#!/usr/bin/env python3
''' plan_gen main functions '''

import time
import numpy as np
import lxml.etree as etree

# constants
# ------------------
MIN_DEPARTURE_TIME = '08:00:00'
MAX_DEPARTURE_TIME = '09:00:00'
WORK_DURATION = '04:00:00'

# utils
# ------------------

def parse_value(string):
    ''' convert string to int, float or string '''
    try:
        return int(string)
    except ValueError:
        try:
            return float(string)
        except ValueError:
            return string

def parse_params(param_str):
    ''' parse a param string to a dict '''
    dict_params = {}
    if param_str:
        for key_value_str in param_str.split(','):
            key, value = key_value_str.split('=')
            dict_params[key] = parse_value(value)
    return dict_params

def get_seconds(time_str):
    ''' returns seconds from a time string '''
    h, m, s = time_str.split(':')
    return int(h) * 3600 + int(m) * 60 + int(s)

def make_gaussian(size, radius=10, center=None):
    ''' make a square gaussian kernel '''
    x = np.arange(0, size, 1, float)
    y = x[:, np.newaxis]
    if center is None:
        x0 = y0 = size // 2
    else:
        x0 = center[0]
        y0 = center[1]
    return np.exp(-4*np.log(2) * ((x-x0)**2 + (y-y0)**2) / radius**2)

# main functions
# ------------------

def make_clusters(nb_clusters, nodes):
    ''' make a grid of (nb_clusters*nb_clusters) from a nodes list '''
    xmin, xmax, ymin, ymax = get_extrem_nodes(nodes)
    dx = (xmax - xmin) / nb_clusters
    dy = (ymax - ymin) / nb_clusters
    clusters = np.empty((nb_clusters, nb_clusters), dtype=object)
    for node in nodes:
        x, y = (float(node.get('x')) - xmin, float(node.get('y')) - ymin)
        i, j = (int(x/dx), int(y/dy))
        if i >= nb_clusters:
            i -= 1
        if j >= nb_clusters:
            j -= 1
        if clusters[i][j] is None:
            clusters[i][j] = []
        clusters[i][j] += [node]
    return clusters

def make_densities(nb_clusters, radius, centers):
    ''' make a list of gaussian probability densities '''
    densities = np.zeros((nb_clusters, nb_clusters))
    if centers is None:
        return densities + 1
    for n, c in enumerate(centers):
        densities += make_gaussian(nb_clusters, radius=radius[n], center=c)
    return densities

# random generators
# ------------------

def rand_time(low, high):
    ''' returns a random time between low and high bounds '''
    low_s = get_seconds(low)
    high_s = get_seconds(high)
    delta = np.random.randint(high_s - low_s)
    return time.strftime('%H:%M:%S', time.gmtime(low_s + delta))

def rand_node_xy(nodes, clusters):
    ''' returns a random node coordinates from a list of nodes '''
    used_nodes = nodes
    if any(clusters):
        cluster = np.random.randint(len(clusters))
        used_nodes = clusters[cluster]
    node = used_nodes[np.random.randint(len(used_nodes))]
    return (node.get('x'), node.get('y'))

def rand_person(nodes, home_clusters, work_clusters):
    ''' returns a person as a dictionnary of random parameters '''
    home_xy = rand_node_xy(nodes, home_clusters)
    work_xy = rand_node_xy(nodes, work_clusters)
    home_departure = rand_time(MIN_DEPARTURE_TIME, MAX_DEPARTURE_TIME)
    return {'home': home_xy, 'work': work_xy, 'home_departure': home_departure}

# xml builders
# ------------------

def make_child(parent_node, child_name, child_attrs=None):
    ''' creates an xml child element and set its attributes '''
    child = etree.SubElement(parent_node, child_name)
    if child_attrs is None:
        return child
    for attr, value in child_attrs.items():
        child.set(attr, value)
    return child

def make_plans(persons):
    ''' makes xml tree of plans based on persons list '''
    plans = etree.Element('plans')
    for n, p in enumerate(persons):
        person = make_child(plans, 'person', {'id': str(n+1)})
        plan = make_child(person, 'plan')
        # plan
        make_child(plan, 'act', {'type': 'h', 'x': p['home'][0], 'y': p['home'][1], 'end_time': p['home_departure']})
        make_child(plan, 'leg', {'mode': 'car'})
        make_child(plan, 'act', {'type': 'w', 'x': p['work'][0], 'y': p['work'][1], 'dur': WORK_DURATION})
        make_child(plan, 'leg', {'mode': 'car'})
        make_child(plan, 'act', {'type': 'h', 'x': p['home'][0], 'y': p['home'][1]})
    return plans

# xml readers
# ------------------

def get_nodes(input_network):
    ''' returns all network nodes as a list '''
    if not input_network:
        return None
    tree = etree.parse(input_network)
    return [node for node in tree.xpath("/network/nodes/node")]

def get_extrem_nodes(nodes):
    ''' returns extremum coordinates of a nodeslist '''
    x = [float(node.get('x')) for node in nodes]
    y = [float(node.get('y')) for node in nodes]
    return min(x), max(x), min(y), max(y)