from math import pow
from math import sqrt
import numpy as np

import PIL.Image
import PIL.ImageDraw

from labelme import logger


def polygons_to_mask(img_shape, polygons, shape_type=None):
    mask = np.zeros(img_shape[:2], dtype=np.uint8)
    mask = PIL.Image.fromarray(mask)
    draw = PIL.ImageDraw.Draw(mask)
    if shape_type == "circle" and len(polygons) == 2:
        ((cx, cy), (px, py)) = polygons
        d = sqrt(pow(cx - px, 2) + pow(cy - py, 2))
        draw.ellipse([cx - d, cy - d, cx + d, cy + d], outline=1, fill=1)
    else:
        xy = list(map(tuple, polygons))
        draw.polygon(xy=xy, outline=1, fill=1)
    mask = np.array(mask, dtype=bool)
    return mask


def shapes_to_label(img_shape, shapes, label_name_to_value, type='class'):
    assert type in ['class', 'instance']

    cls = np.zeros(img_shape[:2], dtype=np.int32)
    if type == 'instance':
        ins = np.zeros(img_shape[:2], dtype=np.int32)
        instance_names = ['_background_']
    for shape in shapes:
        polygons = shape['points']
        label = shape['label']
        shape_type = shape.get('shape_type', None)
        if type == 'class':
            cls_name = label
        elif type == 'instance':
            cls_name = label.split('-')[0]
            if label not in instance_names:
                instance_names.append(label)
            ins_id = len(instance_names) - 1
        cls_id = label_name_to_value[cls_name]
        mask = polygons_to_mask(img_shape[:2], polygons, shape_type)
        cls[mask] = cls_id
        if type == 'instance':
            ins[mask] = ins_id

    if type == 'instance':
        return cls, ins
    return cls


def labelme_shapes_to_label(img_shape, shapes):
    logger.warn('labelme_shapes_to_label is deprecated, so please use '
                'shapes_to_label.')

    label_name_to_value = {'_background_': 0}
    for shape in shapes:
        label_name = shape['label']
        if label_name in label_name_to_value:
            label_value = label_name_to_value[label_name]
        else:
            label_value = len(label_name_to_value)
            label_name_to_value[label_name] = label_value

    lbl = shapes_to_label(img_shape, shapes, label_name_to_value)
    return lbl, label_name_to_value