import gradio as gr
import regex as re
from tqdm import tqdm
import pickle

class Tokenizer:
    
    def __init__(self):
        
        self.vocab = {idx : bytes([idx]) for idx in range(256)}
        self.pattern = r"""'(?i:[sdmt]|ll|ve|re)|[^\r\n\p{L}\p{N}]?+\p{L}+|\p{N}{1,3}| ?[^\s\p{L}\p{N}]++[\r\n]*|\s*[\r\n]|\s+(?!\S)|\s+"""
        self.merges = {}
        
    def merge(self, tokens, target, new_token):

        new_tokens = []
        i = 0
        while i < len(tokens):

            if i + 1 < len(tokens) and tokens[i] == target[0] and tokens[i + 1] == target[1]:
                i += 1
                new_tokens.append(new_token)
            else:
                new_tokens.append(tokens[i])
            i += 1

        return new_tokens

    def get_stats(self, idsList):

        pairs = {}
        if not isinstance(idsList[0], list):
            idsList = [idsList]
        for tokens in idsList:
            for a, b in zip(tokens, tokens[1:]):

                if not (a, b) in pairs:
                    pairs[(a, b)] = 1
                else:
                    pairs[(a, b)] += 1
        return pairs
    
    def get_max_pair(self, idsList):
        
        pairs = self.get_stats(idsList)
        return sorted(pairs.items(), key=lambda item : item[1])[-1][0]

    def get_min(self, idsList):
        
        stats = self.get_stats(idsList)
        pair = min(stats, key=lambda p: self.merges.get(p, float("inf")))
        return pair
        
    def train(self, epochs, text):
        
        pat = re.compile(self.pattern)
        textList = re.findall(pat, text)
        idsList = [list(text.encode('utf-8')) for text in textList]
        for epoch in tqdm(range(epochs)):

            max_pair = self.get_max_pair(idsList)
            new_token = 256 + epoch
            self.merges[max_pair] = new_token
            idsList = [self.merge(tokens, max_pair, new_token) for tokens in idsList]
            self.vocab[new_token] = self.vocab[max_pair[0]] + self.vocab[max_pair[1]]
        
        return [x for xs in idsList for x in xs]
        
    def encode(self, text):

        tokens = list(text.encode('utf-8'))
        while len(tokens) >= 2:

            pair = self.get_min(tokens)
            if pair not in self.merges:
                break
                
            idx = self.merges[pair]
            tokens = self.merge(tokens, pair, idx)
            
        return tokens
    
    def decode(self, tokens):
        
        tokens = b"".join(self.vocab[token] for token in tokens)
        text = tokens.decode('utf-8', errors='replace')
        return text

title = "Ghalib doing tiktok"
description = "A simple Gradio interface to infer urdu tokenizer"

tokenizer = Tokenizer()
temp = Tokenizer()
with open('merges.pkl', 'rb') as files:
    tokenizer.vocab = pickle.load(files)
with open('vocab.pkl', 'rb') as files:
    tokenizer.merges = pickle.load(files)

def inference(text):
    print(len(tokenizer.merges))
    print(len(tokenizer.vocab))
    print(len(temp.encode(text)) / len(tokenizer.encode(text)))
    return tokenizer.encode(text)

iface = gr.Interface(
    inference, 
    inputs = ["text"], 
    outputs = ["text"],
    examples=["سفید رنگ ہیں آخر سیاہ مو کرتے لٹاتے دولت دنیا کو میکدے میں ہم طلائی ساغر مے نقرئی سبو کرتے ہمیشہ میں نے گریباں کو چاک چاک کیا",
              " دل کہ آتے ہیں جس کو دھیان بہت خود بھی آتا ہے اپنے دھیان میں کیاوہ ملے تو یہ پوچھنا ہے مجھےاب بھی ہوں میں تری امان میں کیا"],
    title = title,
    description = description,
)

iface.launch()