#!/usr/bin/env python3
from doctest import OutputChecker
import sys
import torch
import re
import os
import gradio as gr
import requests

#url = "https://github.com/simonepri/lm-scorer/tree/master/lm_scorer/models"
#resp = requests.get(url)

from sentence_transformers import SentenceTransformer, util
#from sentence_transformers import SentenceTransformer, util
#from sklearn.metrics.pairwise import cosine_similarity
#from lm_scorer.models.auto import AutoLMScorer as LMScorer
#from sentence_transformers import SentenceTransformer, util
#from sklearn.metrics.pairwise import cosine_similarity

#device = "cuda:0" if torch.cuda.is_available() else "cpu"
#model_sts = gr.Interface.load('huggingface/sentence-transformers/stsb-distilbert-base') 

model_sts = SentenceTransformer('stsb-distilbert-base')
#model_sts = SentenceTransformer('roberta-large-nli-stsb-mean-tokens')

#batch_size = 1
#scorer = LMScorer.from_pretrained('gpt2' , device=device, batch_size=batch_size)

#import torch
from transformers import GPT2Tokenizer, GPT2LMHeadModel
import numpy as np
import re

def Sort_Tuple(tup):  
  
	# (Sorts in descending order)  
	tup.sort(key = lambda x: x[1])  
	return tup[::-1]


def softmax(x):
	exps = np.exp(x)
	return np.divide(exps, np.sum(exps))
	
# Load pre-trained model 

# model = GPT2LMHeadModel.from_pretrained('distilgpt2', output_hidden_states = True, output_attentions = True)

# #model  =  gr.Interface.load('huggingface/distilgpt2', output_hidden_states = True, output_attentions = True)

# #model.eval()
# #tokenizer =  gr.Interface.load('huggingface/distilgpt2')

# #tokenizer = GPT2Tokenizer.from_pretrained('distilgpt2')
# tokenizer = GPT2Tokenizer.from_pretrained('gpt2')
# #tokenizer = GPT2Tokenizer.from_pretrained('distilgpt2')

tokenizer = GPT2Tokenizer.from_pretrained('gpt2')
model = GPT2LMHeadModel.from_pretrained('gpt2')

# def cloze_prob(text):

# 	whole_text_encoding = tokenizer.encode(text)
# 	# Parse out the stem of the whole sentence (i.e., the part leading up to but not including the critical word)
# 	text_list = text.split()
# 	stem = ' '.join(text_list[:-1])
# 	stem_encoding = tokenizer.encode(stem)
# 	# cw_encoding is just the difference between whole_text_encoding and stem_encoding
# 	# note: this might not correspond exactly to the word itself
# 	cw_encoding = whole_text_encoding[len(stem_encoding):]
# 	# Run the entire sentence through the model. Then go "back in time" to look at what the model predicted for each token, starting at the stem.
# 	# Put the whole text encoding into a tensor, and get the model's comprehensive output
# 	tokens_tensor = torch.tensor([whole_text_encoding])
	
# 	with torch.no_grad():
# 		outputs = model(tokens_tensor)
# 		predictions = outputs[0]   

# 	logprobs = []
# 	# start at the stem and get downstream probabilities incrementally from the model(see above)
# 	start = -1-len(cw_encoding)
# 	for j in range(start,-1,1):
# 			raw_output = []
# 			for i in predictions[-1][j]:
# 					raw_output.append(i.item())
	
# 			logprobs.append(np.log(softmax(raw_output)))
			
# 	# if the critical word is three tokens long, the raw_probabilities should look something like this:
# 	# [ [0.412, 0.001, ... ] ,[0.213, 0.004, ...], [0.002,0.001, 0.93 ...]]
# 	# Then for the i'th token we want to find its associated probability
# 	# this is just: raw_probabilities[i][token_index]
# 	conditional_probs = []
# 	for cw,prob in zip(cw_encoding,logprobs):
# 			conditional_probs.append(prob[cw])
# 	# now that you have all the relevant probabilities, return their product.
# 	# This is the probability of the critical word given the context before it.

# 	return np.exp(np.sum(conditional_probs))

def sentence_prob_mean(text):
    # Tokenize the input text and add special tokens
    input_ids = tokenizer.encode(text, return_tensors='pt')

    # Obtain model outputs
    with torch.no_grad():
        outputs = model(input_ids, labels=input_ids)
        logits = outputs.logits  # logits are the model outputs before applying softmax

    # Shift logits and labels so that tokens are aligned:
    shift_logits = logits[..., :-1, :].contiguous()
    shift_labels = input_ids[..., 1:].contiguous()

    # Calculate the softmax probabilities
    probs = softmax(shift_logits, dim=-1)

    # Gather the probabilities of the actual token IDs
    gathered_probs = torch.gather(probs, 2, shift_labels.unsqueeze(-1)).squeeze(-1)

    # Compute the mean probability across the tokens
    mean_prob = torch.mean(gathered_probs).item()

    return mean_prob




def cos_sim(a, b):
    return np.inner(a, b) / (np.linalg.norm(a) * (np.linalg.norm(b)))


  
def Visual_re_ranker(caption, visual_context_label, visual_context_prob):
    caption = caption 
    visual_context_label= visual_context_label
    visual_context_prob = visual_context_prob
    caption_emb = model_sts.encode(caption, convert_to_tensor=True)
    visual_context_label_emb = model_sts.encode(visual_context_label, convert_to_tensor=True)


    sim =  cosine_scores = util.pytorch_cos_sim(caption_emb, visual_context_label_emb)
    sim = sim.cpu().numpy()
    sim = str(sim)[1:-1]
    sim = str(sim)[1:-1] 

   # LM = cloze_prob(caption)
    LM = sentence_prob_mean(caption)
    #LM  = scorer.sentence_score(caption, reduce="mean")
    score = pow(float(LM),pow((1-float(sim))/(1+ float(sim)),1-float(visual_context_prob)))
    

    #return {"LM": float(LM)/1, "sim": float(sim)/1, "score": float(score)/1 }
    return {"init hypothesis": float(LM)/1, "Visual Belief Revision": float(score)/1 }
    #return LM, sim, score 



demo = gr.Interface(
    fn=Visual_re_ranker,
    description="Demo for Belief Revision based Caption Re-ranker with Visual Semantic Information",
    inputs=[gr.Textbox(value="a city street filled with traffic at night") , gr.Textbox(value="traffic"),  gr.Textbox(value="0.7458009")],
    #outputs=[gr.Textbox(value="Language Model Score") , gr.Textbox(value="Semantic Similarity Score"),  gr.Textbox(value="Belief revision score via visual context")],
    outputs="label",
)
demo.launch()