# SPDX-License-Identifier: Apache-2.0

import math
from collections import OrderedDict
from collections.abc import Iterable, Mapping, Sequence
from functools import cached_property
from typing import List, Literal, Optional, Set, Tuple, TypedDict, Union

import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from transformers import BartTokenizer, BatchFeature, PretrainedConfig

from vllm.config import VllmConfig
from vllm.model_executor.layers.logits_processor import LogitsProcessor
from vllm.model_executor.layers.sampler import SamplerOutput, get_sampler
from vllm.model_executor.model_loader.weight_utils import default_weight_loader
from vllm.model_executor.models.bart import (BartDecoder, BartEncoder,
                                             BartParallelLMHead,
                                             BartScaledWordEmbedding)
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.multimodal import MULTIMODAL_REGISTRY
from vllm.multimodal.inputs import (MultiModalDataDict, MultiModalFieldConfig,
                                    MultiModalKwargs)
from vllm.multimodal.parse import MultiModalDataItems
from vllm.multimodal.processing import (BaseProcessingInfo,
                                        EncDecMultiModalProcessor,
                                        PromptIndexTargets, PromptInsertion,
                                        PromptUpdate)
from vllm.multimodal.profiling import BaseDummyInputsBuilder
from vllm.sequence import IntermediateTensors

from .interfaces import (MultiModalEmbeddings, SupportsMultiModal,
                         SupportsV0Only)
from .utils import AutoWeightsLoader, flatten_bn, merge_multimodal_embeddings


class Florence2ImagePixelInputs(TypedDict):
    type: Literal["pixel_values"]
    data: torch.Tensor
    """Shape: (batch_size, num_channel, height, width)"""


# ViT implementation are all copied from
# https://huggingface.co/microsoft/Florence-2-base/blob/main/modeling_florence2.py
class LearnedAbsolutePositionEmbedding2D(nn.Module):
    """
    This module learns positional embeddings up to a fixed maximum size.
    """

    def __init__(self, embedding_dim=256, num_pos=50):
        super().__init__()
        self.row_embeddings = nn.Embedding(num_pos, embedding_dim // 2)
        self.column_embeddings = nn.Embedding(
            num_pos, embedding_dim - (embedding_dim // 2))

    def forward(self, pixel_values):
        """
        pixel_values: (batch_size, height, width, num_channels) 
        returns: (batch_size, height, width, embedding_dim * 2)
        """
        if len(pixel_values.shape) != 4:
            raise ValueError('pixel_values must be a 4D tensor')
        height, width = pixel_values.shape[1:3]
        width_values = torch.arange(width, device=pixel_values.device)
        height_values = torch.arange(height, device=pixel_values.device)
        x_emb = self.column_embeddings(width_values)
        y_emb = self.row_embeddings(height_values)
        # (height, width, embedding_dim * 2)
        pos = torch.cat([
            x_emb.unsqueeze(0).repeat(height, 1, 1),
            y_emb.unsqueeze(1).repeat(1, width, 1)
        ],
                        dim=-1)
        # (embedding_dim * 2, height, width)
        pos = pos.permute(2, 0, 1)
        pos = pos.unsqueeze(0)
        # (batch_size, embedding_dim * 2, height, width)
        pos = pos.repeat(pixel_values.shape[0], 1, 1, 1)
        # (batch_size, height, width, embedding_dim * 2)
        pos = pos.permute(0, 2, 3, 1)
        return pos


class PositionalEmbeddingCosine1D(nn.Module):
    """
    This class implements a very simple positional encoding. It follows closely
    the encoder from the link below:
    https://pytorch.org/tutorials/beginner/translation_transformer.html
    Args:
        embed_dim: The dimension of the embeddings.
        dropout_prob: The dropout probability.
        max_seq_len: The maximum length to precompute the positional encodings.
    """

    def __init__(self, embed_dim: int = 512, max_seq_len: int = 1024) -> None:
        super().__init__()
        self.embed_dim = embed_dim
        self.max_seq_len = max_seq_len
        # Generate the sinusoidal arrays.
        factor = math.log(10000)
        denominator = torch.exp(-factor * torch.arange(0, self.embed_dim, 2) /
                                self.embed_dim)
        # Matrix where rows correspond to a positional embedding as a function
        # of the position index (i.e., the row index).
        frequencies = \
            torch.arange(0, self.max_seq_len) \
            .reshape(self.max_seq_len, 1) * denominator
        pos_idx_to_embed = torch.zeros((self.max_seq_len, self.embed_dim))
        # Populate uneven entries.
        pos_idx_to_embed[:, 0::2] = torch.sin(frequencies)
        pos_idx_to_embed[:, 1::2] = torch.cos(frequencies)
        # Save the positional embeddings in a constant buffer.
        # self.register_buffer("pos_idx_to_embed", pos_idx_to_embed)
        self.pos_idx_to_embed = nn.Parameter(pos_idx_to_embed,
                                             requires_grad=False)

    def forward(self, seq_embeds: torch.Tensor) -> torch.Tensor:
        """
        Args:
            seq_embeds: The sequence embeddings in order. Allowed size:
                1. [T, D], where T is the length of the sequence, and D is the
                frame embedding dimension.
                2. [B, T, D], where B is the batch size and T and D are the
                same as above.
        Returns a tensor of with the same dimensions as the input: i.e.,
        [1, T, D] or [T, D].
        """
        shape_len = len(seq_embeds.shape)
        assert 2 <= shape_len <= 3
        len_seq = seq_embeds.size(-2)
        assert len_seq <= self.max_seq_len
        pos_embeds = self.pos_idx_to_embed[0:seq_embeds.size(-2), :]
        # Adapt pre-computed positional embeddings to the input.
        if shape_len == 3:
            pos_embeds = pos_embeds.view(
                (1, pos_embeds.size(0), pos_embeds.size(1)))
        return pos_embeds


class MySequential(nn.Sequential):

    def forward(self, *inputs):
        for module in self._modules.values():
            if isinstance(inputs, tuple):
                inputs = module(*inputs)
            else:
                inputs = module(inputs)
        return inputs


class PreNorm(nn.Module):

    def __init__(self, norm, fn):
        super().__init__()
        self.norm = norm
        self.fn = fn

    def forward(self, x, *args, **kwargs):
        shortcut = x
        if self.norm is not None:
            x, size = self.fn(self.norm(x), *args, **kwargs)
        else:
            x, size = self.fn(x, *args, **kwargs)

        x = shortcut + x

        return x, size


class Mlp(nn.Module):

    def __init__(
        self,
        in_features,
        hidden_features=None,
        out_features=None,
        act_layer=nn.GELU,
    ):
        super().__init__()
        out_features = out_features or in_features
        hidden_features = hidden_features or in_features
        self.net = nn.Sequential(
            OrderedDict([("fc1", nn.Linear(in_features, hidden_features)),
                         ("act", act_layer()),
                         ("fc2", nn.Linear(hidden_features, out_features))]))

    def forward(self, x, size):
        return self.net(x), size


class DepthWiseConv2d(nn.Module):

    def __init__(
        self,
        dim_in,
        kernel_size,
        padding,
        stride,
        bias=True,
    ):
        super().__init__()
        self.dw = nn.Conv2d(dim_in,
                            dim_in,
                            kernel_size=kernel_size,
                            padding=padding,
                            groups=dim_in,
                            stride=stride,
                            bias=bias)

    def forward(self, x, size):
        B, N, C = x.shape
        H, W = size
        assert N == H * W

        x = self.dw(x.transpose(1, 2).view(B, C, H, W))
        size = (x.size(-2), x.size(-1))
        x = x.flatten(2).transpose(1, 2)
        return x, size


class ConvEmbed(nn.Module):
    """ Image to Patch Embedding
    """

    def __init__(self,
                 patch_size=7,
                 in_chans=3,
                 embed_dim=64,
                 stride=4,
                 padding=2,
                 norm_layer=None,
                 pre_norm=True):
        super().__init__()
        self.patch_size = patch_size

        self.proj = nn.Conv2d(in_chans,
                              embed_dim,
                              kernel_size=patch_size,
                              stride=stride,
                              padding=padding)

        dim_norm = in_chans if pre_norm else embed_dim
        self.norm = norm_layer(dim_norm) if norm_layer else None

        self.pre_norm = pre_norm

    def forward(self, x, size):
        H, W = size
        if len(x.size()) == 3:
            if self.norm and self.pre_norm:
                x = self.norm(x)
            x = rearrange(x, 'b (h w) c -> b c h w', h=H, w=W)

        x = self.proj(x)

        _, _, H, W = x.shape
        x = rearrange(x, 'b c h w -> b (h w) c')
        if self.norm and not self.pre_norm:
            x = self.norm(x)

        return x, (H, W)


class ChannelAttention(nn.Module):

    def __init__(self, dim, groups=8, qkv_bias=True):
        super().__init__()

        self.groups = groups
        self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
        self.proj = nn.Linear(dim, dim)

    def forward(self, x, size):
        B, N, C = x.shape

        qkv = self.qkv(x).reshape(B, N, 3, self.groups,
                                  C // self.groups).permute(2, 0, 3, 1, 4)
        q, k, v = qkv[0], qkv[1], qkv[2]

        q = q * (float(N)**-0.5)
        attention = q.transpose(-1, -2) @ k
        attention = attention.softmax(dim=-1)
        x = (attention @ v.transpose(-1, -2)).transpose(-1, -2)
        x = x.transpose(1, 2).reshape(B, N, C)
        x = self.proj(x)
        return x, size


class ChannelBlock(nn.Module):

    def __init__(self,
                 dim,
                 groups,
                 mlp_ratio=4.,
                 qkv_bias=True,
                 drop_path_rate=0.,
                 act_layer=nn.GELU,
                 norm_layer=nn.LayerNorm,
                 conv_at_attn=True,
                 conv_at_ffn=True):
        super().__init__()

        self.conv1 = PreNorm(None, DepthWiseConv2d(
            dim, 3, 1, 1)) if conv_at_attn else None
        self.channel_attn = PreNorm(
            norm_layer(dim),
            ChannelAttention(dim, groups=groups, qkv_bias=qkv_bias),
        )
        self.conv2 = PreNorm(None, DepthWiseConv2d(dim, 3, 1,
                                                   1)) if conv_at_ffn else None
        self.ffn = PreNorm(
            norm_layer(dim),
            Mlp(in_features=dim,
                hidden_features=int(dim * mlp_ratio),
                act_layer=act_layer),
        )

    def forward(self, x, size):
        if self.conv1:
            x, size = self.conv1(x, size)
        x, size = self.channel_attn(x, size)

        if self.conv2:
            x, size = self.conv2(x, size)
        x, size = self.ffn(x, size)

        return x, size


def window_partition(x, window_size: int):
    B, H, W, C = x.shape
    x = x.view(B, H // window_size, window_size, W // window_size, window_size,
               C)
    windows = x.permute(0, 1, 3, 2, 4,
                        5).contiguous().view(-1, window_size, window_size, C)
    return windows


def window_reverse(windows, batch_size: int, window_size: int, H: int, W: int):
    B = batch_size

    x = windows.view(B, H // window_size, W // window_size, window_size,
                     window_size, -1)
    x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, H, W, -1)
    return x


class WindowAttention(nn.Module):

    def __init__(self, dim, num_heads, window_size, qkv_bias=True):

        super().__init__()
        self.dim = dim
        self.window_size = window_size
        self.num_heads = num_heads
        head_dim = dim // num_heads
        self.scale = float(head_dim)**-0.5

        self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
        self.proj = nn.Linear(dim, dim)

        self.softmax = nn.Softmax(dim=-1)

    def forward(self, x, size):

        H, W = size
        B, L, C = x.shape
        assert L == H * W, "input feature has wrong size"

        x = x.view(B, H, W, C)

        pad_l = pad_t = 0
        pad_r = (self.window_size - W % self.window_size) % self.window_size
        pad_b = (self.window_size - H % self.window_size) % self.window_size
        x = F.pad(x, (0, 0, pad_l, pad_r, pad_t, pad_b))
        _, Hp, Wp, _ = x.shape

        x = window_partition(x, self.window_size)
        x = x.view(-1, self.window_size * self.window_size, C)

        # W-MSA/SW-MSA
        # attn_windows = self.attn(x_windows)

        B_, N, C = x.shape
        qkv = self.qkv(x).reshape(B_, N, 3, self.num_heads,
                                  C // self.num_heads).permute(2, 0, 3, 1, 4)
        q, k, v = qkv[0], qkv[1], qkv[2]

        q = q * self.scale
        attn = (q @ k.transpose(-2, -1))
        attn = self.softmax(attn)

        x = (attn @ v).transpose(1, 2).reshape(B_, N, C)
        x = self.proj(x)

        # merge windows
        x = x.view(-1, self.window_size, self.window_size, C)
        x = window_reverse(x, B, self.window_size, Hp, Wp)

        if pad_r > 0 or pad_b > 0:
            x = x[:, :H, :W, :].contiguous()

        x = x.view(B, H * W, C)

        return x, size


class SpatialBlock(nn.Module):

    def __init__(self,
                 dim,
                 num_heads,
                 window_size,
                 mlp_ratio=4.,
                 qkv_bias=True,
                 drop_path_rate=0.,
                 act_layer=nn.GELU,
                 norm_layer=nn.LayerNorm,
                 conv_at_attn=True,
                 conv_at_ffn=True):
        super().__init__()

        self.conv1 = PreNorm(None, DepthWiseConv2d(
            dim, 3, 1, 1)) if conv_at_attn else None
        self.window_attn = PreNorm(
            norm_layer(dim),
            WindowAttention(dim, num_heads, window_size, qkv_bias=qkv_bias),
        )
        self.conv2 = PreNorm(None, DepthWiseConv2d(dim, 3, 1,
                                                   1)) if conv_at_ffn else None
        self.ffn = PreNorm(
            norm_layer(dim),
            Mlp(in_features=dim,
                hidden_features=int(dim * mlp_ratio),
                act_layer=act_layer),
        )

    def forward(self, x, size):
        if self.conv1:
            x, size = self.conv1(x, size)
        x, size = self.window_attn(x, size)

        if self.conv2:
            x, size = self.conv2(x, size)
        x, size = self.ffn(x, size)
        return x, size


class DaViT(nn.Module):

    def __init__(
        self,
        in_chans=3,
        num_classes=1000,
        depths=(1, 1, 3, 1),
        patch_size=(7, 2, 2, 2),
        patch_stride=(4, 2, 2, 2),
        patch_padding=(3, 0, 0, 0),
        patch_prenorm=(False, False, False, False),
        embed_dims=(64, 128, 192, 256),
        num_heads=(3, 6, 12, 24),
        num_groups=(3, 6, 12, 24),
        window_size=7,
        mlp_ratio=4.,
        qkv_bias=True,
        drop_path_rate=0.1,
        norm_layer=nn.LayerNorm,
        enable_checkpoint=False,
        conv_at_attn=True,
        conv_at_ffn=True,
    ):
        super().__init__()

        self.num_classes = num_classes
        self.embed_dims = embed_dims
        self.num_heads = num_heads
        self.num_groups = num_groups
        self.num_stages = len(self.embed_dims)
        self.enable_checkpoint = enable_checkpoint
        assert self.num_stages == len(self.num_heads) == len(self.num_groups)

        num_stages = len(embed_dims)
        dpr = [
            x.item() for x in torch.linspace(0, drop_path_rate,
                                             sum(depths) * 2)
        ]

        depth_offset = 0
        convs = []
        blocks = []
        for i in range(num_stages):
            conv_embed = ConvEmbed(
                patch_size=patch_size[i],
                stride=patch_stride[i],
                padding=patch_padding[i],
                in_chans=in_chans if i == 0 else self.embed_dims[i - 1],
                embed_dim=self.embed_dims[i],
                norm_layer=norm_layer,
                pre_norm=patch_prenorm[i])
            convs.append(conv_embed)

            block = MySequential(*[
                MySequential(
                    OrderedDict([('spatial_block',
                                  SpatialBlock(
                                      embed_dims[i],
                                      num_heads[i],
                                      window_size,
                                      drop_path_rate=dpr[depth_offset + j * 2],
                                      qkv_bias=qkv_bias,
                                      mlp_ratio=mlp_ratio,
                                      conv_at_attn=conv_at_attn,
                                      conv_at_ffn=conv_at_ffn,
                                  )),
                                 ('channel_block',
                                  ChannelBlock(
                                      embed_dims[i],
                                      num_groups[i],
                                      drop_path_rate=dpr[depth_offset + j * 2 +
                                                         1],
                                      qkv_bias=qkv_bias,
                                      mlp_ratio=mlp_ratio,
                                      conv_at_attn=conv_at_attn,
                                      conv_at_ffn=conv_at_ffn,
                                  ))])) for j in range(depths[i])
            ])
            blocks.append(block)
            depth_offset += depths[i] * 2

        self.convs = nn.ModuleList(convs)
        self.blocks = nn.ModuleList(blocks)

        self.avgpool = nn.AdaptiveAvgPool1d(1)

    @property
    def dim_out(self):
        return self.embed_dims[-1]

    def forward_features_unpool(self, x):
        """
        forward until avg pooling 
        Args:
            x (_type_): input image tensor
        """
        input_size = (x.size(2), x.size(3))
        for conv, block in zip(self.convs, self.blocks):
            x, input_size = conv(x, input_size)
            x, input_size = block(x, input_size)
        return x

    def forward_features(self, x):
        x = self.forward_features_unpool(x)

        # (batch_size, num_tokens, token_dim)
        x = self.avgpool(x.transpose(1, 2))
        # (batch_size, 1, num_tokens)
        x = torch.flatten(x, 1)
        x = self.norms(x)

        return x

    def forward(self, x):
        x = self.forward_features(x)
        x = self.head(x)
        return x

    @classmethod
    def from_config(cls, config):
        return cls(
            depths=config.depths,
            embed_dims=config.dim_embed,
            num_heads=config.num_heads,
            num_groups=config.num_groups,
            patch_size=config.patch_size,
            patch_stride=config.patch_stride,
            patch_padding=config.patch_padding,
            patch_prenorm=config.patch_prenorm,
            drop_path_rate=config.drop_path_rate,
            window_size=config.window_size,
        )


# Language backbone and processor implementation
class Florence2LanguageModel(nn.Module):

    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
        super().__init__()

        config = vllm_config.model_config.hf_config
        cache_config = vllm_config.cache_config
        quant_config = vllm_config.quant_config

        self.config = config

        self.vocab_size = config.vocab_size

        self.shared = BartScaledWordEmbedding(self.vocab_size, config.d_model)
        self.encoder = BartEncoder(config,
                                   cache_config=cache_config,
                                   quant_config=quant_config,
                                   prefix=f"{prefix}.encoder")
        self.decoder = BartDecoder(config,
                                   cache_config=cache_config,
                                   quant_config=quant_config,
                                   prefix=f"{prefix}.decoder")

        if self.config.tie_word_embeddings:
            self.encoder.embed_tokens.weight = self.shared.weight
            self.decoder.embed_tokens.weight = self.shared.weight

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        encoder_input_ids: torch.Tensor,
        encoder_positions: torch.Tensor,
        inputs_embeds: Optional[torch.Tensor] = None,
    ) -> torch.Tensor:
        r"""
        Args:
            input_ids
                Indices of *decoder* input sequence tokens in the vocabulary.
                Padding will be ignored by default should you
                provide it.
            positions
                Positions of *decoder* input sequence tokens.
            encoder_input_ids
                Indices of *encoder* input sequence tokens in the vocabulary.
            encoder_positions:
                Positions of *encoder* input sequence tokens.
        Returns:
            Model output torch.Tensor
        """

        encoder_hidden_states = None

        if inputs_embeds is not None or encoder_input_ids.numel() > 0:
            # Run encoder attention if a non-zero number of encoder tokens
            # are provided as input
            encoder_hidden_states = self.encoder(input_ids=encoder_input_ids,
                                                 positions=encoder_positions,
                                                 inputs_embeds=inputs_embeds)

        # decoder outputs consists of
        # (dec_features, past_key_value, dec_hidden, dec_attn)
        decoder_outputs = self.decoder(
            decoder_input_ids=input_ids,
            decoder_positions=positions,
            encoder_hidden_states=encoder_hidden_states)

        return decoder_outputs


class Florence2LanguageForConditionalGeneration(nn.Module, SupportsV0Only):

    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
        super().__init__()

        config = vllm_config.model_config.hf_config

        self.config = config
        self.model = Florence2LanguageModel(vllm_config=vllm_config,
                                            prefix=f"{prefix}.model")
        embed_scale = math.sqrt(
            config.d_model) if config.scale_embedding else 1.0

        self.vocab_size = config.vocab_size
        self.lm_head = BartParallelLMHead(self.vocab_size,
                                          config.d_model,
                                          embed_scale=embed_scale)

        self.logits_processor = LogitsProcessor(self.vocab_size,
                                                config.vocab_size)
        self.sampler = get_sampler()

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        encoder_input_ids: torch.Tensor,
        encoder_positions: torch.Tensor,
        inputs_embeds: Optional[torch.Tensor] = None,
        **kwargs,
    ) -> torch.Tensor:
        r"""
        Args:
            input_ids
                torch.Tensor of *decoder* input token ids.
            positions
                torch.Tensor of *decoder* position indices.
            encoder_input_ids
                torch.Tensor of *encoder* input token ids.
            encoder_positions
                torch.Tensor of *encoder* position indices
        Returns:
            Output torch.Tensor
        """

        return self.model(input_ids,
                          positions,
                          encoder_input_ids,
                          encoder_positions,
                          inputs_embeds=inputs_embeds)

    def get_input_embeddings(self, input_ids: torch.Tensor) -> torch.Tensor:
        return self.model.encoder.embed_tokens(input_ids)

    def compute_logits(
        self,
        hidden_states: torch.Tensor,
        sampling_metadata: SamplingMetadata,
    ) -> Optional[torch.Tensor]:
        logits = self.logits_processor(self.lm_head, hidden_states,
                                       sampling_metadata)
        return logits

    def sample(self, logits: torch.Tensor,
               sampling_metadata: SamplingMetadata) -> SamplerOutput:
        next_tokens = self.sampler(logits, sampling_metadata)
        return next_tokens

    def load_weights(self, weights: Iterable[Tuple[str,
                                                   torch.Tensor]]) -> Set[str]:
        stacked_params_mapping = [
            # (param_name, shard_name, shard_id)
            ("qkv_proj", "q_proj", "q"),
            ("qkv_proj", "k_proj", "k"),
            ("qkv_proj", "v_proj", "v"),
        ]

        params_dict = dict(self.named_parameters())
        loaded_params: Set[str] = set()
        for name, loaded_weight in weights:
            for (param_name, weight_name, shard_id) in stacked_params_mapping:
                if weight_name not in name:
                    continue
                name = name.replace(weight_name, param_name)
                param = params_dict[name]
                weight_loader = param.weight_loader
                weight_loader(param, loaded_weight, shard_id)
                break
            else:
                if "final_logits_bias" in name:
                    continue
                if self.config.tie_word_embeddings and "embed_tokens" in name:
                    continue
                param = params_dict[name]
                weight_loader = getattr(param, "weight_loader",
                                        default_weight_loader)
                weight_loader(param, loaded_weight)
            loaded_params.add(name)
        return loaded_params


class Florence2ProcessingInfo(BaseProcessingInfo):

    def get_hf_config(self):
        return self.ctx.get_hf_config()

    def get_hf_processor(self):
        return self.ctx.get_hf_processor()

    def get_supported_mm_limits(self) -> Mapping[str, Optional[int]]:
        return {"image": 1}

    def get_num_image_tokens(self) -> int:
        processor_config = self.ctx.get_hf_image_processor_config()
        return processor_config["image_seq_length"]


class Florence2DummyInputsBuilder(
        BaseDummyInputsBuilder[Florence2ProcessingInfo]):

    def get_dummy_text(self, mm_counts: Mapping[str, int]) -> str:
        return ""

    def get_dummy_mm_data(
        self,
        seq_len: int,
        mm_counts: Mapping[str, int],
    ) -> MultiModalDataDict:
        num_images = mm_counts.get("image", 0)

        target_width = target_height = self.info.get_hf_config().projection_dim

        return {
            "image":
            self._get_dummy_images(width=target_width,
                                   height=target_height,
                                   num_images=num_images)
        }


class Florence2MultiModalProcessor(
        EncDecMultiModalProcessor[Florence2ProcessingInfo]):

    def _hf_processor_applies_updates(
        self,
        prompt_text: str,
        mm_items: MultiModalDataItems,
        hf_processor_mm_kwargs: Mapping[str, object],
    ) -> bool:
        return False

    def create_encoder_prompt(
        self,
        prompt: Union[str, list[int]],
        mm_data: MultiModalDataDict,
    ) -> Union[str, list[int]]:
        return prompt

    def create_decoder_prompt(
        self,
        prompt: Union[str, list[int]],
        mm_data: MultiModalDataDict,
    ) -> Union[str, list[int]]:
        return [self.info.get_hf_config().eos_token_id]

    def _apply_hf_processor_tokens_only(
        self,
        prompt_tokens: list[int],
    ) -> list[int]:
        hf_processor = self.info.get_hf_processor()
        tokenizer: BartTokenizer = hf_processor.tokenizer
        prompt_text = tokenizer.decode(prompt_tokens)
        # convert task tokens to prompt
        prompt_text = hf_processor._construct_prompts([prompt_text])[0]
        prompt_tokens = tokenizer.encode(prompt_text, add_special_tokens=False)
        return prompt_tokens

    def _call_hf_processor(
        self,
        prompt: str,
        mm_data: Mapping[str, object],
        mm_kwargs: Mapping[str, object],
    ) -> BatchFeature:
        if mm_data:
            processed_outputs = super()._call_hf_processor(
                prompt, mm_data, mm_kwargs)
        else:
            hf_processor = self.info.get_hf_processor()
            tokenizer = hf_processor.tokenizer
            prompt = hf_processor._construct_prompts([prompt])[0]
            processed_outputs = tokenizer(prompt,
                                          add_special_tokens=True,
                                          return_tensors="pt")
        return processed_outputs

    def _get_mm_fields_config(
        self,
        hf_inputs: BatchFeature,
        hf_processor_mm_kwargs: Mapping[str, object],
    ) -> Mapping[str, MultiModalFieldConfig]:
        return dict(pixel_values=MultiModalFieldConfig.batched("image"))

    def _get_prompt_updates(
        self,
        mm_items: MultiModalDataItems,
        hf_processor_mm_kwargs: Mapping[str, object],
        out_mm_kwargs: MultiModalKwargs,
    ) -> Sequence[PromptUpdate]:
        hf_config = self.info.get_hf_config()
        pad_token_id = hf_config.pad_token_id
        num_image_tokens = self.info.get_num_image_tokens()
        image_tokens = [pad_token_id] * num_image_tokens

        return [
            PromptInsertion(
                modality="image",
                target=PromptIndexTargets.start(),
                insertion=image_tokens,
            )
        ]


@MULTIMODAL_REGISTRY.register_processor(
    Florence2MultiModalProcessor,
    info=Florence2ProcessingInfo,
    dummy_inputs=Florence2DummyInputsBuilder)
class Florence2ForConditionalGeneration(nn.Module, SupportsMultiModal,
                                        SupportsV0Only):

    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
        super().__init__()
        config = vllm_config.model_config.hf_config
        processor_config = vllm_config.model_config.hf_image_processor_config

        self.config = config
        self.vision_config = config.vision_config
        self.processor_config = processor_config
        assert config.vision_config.model_type == 'davit', (
            'only DaViT is supported for now')
        self.vision_tower = DaViT.from_config(config=config.vision_config)
        self._build_image_projection_layers(config)
        self.language_model = Florence2LanguageForConditionalGeneration(
            vllm_config=vllm_config.with_hf_config(config.text_config),
            prefix=f"{prefix}.language_model",
        )
        self.pad_token_id = config.pad_token_id

    def _build_image_projection_layers(self, config: PretrainedConfig):
        image_dim_out = config.vision_config.dim_embed[-1]
        dim_projection = config.vision_config.projection_dim
        self.image_projection = nn.Parameter(
            torch.empty(image_dim_out, dim_projection))
        self.image_proj_norm = nn.LayerNorm(dim_projection)
        image_pos_embed_config = config.vision_config.image_pos_embed
        if image_pos_embed_config['type'] == 'learned_abs_2d':
            self.image_pos_embed = LearnedAbsolutePositionEmbedding2D(
                embedding_dim=image_dim_out,
                num_pos=image_pos_embed_config['max_pos_embeddings'])
        else:
            raise NotImplementedError("Florence2 only supports learned_abs_2d "
                                      "as image position embedding.")

        self.image_feature_source = config.vision_config.image_feature_source

        # temporal embedding
        visual_temporal_embedding_config = (
            self.vision_config.visual_temporal_embedding)
        if visual_temporal_embedding_config['type'] == 'COSINE':
            self.visual_temporal_embed = PositionalEmbeddingCosine1D(
                embed_dim=image_dim_out,
                max_seq_len=visual_temporal_embedding_config[
                    'max_temporal_embeddings'])
        else:
            raise NotImplementedError(
                'Florence2 only supports COSINE as temporal embedding.')

    @cached_property
    def sampler(self):
        if hasattr(self.language_model, "sampler"):
            return self.language_model.sampler
        return get_sampler()

    def _validate_pixel_values(
        self, data: Union[torch.Tensor, List[torch.Tensor]]
    ) -> Union[torch.Tensor, List[torch.Tensor]]:

        size = self.processor_config["size"]
        h, w = size["height"], size["width"]
        expected_dims = (3, h, w)

        def _validate_shape(d: torch.Tensor):
            actual_dims = tuple(d.shape)

            if actual_dims != expected_dims:
                expected_expr = tuple(*map(str, expected_dims))
                raise ValueError(
                    "The expected shape of pixel values per batch "
                    f"is {expected_expr}. You supplied {tuple(d.shape)}.")

        for d in data:
            _validate_shape(d)

        return data

    def _parse_and_validate_image_input(self, **kwargs: object):
        pixel_values: Optional[Union[List[List[torch.Tensor]],
                                     List[torch.Tensor],
                                     torch.Tensor]] = kwargs.pop(
                                         "pixel_values", None)
        image_embeds: Optional[Union[List[List[torch.Tensor]],
                                     List[torch.Tensor],
                                     torch.Tensor]] = kwargs.pop(
                                         "image_embeds", None)

        if pixel_values is None and image_embeds is None:
            return None

        if pixel_values is not None and image_embeds is not None:
            raise ValueError(
                "Both pixel values and image embeds are provided.")

        if pixel_values is not None:
            return Florence2ImagePixelInputs(
                type="pixel_values",
                data=self._validate_pixel_values(
                    flatten_bn(pixel_values, concat=True)),
            )

        if image_embeds is not None:
            raise NotImplementedError

        raise AssertionError("This line should be unreachable.")

    def _encode_image(self, pixel_values: torch.Tensor) -> torch.Tensor:
        dtype = next(self.vision_tower.parameters()).dtype
        pixel_values = pixel_values.to(dtype)

        batch_size, T = pixel_values.size(0), 1
        x = self.vision_tower.forward_features_unpool(pixel_values)
        if self.image_pos_embed is not None:
            x = x.view(batch_size * T, -1, x.shape[-1])
            num_tokens = x.shape[-2]
            h, w = int(num_tokens**0.5), int(num_tokens**0.5)
            assert h * w == num_tokens, (
                'only support square feature maps for now')
            x = x.view(batch_size * T, h, w, x.shape[-1])
            pos_embed = self.image_pos_embed(x)
            x = x + pos_embed
            x = x.view(batch_size, T * h * w, x.shape[-1])

        if self.visual_temporal_embed is not None:
            visual_temporal_embed = self.visual_temporal_embed(
                x.view(batch_size, T, -1, x.shape[-1])[:, :, 0])
            x = x.view(batch_size, T, -1,
                       x.shape[-1]) + visual_temporal_embed.view(
                           1, T, 1, x.shape[-1])

        x_feat_dict = {}

        spatial_avg_pool_x = x.view(batch_size, T, -1, x.shape[-1]).mean(dim=2)
        x_feat_dict['spatial_avg_pool'] = spatial_avg_pool_x

        temporal_avg_pool_x = x.view(batch_size, T, -1,
                                     x.shape[-1]).mean(dim=1)
        x_feat_dict['temporal_avg_pool'] = temporal_avg_pool_x

        x = x.view(batch_size, T, -1, x.shape[-1])[:, -1]
        x_feat_dict['last_frame'] = x

        new_x = []
        for _image_feature_source in self.image_feature_source:
            if _image_feature_source not in x_feat_dict:
                raise ValueError('invalid image feature source: {}'.format(
                    _image_feature_source))
            new_x.append(x_feat_dict[_image_feature_source])

        x = torch.cat(new_x, dim=1)

        x = x @ self.image_projection
        x = self.image_proj_norm(x)

        return x

    def _process_image_input(
            self, image_input: Florence2ImagePixelInputs) -> torch.Tensor:
        assert image_input["type"] == "pixel_values"
        pixel_values = image_input["data"]
        return self._encode_image(pixel_values)

    def get_language_model(self) -> torch.nn.Module:
        return self.language_model

    def get_multimodal_embeddings(
            self, **kwargs: object) -> Optional[MultiModalEmbeddings]:
        image_input = self._parse_and_validate_image_input(**kwargs)
        if image_input is None:
            return None
        vision_embeddings = self._process_image_input(image_input)
        return vision_embeddings

    def get_input_embeddings(
        self,
        input_ids: torch.Tensor,
        multimodal_embeddings: Optional[MultiModalEmbeddings] = None,
    ) -> torch.Tensor:
        inputs_embeds = self.language_model.get_input_embeddings(input_ids)
        if multimodal_embeddings is not None:
            inputs_embeds = merge_multimodal_embeddings(
                input_ids, inputs_embeds, multimodal_embeddings,
                self.pad_token_id)
        return inputs_embeds

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        intermediate_tensors: Optional[IntermediateTensors] = None,
        *,
        encoder_input_ids: torch.Tensor,
        encoder_positions: torch.Tensor,
        **kwargs,
    ) -> torch.Tensor:
        r"""
        Args:
            input_ids
                torch.Tensor of *decoder* input token ids.
            positions
                torch.Tensor of *decoder* position indices.
            encoder_input_ids
                torch.Tensor of *encoder* input token ids.
            encoder_positions
                torch.Tensor of *encoder* position indices
        Returns:
            Output torch.Tensor
        """
        vision_embeddings = self.get_multimodal_embeddings(**kwargs)
        if encoder_input_ids.numel() > 0 or vision_embeddings is not None:
            inputs_embeds = self.get_input_embeddings(encoder_input_ids,
                                                      vision_embeddings)
        else:
            inputs_embeds = None

        hidden_states = self.language_model(input_ids,
                                            positions,
                                            encoder_input_ids,
                                            encoder_positions,
                                            inputs_embeds=inputs_embeds)
        return hidden_states

    def compute_logits(
        self,
        hidden_states: torch.Tensor,
        sampling_metadata: SamplingMetadata,
    ) -> Optional[torch.Tensor]:
        return self.language_model.compute_logits(hidden_states,
                                                  sampling_metadata)

    def sample(
        self,
        logits: torch.Tensor,
        sampling_metadata: SamplingMetadata,
    ) -> SamplerOutput:
        return self.language_model.sample(logits, sampling_metadata)

    def load_weights(self, weights: Iterable[Tuple[str,
                                                   torch.Tensor]]) -> Set[str]:
        loader = AutoWeightsLoader(self)
        return loader.load_weights(weights)
