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diff --git a/training/functional.py b/training/functional.py
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+++ b/training/functional.py
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+import math
+from contextlib import _GeneratorContextManager, nullcontext
+from typing import Callable, Any, Tuple, Union
+
+import torch
+import torch.nn.functional as F
+from torch.utils.data import DataLoader
+
+from accelerate import Accelerator
+from transformers import CLIPTextModel
+from diffusers import AutoencoderKL, DDPMScheduler, UNet2DConditionModel, DPMSolverMultistepScheduler
+
+from tqdm.auto import tqdm
+
+from pipelines.stable_diffusion.vlpn_stable_diffusion import VlpnStableDiffusion
+from models.clip.embeddings import ManagedCLIPTextEmbeddings, patch_managed_embeddings
+from models.clip.util import get_extended_embeddings
+from models.clip.tokenizer import MultiCLIPTokenizer
+from training.util import AverageMeter
+from trainer.base import Checkpointer
+
+
+def const(result=None):
+    def fn(*args, **kwargs):
+        return result
+    return fn
+
+
+def generate_class_images(
+    accelerator,
+    text_encoder,
+    vae,
+    unet,
+    tokenizer,
+    scheduler,
+    data_train,
+    sample_batch_size,
+    sample_image_size,
+    sample_steps
+):
+    missing_data = [item for item in data_train if not item.class_image_path.exists()]
+
+    if len(missing_data) == 0:
+        return
+
+    batched_data = [
+        missing_data[i:i+sample_batch_size]
+        for i in range(0, len(missing_data), sample_batch_size)
+    ]
+
+    pipeline = VlpnStableDiffusion(
+        text_encoder=text_encoder,
+        vae=vae,
+        unet=unet,
+        tokenizer=tokenizer,
+        scheduler=scheduler,
+    ).to(accelerator.device)
+    pipeline.set_progress_bar_config(dynamic_ncols=True)
+
+    with torch.inference_mode():
+        for batch in batched_data:
+            image_name = [item.class_image_path for item in batch]
+            prompt = [item.cprompt for item in batch]
+            nprompt = [item.nprompt for item in batch]
+
+            images = pipeline(
+                prompt=prompt,
+                negative_prompt=nprompt,
+                height=sample_image_size,
+                width=sample_image_size,
+                num_inference_steps=sample_steps
+            ).images
+
+            for i, image in enumerate(images):
+                image.save(image_name[i])
+
+    del pipeline
+
+    if torch.cuda.is_available():
+        torch.cuda.empty_cache()
+
+
+def get_models(pretrained_model_name_or_path: str):
+    tokenizer = MultiCLIPTokenizer.from_pretrained(pretrained_model_name_or_path, subfolder='tokenizer')
+    text_encoder = CLIPTextModel.from_pretrained(pretrained_model_name_or_path, subfolder='text_encoder')
+    vae = AutoencoderKL.from_pretrained(pretrained_model_name_or_path, subfolder='vae')
+    unet = UNet2DConditionModel.from_pretrained(pretrained_model_name_or_path, subfolder='unet')
+    noise_scheduler = DDPMScheduler.from_pretrained(pretrained_model_name_or_path, subfolder='scheduler')
+    sample_scheduler = DPMSolverMultistepScheduler.from_pretrained(
+        pretrained_model_name_or_path, subfolder='scheduler')
+
+    vae.enable_slicing()
+    vae.set_use_memory_efficient_attention_xformers(True)
+    unet.set_use_memory_efficient_attention_xformers(True)
+
+    embeddings = patch_managed_embeddings(text_encoder)
+
+    return tokenizer, text_encoder, vae, unet, noise_scheduler, sample_scheduler, embeddings
+
+
+def add_placeholder_tokens(
+    tokenizer: MultiCLIPTokenizer,
+    embeddings: ManagedCLIPTextEmbeddings,
+    placeholder_tokens: list[str],
+    initializer_tokens: list[str],
+    num_vectors: Union[list[int], int]
+):
+    initializer_token_ids = [
+        tokenizer.encode(token, add_special_tokens=False)
+        for token in initializer_tokens
+    ]
+    placeholder_token_ids = tokenizer.add_multi_tokens(placeholder_tokens, num_vectors)
+
+    embeddings.resize(len(tokenizer))
+
+    for (placeholder_token_id, initializer_token_id) in zip(placeholder_token_ids, initializer_token_ids):
+        embeddings.add_embed(placeholder_token_id, initializer_token_id)
+
+    return placeholder_token_ids, initializer_token_ids
+
+
+def loss_step(
+    vae: AutoencoderKL,
+    noise_scheduler: DDPMScheduler,
+    unet: UNet2DConditionModel,
+    text_encoder: CLIPTextModel,
+    prior_loss_weight: float,
+    seed: int,
+    step: int,
+    batch: dict[str, Any],
+    eval: bool = False
+):
+    # Convert images to latent space
+    latents = vae.encode(batch["pixel_values"]).latent_dist.sample().detach()
+    latents = latents * 0.18215
+
+    generator = torch.Generator(device=latents.device).manual_seed(seed + step) if eval else None
+
+    # Sample noise that we'll add to the latents
+    noise = torch.randn(
+        latents.shape,
+        dtype=latents.dtype,
+        layout=latents.layout,
+        device=latents.device,
+        generator=generator
+    )
+    bsz = latents.shape[0]
+    # Sample a random timestep for each image
+    timesteps = torch.randint(
+        0,
+        noise_scheduler.config.num_train_timesteps,
+        (bsz,),
+        generator=generator,
+        device=latents.device,
+    )
+    timesteps = timesteps.long()
+
+    # Add noise to the latents according to the noise magnitude at each timestep
+    # (this is the forward diffusion process)
+    noisy_latents = noise_scheduler.add_noise(latents, noise, timesteps)
+    noisy_latents = noisy_latents.to(dtype=unet.dtype)
+
+    # Get the text embedding for conditioning
+    encoder_hidden_states = get_extended_embeddings(
+        text_encoder,
+        batch["input_ids"],
+        batch["attention_mask"]
+    )
+    encoder_hidden_states = encoder_hidden_states.to(dtype=unet.dtype)
+
+    # Predict the noise residual
+    model_pred = unet(noisy_latents, timesteps, encoder_hidden_states).sample
+
+    # Get the target for loss depending on the prediction type
+    if noise_scheduler.config.prediction_type == "epsilon":
+        target = noise
+    elif noise_scheduler.config.prediction_type == "v_prediction":
+        target = noise_scheduler.get_velocity(latents, noise, timesteps)
+    else:
+        raise ValueError(f"Unknown prediction type {noise_scheduler.config.prediction_type}")
+
+    if batch["with_prior"].all():
+        # Chunk the noise and model_pred into two parts and compute the loss on each part separately.
+        model_pred, model_pred_prior = torch.chunk(model_pred, 2, dim=0)
+        target, target_prior = torch.chunk(target, 2, dim=0)
+
+        # Compute instance loss
+        loss = F.mse_loss(model_pred.float(), target.float(), reduction="mean")
+
+        # Compute prior loss
+        prior_loss = F.mse_loss(model_pred_prior.float(), target_prior.float(), reduction="mean")
+
+        # Add the prior loss to the instance loss.
+        loss = loss + prior_loss_weight * prior_loss
+    else:
+        loss = F.mse_loss(model_pred.float(), target.float(), reduction="mean")
+
+    acc = (model_pred == target).float().mean()
+
+    return loss, acc, bsz
+
+
+def train_loop(
+    accelerator: Accelerator,
+    optimizer: torch.optim.Optimizer,
+    lr_scheduler: torch.optim.lr_scheduler._LRScheduler,
+    model: torch.nn.Module,
+    checkpointer: Checkpointer,
+    train_dataloader: DataLoader,
+    val_dataloader: DataLoader,
+    loss_step: Union[Callable[[int, Any], Tuple[Any, Any, int]], Callable[[int, Any, bool], Tuple[Any, Any, int]]],
+    sample_frequency: int = 10,
+    checkpoint_frequency: int = 50,
+    global_step_offset: int = 0,
+    num_epochs: int = 100,
+    on_log: Callable[[], dict[str, Any]] = const({}),
+    on_train: Callable[[int], _GeneratorContextManager] = const(nullcontext()),
+    on_before_optimize: Callable[[int], None] = const(),
+    on_after_optimize: Callable[[float], None] = const(),
+    on_eval: Callable[[], _GeneratorContextManager] = const(nullcontext())
+):
+    num_training_steps_per_epoch = math.ceil(len(train_dataloader) / accelerator.gradient_accumulation_steps)
+    num_val_steps_per_epoch = len(val_dataloader)
+
+    num_training_steps = num_training_steps_per_epoch * num_epochs
+    num_val_steps = num_val_steps_per_epoch * num_epochs
+
+    global_step = 0
+
+    avg_loss = AverageMeter()
+    avg_acc = AverageMeter()
+
+    avg_loss_val = AverageMeter()
+    avg_acc_val = AverageMeter()
+
+    max_acc_val = 0.0
+
+    local_progress_bar = tqdm(
+        range(num_training_steps_per_epoch + num_val_steps_per_epoch),
+        disable=not accelerator.is_local_main_process,
+        dynamic_ncols=True
+    )
+    local_progress_bar.set_description(f"Epoch 1 / {num_epochs}")
+
+    global_progress_bar = tqdm(
+        range(num_training_steps + num_val_steps),
+        disable=not accelerator.is_local_main_process,
+        dynamic_ncols=True
+    )
+    global_progress_bar.set_description("Total progress")
+
+    try:
+        for epoch in range(num_epochs):
+            if accelerator.is_main_process:
+                if epoch % sample_frequency == 0:
+                    checkpointer.save_samples(global_step + global_step_offset)
+
+                if epoch % checkpoint_frequency == 0 and epoch != 0:
+                    checkpointer.checkpoint(global_step + global_step_offset, "training")
+
+            local_progress_bar.set_description(f"Epoch {epoch + 1} / {num_epochs}")
+            local_progress_bar.reset()
+
+            model.train()
+
+            with on_train(epoch):
+                for step, batch in enumerate(train_dataloader):
+                    with accelerator.accumulate(model):
+                        loss, acc, bsz = loss_step(step, batch)
+
+                        accelerator.backward(loss)
+
+                        on_before_optimize(epoch)
+
+                        optimizer.step()
+                        lr_scheduler.step()
+                        optimizer.zero_grad(set_to_none=True)
+
+                        avg_loss.update(loss.detach_(), bsz)
+                        avg_acc.update(acc.detach_(), bsz)
+
+                    # Checks if the accelerator has performed an optimization step behind the scenes
+                    if accelerator.sync_gradients:
+                        on_after_optimize(lr_scheduler.get_last_lr()[0])
+
+                        local_progress_bar.update(1)
+                        global_progress_bar.update(1)
+
+                        global_step += 1
+
+                    logs = {
+                        "train/loss": avg_loss.avg.item(),
+                        "train/acc": avg_acc.avg.item(),
+                        "train/cur_loss": loss.item(),
+                        "train/cur_acc": acc.item(),
+                        "lr": lr_scheduler.get_last_lr()[0],
+                    }
+                    logs.update(on_log())
+
+                    accelerator.log(logs, step=global_step)
+
+                    local_progress_bar.set_postfix(**logs)
+
+                    if global_step >= num_training_steps:
+                        break
+
+            accelerator.wait_for_everyone()
+
+            model.eval()
+
+            cur_loss_val = AverageMeter()
+            cur_acc_val = AverageMeter()
+
+            with torch.inference_mode(), on_eval():
+                for step, batch in enumerate(val_dataloader):
+                    loss, acc, bsz = loss_step(step, batch, True)
+
+                    loss = loss.detach_()
+                    acc = acc.detach_()
+
+                    cur_loss_val.update(loss, bsz)
+                    cur_acc_val.update(acc, bsz)
+
+                    avg_loss_val.update(loss, bsz)
+                    avg_acc_val.update(acc, bsz)
+
+                    local_progress_bar.update(1)
+                    global_progress_bar.update(1)
+
+                    logs = {
+                        "val/loss": avg_loss_val.avg.item(),
+                        "val/acc": avg_acc_val.avg.item(),
+                        "val/cur_loss": loss.item(),
+                        "val/cur_acc": acc.item(),
+                    }
+                    local_progress_bar.set_postfix(**logs)
+
+            logs["val/cur_loss"] = cur_loss_val.avg.item()
+            logs["val/cur_acc"] = cur_acc_val.avg.item()
+
+            accelerator.log(logs, step=global_step)
+
+            local_progress_bar.clear()
+            global_progress_bar.clear()
+
+            if accelerator.is_main_process:
+                if avg_acc_val.avg.item() > max_acc_val:
+                    accelerator.print(
+                        f"Global step {global_step}: Validation accuracy reached new maximum: {max_acc_val:.2e} -> {avg_acc_val.avg.item():.2e}")
+                    checkpointer.checkpoint(global_step + global_step_offset, "milestone")
+                    max_acc_val = avg_acc_val.avg.item()
+
+        # Create the pipeline using using the trained modules and save it.
+        if accelerator.is_main_process:
+            print("Finished!")
+            checkpointer.checkpoint(global_step + global_step_offset, "end")
+            checkpointer.save_samples(global_step + global_step_offset)
+            accelerator.end_training()
+
+    except KeyboardInterrupt:
+        if accelerator.is_main_process:
+            print("Interrupted")
+            checkpointer.checkpoint(global_step + global_step_offset, "end")
+            accelerator.end_training()
+        quit()