import torch.nn as nn
from transformers import AutoModel
class MedBERTClassifier(nn.Module):

    def __init__(self, model_name, num_classes):
        super().__init__()

        self.bert = AutoModel.from_pretrained(model_name)

        self.dropout = nn.Dropout(0.3)
        self.norm = nn.LayerNorm(self.bert.config.hidden_size)
        self.classifier = nn.Linear(self.bert.config.hidden_size, num_classes)

    def forward(self, input_ids, attention_mask):

        outputs = self.bert(
            input_ids=input_ids,
            attention_mask=attention_mask
        )

        cls_output = outputs.pooler_output

        x = self.dropout(cls_output)

        logits = self.classifier(x)

        return logits