import torch
from transformers import (
    AutoModelForSeq2SeqLM,
    AutoTokenizer,
)
from IndicTransToolkit import IndicProcessor

model_name = "ai4bharat/indictrans2-indic-en-1B"
tokenizer = AutoTokenizer.from_pretrained(model_name, trust_remote_code=True)
model = AutoModelForSeq2SeqLM.from_pretrained(model_name, trust_remote_code=True)
ip = IndicProcessor(inference=True)

input_sentences = [
    "जब मैं छोटा था, मैं हर रोज़ पार्क जाता था।",
    "हमने पिछले सप्ताह एक नई फिल्म देखी जो कि बहुत प्रेरणादायक थी।",
    "अगर तुम मुझे उस समय पास मिलते, तो हम बाहर खाना खाने चलते।",
    "मेरे मित्र ने मुझे उसके जन्मदिन की पार्टी में बुलाया है, और मैं उसे एक तोहफा दूंगा।",
]

src_lang, tgt_lang = "hin_Deva", "eng_Latn"

batch = ip.preprocess_batch(
    input_sentences,
    src_lang=src_lang,
    tgt_lang=tgt_lang,
)

DEVICE = "cuda" if torch.cuda.is_available() else "cpu"

# Tokenize the sentences and generate input encodings
inputs = tokenizer(
    batch,
    truncation=True,
    padding="longest",
    return_tensors="pt",
    return_attention_mask=True,
).to(DEVICE)

# Generate translations using the model
with torch.no_grad():
    generated_tokens = model.generate(
        **inputs,
        use_cache=True,
        min_length=0,
        max_length=256,
        num_beams=5,
        num_return_sequences=1,
    )

# Decode the generated tokens into text
with tokenizer.as_target_tokenizer():
    generated_tokens = tokenizer.batch_decode(
        generated_tokens.detach().cpu().tolist(),
        skip_special_tokens=True,
        clean_up_tokenization_spaces=True,
    )

# Postprocess the translations, including entity replacement
translations = ip.postprocess_batch(generated_tokens, lang=tgt_lang)

for input_sentence, translation in zip(input_sentences, translations):
    print(f"{src_lang}: {input_sentence}")
    print(f"{tgt_lang}: {translation}")