"""
From https://github.com/deepseek-ai/DeepSeek-VL2
"""

import math
from dataclasses import dataclass
from typing import Dict, List, Literal, Optional, Tuple

import mlx.core as mx
import mlx.nn as nn
import numpy as np
from PIL import Image, ImageOps
from transformers import LlamaTokenizerFast
from transformers.processing_utils import ProcessorMixin

from .conversation import get_conv_template


def find_closest_aspect_ratio(aspect_ratio, target_ratios, width, height, image_size):
    best_ratio_diff = float("inf")
    best_ratio = (1, 1)
    area = width * height
    for ratio in target_ratios:
        target_aspect_ratio = ratio[0] / ratio[1]
        ratio_diff = abs(aspect_ratio - target_aspect_ratio)
        if ratio_diff < best_ratio_diff:
            best_ratio_diff = ratio_diff
            best_ratio = ratio
        elif ratio_diff == best_ratio_diff:
            if area > 0.5 * image_size * image_size * ratio[0] * ratio[1]:
                best_ratio = ratio
    # print(f'width: {width}, height: {height}, best_ratio: {best_ratio}')
    return best_ratio


def dynamic_preprocess(
    image, min_num=2, max_num=9, image_size=640, use_thumbnail=False
):
    orig_width, orig_height = image.size
    aspect_ratio = orig_width / orig_height

    # calculate the existing image aspect ratio
    target_ratios = set(
        (i, j)
        for n in range(min_num, max_num + 1)
        for i in range(1, n + 1)
        for j in range(1, n + 1)
        if i * j <= max_num and i * j >= min_num
    )
    # print(target_ratios)
    target_ratios = sorted(target_ratios, key=lambda x: x[0] * x[1])

    # find the closest aspect ratio to the target
    target_aspect_ratio = find_closest_aspect_ratio(
        aspect_ratio, target_ratios, orig_width, orig_height, image_size
    )

    # print(target_aspect_ratio)
    # calculate the target width and height
    target_width = image_size * target_aspect_ratio[0]
    target_height = image_size * target_aspect_ratio[1]
    blocks = target_aspect_ratio[0] * target_aspect_ratio[1]

    # resize the image
    resized_img = image.resize((target_width, target_height))
    processed_images = []
    for i in range(blocks):
        box = (
            (i % (target_width // image_size)) * image_size,
            (i // (target_width // image_size)) * image_size,
            ((i % (target_width // image_size)) + 1) * image_size,
            ((i // (target_width // image_size)) + 1) * image_size,
        )
        # split the image
        split_img = resized_img.crop(box)
        processed_images.append(split_img)
    assert len(processed_images) == blocks
    if use_thumbnail and len(processed_images) != 1:
        thumbnail_img = image.resize((image_size, image_size))
        processed_images.append(thumbnail_img)
    return processed_images, target_aspect_ratio


class DictOutput(object):
    def keys(self):
        return self.__dict__.keys()

    def __getitem__(self, item):
        if isinstance(item, int):
            return list(self.__dict__.values())[item]
        if item not in self.__dict__:
            raise KeyError(item)
        return self.__dict__[item]

    def __setitem__(self, key, value):
        self.__dict__[key] = value


@dataclass
class VLChatProcessorOutput(DictOutput):
    sft_format: str
    input_ids: mx.array
    target_ids: mx.array
    images: mx.array
    images_seq_mask: mx.array
    images_spatial_crop: mx.array
    num_image_tokens: List[int]

    def __len__(self):
        return len(self.input_ids)


@dataclass
class BatchCollateOutput(DictOutput):
    sft_format: List[str]
    input_ids: mx.array
    labels: mx.array
    images: mx.array
    attention_mask: mx.array
    images_seq_mask: mx.array
    images_spatial_crop: mx.array
    seq_lens: List[int]


class ImageTransform:
    def __init__(
        self,
        mean: Optional[Tuple[float, float, float]] = (0.5, 0.5, 0.5),
        std: Optional[Tuple[float, float, float]] = (0.5, 0.5, 0.5),
        normalize: bool = True,
    ):
        self.mean = mean
        self.std = std
        self.normalize = normalize

    def __call__(self, pil_img: Image.Image):
        # Convert PIL image to numpy array and normalize

        img = mx.array(np.array(pil_img)) / 255.0

        # Transpose from HWC to CHW format
        img = mx.transpose(img, [2, 0, 1])

        if self.normalize:
            mean = mx.array(self.mean).reshape(-1, 1, 1)
            std = mx.array(self.std).reshape(-1, 1, 1)
            img = (img - mean) / std

        return img


class DeepseekVLV2Processor(ProcessorMixin):
    tokenizer_class = ("LlamaTokenizer", "LlamaTokenizerFast")
    attributes = ["tokenizer"]

    def __init__(
        self,
        tokenizer: LlamaTokenizerFast,
        candidate_resolutions: Tuple[Tuple[int, int]],
        patch_size: int,
        downsample_ratio: int,
        image_mean: Tuple[float, float, float] = (0.5, 0.5, 0.5),
        image_std: Tuple[float, float, float] = (0.5, 0.5, 0.5),
        normalize: bool = True,
        image_token: str = "<image>",
        pad_token: str = "<｜▁pad▁｜>",
        add_special_token: bool = False,
        sft_format: str = "deepseek",
        mask_prompt: bool = True,
        ignore_id: int = -100,
        **kwargs,
    ):
        self.candidate_resolutions = candidate_resolutions
        self.image_size = candidate_resolutions[0][0]
        self.patch_size = patch_size
        self.image_mean = image_mean
        self.image_std = image_std
        self.normalize = normalize
        self.downsample_ratio = downsample_ratio

        self.image_transform = ImageTransform(
            mean=image_mean, std=image_std, normalize=normalize
        )
        self.tokenizer = tokenizer
        self.tokenizer.padding_side = "left"

        # Add special tokens
        if tokenizer.pad_token is None:
            self.tokenizer.add_special_tokens({"pad_token": pad_token})
        print(
            f"Add pad token = ['{pad_token}'] to the tokenizer\n"
            f"{pad_token}:{tokenizer.encode(pad_token, add_special_tokens=False)[0]}"
        )

        image_token_id = self.tokenizer.vocab.get(image_token)
        if image_token_id is None:
            special_tokens = [image_token]
            special_tokens_dict = {"additional_special_tokens": special_tokens}
            self.tokenizer.add_special_tokens(special_tokens_dict)
        self.image_token_id = self.tokenizer.vocab.get(image_token)
        print(
            f"Add image token = ['{image_token}'] to the tokenizer\n"
            f"{image_token}:{tokenizer.encode(image_token, add_special_tokens=False)[0]}"
        )

        # Add grounding-related tokens
        special_tokens = ["<|ref|>", "<|/ref|>", "<|det|>", "<|/det|>", "<|grounding|>"]
        special_tokens_dict = {"additional_special_tokens": special_tokens}
        self.tokenizer.add_special_tokens(special_tokens_dict)
        print("Added grounding-related tokens")

        # Add chat tokens
        special_tokens = ["<|User|>", "<|Assistant|>"]
        special_tokens_dict = {"additional_special_tokens": special_tokens}
        self.tokenizer.add_special_tokens(special_tokens_dict)
        print("Added chat tokens")

        self.image_token = image_token
        self.pad_token = pad_token
        self.add_special_token = add_special_token
        self.sft_format = sft_format
        self.mask_prompt = mask_prompt
        self.ignore_id = ignore_id

        super().__init__(tokenizer, **kwargs)

        # Add chat template
        self.chat_template = kwargs.pop("chat_template", self.default_chat_template)

    @property
    def default_chat_template(self):
        return (
            "{% for message in messages %}"
            "{% if message['role'] == 'user' %}"
            "{% elif message['role'] == 'assistant' %}{% endif %}"
            "{{message['content']}} "
            "{% endfor %}"
            "{% if add_generation_prompt %}{% endif %}"
        )

    @property
    def bos_id(self):
        return self.tokenizer.bos_token_id

    @property
    def eos_id(self):
        return self.tokenizer.eos_token_id

    @property
    def pad_id(self):
        return self.tokenizer.pad_token_id

    def encode(self, text: str, bos: bool = True, eos: bool = False):
        t = self.tokenizer.encode(text, add_special_tokens=False)

        if bos:
            t = [self.bos_id] + t
        if eos:
            t = t + [self.eos_id]

        return t

    def decode(self, t: List[int], **kwargs) -> str:
        return self.tokenizer.decode(t, **kwargs)

    def process_one(
        self,
        prompt: str = None,
        images: List[Image.Image] = None,
        inference_mode: bool = True,
        base_size: int = 1024,
        image_size: int = 640,
        cropping: bool = True,
    ):

        sft_format = prompt
        (
            tokenized_str,
            images_list,
            images_seq_mask,
            images_spatial_crop,
            num_image_tokens,
        ) = self.tokenize_with_images(
            sft_format,
            images,
            base_size=base_size,
            image_size=image_size,
            cropping=cropping,
        )

        masked_tokenized_str = []
        for token_index in tokenized_str:
            if token_index != self.image_token_id:
                masked_tokenized_str.append(token_index)
            else:
                masked_tokenized_str.append(self.ignore_id)

        input_ids = mx.array(tokenized_str)
        target_ids = mx.array(masked_tokenized_str)
        images_seq_mask = mx.array(images_seq_mask)

        # Set ignored indices
        target_ids = mx.where(
            (input_ids < 0) | (input_ids == self.image_token_id),
            self.ignore_id,
            target_ids,
        )
        input_ids = mx.where(input_ids < 0, self.pad_id, input_ids)

        if inference_mode:
            input_ids = input_ids[:-1]
            target_ids = target_ids[:-1]
            images_seq_mask = images_seq_mask[:-1]

        return {
            "input_ids": input_ids[None, :],
            "attention_mask": input_ids != self.pad_id,
            "labels": target_ids,
            "images": images_list,
            "images_seq_mask": images_seq_mask[None, ...],
            "images_spatial_crop": images_spatial_crop,
            "num_image_tokens": num_image_tokens,
        }

    def pad_sequence(self, sequences, padding_value):
        # Get max length of sequences
        max_len = max(len(seq) for seq in sequences)

        # Pad each sequence to max length
        padded_seqs = []
        for seq in sequences:
            pad_length = max_len - len(seq)
            if pad_length > 0:
                padding = mx.full((pad_length,), padding_value)
                padded_seq = mx.concatenate([seq, padding])
            else:
                padded_seq = seq
            padded_seqs.append(padded_seq)

        return mx.stack(padded_seqs)

    def tokenize_with_images(
        self,
        conversation: str,
        images: List[Image.Image],
        base_size: int = 1024,
        image_size: int = 640,
        cropping: bool = True,
    ):

        patch_size = 16
        downsample_ratio = 4
        valid_img_tokens = 0
        ratio = 1

        image_draw = images[0].copy()

        w, h = image_draw.size

        ratio = 1 - ((max(w, h) - min(w, h)) / (max(w, h)))

        """Tokenize text with <image> tags."""
        assert conversation.count(self.image_token) == len(
            images
        ), f"The number of image tokens in the prompt does not match the number of images: {conversation.count(self.image_token)} != {len(images)}"
        text_splits = conversation.split(self.image_token)

        images_list, images_crop_list, images_seq_mask = [], [], []
        tokenized_str = []
        images_spatial_crop = []
        for text_sep, image in zip(text_splits, images):

            tokenized_sep = self.encode(text_sep, bos=False, eos=False)
            tokenized_str += tokenized_sep
            images_seq_mask += [False] * len(tokenized_sep)

            if cropping:

                if image.size[0] <= 640 and image.size[1] <= 640:
                    crop_ratio = [1, 1]

                else:
                    if cropping:
                        # best_width, best_height = select_best_resolution(image.size, self.candidate_resolutions)
                        images_crop_raw, crop_ratio = dynamic_preprocess(image)

                    else:
                        # best_width, best_height = self.image_size, self.image_size
                        crop_ratio = [1, 1]

                """process the global view"""
                # image = image.resize((base_size, base_size))
                global_view = ImageOps.pad(
                    image,
                    (base_size, base_size),
                    color=tuple(int(x * 255) for x in self.image_transform.mean),
                )

                if base_size == 1024:
                    valid_img_tokens += int(256 * ratio)
                elif base_size == 1280:
                    valid_img_tokens += int(400 * ratio)
                elif base_size == 640:
                    valid_img_tokens += int(100 * ratio)

                images_list.append(
                    self.image_transform(global_view).astype(mx.bfloat16)
                )

                width_crop_num, height_crop_num = crop_ratio

                images_spatial_crop.append([width_crop_num, height_crop_num])

                if width_crop_num > 1 or height_crop_num > 1:
                    """process the local views"""

                    for i in range(len(images_crop_raw)):
                        images_crop_list.append(
                            self.image_transform(images_crop_raw[i]).astype(mx.bfloat16)
                        )

                if image_size == 640:
                    valid_img_tokens += len(images_crop_list) * 100

                num_queries = math.ceil((image_size // patch_size) / downsample_ratio)
                num_queries_base = math.ceil(
                    (base_size // patch_size) / downsample_ratio
                )

                """add image tokens"""

                tokenized_image = (
                    [self.image_token_id] * num_queries_base + [self.image_token_id]
                ) * num_queries_base
                tokenized_image += [self.image_token_id]
                if width_crop_num > 1 or height_crop_num > 1:
                    tokenized_image += (
                        [self.image_token_id] * (num_queries * width_crop_num)
                        + [self.image_token_id]
                    ) * (num_queries * height_crop_num)
                tokenized_str += tokenized_image
                images_seq_mask += [True] * len(tokenized_image)

            else:

                """process the global view"""
                if image_size <= 640:
                    print("directly resize")
                    image = image.resize((image_size, image_size))

                global_view = ImageOps.pad(
                    image,
                    (image_size, image_size),
                    color=tuple(int(x * 255) for x in self.image_transform.mean),
                )
                images_list.append(
                    self.image_transform(global_view).astype(mx.bfloat16)
                )

                if base_size == 1024:
                    valid_img_tokens += int(256 * ratio)
                elif base_size == 1280:
                    valid_img_tokens += int(400 * ratio)
                elif base_size == 640:
                    valid_img_tokens += int(100 * 1)
                elif base_size == 512:
                    valid_img_tokens += int(64 * 1)

                width_crop_num, height_crop_num = 1, 1

                images_spatial_crop.append([width_crop_num, height_crop_num])

                """add image tokens"""
                num_queries = math.ceil((image_size // patch_size) / downsample_ratio)

                tokenized_image = (
                    [self.image_token_id] * num_queries + [self.image_token_id]
                ) * num_queries
                tokenized_image += [self.image_token_id]

                tokenized_str += tokenized_image
                images_seq_mask += [True] * len(tokenized_image)

        tokenized_sep = self.encode(text_splits[-1], bos=False, eos=False)
        tokenized_str += tokenized_sep
        images_seq_mask += [False] * len(tokenized_sep)

        """add the bos tokens"""
        bos_id = 0
        tokenized_str = [bos_id] + tokenized_str
        images_seq_mask = [False] + images_seq_mask

        images_seq_mask = mx.array(images_seq_mask)

        if len(images_list) == 0:
            images_ori = mx.zeros((1, 3, image_size, image_size))
            images_spatial_crop = mx.zeros((1, 2))
            images_crop = mx.zeros((1, 3, base_size, base_size))

        else:
            images_ori = mx.stack(images_list, axis=0)
            images_spatial_crop = mx.array(images_spatial_crop)
            if images_crop_list:
                images_crop = mx.stack(images_crop_list, axis=0)
            else:
                images_crop = mx.zeros((1, 3, base_size, base_size))

        assert len(tokenized_str) == len(
            images_seq_mask
        ), f"tokenize_with_images func: tokenized_str's length {len(tokenized_str)} is not equal to imags_seq_mask's length {len(images_seq_mask)}"

        return (
            tokenized_str,
            [images_crop, images_ori],
            images_seq_mask,
            images_spatial_crop,
            valid_img_tokens,
        )

    def __call__(
        self,
        *,
        text: str = None,
        images: List[Image.Image] = None,
        inference_mode: bool = True,
        image_size: int = 640,
        base_size: int = 1024,
        cropping: bool = True,
        padding: bool = True,
        return_tensors: Literal["np", "mx", "pt"] = "mx",
    ):
        """

        Args:
            text (str): the formatted prompt;
            images (List[ImageType]): the list of images;
            inference_mode (bool): if True, then remove the last eos token;

        Returns:
            outputs (BaseProcessorOutput): the output of the processor,
                - input_ids (mx.array): [N + image tokens]
                - images (mx.array): [n_images, 3, H, W]
                - image_id (int): the id of the image token
                - num_image_tokens (List[int]): the number of image tokens
        """

        prepare = self.process_one(
            prompt=text,
            images=images,
            inference_mode=inference_mode,
            image_size=image_size,
            base_size=base_size,
            cropping=cropping,
        )

        return prepare