"""
Geometry helper
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2022 Concordia CERC group
Project Coder Guille Gutierrez guillermo.gutierrezmorote@concordia.ca
Code contributors: Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
"""
import math
from pathlib import Path

import numpy as np
from PIL import Image
from trimesh import Trimesh
from trimesh import intersections

from hub.city_model_structure.attributes.polygon import Polygon
from hub.city_model_structure.attributes.polyhedron import Polyhedron
from hub.helpers.location import Location


class MapPoint:
  def __init__(self, x, y):
    self._x = int(x)
    self._y = int(y)

  @property
  def x(self):
    return self._x

  @property
  def y(self):
    return self._y

  def __str__(self):
    return f'({self.x}, {self.y})'

  def __len__(self):
    return 1

  def __getitem__(self, index):
    if index == 0:
      return self._x
    elif index == 1:
      return self._y
    else:
      raise IndexError('Index error')


class GeometryHelper:
  """
  Geometry helper class
  """
  # todo: complete dictionary
  srs_transformations = {
    'urn:adv:crs:ETRS89_UTM32*DE_DHHN92_NH': 'epsg:25832'
  }

  @staticmethod
  def factor():
    return 0.5

  def __init__(self, delta=0, area_delta=0):
    self._delta = delta
    self._area_delta = area_delta

  @staticmethod
  def coordinate_to_map_point(coordinate, city):
    factor = GeometryHelper.factor()
    return MapPoint(((coordinate[0] - city.lower_corner[0]) * factor), ((coordinate[1] - city.lower_corner[1]) * factor))

  @staticmethod
  def city_mapping(city, building_names=None, plot=False):
    """
    Returns a shared_information dictionary
    """
    lines_information = {}
    if building_names is None:
      building_names = [b.name for b in city.buildings]
    factor = GeometryHelper.factor()
    x = math.ceil((city.upper_corner[0] - city.lower_corner[0]) * factor) + 1
    y = math.ceil((city.upper_corner[1] - city.lower_corner[1]) * factor) + 1
    city_map = [['' for _ in range(y + 1)] for _ in range(x + 1)]
    map_info = [[{} for _ in range(y + 1)] for _ in range(x + 1)]
    img = Image.new('RGB', (x + 1, y + 1), "black")  # create a new black image
    city_image = img.load()  # create the pixel map
    for building_name in building_names:
      building = city.city_object(building_name)
      line = 0
      for ground in building.grounds:
        length = len(ground.perimeter_polygon.coordinates) - 1
        for i, coordinate in enumerate(ground.perimeter_polygon.coordinates):

          j = i + 1
          if i == length:
            j = 0
          next_coordinate = ground.perimeter_polygon.coordinates[j]
          distance = GeometryHelper.distance_between_points(coordinate, next_coordinate)
          steps = int(distance * factor * 2)
          if steps == 0:
            continue
          delta_x = (next_coordinate[0] - coordinate[0]) / steps
          delta_y = (next_coordinate[1] - coordinate[1]) / steps

          for k in range(0, steps):
            new_coordinate = (coordinate[0] + (delta_x * k), coordinate[1] + (delta_y * k))
            point = GeometryHelper.coordinate_to_map_point(new_coordinate, city)
            x = point.x
            y = point.y
            if city_map[x][y] == '':
              city_map[x][y] = building.name
              map_info[x][y] = {
                'line_start': (coordinate[0], coordinate[1]),
                'line_end': (next_coordinate[0], next_coordinate[1]),
              }
              city_image[x, y] = (100, 0, 0)
            elif city_map[x][y] != building.name:
              neighbour = city.city_object(city_map[x][y])
              neighbour_info = map_info[x][y]

              # prepare the keys
              neighbour_start_coordinate = f'{GeometryHelper.coordinate_to_map_point(neighbour_info["line_start"], city)}'
              building_start_coordinate = f'{GeometryHelper.coordinate_to_map_point(coordinate, city)}'
              neighbour_key = f'{neighbour.name}_{neighbour_start_coordinate}_{building_start_coordinate}'
              building_key = f'{building.name}_{building_start_coordinate}_{neighbour_start_coordinate}'

              # Add my neighbour info to my shared lines
              if building.name in lines_information.keys() and neighbour_key in lines_information[building.name]:
                shared_points = int(lines_information[building.name][neighbour_key]['shared_points'])
                lines_information[building.name][neighbour_key]['shared_points'] = shared_points + 1
              else:
                if building.name not in lines_information.keys():
                  lines_information[building.name] = {}
                lines_information[building.name][neighbour_key] = {
                  'neighbour_name': neighbour.name,
                  'line_start': (coordinate[0], coordinate[1]),
                  'line_end': (next_coordinate[0], next_coordinate[1]),
                  'neighbour_line_start': neighbour_info['line_start'],
                  'neighbour_line_end': neighbour_info['line_end'],
                  'coordinate_start': f"{GeometryHelper.coordinate_to_map_point(coordinate, city)}",
                  'coordinate_end': f"{GeometryHelper.coordinate_to_map_point(next_coordinate, city)}",
                  'neighbour_start': f"{GeometryHelper.coordinate_to_map_point(neighbour_info['line_start'], city)}",
                  'neighbour_end': f"{GeometryHelper.coordinate_to_map_point(neighbour_info['line_end'], city)}",
                  'shared_points': 1
                }

              # Add my info to my neighbour shared lines
              if neighbour.name in lines_information.keys() and building_key in lines_information[neighbour.name]:
                shared_points = int(lines_information[neighbour.name][building_key]['shared_points'])
                lines_information[neighbour.name][building_key]['shared_points'] = shared_points + 1
              else:
                if neighbour.name not in lines_information.keys():
                  lines_information[neighbour.name] = {}
                lines_information[neighbour.name][building_key] = {
                  'neighbour_name': building.name,
                  'line_start': neighbour_info['line_start'],
                  'line_end': neighbour_info['line_end'],
                  'neighbour_line_start': (coordinate[0], coordinate[1]),
                  'neighbour_line_end': (next_coordinate[0], next_coordinate[1]),
                  'neighbour_start': f"{GeometryHelper.coordinate_to_map_point(coordinate, city)}",
                  'neighbour_end': f"{GeometryHelper.coordinate_to_map_point(next_coordinate, city)}",
                  'coordinate_start': f"{GeometryHelper.coordinate_to_map_point(neighbour_info['line_start'], city)}",
                  'coordinate_end': f"{GeometryHelper.coordinate_to_map_point(neighbour_info['line_end'], city)}",
                  'shared_points': 1
                }

              if building.neighbours is None:
                building.neighbours = [neighbour]
              elif neighbour not in building.neighbours:
                building.neighbours.append(neighbour)
              if neighbour.neighbours is None:
                neighbour.neighbours = [building]
              elif building not in neighbour.neighbours:
                neighbour.neighbours.append(building)
          line += 1

    if plot:
      img.show()
    return lines_information

  @staticmethod
  def segment_list_to_trimesh(lines) -> Trimesh:
    """
    Transform a list of segments into a Trimesh
    """
    # todo: trimesh has a method for this
    line_points = [lines[0][0], lines[0][1]]
    lines.remove(lines[0])
    while len(lines) > 1:
      i = 0
      for line in lines:
        i += 1
        if GeometryHelper.distance_between_points(line[0], line_points[len(line_points) - 1]) < 1e-8:
          line_points.append(line[1])
          lines.pop(i - 1)
          break
        if GeometryHelper.distance_between_points(line[1], line_points[len(line_points) - 1]) < 1e-8:
          line_points.append(line[0])
          lines.pop(i - 1)
          break
    polyhedron = Polyhedron(Polygon(line_points).triangles)
    trimesh = Trimesh(polyhedron.vertices, polyhedron.faces)
    return trimesh

  @staticmethod
  def _merge_meshes(mesh1, mesh2):
    v_1 = mesh1.vertices
    f_1 = mesh1.faces
    v_2 = mesh2.vertices
    f_2 = mesh2.faces
    length = len(v_1)
    v_merge = np.concatenate((v_1, v_2))
    f_merge = np.asarray(f_1)

    for item in f_2:
      point1 = item.item(0) + length
      point2 = item.item(1) + length
      point3 = item.item(2) + length
      surface = np.asarray([point1, point2, point3])
      f_merge = np.concatenate((f_merge, [surface]))

    mesh_merge = Trimesh(vertices=v_merge, faces=f_merge)
    mesh_merge.fix_normals()

    return mesh_merge

  @staticmethod
  def divide_mesh_by_plane(trimesh, normal_plane, point_plane):
    """
    Divide a mesh by a plane
    :param trimesh: Trimesh
    :param normal_plane: [x, y, z]
    :param point_plane: [x, y, z]
    :return: [Trimesh]
    """
    # The first mesh returns the positive side of the plane and the second the negative side.
    # If the plane does not divide the mesh (i.e. it does not touch it or it is coplanar with one or more faces),
    # then it returns only the original mesh.
    # todo: review split method in https://github.com/mikedh/trimesh/issues/235,
    #  once triangulate_polygon in Polygon class is solved

    normal_plane_opp = [None] * len(normal_plane)
    for i in range(0, len(normal_plane)):
      normal_plane_opp[i] = - normal_plane[i]

    section_1 = intersections.slice_mesh_plane(trimesh, normal_plane, point_plane)
    if section_1 is None:
      return [trimesh]
    lines = list(intersections.mesh_plane(trimesh, normal_plane, point_plane))
    cap = GeometryHelper.segment_list_to_trimesh(lines)
    trimesh_1 = GeometryHelper._merge_meshes(section_1, cap)

    section_2 = intersections.slice_mesh_plane(trimesh, normal_plane_opp, point_plane)
    if section_2 is None:
      return [trimesh_1]
    trimesh_2 = GeometryHelper._merge_meshes(section_2, cap)

    return [trimesh_1, trimesh_2]

  @staticmethod
  def get_location(latitude, longitude) -> Location:
    """
    Get Location from latitude and longitude
    """
    _data_path = Path(Path(__file__).parent.parent / 'data/geolocation/cities15000.txt').resolve()
    latitude = float(latitude)
    longitude = float(longitude)
    distance = math.inf
    country = 'Unknown'
    city = 'Unknown'
    with open(_data_path, 'r', encoding='utf-8') as f:
      for line_number, line in enumerate(f):
        fields = line.split('\t')
        file_city_name = fields[2]
        file_latitude = float(fields[4])
        file_longitude = float(fields[5])
        file_country_code = fields[8]
        new_distance = math.sqrt(pow((latitude - file_latitude), 2) + pow((longitude - file_longitude), 2))
        if distance > new_distance:
          distance = new_distance
          country = file_country_code
          city = file_city_name
    return Location(country, city)

  @staticmethod
  def distance_between_points(vertex1, vertex2):
    """
    distance between points in an n-D Euclidean space
    :param vertex1: point or vertex
    :param vertex2: point or vertex
    :return: float
    """
    power = 0
    for dimension in range(0, len(vertex1)):
      power += math.pow(vertex2[dimension] - vertex1[dimension], 2)
    distance = math.sqrt(power)
    return distance