# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# Adapted from https://github.com/huggingface/transformers/tree/main/src/transformers/models/aya_vision
from collections.abc import Iterable, Mapping, Sequence
from typing import Annotated, Literal, Optional, Union, cast

import torch
from torch import nn
from transformers import BatchFeature, GotOcr2ImageProcessor
from transformers.activations import ACT2FN
from transformers.image_processing_utils import get_size_dict
from transformers.models.aya_vision import AyaVisionConfig
from transformers.models.aya_vision.processing_aya_vision import (
    AyaVisionProcessor)
from transformers.models.got_ocr2.image_processing_got_ocr2 import (
    get_optimal_tiled_canvas)

from vllm.config import VllmConfig
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.multimodal import MULTIMODAL_REGISTRY
from vllm.multimodal.inputs import MultiModalDataDict, MultiModalKwargsItems
from vllm.multimodal.parse import (ImageProcessorItems, ImageSize,
                                   MultiModalDataItems)
from vllm.multimodal.processing import (BaseMultiModalProcessor,
                                        BaseProcessingInfo,
                                        MultiModalFieldConfig,
                                        PromptReplacement, PromptUpdate,
                                        PromptUpdateDetails)
from vllm.multimodal.profiling import BaseDummyInputsBuilder
from vllm.sequence import IntermediateTensors
from vllm.utils.jsontree import json_map_leaves
from vllm.utils.tensor_schema import TensorSchema, TensorShape

from .interfaces import MultiModalEmbeddings, SupportsMultiModal, SupportsPP
from .siglip import SiglipVisionModel
from .utils import (AutoWeightsLoader, WeightsMapper, flatten_bn,
                    init_vllm_registered_model, maybe_prefix,
                    merge_multimodal_embeddings)


class AyaVisionImagePixelInputs(TensorSchema):
    """
    Dimensions:
        - np: The total number of patches over each image over each prompt in
              the batch
        - c: Number of channels
        - h: Height of each image patch
        - w: Width of each image patch
        - bn: Batch size * number of images
    """

    type: Literal["pixel_values"]

    pixel_values: Annotated[
        torch.Tensor,
        TensorShape("np", 3, "h", "w"),
    ]

    num_patches: Annotated[
        torch.Tensor,
        TensorShape("bn"),
    ]


class AyaVisionMultiModalProjector(nn.Module):

    def __init__(self, config: AyaVisionConfig):
        super().__init__()
        self.config = config
        self.downsample_factor = config.downsample_factor
        self.alignment_intermediate_size = getattr(
            config, "alignment_intermediate_size",
            config.text_config.hidden_size)
        self.layernorm = nn.LayerNorm(config.vision_config.hidden_size *
                                      (config.downsample_factor**2),
                                      eps=config.adapter_layer_norm_eps)

        self.linear_1 = nn.Linear(
            config.vision_config.hidden_size * (config.downsample_factor**2),
            self.alignment_intermediate_size,
            bias=True,
        )

        self.act = ACT2FN["silu"]  # SwiGLU uses SiLU activation
        # For SwiGLU, project down to half size since we split intermediate dim
        self.linear_2 = nn.Linear(self.alignment_intermediate_size // 2,
                                  config.text_config.hidden_size,
                                  bias=True)

    def forward(self, image_features: torch.Tensor) -> torch.Tensor:
        image_features = self.pixel_shuffle(image_features)
        image_features = self.layernorm(image_features)
        hidden_states = self.linear_1(image_features)

        # Split along last dimension and apply SwiGLU
        x, gate = hidden_states.chunk(2, dim=-1)
        hidden_states = self.act(gate) * x

        hidden_states = self.linear_2(hidden_states)
        return hidden_states

    def pixel_shuffle(self,
                      image_features: torch.Tensor) -> torch.Tensor:  # B, S, D
        batch_size, seq_length, _ = image_features.shape
        height = width = int(seq_length**0.5)
        image_features = image_features.reshape(image_features.shape[0], width,
                                                height, -1)
        channels = image_features.shape[-1]
        image_features = image_features.reshape(
            batch_size, width, int(height / self.downsample_factor),
            int(channels * self.downsample_factor))
        image_features = image_features.permute(0, 2, 1, 3)
        image_features = image_features.reshape(
            batch_size, int(height / self.downsample_factor),
            int(width / self.downsample_factor), -1)
        image_features = image_features.permute(0, 2, 1, 3)
        return image_features


class AyaVisionProcessingInfo(BaseProcessingInfo):

    def get_hf_config(self) -> AyaVisionConfig:
        return self.ctx.get_hf_config(AyaVisionConfig)

    def get_hf_processor(self, **kwargs: object) -> AyaVisionProcessor:
        return self.ctx.get_hf_processor(AyaVisionProcessor, **kwargs)

    def get_image_processor(self, **kwargs: object) -> GotOcr2ImageProcessor:
        return self.get_hf_processor(**kwargs).image_processor

    def get_supported_mm_limits(self) -> Mapping[str, Optional[int]]:
        return {"image": None}

    def get_image_size_with_most_features(self) -> ImageSize:
        image_processor = self.get_image_processor()
        height = image_processor.size['height']
        width = image_processor.size['width']
        max_patches = image_processor.max_patches
        return ImageSize(height=height * max_patches,
                         width=width * max_patches)

    def get_num_patches(self, *, image_width: int, image_height: int,
                        size: dict, min_patches: int, max_patches: int) -> int:
        """
        Calculate the number of patches needed for a given image based on size
        constraints.  This method replicates and adjusts the logic from:
        transformers/models/got_ocr2/image_processing_got_ocr2
        """
        size = get_size_dict(size, default_to_square=False)
        num_columns, num_rows = get_optimal_tiled_canvas(
            (image_height, image_width), (size["height"], size["width"]),
            min_patches, max_patches)
        num_blocks = num_columns * num_rows
        return num_blocks if num_blocks == 1 else num_blocks + 1


class AyaVisionDummyInputsBuilder(
        BaseDummyInputsBuilder[AyaVisionProcessingInfo]):

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

        processor = self.info.get_hf_processor()
        image_token = processor.image_token

        return image_token * num_images

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

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


class AyaVisionMultiModalProcessor(
        BaseMultiModalProcessor[AyaVisionProcessingInfo]):

    def _call_hf_processor(
        self,
        prompt: str,
        mm_data: Mapping[str, object],
        mm_kwargs: Mapping[str, object],
        tok_kwargs: Mapping[str, object],
    ) -> BatchFeature:
        processed_outputs = super()._call_hf_processor(
            prompt,
            mm_data,
            mm_kwargs,
            tok_kwargs,
        )
        hf_processor = self.info.get_hf_processor(**mm_kwargs)
        image_processor = hf_processor.image_processor

        # HF processor pops the `num_patches` kwarg, which is needed by vLLM
        if (images := mm_data.get("images")) is not None:
            parsed_images = (self._get_data_parser().parse_mm_data({
                "image":
                images
            }).get_items("image", ImageProcessorItems))
            image_sizes = [
                parsed_images.get_image_size(i)
                for i in range(len(parsed_images))
            ]

            num_patches = [
                self.info.get_num_patches(
                    image_width=image_size.width,
                    image_height=image_size.height,
                    size=image_processor.size,
                    min_patches=image_processor.min_patches,
                    max_patches=image_processor.max_patches)
                for image_size in image_sizes
            ]
            processed_outputs["num_patches"] = torch.tensor(num_patches)

        return processed_outputs

    def _get_mm_fields_config(
        self,
        hf_inputs: BatchFeature,
        hf_processor_mm_kwargs: Mapping[str, object],
    ) -> Mapping[str, MultiModalFieldConfig]:
        num_patches = hf_inputs.get("num_patches", torch.empty(0))
        return dict(
            pixel_values=MultiModalFieldConfig.flat_from_sizes(
                "image", num_patches),
            num_patches=MultiModalFieldConfig.batched("image"),
            image_embeds=MultiModalFieldConfig.batched("image"),
        )

    def _get_prompt_updates(
        self,
        mm_items: MultiModalDataItems,
        hf_processor_mm_kwargs: Mapping[str, object],
        out_mm_kwargs: MultiModalKwargsItems,
    ) -> Sequence[PromptUpdate]:
        hf_processor = self.info.get_hf_processor(**hf_processor_mm_kwargs)
        image_token = hf_processor.image_token
        img_patch_token = hf_processor.img_patch_token
        image_processor = hf_processor.image_processor

        def get_replacement(item_idx: int):
            images = mm_items.get_items("image", ImageProcessorItems)
            image_size: ImageSize = images.get_image_size(item_idx)
            num_patches = self.info.get_num_patches(
                image_width=image_size.width,
                image_height=image_size.height,
                size=image_processor.size,
                min_patches=image_processor.min_patches,
                max_patches=image_processor.max_patches,
            )
            repl = hf_processor._prompt_split_image(num_patches=num_patches)

            return PromptUpdateDetails.select_text(repl, img_patch_token)

        return [
            PromptReplacement(
                modality="image",
                target=image_token,
                replacement=get_replacement,
            )
        ]


def _get_num_hidden_layers(hf_config: AyaVisionConfig) -> int:
    feature_layers = hf_config.vision_feature_layer
    num_hidden_layers = hf_config.vision_config.num_hidden_layers
    # If we have one feature layer, initialize up to that layer
    if isinstance(feature_layers, int):
        return _get_layer_index(feature_layers, num_hidden_layers)
    # If we have multiple feature layers, initialize up to the deepest m
    elif isinstance(feature_layers, (list, tuple)):
        return max(
            _get_layer_index(idx, num_hidden_layers) for idx in feature_layers)
    raise TypeError(f"vision_layer_feature type: {type(feature_layers)}"
                    " is not supported")


def _get_layer_index(feature_layer_index: int, num_hidden_layers: int) -> int:
    if feature_layer_index < 0:
        return num_hidden_layers + feature_layer_index + 1
    return feature_layer_index


@MULTIMODAL_REGISTRY.register_processor(
    AyaVisionMultiModalProcessor,
    info=AyaVisionProcessingInfo,
    dummy_inputs=AyaVisionDummyInputsBuilder)
class AyaVisionForConditionalGeneration(nn.Module, SupportsMultiModal,
                                        SupportsPP):

    hf_to_vllm_mapper = WeightsMapper(
        orig_to_new_prefix={
            # mapping for new names in checkpoint saved after transformers v4.52
            "model.language_model.": "language_model.model.",
            "model.vision_tower.": "vision_tower.",
            "model.multi_modal_projector.": "multi_modal_projector.",
            "lm_head.": "language_model.lm_head.",
        })

    @classmethod
    def get_placeholder_str(cls, modality: str, i: int) -> Optional[str]:
        if modality.startswith("image"):
            return "<image>"

        raise ValueError("Only image modality is supported")

    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
        super().__init__()
        config: AyaVisionConfig = vllm_config.model_config.hf_config
        quant_config = vllm_config.quant_config
        multimodal_config = vllm_config.model_config.multimodal_config
        num_hidden_layers = _get_num_hidden_layers(config)
        self.config = config
        self.quant_config = quant_config
        self.multimodal_config = multimodal_config

        self.vision_tower = SiglipVisionModel(
            config.vision_config,
            quant_config,
            num_hidden_layers_override=num_hidden_layers,
            prefix=maybe_prefix(prefix, "vision_model"))
        self.vocab_size = config.text_config.vocab_size
        self.multi_modal_projector = AyaVisionMultiModalProjector(config)
        self.language_model = init_vllm_registered_model(
            vllm_config=vllm_config,
            hf_config=config.text_config,
            prefix=maybe_prefix(prefix, "model"),
            # Cohere2ForCausalLM and CohereForCausalLM are the same on vllm
            architectures=["Cohere2ForCausalLM"])

    @property
    def dtype(self):
        return next(self.parameters()).dtype

    def load_weights(self, weights: Iterable[tuple[str,
                                                   torch.Tensor]]) -> set[str]:
        loader = AutoWeightsLoader(self)
        return loader.load_weights(weights, mapper=self.hf_to_vllm_mapper)

    def _image_pixels_to_features(self, vision_tower: SiglipVisionModel,
                                  pixel_values: torch.Tensor,
                                  **kwargs) -> torch.Tensor:
        target_dtype = vision_tower.get_input_embeddings().weight.dtype
        image_features = vision_tower(pixel_values.to(dtype=target_dtype),
                                      **kwargs)

        def select_features(leaf: torch.Tensor):
            return self._select_image_features(
                leaf,
                strategy=self.config.vision_feature_select_strategy,
            )

        return cast(
            Union[torch.Tensor, tuple[torch.Tensor, ...]],
            json_map_leaves(select_features, image_features),
        )

    def _select_image_features(self, image_features: torch.Tensor, *,
                               strategy: str) -> torch.Tensor:
        if strategy == "default":
            return image_features[:, 1:]
        elif strategy == "full":
            return image_features

        raise ValueError(f"Unexpected select feature strategy: {strategy}")

    def _process_image_input(self, image_input: AyaVisionImagePixelInputs,
                             **kwargs) -> list[torch.Tensor]:
        assert self.vision_tower is not None
        pixel_values = image_input["pixel_values"]
        num_patches = image_input["num_patches"]
        image_features = self._image_pixels_to_features(
            self.vision_tower, pixel_values=pixel_values)
        image_embeds = self.multi_modal_projector(image_features)
        return [
            e.flatten(0, 2) for e in image_embeds.split(num_patches.tolist())
        ]

    def _parse_and_validate_image_input(
            self, **kwargs: object) -> Optional[AyaVisionImagePixelInputs]:
        pixel_values = kwargs.pop("pixel_values", None)
        num_patches = kwargs.pop("num_patches", None)
        image_embeds = kwargs.pop("image_embeds", None)
        assert image_embeds is None, "Aya Vision does not support image_embeds."

        if pixel_values is None:
            return None

        return AyaVisionImagePixelInputs(
            type="pixel_values",
            pixel_values=flatten_bn(pixel_values, concat=True),
            num_patches=flatten_bn(num_patches, concat=True),
            resolve_bindings={
                "h": self.config.vision_config.image_size,
                "w": self.config.vision_config.image_size,
            })

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

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

        return self._process_image_input(image_input, **kwargs)

    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 \
            and len(multimodal_embeddings) != 0:
            inputs_embeds = merge_multimodal_embeddings(
                input_ids=input_ids,
                inputs_embeds=inputs_embeds,
                multimodal_embeddings=multimodal_embeddings,
                placeholder_token_id=self.config.image_token_index,
            )

        return inputs_embeds

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        intermediate_tensors: Optional[IntermediateTensors] = None,
        inputs_embeds: Optional[torch.Tensor] = None,
        **kwargs: object,
    ) -> Union[torch.Tensor, IntermediateTensors]:
        if intermediate_tensors is not None:
            inputs_embeds = None

        # NOTE: In v1, inputs_embeds is always generated at model runner, this
        # condition is for v0 compatibility.
        elif inputs_embeds is None:
            vision_embeddings = self.get_multimodal_embeddings(**kwargs)
            inputs_embeds = self.get_input_embeddings(input_ids,
                                                      vision_embeddings)
            input_ids = None

        hidden_states = self.language_model.model(
            input_ids=input_ids,
            positions=positions,
            intermediate_tensors=intermediate_tensors,
            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)
