import math

import torch

from backend import memory_management
from backend.modules.k_prediction import k_prediction_from_diffusers_scheduler


class KModel(torch.nn.Module):
    def __init__(self, model: torch.nn.Module, diffusers_scheduler, k_predictor=None, config=None):
        super().__init__()

        self.config = config

        self.storage_dtype = model.storage_dtype
        self.computation_dtype = model.computation_dtype

        print(f"K-Model Created: {dict(storage_dtype=self.storage_dtype, computation_dtype=self.computation_dtype)}")

        self.diffusion_model = model
        self.diffusion_model.eval()
        self.diffusion_model.requires_grad_(False)

        if k_predictor is None:
            self.predictor = k_prediction_from_diffusers_scheduler(diffusers_scheduler)
        else:
            self.predictor = k_predictor

    def apply_model(self, x, t, c_concat=None, c_crossattn=None, control=None, transformer_options={}, **kwargs):
        sigma = t
        xc = self.predictor.calculate_input(sigma, x)
        if c_concat is not None:
            xc = torch.cat([xc] + [c_concat], dim=1)

        context = c_crossattn
        dtype = self.computation_dtype

        xc = xc.to(dtype)
        t = self.predictor.timestep(t).float()
        context = context.to(dtype)
        extra_conds = {}
        for o in kwargs:
            extra = kwargs[o]
            if hasattr(extra, "dtype"):
                if extra.dtype != torch.int and extra.dtype != torch.long:
                    extra = extra.to(dtype)
            extra_conds[o] = extra

        model_output = self.diffusion_model(xc, t, context=context, control=control, transformer_options=transformer_options, **extra_conds).float()
        return self.predictor.calculate_denoised(sigma, model_output, x)

    def memory_required(self, input_shape: list[int]) -> float:
        """https://github.com/comfyanonymous/ComfyUI/blob/v0.3.64/comfy/model_base.py#L354"""
        input_shapes = [input_shape]
        area = sum(map(lambda input_shape: input_shape[0] * math.prod(input_shape[2:]), input_shapes))

        if memory_management.xformers_enabled():
            return (area * memory_management.dtype_size(self.computation_dtype) * 0.01 * self.config.memory_usage_factor) * (1024 * 1024)
        else:
            return (area * 0.15 * self.config.memory_usage_factor) * (1024 * 1024)

    def cleanup(self):
        del self.config
        del self.predictor
        del self.diffusion_model