import numpy as np
from sklearn.metrics import accuracy_score, precision_recall_fscore_support
from transformers import BertForSequenceClassification, BertTokenizer

def compute_metrics(pred):
    labels = pred.label_ids
    preds = np.argmax(pred.predictions, axis=1)
    acc = accuracy_score(labels, preds)
    precision, recall, f1, _ = precision_recall_fscore_support(labels, preds, average="binary")
    return {
        "accuracy": acc,
        "precision": precision,
        "recall": recall,
        "f1": f1,
    }

def load_model_and_tokenizer(model_dir, device):
    model = BertForSequenceClassification.from_pretrained(model_dir).to(device)
    tokenizer = BertTokenizer.from_pretrained(model_dir)
    return model, tokenizer