"""
模型工作器执行模型。
复制并修改自 https://github.com/OpenGVLab/InternVL/blob/main/streamlit_demo/model_worker.py
"""
# 在导入transformers之前导入torch可能导致`segmentation fault`
from transformers import AutoModel, AutoTokenizer, TextIteratorStreamer, AutoConfig

import argparse
import base64
import json
import os
import decord
import threading
import time
from io import BytesIO
from threading import Thread
import math
import requests
import torch
import torchvision.transforms as T
from PIL import Image
from torchvision.transforms.functional import InterpolationMode
import numpy as np


IMAGENET_MEAN = (0.485, 0.456, 0.406)
IMAGENET_STD = (0.229, 0.224, 0.225)

SIGLIP_MEAN = (0.5, 0.5, 0.5)
SIGLIP_STD = (0.5, 0.5, 0.5)


def get_seq_frames(total_num_frames, desired_num_frames=-1, stride=-1):
    """
    计算从视频中提取的帧索引。

    参数:
    total_num_frames (int): 视频中的总帧数。
    desired_num_frames (int): 要提取的期望帧数。

    返回:
    list: 要提取的帧索引列表。
    """
    
    assert desired_num_frames > 0 or stride > 0 and not (desired_num_frames > 0 and stride > 0)

    if stride > 0:
        return list(range(0, total_num_frames, stride))
    
    # 计算从中提取帧的每个段的大小
    seg_size = float(total_num_frames - 1) / desired_num_frames

    seq = []
    for i in range(desired_num_frames):
        # 计算每个段的开始和结束索引
        start = int(np.round(seg_size * i))
        end = int(np.round(seg_size * (i + 1)))

        # 将段的中间索引添加到列表中
        seq.append((start + end) // 2)

    return seq

def build_video_prompt(meta_list, num_frames, time_position=False):
    # 如果time_position为True，则使用frame_timestamp。
    # 1. 传递time_position，2. 使用环境变量TIME_POSITION
    time_position = os.environ.get("TIME_POSITION", time_position)
    prefix = f"这是一个视频：\n"
    for i in range(num_frames):
        if time_position:
            frame_txt = f"第{i+1}帧采样于{meta_list[i]:.2f}秒：<image>\n"
        else:
            frame_txt = f"第{i+1}帧：<image>\n"
        prefix += frame_txt
    return prefix

def load_video(video_path, num_frames=64, frame_cache_root=None):
    if isinstance(video_path, str):
        video = decord.VideoReader(video_path)
    elif isinstance(video_path, dict):
        assert False, '我们不支持输入为"video_path"的视频'
    fps = video.get_avg_fps()
    sampled_frames = get_seq_frames(len(video), num_frames)
    samepld_timestamps = [i / fps for i in sampled_frames]
    frames = video.get_batch(sampled_frames).asnumpy()
    images = [Image.fromarray(frame) for frame in frames]
    
    return images, build_video_prompt(samepld_timestamps, len(images), time_position=True)

def load_image(image):
    if isinstance(image, str) and os.path.exists(image):
        return Image.open(image)
    elif isinstance(image, dict):
        if 'disk_path' in image:
            return Image.open(image['disk_path'])
        elif 'base64' in image:
            return Image.open(BytesIO(base64.b64decode(image['base64'])))
        elif 'url' in image:
            response = requests.get(image['url'])
            return Image.open(BytesIO(response.content))
        elif 'bytes' in image:
            return Image.open(BytesIO(image['bytes']))
        else:
            raise ValueError(f'无效的图像：{image}')
    else:
        raise ValueError(f'无效的图像：{image}')

def build_transform(input_size, norm_type='imagenet'):
    if norm_type == 'imagenet':
        MEAN, STD = IMAGENET_MEAN, IMAGENET_STD
    elif norm_type == 'siglip':
        MEAN, STD = SIGLIP_MEAN, SIGLIP_STD
        
    transform = T.Compose([
        T.Lambda(lambda img: img.convert('RGB') if img.mode != 'RGB' else img),
        T.Resize((input_size, input_size), interpolation=InterpolationMode.BICUBIC),
        T.ToTensor(),
        T.Normalize(mean=MEAN, std=STD)
    ])
    return transform


def find_closest_aspect_ratio(aspect_ratio, target_ratios, width, height, image_size):
    """
    之前的版本主要关注比例。
    我们在这里也考虑面积比例。
    """
    best_factor = 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)
        area_ratio = (ratio[0]*ratio[1]*image_size*image_size)/ area
        """
        新面积大于原始图像面积的60%就足够了。
        """
        factor_based_on_area_n_ratio = min((ratio[0]*ratio[1]*image_size*image_size)/ area, 0.6)* \
                                     min(target_aspect_ratio/aspect_ratio, aspect_ratio/target_aspect_ratio)
        
        if factor_based_on_area_n_ratio > best_factor:
            best_factor = factor_based_on_area_n_ratio
            best_ratio = ratio
        
    return best_ratio


def dynamic_preprocess(image, min_num=1, max_num=6, image_size=448, use_thumbnail=False):
    orig_width, orig_height = image.size
    aspect_ratio = orig_width / orig_height

    # 计算现有图像的宽高比
    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)
    target_ratios = sorted(target_ratios, key=lambda x: x[0] * x[1])

    # 找到最接近目标宽高比的宽高比
    target_aspect_ratio = find_closest_aspect_ratio(
        aspect_ratio, target_ratios, orig_width, orig_height, image_size)

    # 计算目标宽度和高度
    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]

    # 调整图像大小
    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
        )
        # 分割图像
        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

def split_model(model_path, device):

    device_map = {}
    world_size = torch.cuda.device_count()
    config = AutoConfig.from_pretrained(model_path, trust_remote_code=True)
    num_layers = config.llm_config.num_hidden_layers

    print('world_size', world_size)
    num_layers_per_gpu_ = math.floor(num_layers / (world_size - 1))
    num_layers_per_gpu = [num_layers_per_gpu_] * world_size
    num_layers_per_gpu[device] = num_layers - num_layers_per_gpu_ * (world_size-1)
    print(num_layers_per_gpu)
    layer_cnt = 0
    for i, num_layer in enumerate(num_layers_per_gpu):
        for j in range(num_layer):
            device_map[f'language_model.model.layers.{layer_cnt}'] = i
            layer_cnt += 1
    device_map['vision_model'] = device
    device_map['mlp1'] = device
    device_map['language_model.model.tok_embeddings'] = device
    device_map['language_model.model.embed_tokens'] = device
    device_map['language_model.output'] = device
    device_map['language_model.model.norm'] = device
    device_map['language_model.lm_head'] = device
    device_map['language_model.model.rotary_emb'] = device
    device_map[f'language_model.model.layers.{num_layers - 1}'] = device
    return device_map

class ModelWorker:
    def __init__(self, model_path, model_name,
                 load_8bit, device):

        if model_path.endswith('/'):
            model_path = model_path[:-1]
        if model_name is None:
            model_paths = model_path.split('/')
            if model_paths[-1].startswith('checkpoint-'):
                self.model_name = model_paths[-2] + '_' + model_paths[-1]
            else:
                self.model_name = model_paths[-1]
        else:
            self.model_name = model_name

        print(f'加载模型 {self.model_name}')

        tokenizer = AutoTokenizer.from_pretrained(model_path, trust_remote_code=True, use_fast=False)
        tokens_to_keep = ['<box>', '</box>', '<ref>', '</ref>']
        tokenizer.additional_special_tokens = [item for item in tokenizer.additional_special_tokens if item not in tokens_to_keep]
        self.tokenizer = tokenizer
        config = AutoConfig.from_pretrained(model_path, trust_remote_code=True)
        model_type = config.vision_config.model_type
        self.device = torch.cuda.current_device()
        if model_type == 'siglip_vision_model':
            self.norm_type = 'siglip'
        elif model_type == 'MOB':
            self.norm_type = 'siglip'
        else:
            self.norm_type = 'imagenet'

        if any(x in model_path.lower() for x in ['34b']):
            device_map = split_model(model_path, self.device)
        else:
            device_map = None
        
        if device_map is not None:    
            self.model = AutoModel.from_pretrained(model_path, torch_dtype=torch.bfloat16,
                                               low_cpu_mem_usage=True,
                                               device_map=device_map, 
                                               trust_remote_code=True,
                                               load_in_8bit=load_8bit).eval()
        else:
            self.model = AutoModel.from_pretrained(model_path, torch_dtype=torch.bfloat16,
                                               trust_remote_code=True,
                                               load_in_8bit=load_8bit).eval()  

        if not load_8bit and device_map is None:
            self.model = self.model.to(device)
        self.load_8bit = load_8bit
        
        self.model_path = model_path
        self.image_size = self.model.config.force_image_size
        self.context_len = tokenizer.model_max_length
        self.per_tile_len = 256

    def reload_model(self):
        del self.model
        torch.cuda.empty_cache()
        if self.device == 'auto':
            os.environ['CUDA_LAUNCH_BLOCKING'] = '1'
            # 这可以使分布式部署正常工作
            self.model = AutoModel.from_pretrained(
                self.model_path,
                load_in_8bit=self.load_8bit,
                torch_dtype=torch.bfloat16,
                device_map=self.device_map,
                trust_remote_code=True).eval()
        else:
            self.model = AutoModel.from_pretrained(
                self.model_path,
                load_in_8bit=self.load_8bit,
                torch_dtype=torch.bfloat16,
                trust_remote_code=True).eval()
        if not self.load_8bit and not self.device == 'auto':
            self.model = self.model.cuda()

    @torch.inference_mode()
    def generate(self, params):
        system_message = params['prompt'][0]['content']
        send_messages = params['prompt'][1:]
        max_input_tiles = params['max_input_tiles']
        temperature = params['temperature']
        top_p = params['top_p']
        max_new_tokens = params['max_new_tokens']
        repetition_penalty = params['repetition_penalty']
        video_frame_num = params.get('video_frame_num', 64)
        do_sample = True if temperature > 0.0 else False

        global_image_cnt = 0
        history, pil_images, max_input_tile_list = [], [], []
        for message in send_messages:
            if message['role'] == 'user':
                prefix = ''
                if 'image' in message:
                    for image_data in message['image']:
                        pil_images.append(load_image(image_data))
                        prefix = prefix + f'<image {global_image_cnt + 1}><image>\n'
                        global_image_cnt += 1
                        max_input_tile_list.append(max_input_tiles)
                if 'video' in message:
                    for video_data in message['video']:
                        video_frames, tmp_prefix = load_video(video_data, num_frames=video_frame_num)
                        pil_images.extend(video_frames)
                        prefix = prefix + tmp_prefix
                        global_image_cnt += len(video_frames)
                        max_input_tile_list.extend([1] * len(video_frames))
                content = prefix + message['content']
                history.append([content, ])
            else:
                history[-1].append(message['content'])
        question, history = history[-1][0], history[:-1]

        if global_image_cnt == 1:
            question = question.replace('<image 1><image>\n', '<image>\n')
            history = [[item[0].replace('<image 1><image>\n', '<image>\n'), item[1]] for item in history]


        try:
            assert len(max_input_tile_list) == len(pil_images), 'max_input_tile_list和pil_images的数量应该相同。'
        except Exception as e:
            from IPython import embed; embed()
            exit()
            print(f'错误：{e}')
            print(f'max_input_tile_list：{max_input_tile_list}，pil_images：{pil_images}')
            # raise e

        old_system_message = self.model.system_message
        self.model.system_message = system_message
        
        transform = build_transform(input_size=self.image_size, norm_type=self.norm_type)
        if len(pil_images) > 0:
            max_input_tiles_limited_by_contect = params['max_input_tiles']
            while True:
                image_tiles = []
                for current_max_input_tiles, pil_image in zip(max_input_tile_list, pil_images):
                    if self.model.config.dynamic_image_size:
                        tiles = dynamic_preprocess(
                            pil_image, image_size=self.image_size, max_num=min(current_max_input_tiles, max_input_tiles_limited_by_contect),
                            use_thumbnail=self.model.config.use_thumbnail)
                    else:
                        tiles = [pil_image]
                    image_tiles += tiles
                if (len(image_tiles) * self.per_tile_len < self.context_len):
                    break
                else:
                    max_input_tiles_limited_by_contect -= 2
                
                if max_input_tiles_limited_by_contect < 1:
                    break
                    
            pixel_values = [transform(item) for item in image_tiles]
            pixel_values = torch.stack(pixel_values).to(self.model.device, dtype=torch.bfloat16)
            print(f'将图像分割为{pixel_values.shape}')
        else:
            pixel_values = None

        generation_config = dict(
            num_beams=1,
            max_new_tokens=max_new_tokens,
            do_sample=do_sample,
            temperature=temperature,
            repetition_penalty=repetition_penalty,
            max_length=self.context_len,
            top_p=top_p,
        )

        response = self.model.chat(
            tokenizer=self.tokenizer,
            pixel_values=pixel_values,
            question=question,
            history=history,
            return_history=False,
            generation_config=generation_config,
        )
        self.model.system_message = old_system_message
        return {'text': response, 'error_code': 0}