import random
import torch
from albumentations.pytorch import ToTensorV2
import albumentations as A
import cv2
import glob2
import config
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as patches
from lightning_utils import YOLOv3Lightning
from pytorch_grad_cam import GradCAM, EigenCAM
from pytorch_grad_cam.utils.image import show_cam_on_image
from pytorch_grad_cam.utils.model_targets import FasterRCNNBoxScoreTarget

from utils import cells_to_bboxes, non_max_suppression


cmap = plt.get_cmap("tab20b")
class_labels = config.PASCAL_CLASSES
height, width = config.INFERENCE_IMAGE_SIZE, config.INFERENCE_IMAGE_SIZE
colors = [cmap(i) for i in np.linspace(0, 1, len(class_labels))]

icons = [
    'flight', 'pedal_bike', 'flutter_dash', 'sailing',
    'liquor', 'directions_bus', 'directions_car',
    'pets', "chair", 'pets', 'table_restaurant',
    'pets', 'bedroom_baby', 'motorcycle', 'person', 'yard',
    'kebab_dining', 'chair', "train", "tvmonitor"]

icons_mapping = {config.PASCAL_CLASSES[i]:icons[i] for i in range(len(icons))}

model = YOLOv3Lightning()
model = model.load_from_checkpoint('YoLoV3Model.ckpt',
                                   map_location=torch.device('cpu'))
model.eval()

scaled_anchors = (
        torch.tensor(config.ANCHORS)
        * torch.tensor(config.S[0]).unsqueeze(1).unsqueeze(1).repeat(1, 3, 2)
    ).to(config.DEVICE)

def get_examples():
  example_images = glob2.glob('*.jpg')
  example_transparency = [random.choice([0.7, 0.8]) for r in range(len(example_images))]
  examples = [[example_images[i], example_transparency[i]] for i in range(len(example_images))]
  return(examples)



def yolov3_reshape_transform(x):
  activations = []
  size = x[0].size()[2:4]

  for x_item in x:
    x_permute = x_item.permute(0, 1, 4, 2, 3 )
    x_permute = x_permute.reshape((x_permute.shape[0], 
                                   x_permute.shape[1]*x_permute.shape[2], 
                                   *x_permute.shape[3:]))
    activations.append(torch.nn.functional.interpolate(torch.abs(x_permute), size, mode='bilinear'))

  activations = torch.cat(activations, axis=1)

  return(activations)


def infer_transform(IMAGE_SIZE=config.INFERENCE_IMAGE_SIZE):
    transforms = A.Compose(
        [
            A.LongestMaxSize(max_size=IMAGE_SIZE),
            A.PadIfNeeded(
                min_height=IMAGE_SIZE, min_width=IMAGE_SIZE, border_mode=cv2.BORDER_CONSTANT
            ),
            A.Normalize(mean=[0, 0, 0], std=[1, 1, 1], max_pixel_value=255,),
            ToTensorV2(),
        ]
  )
    return(transforms)

def generate_html():
    # Start the HTML string with some style and the Material Icons stylesheet
    classes = config.PASCAL_CLASSES
    html_string = """
    <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
    <style>
        .title {
            font-size: 24px;
            font-weight: bold;
            text-align: center;
            margin-bottom: 20px;
            color: #4a4a4a;
        }
        .subtitle {
            font-size: 18px;
            text-align: center;
            margin-bottom: 10px;
            color: #7a7a7a;
        }
        .class-container {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            align-items: center;
            padding: 20px;
            border: 2px solid #e0e0e0;
            border-radius: 10px;
            background-color: #f5f5f5;
        }
        .class-item {
            display: inline-flex;  /* Changed from flex to inline-flex */
            align-items: center;
            margin: 5px 10px;
            padding: 5px 8px;     /* Adjusted padding */
            border: 1px solid #d1d1d1;
            border-radius: 20px;
            background-color: #ffffff;
            font-weight: bold;
            color: #333;
            box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.1);
            transition: transform 0.2s, box-shadow 0.2s;
        }
        .class-item:hover {
            transform: scale(1.05);
            box-shadow: 2px 2px 10px rgba(0, 0, 0, 0.2);
            background-color: #e7e7e7;
        }
        .material-icons {
            margin-right: 8px;
        }
    </style>
    <div class="title">Object Detection Prediction & Grad-Cam for YOLOv3</div>
    <div class="subtitle">Supported Classes</div>
    <div class="class-container">
    """

    # Loop through each class and add it to the HTML string with its corresponding icon
    for class_name in classes:
        icon_name = class_name.lower()  # Assuming the icon name is the lowercase version of the class name
        icon_name = icons_mapping[icon_name]
        html_string += f'<div class="class-item"><i class="material-icons">{icon_name}</i>{class_name}</div>'

    # Close the HTML string
    html_string += "</div>"

    return html_string



def upload_image_inference(img, transparency):
  bboxes = [[] for _ in range(1)]
  nms_boxes_output, annotations = [], []
  img_copy = img.copy()

  transform = infer_transform()
  img = transform(image=img)['image'].unsqueeze(0)

  out = model(img)

  for i in range(3):
      batch_size, A, S, _, _ = out[i].shape
      anchor = scaled_anchors[i]
      boxes_scale_i = cells_to_bboxes(
          out[i], anchor, S=S, is_preds=True
      )

      for idx, (box) in enumerate(boxes_scale_i):
          bboxes[idx] += box

  for i in range(img.shape[0]):
      iou_thresh, thresh = 0.5, 0.6
      nms_boxes = non_max_suppression(
          bboxes[i], iou_threshold=iou_thresh, threshold=thresh, box_format="midpoint",
      )

      nms_boxes_output.append(nms_boxes)

  for box in nms_boxes_output[0]:
    class_prediction = int(box[0])
    box = box[2:]

    upper_left_x = box[0] - box[2] / 2
    upper_left_y = box[1] - box[3] / 2
    rect = patches.Rectangle(
            (upper_left_x * width, upper_left_y * height),
            box[2] * width,
            box[3] * height,
            linewidth=2,
            edgecolor=colors[class_prediction],
            facecolor="none",
    )
    rect = rect.get_bbox().get_points()
    annotations.append([rect[0].astype(int).tolist()+rect[1].astype(int).tolist(),
                        config.PASCAL_CLASSES[class_prediction]])


  objs = [b[1] for b in nms_boxes_output[0]]
  bbox_coord = [b[2:] for b in nms_boxes_output[0]]
  targets = [FasterRCNNBoxScoreTarget(objs, bbox_coord)]

  cam = EigenCAM(model=model, 
                target_layers=[model.model], 
                reshape_transform=yolov3_reshape_transform)

  grayscale_cam = cam(input_tensor=img, targets=targets)
  grayscale_cam = grayscale_cam[0, :]
  
  visualization = show_cam_on_image(img_copy/255, grayscale_cam, use_rgb=False, image_weight=transparency)

  return([[img_copy, annotations],
          [grayscale_cam, visualization]])