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

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

# 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('=')
            if key in ['hc', 'hw', 'wc', 'ww']:
                coords = value.split('|')
                dict_params[key] = [np.fromstring(str(x), dtype=int, sep=':') for x in coords]
            elif key in ['hr', 'wr']:
                dict_params[key] = np.fromstring(str(value), dtype=int, sep='|')
            else:
                dict_params[key] = parse_value(value)
    return dict_params

def parse_latlon(csv):
    ''' parse lat and lon from a csv '''
    df = pandas.read_csv(csv, sep=';')
    lat = df.lat.tolist()
    lon = df.lon.tolist()
    return lat, lon

def parse_weights(csv):
    ''' parse weights from a csv '''
    df = pandas.read_csv(csv, sep=';')
    weights = df.nbpeople.tolist()
    return weights

def latlon_to_utm(lat, lon):
    ''' convert lat lon to utm coordinates '''
    utms = [utm.from_latlon(a, b) for a, b in zip(lat, lon)]
    xutm = [utm_coords[0] for utm_coords in utms]
    yutm = [utm_coords[1] for utm_coords in utms]
    return xutm, yutm

def xy_to_ij(x, y, dx, dy, nb_clusters):
    i, j = (int(x/dx), int(y/dy))
    if i >= nb_clusters:
        i -= 1
    if j >= nb_clusters:
        j -= 1
    return i, j

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, center=None, radius=10):
    ''' 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, dx, dy = get_min_max_steps(nodes, 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 = xy_to_ij(x, y, dx, dy, nb_clusters)
        if clusters[i][j] is None:
            clusters[i][j] = []
        clusters[i][j] += [node]
    return clusters

def make_centers(csv, nb_clusters, nodes):
    ''' make centers from a csv file '''
    lat, lon = parse_latlon(csv)
    xutm, yutm = latlon_to_utm(lat, lon)
    xmin, xmax, ymin, ymax, dx, dy = get_min_max_steps(nodes, nb_clusters)
    centers = []
    for x, y in zip(xutm, yutm):
        i, j = xy_to_ij(x - xmin, y - ymin, dx, dy, nb_clusters)
        centers.append([i, j])
    return centers

def make_densities(nb_clusters, centers=None, radius=None, weights=None):
    ''' make a list of gaussian probability densities '''
    if centers is None:
        return make_gaussian(nb_clusters, radius=nb_clusters/2)
    densities = np.zeros((nb_clusters, nb_clusters))
    for n, (c, w) in enumerate(zip(centers, weights)):
        densities += w * make_gaussian(nb_clusters, center=c, radius=radius[n])
    return densities

def clean_densities(densities, clusters):
    ''' clean density probability if a cluster is empty '''
    densities = densities.flatten()
    clusters = clusters.flatten()
    for n, c in enumerate(clusters):
        if c is None:
            densities[n] = 0.0
    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, densities):
    ''' returns a random node coordinates from a random cluster '''
    node = None
    clusters = clusters.flatten()
    densities = densities.flatten()
    cluster = np.random.choice(clusters, p=densities/sum(densities))
    node = cluster[np.random.randint(len(cluster))]
    return (node.get('x'), node.get('y'))

def rand_person(nodes, clusters, h_dens, w_dens):
    ''' returns a person as a dictionnary of random parameters '''
    home_xy = rand_node_xy(nodes, clusters, h_dens)
    work_xy = rand_node_xy(nodes, clusters, w_dens)
    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)

def get_min_max_steps(nodes, nb_clusters):
    ''' returns min max steps '''
    xmin, xmax, ymin, ymax = get_extrem_nodes(nodes)
    dx = (xmax - xmin) / nb_clusters
    dy = (ymax - ymin) / nb_clusters
    return xmin, xmax, ymin, ymax, dx, dy