#! fork: https://github.com/NVIDIA/TensorRT/blob/main/demo/Diffusion/models.py

#
# SPDX-FileCopyrightText: Copyright (c) 1993-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# 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.
#

import onnx_graphsurgeon as gs
import torch
from onnx import shape_inference
from polygraphy.backend.onnx.loader import fold_constants


class Optimizer:
    def __init__(self, onnx_graph, verbose=False):
        self.graph = gs.import_onnx(onnx_graph)
        self.verbose = verbose

    def info(self, prefix):
        if self.verbose:
            print(
                f"{prefix} .. {len(self.graph.nodes)} nodes, {len(self.graph.tensors().keys())} tensors, {len(self.graph.inputs)} inputs, {len(self.graph.outputs)} outputs"
            )

    def cleanup(self, return_onnx=False):
        self.graph.cleanup().toposort()
        if return_onnx:
            return gs.export_onnx(self.graph)

    def select_outputs(self, keep, names=None):
        self.graph.outputs = [self.graph.outputs[o] for o in keep]
        if names:
            for i, name in enumerate(names):
                self.graph.outputs[i].name = name

    def fold_constants(self, return_onnx=False):
        onnx_graph = fold_constants(gs.export_onnx(self.graph), allow_onnxruntime_shape_inference=True)
        self.graph = gs.import_onnx(onnx_graph)
        if return_onnx:
            return onnx_graph

    def infer_shapes(self, return_onnx=False):
        onnx_graph = gs.export_onnx(self.graph)
        if onnx_graph.ByteSize() > 2147483648:
            raise TypeError("ERROR: model size exceeds supported 2GB limit")
        else:
            onnx_graph = shape_inference.infer_shapes(onnx_graph)

        self.graph = gs.import_onnx(onnx_graph)
        if return_onnx:
            return onnx_graph


class BaseModel:
    def __init__(
        self,
        fp16=False,
        device="cuda",
        verbose=True,
        max_batch_size=16,
        min_batch_size=1,
        embedding_dim=768,
        text_maxlen=77,
    ):
        self.name = "SD Model"
        self.fp16 = fp16
        self.device = device
        self.verbose = verbose

        self.min_batch = min_batch_size
        self.max_batch = max_batch_size
        self.min_image_shape = 256  # min image resolution: 256x256
        self.max_image_shape = 1024  # max image resolution: 1024x1024
        self.min_latent_shape = self.min_image_shape // 8
        self.max_latent_shape = self.max_image_shape // 8

        self.embedding_dim = embedding_dim
        self.text_maxlen = text_maxlen

    def get_model(self):
        pass

    def get_input_names(self):
        pass

    def get_output_names(self):
        pass

    def get_dynamic_axes(self):
        return None

    def get_sample_input(self, batch_size, image_height, image_width):
        pass

    def get_input_profile(self, batch_size, image_height, image_width, static_batch, static_shape):
        return None

    def get_shape_dict(self, batch_size, image_height, image_width):
        return None

    def optimize(self, onnx_graph):
        opt = Optimizer(onnx_graph, verbose=self.verbose)
        opt.info(self.name + ": original")
        opt.cleanup()
        opt.info(self.name + ": cleanup")
        opt.fold_constants()
        opt.info(self.name + ": fold constants")
        opt.infer_shapes()
        opt.info(self.name + ": shape inference")
        onnx_opt_graph = opt.cleanup(return_onnx=True)
        opt.info(self.name + ": finished")
        return onnx_opt_graph

    def check_dims(self, batch_size, image_height, image_width):
        assert batch_size >= self.min_batch and batch_size <= self.max_batch
        assert image_height % 8 == 0 or image_width % 8 == 0
        latent_height = image_height // 8
        latent_width = image_width // 8
        assert latent_height >= self.min_latent_shape and latent_height <= self.max_latent_shape
        assert latent_width >= self.min_latent_shape and latent_width <= self.max_latent_shape
        return (latent_height, latent_width)

    def get_minmax_dims(self, batch_size, image_height, image_width, static_batch, static_shape):
        min_batch = batch_size if static_batch else self.min_batch
        max_batch = batch_size if static_batch else self.max_batch
        latent_height = image_height // 8
        latent_width = image_width // 8
        min_image_height = image_height if static_shape else self.min_image_shape
        max_image_height = image_height if static_shape else self.max_image_shape
        min_image_width = image_width if static_shape else self.min_image_shape
        max_image_width = image_width if static_shape else self.max_image_shape
        min_latent_height = latent_height if static_shape else self.min_latent_shape
        max_latent_height = latent_height if static_shape else self.max_latent_shape
        min_latent_width = latent_width if static_shape else self.min_latent_shape
        max_latent_width = latent_width if static_shape else self.max_latent_shape
        return (
            min_batch,
            max_batch,
            min_image_height,
            max_image_height,
            min_image_width,
            max_image_width,
            min_latent_height,
            max_latent_height,
            min_latent_width,
            max_latent_width,
        )


class CLIP(BaseModel):
    def __init__(self, device, max_batch_size, embedding_dim, min_batch_size=1):
        super(CLIP, self).__init__(
            device=device,
            max_batch_size=max_batch_size,
            min_batch_size=min_batch_size,
            embedding_dim=embedding_dim,
        )
        self.name = "CLIP"

    def get_input_names(self):
        return ["input_ids"]

    def get_output_names(self):
        return ["text_embeddings", "pooler_output"]

    def get_dynamic_axes(self):
        return {"input_ids": {0: "B"}, "text_embeddings": {0: "B"}}

    def get_input_profile(self, batch_size, image_height, image_width, static_batch, static_shape):
        self.check_dims(batch_size, image_height, image_width)
        min_batch, max_batch, _, _, _, _, _, _, _, _ = self.get_minmax_dims(
            batch_size, image_height, image_width, static_batch, static_shape
        )
        return {
            "input_ids": [
                (min_batch, self.text_maxlen),
                (batch_size, self.text_maxlen),
                (max_batch, self.text_maxlen),
            ]
        }

    def get_shape_dict(self, batch_size, image_height, image_width):
        self.check_dims(batch_size, image_height, image_width)
        return {
            "input_ids": (batch_size, self.text_maxlen),
            "text_embeddings": (batch_size, self.text_maxlen, self.embedding_dim),
        }

    def get_sample_input(self, batch_size, image_height, image_width):
        self.check_dims(batch_size, image_height, image_width)
        return torch.zeros(batch_size, self.text_maxlen, dtype=torch.int32, device=self.device)

    def optimize(self, onnx_graph):
        opt = Optimizer(onnx_graph)
        opt.info(self.name + ": original")
        opt.select_outputs([0])  # delete graph output#1
        opt.cleanup()
        opt.info(self.name + ": remove output[1]")
        opt.fold_constants()
        opt.info(self.name + ": fold constants")
        opt.infer_shapes()
        opt.info(self.name + ": shape inference")
        opt.select_outputs([0], names=["text_embeddings"])  # rename network output
        opt.info(self.name + ": remove output[0]")
        opt_onnx_graph = opt.cleanup(return_onnx=True)
        opt.info(self.name + ": finished")
        return opt_onnx_graph


class UNet(BaseModel):
    def __init__(
        self,
        fp16=False,
        device="cuda",
        max_batch_size=16,
        min_batch_size=1,
        embedding_dim=768,
        text_maxlen=77,
        unet_dim=4,
    ):
        super(UNet, self).__init__(
            fp16=fp16,
            device=device,
            max_batch_size=max_batch_size,
            min_batch_size=min_batch_size,
            embedding_dim=embedding_dim,
            text_maxlen=text_maxlen,
        )
        self.unet_dim = unet_dim
        self.name = "UNet"

    def get_input_names(self):
        return ["sample", "timestep", "encoder_hidden_states"]

    def get_output_names(self):
        return ["latent"]

    def get_dynamic_axes(self):
        return {
            "sample": {0: "2B", 2: "H", 3: "W"},
            "timestep": {0: "2B"},
            "encoder_hidden_states": {0: "2B"},
            "latent": {0: "2B", 2: "H", 3: "W"},
        }

    def get_input_profile(self, batch_size, image_height, image_width, static_batch, static_shape):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        (
            min_batch,
            max_batch,
            _,
            _,
            _,
            _,
            min_latent_height,
            max_latent_height,
            min_latent_width,
            max_latent_width,
        ) = self.get_minmax_dims(batch_size, image_height, image_width, static_batch, static_shape)
        return {
            "sample": [
                (min_batch, self.unet_dim, min_latent_height, min_latent_width),
                (batch_size, self.unet_dim, latent_height, latent_width),
                (max_batch, self.unet_dim, max_latent_height, max_latent_width),
            ],
            "timestep": [(min_batch,), (batch_size,), (max_batch,)],
            "encoder_hidden_states": [
                (min_batch, self.text_maxlen, self.embedding_dim),
                (batch_size, self.text_maxlen, self.embedding_dim),
                (max_batch, self.text_maxlen, self.embedding_dim),
            ],
        }

    def get_shape_dict(self, batch_size, image_height, image_width):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        return {
            "sample": (2 * batch_size, self.unet_dim, latent_height, latent_width),
            "timestep": (2 * batch_size,),
            "encoder_hidden_states": (2 * batch_size, self.text_maxlen, self.embedding_dim),
            "latent": (2 * batch_size, 4, latent_height, latent_width),
        }

    def get_sample_input(self, batch_size, image_height, image_width):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        dtype = torch.float16 if self.fp16 else torch.float32
        return (
            torch.randn(
                2 * batch_size, self.unet_dim, latent_height, latent_width, dtype=torch.float32, device=self.device
            ),
            torch.ones((2 * batch_size,), dtype=torch.float32, device=self.device),
            torch.randn(2 * batch_size, self.text_maxlen, self.embedding_dim, dtype=dtype, device=self.device),
        )


class VAE(BaseModel):
    def __init__(self, device, max_batch_size, min_batch_size=1):
        super(VAE, self).__init__(
            device=device,
            max_batch_size=max_batch_size,
            min_batch_size=min_batch_size,
            embedding_dim=None,
        )
        self.name = "VAE decoder"

    def get_input_names(self):
        return ["latent"]

    def get_output_names(self):
        return ["images"]

    def get_dynamic_axes(self):
        return {
            "latent": {0: "B", 2: "H", 3: "W"},
            "images": {0: "B", 2: "8H", 3: "8W"},
        }

    def get_input_profile(self, batch_size, image_height, image_width, static_batch, static_shape):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        (
            min_batch,
            max_batch,
            _,
            _,
            _,
            _,
            min_latent_height,
            max_latent_height,
            min_latent_width,
            max_latent_width,
        ) = self.get_minmax_dims(batch_size, image_height, image_width, static_batch, static_shape)
        return {
            "latent": [
                (min_batch, 4, min_latent_height, min_latent_width),
                (batch_size, 4, latent_height, latent_width),
                (max_batch, 4, max_latent_height, max_latent_width),
            ]
        }

    def get_shape_dict(self, batch_size, image_height, image_width):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        return {
            "latent": (batch_size, 4, latent_height, latent_width),
            "images": (batch_size, 3, image_height, image_width),
        }

    def get_sample_input(self, batch_size, image_height, image_width):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        return torch.randn(
            batch_size,
            4,
            latent_height,
            latent_width,
            dtype=torch.float32,
            device=self.device,
        )


class VAEEncoder(BaseModel):
    def __init__(self, device, max_batch_size, min_batch_size=1):
        super(VAEEncoder, self).__init__(
            device=device,
            max_batch_size=max_batch_size,
            min_batch_size=min_batch_size,
            embedding_dim=None,
        )
        self.name = "VAE encoder"

    def get_input_names(self):
        return ["images"]

    def get_output_names(self):
        return ["latent"]

    def get_dynamic_axes(self):
        return {
            "images": {0: "B", 2: "8H", 3: "8W"},
            "latent": {0: "B", 2: "H", 3: "W"},
        }

    def get_input_profile(self, batch_size, image_height, image_width, static_batch, static_shape):
        assert batch_size >= self.min_batch and batch_size <= self.max_batch
        min_batch = batch_size if static_batch else self.min_batch
        max_batch = batch_size if static_batch else self.max_batch
        self.check_dims(batch_size, image_height, image_width)
        (
            min_batch,
            max_batch,
            min_image_height,
            max_image_height,
            min_image_width,
            max_image_width,
            _,
            _,
            _,
            _,
        ) = self.get_minmax_dims(batch_size, image_height, image_width, static_batch, static_shape)

        return {
            "images": [
                (min_batch, 3, min_image_height, min_image_width),
                (batch_size, 3, image_height, image_width),
                (max_batch, 3, max_image_height, max_image_width),
            ],
        }

    def get_shape_dict(self, batch_size, image_height, image_width):
        latent_height, latent_width = self.check_dims(batch_size, image_height, image_width)
        return {
            "images": (batch_size, 3, image_height, image_width),
            "latent": (batch_size, 4, latent_height, latent_width),
        }

    def get_sample_input(self, batch_size, image_height, image_width):
        self.check_dims(batch_size, image_height, image_width)
        return torch.randn(
            batch_size,
            3,
            image_height,
            image_width,
            dtype=torch.float32,
            device=self.device,
        )