num_length))
            mem_list = node.vector_list
            values = [[mem_list[3*i], mem_list[3*i + 1], mem_list[3*i + 2]] for i in range(num_length)]

        gene = cls(name=node.name, g_type=num_type, num_length=num_length, init_val=init_val, values=values)
        return gene

    def set_node_with_gene(self, tree, agent_gene):
        if self.g_type == 'int_list':
            node = tree.nodes[self.name]
            listinput_setI(node, agent_gene, self)
        elif self.g_type == 'float_list':
            node = tree.nodes[self.name]
            listinput_setF(node, agent_gene, self)
        else:
            for i in range(self.num_length):
                node.vector_list[3*i] = self.values[agent_gene[i][0]]
                node.vector_list[3*i + 1] = self.values[agent_gene[i][1]]
                node.vector_list[3*i + 2] = self.values[agent_gene[i][2]]

    def random_variation(self):
        agent_gene = list(range(self.num_length))
        np.random.shuffle(agent_gene)
        return agent_gene

    def cross(self, ancestor1, ancestor2):
        mixing_factor = int(random() * self.num_length)
        new_gene = [ancestor1[i] for i in range(mixing_factor)]
        for g in ancestor2:
            if not g in new_gene:
                new_gene.append(g)
        return new_gene

    def small_mutation(self, gene, mutation_factor):
        swap_times = int(max(mutation_factor*100, 1))
        for i in range(swap_times):
            random_element_swap(gene)
        return gene


class NumberMultiGene(NamedTuple):
    name: str
    mode: str
    num_type: int
    mins: list
    maxs: list
    ranges: list
    num_length: int
    init_val: list
    values: list


    @classmethod
    def init_from_node(cls, node):

        list_limits = node.get_list_limits()
        values = node.node_mem[node.node_id]
        if node.mode == 'range':
            init_val = values
        else:
            init_val = list(range(len(values)))
        if node.number_type == 'vector':
            ranges = [list_limits[1][i]-list_limits[0][i] for i in range(3)]
        else:
            ranges = list_limits[1]-list_limits[0]

        gene = cls(
            name=node.name,
            mode=node.mode,
            num_type=node.number_type,
            mins=list_limits[0],
            maxs=list_limits[1],
            ranges=ranges,
            num_length=len(init_val),
            init_val=init_val,
            values=values)
        return gene

    def set_node_with_gene(self, tree, agent_gene):

        tree.nodes[self.name].fill_from_data(agent_gene)

    def random_variation(self):
        agent = []
        if self.mode == 'range':
            if self.num_type == 'vector':
                for i in range(self.num_length):
                    v = []
                    for j in range(3):
                        v.append(self.mins[j]+random()*self.ranges[j])
                    agent.append(v)
            else:
                for i in range(self.num_length):
                    num = self.mins+random()*self.ranges
                    if self.num_type == 'int':
                        num = int(num)
                    agent.append(num)
        else:
            agent = list(range(self.num_length))
            np.random.shuffle(agent)


        return agent

    def cross(self, ancestor1, ancestor2):
        agent = []
        if self.mode == 'range':
            if self.num_type == 'vector':
                for v1, v2 in zip(ancestor1, ancestor2):
                    v = []
                    for j in range(3):
                        mixing_factor = random()

                        new_gene = v1[j] * mixing_factor + v2[j] * (1 - mixing_factor)
                        v.append(new_gene)
                    agent.append(v)
            else:
                for n1, n2 in zip(ancestor1, ancestor2):
                    mixing_factor = random()
                    new_gene = n1 * mixing_factor + n2 * (1 - mixing_factor)
                    if self.num_type == 'int':
                        new_gene = int(new_gene)
                    agent.append(new_gene)
        else:

            mixing_factor = int(random() * self.num_length)

            agent = [ancestor1[i] for i in range(mixing_factor)]
            for g in ancestor2:
                if not g in agent:
                    agent.append(g)


        return agent

    def small_mutation(self, gene, mutation_factor):
        agent = []

        if self.mode == 'range':
            if self.num_type == 'vector':
                for vec in gene:
                    v = []
                    for j in range(3):
                        mutation = (random() - 0.5) * self.ranges[j] * mutation_factor
                        new_gene = vec[j] + mutation
                        v.append(new_gene)
                    agent.append(v)
            else:
                for num in gene:

                    mutation = (random() - 0.5) * self.ranges * mutation_factor
                    new_gene = num + mutation
                    if self.num_type == 'int':
                        new_gene = int(new_gene)
                    agent.append(new_gene)
        else:
            swap_times = int(max(mutation_factor*100, 1))
            for i in range(swap_times):
                random_element_swap(gene)
            agent = gene
        return agent


evolver_mem = {}

GENE_NODES = ["SvNumberNode", "SvListInputNode", "SvGenesHolderNode"]

def is_valid_node(node, genotype_frame):

    if genotype_frame == 'All' and node.bl_idname in GENE_NODES:
        return True
    if node.parent and node.parent.name == genotype_frame and node.bl_idname in GENE_NODES:
        return True
    return False


def get_genes(target_tree, genotype_frame):
    genes = []
    for node in target_tree.nodes:
        if is_valid_node(node, genotype_frame):

            if node.bl_idname == "SvNumberNode":
                gene = NumberGene.init_from_node(node)
            elif node.bl_idname == "SvListInputNode":
                gene = ListInputGene.init_from_node(node)
            else:
                gene = NumberMultiGene.init_from_node(node)

            genes.append(gene)
    return genes

def genes_to_string(genes):
    text = ''
    for gene in genes:
        text += gene.name + ','
    return text

def build_genes_from_name(genes_names, tree):
    g_names = genes_names.split(',')[:-1]

    genes = []
    for name in g_names:
        if name in tree.nodes:
            node = tree.nodes[name]
            if node.bl_idname == "SvNumberNode":
                genes.append(NumberGene.init_from_node(node))
            elif node.bl_idname == "SvListInputNode":
                genes.append(ListInputGene.init_from_node(node))
            else:
                genes.append(NumberMultiGene.init_from_node(node))
    return genes

def random_element_swap(new_gene):

    item_a = int(random() * len(new_gene))
    item_b = int(random() * len(new_gene))
    temp_g = new_gene[item_a]
    new_gene[item_a] = new_gene[item_b]
    new_gene[item_b] = temp_g

class DNA:

    def __init__(self, genes_def, random_val=True, empty=False):
        self.genes_def = genes_def
        self.genes = []
        self.fitness = 0
        if empty:
            return
        self.fill_genes(random_val=random_val)

    def fill_genes(self, random_val=True):
        if random_val:
            for gene in self.genes_def:
                agent_gene = gene.random_variation()
                self.genes.append(agent_gene)
        else:
            for gene in self.genes_def:
                agent_gene = gene.init_val
                self.genes.append(agent_gene)



    def evaluate_fitness(self, tree, update_list, node):
        try:
            tree.sv_process = False
            for gen_data, agent_gene in zip(self.genes_def, self.genes):
                gen_data.set_node_with_gene(tree, agent_gene)

            tree.sv_process = True
            do_update(update_list, tree.nodes)
            agent_fitness = node.inputs[0].sv_get(deepcopy=False)[0]
            if isinstance(agent_fitness, list):
                agent_fitness = agent_fitness[0]
            self.fitness = agent_fitness
        finally:
            tree.sv_process = True

    def cross_over(self, other_ancestor, mutation_threshold):

        new_agent = DNA(self.genes_def, empty=True)
        for ancestor1_gene, ancestor2_gene, gen_data in zip(self.genes, other_ancestor.genes, self.genes_def):
            mutation_succes = random()
            if mutation_succes < mutation_threshold:
                total_reset_chance = random()
                total_reset_barrier = 0.5
                if total_reset_chance < total_reset_barrier:
                    #total gene reset
                    new_gene = gen_data.random_variation()
                else:
                    #small gene mutation

                    new_gene = gen_data.cross(ancestor1_gene, ancestor2_gene)
                    new_gene = gen_data.small_mutation(new_gene, mutation_threshold)
            else:

                new_gene = gen_data.cross(ancestor1_gene, ancestor2_gene)

            new_agent.genes.append(new_gene)

        return new_agent

class Population:

    def __init__(self, genotype_frame, node, tree):
        self.node = node
        self.tree = tree
        self.time_start = time.time()
        self.genes = get_genes(tree, genotype_frame)
        self.update_list = make_tree_from_nodes([g.name for g in self.genes], tree)
        self.population_g = []
        self.init_population(node.population_n)


    def init_population(self, population_n):

        if self.node.reuse_population:
            self.init_population_from_previous(population_n)

        if not self.population_g:
            self.population_g.append(DNA(self.genes, random_val=False))
            for i in range(population_n-1):
                self.population_g.append(DNA(self.genes))

    def init_population_from_previous(self, population_n):
        if self.node.has_been_runned() and self.genes == evolver_mem[self.node.node_id]["genes"]:
            previous_population = evolver_mem[self.node.node_id]["population"]
            for i in range(min(population_n, len(previous_population))):
                agent = DNA(self.genes, empty=True)
                agent.genes = previous_population[i]
                self.population_g.append(agent)
            for i in range(population_n-len(previous_population)):
                self.population_g.append(DNA(self.genes))

    def  evaluate_fitness_g(self):
        try:
            for agent in self.population_g:
                agent.evaluate_fitness(self.tree, self.update_list, self.node)
        finally:
            self.tree.sv_process = True
    def population_genes(self):
        return [agent.genes for agent in self.population_g]

    def population_fitness(self):
        return [agent.fitness for agent in self.population_g]

    def get_new_population(self, fitness, mode):
        '''Crossover and mutation of previous population to create the new population'''
        if mode == 'MAX':
            weights = np.power(np.array(fitness), self.node.fitness_booster)
        else:
            weights = 1/np.power(np.array(fitness), self.node.fitness_booster)
        weights = weights/np.sum(weights)

        parents_id = np.random.choice(len(self.population_g), [len(self.population_g)-1, 2], replace=True, p=weights)
        # we keep the fittest for the next generation
        new_population = [self.population_g[0]]
        mutation = self.node.mutation

        for ancestors in  parents_id:
            p0 = self.population_g[ancestors[0]]
            p1 = self.population_g[ancestors[1]]

            new_agent = p0.cross_over(p1, mutation)

            new_population.append(new_agent)

        return new_population

    def print_time_info(self, iteration):
        print(' '*80,end='\r')
        print("Evolver on %s iteration" % (iteration + 1),"%s sec" % (time.time() - self.time_start), end='\r')

    def goal_achieved(self, fittest, mode, goal):
        if mode == "MAX":
            return fittest > goal
        if mode == "MIN":
            return fittest < goal

    def store_data(self, population_all, fitness_all):

        write_memory_prop(genes_to_string(self.genes), [population_all, fitness_all], self.node)

        node_id = self.node.node_id
        evolver_mem[node_id]["population_all"] = population_all
        evolver_mem[node_id]["fitness_all"] = fitness_all
        evolver_mem[node_id]["genes"] = self.genes
        evolver_mem[node_id]["population"] = population_all[-1]
        evolver_mem[node_id]["fitness"] = fitness_all[-1]

    def evolve(self):
        population_all = []
        fitness_all = []
        info = "Evolver Runned"
        goal_achieved = False
        iterations = self.node.iterations
        mode = self.node.mode
        max_time = self.node.max_time
        use_fitness_goal = self.node.use_fitness_goal
        goal = self.node.fitness_goal

        for iteration in range(iterations - 1):
            self.evaluate_fitness_g()
            self.population_g.sort(key=lambda x: x.fitness, reverse=(mode == "MAX"))
            population_all.append(self.population_genes())
            actual_population_fitenss = self.population_fitness()
            fitness_all.append(actual_population_fitenss)

            if use_fitness_goal and self.goal_achieved(actual_population_fitenss[0], mode, goal):
                goal_achieved = True
                info = "Goal achieved in %s iterations  " % (iteration + 1)
                print(info)
                break

            self.print_time_info(iteration)
            if (time.time() - self.time_start) > max_time:
                info = "Max. time reached in %s iterations  " % (iteration + 1)
                print(info)
                break

            self.population_g = self.get_new_population(actual_population_fitenss, mode)


        if not goal_achieved:
            self.evaluate_fitness_g()
            self.population_g.sort(key=lambda x: x.fitness, reverse=(mode == "MAX"))
            population_all.append(self.population_genes())
            fitness_all.append(self.population_fitness())

        self.store_data(population_all, fitness_all)
        self.node.info_label = info


class SvEvolverRun(bpy.types.Operator, SvGenericNodeLocator):

    bl_idname = "node.evolver_run"
    bl_label = "Evolver Run"

    def sv_execute(self, context, node):

        if not node.inputs[0].is_linked:
            node.info_label = "Stopped - Fitness not linked"
            return

        tree = node.id_data
        
        genotype_frame = node.genotype
        evolver_mem[node.node_id] = {}
        
        seed_set(node.r_seed)
        np.random.seed(node.r_seed)
        population = Population(genotype_frame, node, tree)
        population.evolve()
        update_list = make_tree_from_nodes([node.name], tree)
        do_update(update_list, tree.nodes)


def set_fittest(tree, genes, agent, update_list):
    '''sets the nodetree with the best value'''
    try:
        tree.sv_process = False
        for gen_data, agent_gene in zip(genes, agent):
            gen_data.set_node_with_gene(tree, agent_gene)

        tree.sv_process = True
        do_update(update_list, tree.nodes)
    finally:
        tree.sv_process = True

class SvEvolverSetFittest(bpy.types.Operator, SvGenericNodeLocator):

    bl_idname = "node.evolver_set_fittest"
    bl_label = "Evolver Run"

    def sv_execute(self, context, node):
        tree = node.id_data
        
        data = evolver_mem[node.node_id]
        genes = data["genes"]
        population = data["population"]
        update_list = make_tree_from_nodes([g.name for g in genes], tree)
        set_fittest(tree, genes, population[0], update_list)


def get_framenodes(base_node, _):

    items = [
        ('All', "All", "Use all 'A number' nodes. Create Frame around 'A Number' nodes the restrict genotype", 0),

    ]

    tree = base_node.id_data

    for node in tree.nodes:
        if node.bl_idname == 'NodeFrame':
            items.append((node.name, node.name, "Use Number nodes inside %s as genotype" % node.name, len(items)))
    return items

class SvEvolverNode(bpy.types.Node, SverchCustomTreeNode):
    """
    Triggers: Genetics algorithm
    Tooltip: Advanced node to find the best solution to a defined problem using a genetics algorithm technique
    """
    bl_idname = 'SvEvolverNode'
    bl_label = 'Evolver'
    bl_icon = 'RNA'

    def props_changed(self, context):
        if self.node_id in evolver_mem:
            self.info_label = "Props changed since execution"
    def props_changed_and_update(self, context):
        if self.node_id in evolver_mem:
            self.info_label = "Props changed since execution"
        updateNode(self, context)

    output_all: BoolProperty(
        name="Output all iterations",
        description="Output all iterations data or just last generation",
        default=False,
        update=updateNode
        )
    reuse_population: BoolProperty(
        name="Re-use population",
        description="Re-use last iteration population on new Run (if genotype is identical)",
        default=False,
        update=updateNode
        )
    genotype: EnumProperty(
        name="Genotype",
        description="Define frame containing genotype or use all number nodes",
        items=get_framenodes,
        update=props_changed
        )
    mode_items = [
        ('MAX', 'Maximum', '', 0),
        ('MIN', 'Minimum', '', 1),
        ]
    mode: EnumProperty(
        name="Mode",
        description="Set Fitness as maximum or as minimum",
        items=mode_items,
        update=props_changed
        )
    population_n: IntProperty(
        default=20,
        name='Population amount', description='Number of agents',
        update=props_changed)
    iterations: IntProperty(
        default=1,
        min=1,
        name='Iterations', description='Iterations',
        update=props_changed)

    r_seed: IntProperty(
        default=1,
        min=1,
        name='Random Seed', description='Random Seed',
        update=props_changed)

    mutation: FloatProperty(
        name="Mutation",
        description="Mutation Factor",
        default=0.01,
        min=0,
        update=props_changed
    )
    fitness_goal: FloatProperty(
        name="Goal",
        description="Stop if fitness achieves or improves this value",
        default=0.01,
        update=props_changed
    )
    use_fitness_goal: BoolProperty(
        name="Stop on Goal",
        description="Stop evolving if defined value is achieved or improved",
        default=False,
        update=props_changed_and_update
        )
    fitness_booster: IntProperty(
        name="Fitness boost",
        description="Fittest population will be more probable to be chosen (power)",
        default=3,
        min=1,
        update=props_changed
    )

    max_time: IntProperty(
        default=10,
        min=1,
        name='Max Seconds', description='Maximum execution Time',
        update=props_changed)

    info_label: StringProperty(default="Not Executed")

    memory: StringProperty(default="")

    def sv_init(self, context):
        self.width = 200
        self.inputs.new('SvStringsSocket', 'Fitness')
        self.outputs.new('SvStringsSocket', 'Genes')
        self.outputs.new('SvStringsSocket', 'Population')
        self.outputs.new('SvStringsSocket', 'Fitness')


    def draw_buttons(self, context, layout):
        layout.label(text=self.info_label)
        genotype_row = layout.split(factor=0.4, align=False)
        genotype_row.label(text="Genotype:")
        genotype_row.prop(self, "genotype", text="")
        mode_row = layout.split(factor=0.4, align=False)
        mode_row.label(text="Mode:")
        mode_row.prop(self, "mode", text="")
        layout.prop(self, "population_n")
        layout.prop(self, "iterations")
        layout.prop(self, "r_seed")
        layout.prop(self, "fitness_booster")
        layout.prop(self, "mutation")
        layout.prop(self, "max_time")
        if self.use_fitness_goal:
            goal_row = layout.row(align=True)
            goal_row.prop(self, "use_fitness_goal", text="")
            goal_row.prop(self, "fitness_goal")
        else:
            layout.prop(self, "use_fitness_goal")
        if self.node_id in evolver_mem:
            layout.prop(self, "reuse_population")
        row = layout.row(align=True)
        row.scale_y = 2
        self.wrapper_tracked_ui_draw_op(row, "node.evolver_run", icon='RNA', text="RUN")
        if self.node_id in evolver_mem:
            self.wrapper_tracked_ui_draw_op(layout, "node.evolver_set_fittest", icon='RNA_ADD', text="Set Fittest")
            layout.prop(self, "output_all")

    def has_been_runned(self):
        if self.node_id in evolver_mem and 'genes' in evolver_mem[self.node_id]:
            return True

        text_block_memory = check_memory_prop(self.memory)
        if text_block_memory:
            evolver_mem[self.node_id] = {}
            genes = build_genes_from_name(text_block_memory[0], self.id_data)
            evolver_mem[self.node_id]['genes'] = genes
            evolver_mem[self.node_id]['population_all'] = text_block_memory[1][0]
            evolver_mem[self.node_id]['fitness_all'] = text_block_memory[1][1]
            evolver_mem[self.node_id]['population'] = text_block_memory[1][0][-1]
            evolver_mem[self.node_id]['fitness'] = text_block_memory[1][1][-1]

            return True
        return False


    def process(self):

        # if self.node_id in evolver_mem and 'genes' in evolver_mem[self.node_id]:
        if self.has_been_runned():
            outputs = self.outputs
            outputs['Genes'].sv_set(evolver_mem[self.node_id]['genes'])
            if self.output_all:
                outputs['Population'].sv_set(evolver_mem[self.node_id]['population_all'])
                outputs['Fitness'].sv_set(evolver_mem[self.node_id]['fitness_all'])
            else:
                outputs['Population'].sv_set([evolver_mem[self.node_id]['population']])
                outputs['Fitness'].sv_set([evolver_mem[self.node_id]['fitness']])
        else:
            self.info_label = "Not Executed"
            for s in self.outputs:
                s.sv_set([])


classes = [SvEvolverRun, SvEvolverSetFittest, SvEvolverNode]
register, unregister = bpy.utils.register_classes_factory(classes)
