# coding=utf-8
# Copyright 2024 The HuggingFace Inc. team.
#
# 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
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"""
Processor class for Idefics3.
"""

import re
from itertools import accumulate
from typing import TYPE_CHECKING, Dict, List, Optional, Union

from ...feature_extraction_utils import BatchFeature
from ...image_utils import ImageInput, is_valid_image, load_image
from ...processing_utils import ImagesKwargs, ProcessingKwargs, ProcessorMixin, Unpack
from ...tokenization_utils_base import AddedToken, BatchEncoding, TextInput
from ...utils import logging


if TYPE_CHECKING:
    from ...tokenization_utils_base import PreTokenizedInput

logger = logging.get_logger(__name__)


def is_url(val) -> bool:
    return isinstance(val, str) and val.startswith("http")


def is_image_or_image_url(elem):
    return is_url(elem) or is_valid_image(elem)


def _prompt_split_image(image_seq_len, image_rows, image_cols, fake_token_around_image, image_token, global_img_token):
    """Prompt with expanded image tokens for when the image is split into patches."""
    text_split_images = ""
    for n_h in range(image_rows):
        for n_w in range(image_cols):
            text_split_images += (
                f"{fake_token_around_image}" + f"<row_{n_h + 1}_col_{n_w + 1}>" + f"{image_token}" * image_seq_len
            )
        text_split_images += "\n"

    text_split_images += (
        f"\n{fake_token_around_image}"
        + f"{global_img_token}"
        + f"{image_token}" * image_seq_len
        + f"{fake_token_around_image}"
    )
    return text_split_images


def _prompt_single_image(image_seq_len, fake_token_around_image, image_token, global_img_token):
    """Prompt with expanded image tokens for a single image."""
    return (
        f"{fake_token_around_image}"
        + f"{global_img_token}"
        + f"{image_token}" * image_seq_len
        + f"{fake_token_around_image}"
    )


def get_image_prompt_string(
    image_rows, image_cols, image_seq_len, fake_token_around_image, image_token, global_img_token
):
    if image_rows == 0 and image_cols == 0:
        return _prompt_single_image(
            image_seq_len,
            fake_token_around_image=fake_token_around_image,
            image_token=image_token,
            global_img_token=global_img_token,
        )
    return _prompt_split_image(
        image_seq_len, image_rows, image_cols, fake_token_around_image, image_token, global_img_token
    )


class Idefics3ImagesKwargs(ImagesKwargs, total=False):
    return_row_col_info: Optional[bool]
    max_image_size: Optional[Dict[str, int]]


class Idefics3ProcessorKwargs(ProcessingKwargs, total=False):
    images_kwargs: Idefics3ImagesKwargs

    _defaults = {
        "text_kwargs": {
            "add_special_tokens": True,
            "padding": False,
            "is_split_into_words": False,
        },
        "images_kwargs": {
            "return_row_col_info": True,
        },
    }


Idefics3ProcessorKwargs.__annotations__["images_kwargs"] = Idefics3ImagesKwargs  # python 3.8 compatibility


class Idefics3Processor(ProcessorMixin):
    r"""
    Constructs a Idefics3 processor which wraps a LLama tokenizer and Idefics3 image processor into a single processor.

    [`Idefics3Processor`] offers all the functionalities of [`Idefics3ImageProcessor`] and [`Idefics3TokenizerFast`]. See
    the docstring of [`~IdeficsProcessor.__call__`] and [`~IdeficsProcessor.decode`] for more information.

    Args:
        image_processor (`Idefics3ImageProcessor`):
            An instance of [`Idefics3ImageProcessor`]. The image processor is a required input.
        tokenizer (`PreTrainedTokenizerBase`, *optional*):
            An instance of [`PreTrainedTokenizerBase`]. This should correspond with the model's text model. The tokenizer is a required input.
        image_seq_len (`int`, *optional*, defaults to 169):
            The length of the image sequence i.e. the number of <image> tokens per image in the input.
            This parameter is used to build the string from the input prompt and image tokens and should match the
            value the model used. It is computed as: image_seq_len = int(((image_size // patch_size) ** 2) / (scale_factor**2))
        chat_template (`str`, *optional*): A Jinja template which will be used to convert lists of messages
            in a chat into a tokenizable string.
    """

    attributes = ["image_processor", "tokenizer"]
    valid_kwargs = ["image_seq_len", "chat_template"]
    image_processor_class = "Idefics3ImageProcessor"
    tokenizer_class = "AutoTokenizer"

    def __init__(self, image_processor, tokenizer=None, image_seq_len: int = 169, chat_template: str = None, **kwargs):
        if image_processor is None:
            raise ValueError("You need to specify an `image_processor`.")
        if tokenizer is None:
            raise ValueError("You need to specify a `tokenizer`.")

        self.fake_image_token = AddedToken("<fake_token_around_image>", normalized=False, special=True)
        self.image_token = AddedToken("<image>", normalized=False, special=True)
        self.end_of_utterance_token = AddedToken("<end_of_utterance>", normalized=False, special=True)
        self.global_image_tag = "<global-img>"  # https://github.com/huggingface/transformers/pull/32473/files/8063e5e17362571b693f1db95167f5443a3be1b2#r1734825341
        self.image_seq_len = image_seq_len

        # This regex matches one or more occurrences of <global-img> tags (optionally surrounded by newline characters)
        # or <row_x_col_y> tags (where x and y are digits, also optionally surrounded by newline characters).
        self._regex_to_remove_extra_special_tokens = re.compile(r"(\n?<global-img>\n?|<row_\d+_col_\d+>\n?)+")

        tokens_to_add = {
            "additional_special_tokens": [
                self.fake_image_token,
                self.image_token,
                self.end_of_utterance_token,
            ]
        }
        tokenizer.add_special_tokens(tokens_to_add)

        super().__init__(image_processor, tokenizer, chat_template=chat_template, **kwargs)

    def _extract_images_from_prompts(self, prompts):
        prompt_images = []
        for prompt in prompts:
            images = []
            for elem in prompt:
                if is_valid_image(elem):
                    images.append(elem)
                elif is_url(elem):
                    images.append(load_image(elem))
            prompt_images.append(images)
        return prompt_images

    def __call__(
        self,
        images: Union[ImageInput, List[ImageInput], List[List[ImageInput]]] = None,
        text: Union[TextInput, "PreTokenizedInput", List[TextInput], List["PreTokenizedInput"]] = None,
        audio=None,
        videos=None,
        image_seq_len: Optional[int] = None,
        **kwargs: Unpack[Idefics3ProcessorKwargs],
    ) -> BatchEncoding:
        """
        Processes the input prompts and returns a BatchEncoding.

        Example:

        ```python
        >>> import requests
        >>> from my_transformers import Idefics3Processor
        >>> from my_transformers.image_utils import load_image

        >>> processor = Idefics3Processor.from_pretrained("HuggingFaceM4/Idefics3-8B-Llama3")
        >>> processor.image_processor.do_image_splitting = False  # Force as False to simplify the example

        >>> url1 = "https://cdn.britannica.com/61/93061-050-99147DCE/Statue-of-Liberty-Island-New-York-Bay.jpg"
        >>> url2 = "https://cdn.britannica.com/59/94459-050-DBA42467/Skyline-Chicago.jpg"

        >>> image1, image2 = load_image(url1), load_image(url2)
        >>> images = [[image1], [image2]]

        >>> text = [
        ...     "<image>In this image, we see",
        ...     "bla bla bla<image>",
        ... ]
        >>> outputs = processor(images=images, text=text, return_tensors="pt", padding=True)
        >>> input_ids = outputs.input_ids
        >>> input_tokens = processor.tokenizer.batch_decode(input_ids)
        >>> print(input_tokens)
        ['<|begin_of_text|><fake_token_around_image><global-img>((<image>)*169)<fake_token_around_image> In this image, we see', '<|reserved_special_token_0|><|reserved_special_token_0|><|reserved_special_token_0|><|begin_of_text|>bla bla bla<fake_token_around_image><global-img>((<image>)*169)<fake_token_around_image>']
        ```

        Args:
            images (`PIL.Image.Image`, `np.ndarray`, `torch.Tensor`, `List[PIL.Image.Image]`, `List[np.ndarray]`, `List[torch.Tensor]`, *optional*):
                The image or batch of images to be prepared. Each image can be a PIL image, NumPy array or PyTorch
                tensor. If is of type `List[ImageInput]`, it's assumed that this is for a single prompt i.e. of batch size 1.
            text (`Union[TextInput, PreTokenizedInput, List[TextInput], List[PreTokenizedInput]]`, *optional*):
                The sequence or batch of sequences to be encoded. Each sequence can be a string or a list of strings
                (pretokenized string). If the sequences are provided as list of strings (pretokenized), you must set
                `is_split_into_words=True` (to lift the ambiguity with a batch of sequences).
                Wherever an image token, `<image>` is encountered it is expanded to
                `<fake_token_around_image>` + `<row_x_col_y>` + `<image>` * `image_seq_len` * <fake_token_around_image>`.
            image_seq_len (`int`, *optional*):
                The length of the image sequence. If not provided, the default value of self.image_seq_len is used.
                image_seq_len should be equal to int(((image_size // patch_size) ** 2) / (scale_factor**2))
            return_tensors (`Union[str, TensorType]`, *optional*):
                If set, will return tensors of a particular framework. See [`PreTrainedTokenizerFast.__call__`] for more
                information.
        """
        if text is None and images is None:
            raise ValueError("You must provide either `text` or `images`.")

        output_kwargs = self._merge_kwargs(
            Idefics3ProcessorKwargs,
            tokenizer_init_kwargs=self.tokenizer.init_kwargs,
            **kwargs,
        )

        image_seq_len = image_seq_len if image_seq_len is not None else self.image_seq_len

        n_images_in_text = []
        n_images_in_images = []
        inputs = BatchFeature()

        if text is not None:
            if isinstance(text, str):
                text = [text]
            elif not isinstance(text, list) and not isinstance(text[0], str):
                raise ValueError("Invalid input text. Please provide a string, or a list of strings")
            n_images_in_text = [sample.count(self.image_token.content) for sample in text]

        if images is not None:
            if is_image_or_image_url(images):
                images = [[images]]
            elif isinstance(images, (list, tuple)) and is_image_or_image_url(images[0]):
                if text is not None:
                    if sum(n_images_in_text) != len(images):
                        raise ValueError(
                            f"The total number of {self.image_token.content} tokens in the prompts should be the same as the number of images passed."
                            f" Found {sum(n_images_in_text)} {self.image_token.content} tokens and {len(images)} images."
                        )
                    # Reorganize the images to match the prompts
                    cumsum_images_in_text = [0] + list(accumulate(n_images_in_text))
                    images = [
                        images[cumsum_images_in_text[i] : cumsum_images_in_text[i + 1]]
                        for i in range(len(n_images_in_text))
                    ]
                else:
                    images = [images]
            elif (
                not isinstance(images, (list, tuple))
                and not isinstance(images[0], (list, tuple))
                and not is_image_or_image_url(images[0][0])
            ):
                raise ValueError(
                    "Invalid input images. Please provide a single image or a list of images or a list of list of images."
                )
            n_images_in_images = [len(sample) for sample in images]

            # Load images if they are URLs
            images = [[load_image(im) if is_url(im) else im for im in sample] for sample in images]

            image_inputs = self.image_processor(images, **output_kwargs["images_kwargs"])
            inputs.update(image_inputs)

            if text is not None:
                if n_images_in_images != n_images_in_text:
                    raise ValueError(
                        f"The number of images in the text {n_images_in_text} and images {n_images_in_images} should be the same."
                    )

                image_rows = inputs.pop("rows", [[0] * len(text)])
                image_cols = inputs.pop("cols", [[0] * len(text)])

                fake_image_token = self.fake_image_token.content
                image_token = self.image_token.content
                global_img_token = self.global_image_tag

                prompt_strings = []
                for sample, sample_rows, sample_cols in zip(text, image_rows, image_cols):
                    # Replace the image token with fake tokens around the expanded image token sequence of length `image_seq_len`
                    image_prompt_strings = []
                    for n_rows, n_cols in zip(sample_rows, sample_cols):
                        image_prompt_string = get_image_prompt_string(
                            n_rows,
                            n_cols,
                            image_seq_len,
                            image_token=image_token,
                            fake_token_around_image=fake_image_token,
                            global_img_token=global_img_token,
                        )
                        image_prompt_strings.append(image_prompt_string)

                    split_sample = sample.split(image_token)
                    if len(split_sample) == 0:
                        raise ValueError("The image token should be present in the text.")

                    # Place in the image prompt strings where the image tokens are
                    sample = split_sample[0]
                    for i, image_prompt_string in enumerate(image_prompt_strings):
                        sample += image_prompt_string + split_sample[i + 1]
                    prompt_strings.append(sample)

                text_inputs = self.tokenizer(text=prompt_strings, **output_kwargs["text_kwargs"])
                inputs.update(text_inputs)

        elif text is not None:
            if any(n_images_in_text):
                raise ValueError(
                    f"Found {sum(n_images_in_text)} {self.image_token.content} tokens in the text but no images were passed."
                )
            text_inputs = self.tokenizer(text=text, **output_kwargs["text_kwargs"])
            inputs.update(text_inputs)

        return inputs

    def batch_decode(self, *args, **kwargs):
        """
        This method forwards all its arguments to Idefics3TokenizerFast's [`~PreTrainedTokenizer.batch_decode`]. Please
        refer to the docstring of this method for more information.
        """
        batched_decode_output = self.tokenizer.batch_decode(*args, **kwargs)
        return [self._regex_to_remove_extra_special_tokens.sub("<image>", s) for s in batched_decode_output]

    def decode(self, *args, **kwargs):
        """
        This method forwards all its arguments to Idefics3TokenizerFast's [`~PreTrainedTokenizer.decode`]. Please refer to
        the docstring of this method for more information.
        """
        decode_output = self.tokenizer.decode(*args, **kwargs)
        return self._regex_to_remove_extra_special_tokens.sub("<image>", decode_output)

    @property
    def model_input_names(self):
        tokenizer_input_names = self.tokenizer.model_input_names
        image_processor_input_names = self.image_processor.model_input_names
        return list(dict.fromkeys(image_processor_input_names + tokenizer_input_names))


__all__ = ["Idefics3Processor"]
