# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


from typing import Optional, Union, Tuple, List, Callable, Dict
from tqdm import tqdm
import torch
import torch.nn.functional as nnf
import numpy as np
import abc
from . import ptp_utils
from . import seq_aligner
import shutil
from torch.optim.adam import Adam
from PIL import Image


LOW_RESOURCE = False 
NUM_DDIM_STEPS = 50
MAX_NUM_WORDS = 77
device = torch.device('cuda')
from transformers import CLIPTextModel, CLIPTokenizer

pretrained_model_path = "checkpoints/CompVis/stable-diffusion-v1-4/"

ldm_stable = None
tokenizer = CLIPTokenizer.from_pretrained(pretrained_model_path, subfolder="tokenizer")


class LocalBlend:
    
    def get_mask(self, maps, alpha, use_pool):
        k = 1
        maps = (maps * alpha).sum(-1).mean(1)
        if use_pool:
            maps = nnf.max_pool2d(maps, (k * 2 + 1, k * 2 +1), (1, 1), padding=(k, k))
        mask = nnf.interpolate(maps, size=(x_t.shape[2:]))
        mask = mask / mask.max(2, keepdims=True)[0].max(3, keepdims=True)[0]
        mask = mask.gt(self.th[1-int(use_pool)])
        mask = mask[:1] + mask
        return mask
    
    def __call__(self, x_t, attention_store):
        self.counter += 1
        if self.counter > self.start_blend:
           
            maps = attention_store["down_cross"][2:4] + attention_store["up_cross"][:3]
            maps = [item.reshape(self.alpha_layers.shape[0], -1, 1, 16, 16, MAX_NUM_WORDS) for item in maps]
            maps = torch.cat(maps, dim=1)
            mask = self.get_mask(maps, self.alpha_layers, True)
            if self.substruct_layers is not None:
                maps_sub = ~self.get_mask(maps, self.substruct_layers, False)
                mask = mask * maps_sub
            mask = mask.float()
            x_t = x_t[:1] + mask * (x_t - x_t[:1])
        return x_t
       
    def __init__(self, prompts: List[str], words: List[List[str]], substruct_words=None, start_blend=0.2, th=(.3, .3)):
        alpha_layers = torch.zeros(len(prompts),  1, 1, 1, 1, MAX_NUM_WORDS)
        for i, (prompt, words_) in enumerate(zip(prompts, words)):
            if type(words_) is str:
                words_ = [words_]
            for word in words_:
                ind = ptp_utils.get_word_inds(prompt, word, tokenizer)
                alpha_layers[i, :, :, :, :, ind] = 1
        
        if substruct_words is not None:
            substruct_layers = torch.zeros(len(prompts),  1, 1, 1, 1, MAX_NUM_WORDS)
            for i, (prompt, words_) in enumerate(zip(prompts, substruct_words)):
                if type(words_) is str:
                    words_ = [words_]
                for word in words_:
                    ind = ptp_utils.get_word_inds(prompt, word, tokenizer)
                    substruct_layers[i, :, :, :, :, ind] = 1
            self.substruct_layers = substruct_layers.to(device)
        else:
            self.substruct_layers = None
        self.alpha_layers = alpha_layers.to(device)
        self.start_blend = int(start_blend * NUM_DDIM_STEPS)
        self.counter = 0 
        self.th=th


class EmptyControl:
    
    
    def step_callback(self, x_t):
        return x_t
    
    def between_steps(self):
        return
    
    def __call__(self, attn, is_cross: bool, place_in_unet: str):
        return attn

    
class AttentionControl(abc.ABC):
    
    def step_callback(self, x_t):
        return x_t
    
    def between_steps(self):
        return
    
    @property
    def num_uncond_att_layers(self):
        return self.num_att_layers if LOW_RESOURCE else 0
    
    @abc.abstractmethod
    def forward (self, attn, is_cross: bool, place_in_unet: str):
        raise NotImplementedError

    def __call__(self, attn, is_cross: bool, place_in_unet: str):
        if self.cur_att_layer >= self.num_uncond_att_layers:
            if LOW_RESOURCE:
                attn = self.forward(attn, is_cross, place_in_unet)
            else:
                h = attn.shape[0]
                attn[h // 2:] = self.forward(attn[h // 2:], is_cross, place_in_unet)
        self.cur_att_layer += 1
        if self.cur_att_layer == self.num_att_layers + self.num_uncond_att_layers:
            self.cur_att_layer = 0
            self.cur_step += 1
            self.between_steps()
        return attn
    
    def reset(self):
        self.cur_step = 0
        self.cur_att_layer = 0

    def __init__(self):
        self.cur_step = 0
        self.num_att_layers = -1
        self.cur_att_layer = 0


class SpatialReplace(EmptyControl):
    
    def step_callback(self, x_t):
        if self.cur_step < self.stop_inject:
            b = x_t.shape[0]
            x_t = x_t[:1].expand(b, *x_t.shape[1:])
        return x_t

    def __init__(self, stop_inject: float):
        super(SpatialReplace, self).__init__()
        self.stop_inject = int((1 - stop_inject) * NUM_DDIM_STEPS)
        

class AttentionStore(AttentionControl):

    @staticmethod
    def get_empty_store():
        return {"down_cross": [], "mid_cross": [], "up_cross": [],
                "down_self": [],  "mid_self": [],  "up_self": []}

    def forward(self, attn, is_cross: bool, place_in_unet: str):
        key = f"{place_in_unet}_{'cross' if is_cross else 'self'}"
        if attn.shape[1] <= 32 ** 2:  # avoid memory overhead
            self.step_store[key].append(attn)
        return attn

    def between_steps(self):
        if len(self.attention_store) == 0:
            self.attention_store = self.step_store
        else:
            for key in self.attention_store:
                for i in range(len(self.attention_store[key])):
                    self.attention_store[key][i] += self.step_store[key][i]
        self.step_store = self.get_empty_store()

    def get_average_attention(self):
        average_attention = {key: [item / self.cur_step for item in self.attention_store[key]] for key in self.attention_store}
        return average_attention


    def reset(self):
        super(AttentionStore, self).reset()
        self.step_store = self.get_empty_store()
        self.attention_store = {}

    def __init__(self):
        super(AttentionStore, self).__init__()
        self.step_store = self.get_empty_store()
        self.attention_store = {}

        
class AttentionControlEdit(AttentionStore, abc.ABC):
    
    def step_callback(self, x_t):
        if self.local_blend is not None:
            x_t = self.local_blend(x_t, self.attention_store)
        return x_t
        
    def replace_self_attention(self, attn_base, att_replace, place_in_unet):
        if att_replace.shape[2] <= 32 ** 2:
            attn_base = attn_base.unsqueeze(0).expand(att_replace.shape[0], *attn_base.shape)
            return attn_base
        else:
            return att_replace
    
    @abc.abstractmethod
    def replace_cross_attention(self, attn_base, att_replace):
        raise NotImplementedError
    
    def forward(self, attn, is_cross: bool, place_in_unet: str):
        super(AttentionControlEdit, self).forward(attn, is_cross, place_in_unet)
        if is_cross or (self.num_self_replace[0] <= self.cur_step < self.num_self_replace[1]):
            h = attn.shape[0] // (self.batch_size)
            attn = attn.reshape(self.batch_size, h, *attn.shape[1:])
            attn_base, attn_repalce = attn[0], attn[1:]
            if is_cross:
                alpha_words = self.cross_replace_alpha[self.cur_step]
                attn_repalce_new = self.replace_cross_attention(attn_base, attn_repalce) * alpha_words + (1 - alpha_words) * attn_repalce
                attn[1:] = attn_repalce_new
            else:
                attn[1:] = self.replace_self_attention(attn_base, attn_repalce, place_in_unet)
            attn = attn.reshape(self.batch_size * h, *attn.shape[2:])
        return attn
    
    def __init__(self, prompts, num_steps: int,
                 cross_replace_steps: Union[float, Tuple[float, float], Dict[str, Tuple[float, float]]],
                 self_replace_steps: Union[float, Tuple[float, float]],
                 local_blend: Optional[LocalBlend]):
        super(AttentionControlEdit, self).__init__()
        self.batch_size = len(prompts)
        self.cross_replace_alpha = ptp_utils.get_time_words_attention_alpha(prompts, num_steps, cross_replace_steps, tokenizer).to(device)
        if type(self_replace_steps) is float:
            self_replace_steps = 0, self_replace_steps
        self.num_self_replace = int(num_steps * self_replace_steps[0]), int(num_steps * self_replace_steps[1])
        self.local_blend = local_blend

class AttentionReplace(AttentionControlEdit):

    def replace_cross_attention(self, attn_base, att_replace):
        return torch.einsum('hpw,bwn->bhpn', attn_base, self.mapper)
      
    def __init__(self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float,
                 local_blend: Optional[LocalBlend] = None):
        super(AttentionReplace, self).__init__(prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend)
        self.mapper = seq_aligner.get_replacement_mapper(prompts, tokenizer).to(device)
        

class AttentionRefine(AttentionControlEdit):

    def replace_cross_attention(self, attn_base, att_replace):
        attn_base_replace = attn_base[:, :, self.mapper].permute(2, 0, 1, 3)
        attn_replace = attn_base_replace * self.alphas + att_replace * (1 - self.alphas)
        # attn_replace = attn_replace / attn_replace.sum(-1, keepdims=True)
        return attn_replace

    def __init__(self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float,
                 local_blend: Optional[LocalBlend] = None):
        super(AttentionRefine, self).__init__(prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend)
        self.mapper, alphas = seq_aligner.get_refinement_mapper(prompts, tokenizer)
        self.mapper, alphas = self.mapper.to(device), alphas.to(device)
        self.alphas = alphas.reshape(alphas.shape[0], 1, 1, alphas.shape[1])


class AttentionReweight(AttentionControlEdit):

    def replace_cross_attention(self, attn_base, att_replace):
        if self.prev_controller is not None:
            attn_base = self.prev_controller.replace_cross_attention(attn_base, att_replace)
        attn_replace = attn_base[None, :, :, :] * self.equalizer[:, None, None, :]
        # attn_replace = attn_replace / attn_replace.sum(-1, keepdims=True)
        return attn_replace

    def __init__(self, prompts, num_steps: int, cross_replace_steps: float, self_replace_steps: float, equalizer,
                local_blend: Optional[LocalBlend] = None, controller: Optional[AttentionControlEdit] = None):
        super(AttentionReweight, self).__init__(prompts, num_steps, cross_replace_steps, self_replace_steps, local_blend)
        self.equalizer = equalizer.to(device)
        self.prev_controller = controller


def get_equalizer(text: str, word_select: Union[int, Tuple[int, ...]], values: Union[List[float],
                  Tuple[float, ...]]):
    if type(word_select) is int or type(word_select) is str:
        word_select = (word_select,)
    equalizer = torch.ones(1, 77)
    
    for word, val in zip(word_select, values):
        inds = ptp_utils.get_word_inds(text, word, tokenizer)
        equalizer[:, inds] = val
    return equalizer

def aggregate_attention(attention_store: AttentionStore, res: int, from_where: List[str], is_cross: bool, select: int):
    out = []
    attention_maps = attention_store.get_average_attention()
    num_pixels = res ** 2
    for location in from_where:
        for item in attention_maps[f"{location}_{'cross' if is_cross else 'self'}"]:
            if item.shape[1] == num_pixels:
                cross_maps = item.reshape(len(prompts), -1, res, res, item.shape[-1])[select]
                out.append(cross_maps)
    out = torch.cat(out, dim=0)
    out = out.sum(0) / out.shape[0]
    return out.cpu()


def make_controller(prompts: List[str], is_replace_controller: bool, cross_replace_steps: Dict[str, float], self_replace_steps: float, blend_words=None, equilizer_params=None) -> AttentionControlEdit:
    if blend_words is None:
        lb = None
    else:
        lb = LocalBlend(prompts, blend_word)
    if is_replace_controller:
        controller = AttentionReplace(prompts, NUM_DDIM_STEPS, cross_replace_steps=cross_replace_steps, self_replace_steps=self_replace_steps, local_blend=lb)
    else:
        controller = AttentionRefine(prompts, NUM_DDIM_STEPS, cross_replace_steps=cross_replace_steps, self_replace_steps=self_replace_steps, local_blend=lb)
    if equilizer_params is not None:
        eq = get_equalizer(prompts[1], equilizer_params["words"], equilizer_params["values"])
        controller = AttentionReweight(prompts, NUM_DDIM_STEPS, cross_replace_steps=cross_replace_steps,
                                       self_replace_steps=self_replace_steps, equalizer=eq, local_blend=lb, controller=controller)
    return controller


def show_cross_attention(attention_store: AttentionStore, res: int, from_where: List[str], select: int = 0):
    tokens = tokenizer.encode(prompts[select])
    decoder = tokenizer.decode
    attention_maps = aggregate_attention(attention_store, res, from_where, True, select)
    images = []
    for i in range(len(tokens)):
        image = attention_maps[:, :, i]
        image = 255 * image / image.max()
        image = image.unsqueeze(-1).expand(*image.shape, 3)
        image = image.numpy().astype(np.uint8)
        image = np.array(Image.fromarray(image).resize((256, 256)))
        image = ptp_utils.text_under_image(image, decoder(int(tokens[i])))
        images.append(image)
    ptp_utils.view_images(np.stack(images, axis=0))


class NullInversion:
    
    def prev_step(self, model_output: Union[torch.FloatTensor, np.ndarray], timestep: int, sample: Union[torch.FloatTensor, np.ndarray]):
        prev_timestep = timestep - self.scheduler.config.num_train_timesteps // self.scheduler.num_inference_steps
        alpha_prod_t = self.scheduler.alphas_cumprod[timestep]
        alpha_prod_t_prev = self.scheduler.alphas_cumprod[prev_timestep] if prev_timestep >= 0 else self.scheduler.final_alpha_cumprod
        beta_prod_t = 1 - alpha_prod_t
        pred_original_sample = (sample - beta_prod_t ** 0.5 * model_output) / alpha_prod_t ** 0.5
        pred_sample_direction = (1 - alpha_prod_t_prev) ** 0.5 * model_output
        prev_sample = alpha_prod_t_prev ** 0.5 * pred_original_sample + pred_sample_direction
        return prev_sample
    
    def next_step(self, model_output: Union[torch.FloatTensor, np.ndarray], timestep: int, sample: Union[torch.FloatTensor, np.ndarray]):
        timestep, next_timestep = min(timestep - self.scheduler.config.num_train_timesteps // self.scheduler.num_inference_steps, 999), timestep
        alpha_prod_t = self.scheduler.alphas_cumprod[timestep] if timestep >= 0 else self.scheduler.final_alpha_cumprod
        alpha_prod_t_next = self.scheduler.alphas_cumprod[next_timestep]
        beta_prod_t = 1 - alpha_prod_t
        next_original_sample = (sample - beta_prod_t ** 0.5 * model_output) / alpha_prod_t ** 0.5
        next_sample_direction = (1 - alpha_prod_t_next) ** 0.5 * model_output
        next_sample = alpha_prod_t_next ** 0.5 * next_original_sample + next_sample_direction
        return next_sample
    
    def get_noise_pred_single(self, latents, t, context, normal_infer=True):
        noise_pred = self.model.unet(latents, t, encoder_hidden_states=context, normal_infer=normal_infer)["sample"]
        return noise_pred

    def get_noise_pred(self, latents, t, is_forward=True, context=None, normal_infer=True):
        latents_input = torch.cat([latents] * 2)
        if context is None:
            context = self.context
        guidance_scale = 1 if is_forward else self.guidance_scale
        noise_pred = self.model.unet(latents_input, t, encoder_hidden_states=context, normal_infer=normal_infer)["sample"]
        noise_pred_uncond, noise_prediction_text = noise_pred.chunk(2)
        noise_pred = noise_pred_uncond + guidance_scale * (noise_prediction_text - noise_pred_uncond)
        if is_forward:
            latents = self.next_step(noise_pred, t, latents)
        else:
            latents = self.prev_step(noise_pred, t, latents)
        return latents

    @torch.no_grad()
    def latent2image(self, latents, return_type='np'):
        latents = 1 / 0.18215 * latents.detach()
        image = self.model.vae.decode(latents)['sample']
        if return_type == 'np':
            image = (image / 2 + 0.5).clamp(0, 1)
            image = image.cpu().permute(0, 2, 3, 1).numpy()[0]
            image = (image * 255).astype(np.uint8)
        return image

    @torch.no_grad()
    def image2latent(self, image):
        with torch.no_grad():
            if type(image) is Image:
                image = np.array(image)
            if type(image) is torch.Tensor and image.dim() == 4:
                latents = image
            else:
                image = torch.from_numpy(image).float() / 127.5 - 1
                image = image.permute(2, 0, 1).unsqueeze(0).to(device)
                latents = self.model.vae.encode(image)['latent_dist'].mean
                latents = latents * 0.18215
        return latents

    @torch.no_grad()
    def init_prompt(self, prompt: str):
        uncond_input = self.model.tokenizer(
            [""], padding="max_length", max_length=self.model.tokenizer.model_max_length,
            return_tensors="pt"
        )
        uncond_embeddings = self.model.text_encoder(uncond_input.input_ids.to(self.model.device))[0]
        text_input = self.model.tokenizer(
            [prompt],
            padding="max_length",
            max_length=self.model.tokenizer.model_max_length,
            truncation=True,
            return_tensors="pt",
        )
        # (1, 77, 768)
        text_embeddings = self.model.text_encoder(text_input.input_ids.to(self.model.device))[0]
        # (2, 77, 768)
        self.context = torch.cat([uncond_embeddings, text_embeddings])
        self.prompt = prompt

    @torch.no_grad()
    def ddim_loop(self, latent):
        uncond_embeddings, cond_embeddings = self.context.chunk(2)
        cond = cond_embeddings if self.null_inv_with_prompt else uncond_embeddings
        all_latent = [latent]
        latent = latent.clone().detach()
        for i in range(NUM_DDIM_STEPS):
            t = self.model.scheduler.timesteps[len(self.model.scheduler.timesteps) - i - 1]
            noise_pred = self.get_noise_pred_single(latent, t, cond, normal_infer=True)
            latent = self.next_step(noise_pred, t, latent)
            all_latent.append(latent)
        return all_latent

    @property
    def scheduler(self):
        return self.model.scheduler

    @torch.no_grad()
    def ddim_inversion(self, latent):
        ddim_latents = self.ddim_loop(latent)
        return ddim_latents

    def null_optimization(self, latents, null_inner_steps, epsilon, null_base_lr=1e-2):
        uncond_embeddings, cond_embeddings = self.context.chunk(2)
        uncond_embeddings_list = []
        latent_cur = latents[-1]
        bar = tqdm(total=null_inner_steps * NUM_DDIM_STEPS)
        for i in range(NUM_DDIM_STEPS):
            uncond_embeddings = uncond_embeddings.clone().detach()
            uncond_embeddings.requires_grad = True
            optimizer = Adam([uncond_embeddings], lr=null_base_lr * (1. - i / 100.))
            latent_prev = latents[len(latents) - i - 2]
            t = self.model.scheduler.timesteps[i]
            with torch.no_grad():
                noise_pred_cond = self.get_noise_pred_single(latent_cur, t, cond_embeddings, normal_infer=self.null_normal_infer)
            for j in range(null_inner_steps):
                noise_pred_uncond = self.get_noise_pred_single(latent_cur, t, uncond_embeddings, normal_infer=self.null_normal_infer)
                noise_pred = noise_pred_uncond + self.guidance_scale * (noise_pred_cond - noise_pred_uncond)
                latents_prev_rec = self.prev_step(noise_pred, t, latent_cur)
                loss = nnf.mse_loss(latents_prev_rec, latent_prev)
                optimizer.zero_grad()
                loss.backward()
                optimizer.step()
                assert not torch.isnan(uncond_embeddings.abs().mean())
                loss_item = loss.item()
                bar.update()
                if loss_item < epsilon + i * 2e-5:
                    break
            for j in range(j + 1, null_inner_steps):
                bar.update()
            uncond_embeddings_list.append(uncond_embeddings[:1].detach())
            with torch.no_grad():
                context = torch.cat([uncond_embeddings, cond_embeddings])
                latent_cur = self.get_noise_pred(latent_cur, t, False, context, normal_infer=self.null_normal_infer)
        bar.close()
        return uncond_embeddings_list
    
    def invert(self, latents: torch.Tensor, prompt: str, null_inner_steps=10, early_stop_epsilon=1e-5, verbose=False, null_base_lr=1e-2):
        self.init_prompt(prompt)
        if verbose:
            print("DDIM inversion...")
        ddim_latents = self.ddim_inversion(latents.to(torch.float32))
        if verbose:
            print("Null-text optimization...")
        uncond_embeddings = self.null_optimization(ddim_latents, null_inner_steps, early_stop_epsilon, null_base_lr=null_base_lr)
        return ddim_latents[-1], uncond_embeddings
        
    
    def __init__(self, model, guidance_scale, null_inv_with_prompt, null_normal_infer=True):
        self.null_normal_infer = null_normal_infer
        self.null_inv_with_prompt = null_inv_with_prompt
        self.guidance_scale = guidance_scale
        self.model = model
        self.tokenizer = self.model.tokenizer
        self.model.scheduler.set_timesteps(NUM_DDIM_STEPS)
        self.prompt = None
        self.context = None