import numpy as np
import torch
import matplotlib.pyplot as plt
import cv2
from segment_anything import sam_model_registry, SamPredictor
import os

def show_mask(mask, ax, random_color=False):
    if random_color:
        color = np.concatenate([np.random.random(3), np.array([0.6])], axis=0)
    else:
        color = np.array([30/255, 144/255, 255/255, 0.6])
    h, w = mask.shape[-2:]
    mask_image = mask.reshape(h, w, 1) * color.reshape(1, 1, -1)
    ax.imshow(mask_image)
    
def show_points(coords, labels, ax, marker_size=375):
    pos_points = coords[labels==1]
    neg_points = coords[labels==0]
    ax.scatter(pos_points[:, 0], pos_points[:, 1], color='green', marker='*', s=marker_size, edgecolor='white', linewidth=1.25)
    ax.scatter(neg_points[:, 0], neg_points[:, 1], color='red', marker='*', s=marker_size, edgecolor='white', linewidth=1.25)   
    
def show_box(box, ax):
    x0, y0 = box[0], box[1]
    w, h = box[2] - box[0], box[3] - box[1]
    ax.add_patch(plt.Rectangle((x0, y0), w, h, edgecolor='green', facecolor=(0,0,0,0), lw=2))    


def show_res(masks, scores, input_point, input_label, input_box, filename, image):
    for i, (mask, score) in enumerate(zip(masks, scores)):
        plt.figure(figsize=(10,10))
        plt.imshow(image)
        show_mask(mask, plt.gca())
        if input_box is not None:
            box = input_box[i]
            show_box(box, plt.gca())
        if (input_point is not None) and (input_label is not None): 
            show_points(input_point, input_label, plt.gca())
        
        print(f"Score: {score:.3f}")
        plt.axis('off')
        plt.savefig(filename+'_'+str(i)+'.png',bbox_inches='tight',pad_inches=-0.1)
        plt.close()

def show_res_multi(masks, scores, input_point, input_label, input_box, filename, image):
    plt.figure(figsize=(10, 10))
    plt.imshow(image)
    for mask in masks:
        show_mask(mask, plt.gca(), random_color=True)
    for box in input_box:
        show_box(box, plt.gca())
    for score in scores:
        print(f"Score: {score:.3f}")
    plt.axis('off')
    plt.savefig(filename +'.png',bbox_inches='tight',pad_inches=-0.1)
    plt.close()


if __name__ == "__main__":
    sam_checkpoint = "./pretrained_checkpoint/sam_hq_vit_tiny.pth"
    model_type = "vit_tiny"

    device = "cuda"
    sam = sam_model_registry[model_type](checkpoint=sam_checkpoint)
    sam.to(device=device)
    sam.eval()
    predictor = SamPredictor(sam)


    image = cv2.imread('demo/input_imgs/dog.jpg')
    image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
    predictor.set_image(image)
    # hq_token_only: False means use hq output to correct SAM output. 
    #                True means use hq output only. 
    #                Default: False
    hq_token_only = False 
    # To achieve best visualization effect, for images contain multiple objects (like typical coco images), we suggest to set hq_token_only=False
    # For images contain single object, we suggest to set hq_token_only = True
    # For quantiative evaluation on COCO/YTVOS/DAVIS/UVO/LVIS etc., we set hq_token_only = False
    
    # box prompt
    input_box = np.array([[784,500,1789,1000]])
    input_point, input_label = None, None

    masks, scores, logits = predictor.predict(
        point_coords=input_point,
        point_labels=input_label,
        box = input_box,
        multimask_output=False,
        hq_token_only=hq_token_only, 
    )
    result_path = 'demo/hq_sam_tiny_result/'
    os.makedirs(result_path, exist_ok=True)
    show_res(masks,scores,input_point, input_label, input_box, result_path + 'dog', image)



    image = cv2.imread('demo/input_imgs/example3.png')
    image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
    predictor.set_image(image)
    hq_token_only = True
    # point prompt
    input_point = np.array([[221,482],[498,633],[750,379]])
    input_label = np.ones(input_point.shape[0])
    input_box = None

    masks, scores, logits = predictor.predict(
        point_coords=input_point,
        point_labels=input_label,
        box = input_box,
        multimask_output=False,
        hq_token_only=hq_token_only, 
    )
    show_res(masks,scores,input_point, input_label, input_box, result_path + 'example3', image)


    image = cv2.imread('demo/input_imgs/example7.png')
    image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
    predictor.set_image(image)
    hq_token_only = False
    # multi box prompt
    input_box = torch.tensor([[45,260,515,470], [310,228,424,296]],device=predictor.device)
    transformed_box = predictor.transform.apply_boxes_torch(input_box, image.shape[:2])
    input_point, input_label = None, None
    masks, scores, logits = predictor.predict_torch(
        point_coords=input_point,
        point_labels=input_label,
        boxes=transformed_box,
        multimask_output=False,
        hq_token_only=hq_token_only,
    )
    masks = masks.squeeze(1).cpu().numpy()
    scores = scores.squeeze(1).cpu().numpy()
    input_box = input_box.cpu().numpy()
    show_res_multi(masks, scores, input_point, input_label, input_box, result_path + 'example7', image)