import functools
import re
from pathlib import Path
from shutil import copy2

import pymupdf


def remove_images_from_markdown(markdown_text):
    # remove <image> and ![image](path) from markdown
    markdown_text = re.sub(r"<img[^>]*>", "", markdown_text)
    markdown_text = re.sub(r"!\[[^\]]*\]\([^)]*\)", "", markdown_text)
    return markdown_text


@functools.lru_cache(maxsize=None)
def trim_pages(pdf_path, output_path, start_page=0, trim_pages=5):
    doc = pymupdf.open(pdf_path)
    parent_dir_name = Path(pdf_path).parent.name
    output_file_path = Path(output_path) / f"{parent_dir_name}.pdf"

    num_pages = len(doc)
    if num_pages > trim_pages:
        to_select = list(range(start_page, min(start_page + trim_pages, num_pages)))
        doc.select(to_select)
        doc.ez_save(output_file_path)
        print("Trimmed pdf to with pages", to_select, "path", output_file_path)
    else:
        copy2(pdf_path, str(output_file_path))

    return str(output_file_path)


def patch_unimernet_model():
    from unimernet.models.unimernet.encoder_decoder import CustomMBartForCausalLM

    # Save the original __init__ method
    original_init = CustomMBartForCausalLM.__init__

    # Define a new __init__ method
    def new_init(self, config):
        config._attn_implementation = "eager"
        original_init(self, config)

    # Monkey patch the __init__ method
    CustomMBartForCausalLM.__init__ = new_init


def fix_problematic_imports():
    import sys
    import types

    # Create a fake 'UnimernetModel' class inside a fake 'Unimernet' module
    fake_unimernet_module = types.ModuleType(
        "magic_pdf.model.sub_modules.mfr.unimernet.Unimernet"
    )
    fake_unimernet_module.UnimernetModel = type(  # type: ignore
        "UnimernetModel", (), {}
    )

    # Register fake module in sys.modules
    sys.modules[
        "magic_pdf.model.sub_modules.mfr.unimernet.Unimernet"
    ] = fake_unimernet_module
    
    
def setup_mineru_config():
    import json
    import os
    import requests
    from huggingface_hub import snapshot_download


    def download_json(url):
        response = requests.get(url)
        response.raise_for_status()
        return response.json()


    def download_and_modify_json(url, local_filename, modifications):
        if os.path.exists(local_filename):
            data = json.load(open(local_filename))
            config_version = data.get('config_version', '0.0.0')
            if config_version < '1.2.0':
                data = download_json(url)
        else:
            data = download_json(url)

        for key, value in modifications.items():
            data[key] = value

        with open(local_filename, 'w', encoding='utf-8') as f:
            json.dump(data, f, ensure_ascii=False, indent=4)

    mineru_patterns = [
        "models/Layout/YOLO/*",
        "models/MFD/YOLO/*",
        "models/MFR/unimernet_hf_small_2503/*",
        "models/OCR/paddleocr_torch/*",
    ]
    model_dir = snapshot_download('opendatalab/PDF-Extract-Kit-1.0', allow_patterns=mineru_patterns)

    layoutreader_pattern = [
        "*.json",
        "*.safetensors",
    ]
    layoutreader_model_dir = snapshot_download('hantian/layoutreader', allow_patterns=layoutreader_pattern)

    model_dir = model_dir + '/models'
    print(f'model_dir is: {model_dir}')
    print(f'layoutreader_model_dir is: {layoutreader_model_dir}')

    json_url = 'https://raw.githubusercontent.com/opendatalab/MinerU/refs/heads/release-1.3.12/magic-pdf.template.json'
    config_file_name = 'magic-pdf.json'
    home_dir = os.path.expanduser('~')
    config_file = os.path.join(home_dir, config_file_name)

    json_mods = {
        'models-dir': model_dir,
        'layoutreader-model-dir': layoutreader_model_dir,
    }

    download_and_modify_json(json_url, config_file, json_mods)
    print(f'The configuration file has been configured successfully, the path is: {config_file}')


def prepare_env_mineru():
    import json
    import os
    import nltk

    # download nltk data
    nltk.download("punkt_tab")
    nltk.download("averaged_perceptron_tagger_eng")

    home_path = Path.home()
    config_path = home_path / "magic-pdf.json"
    # skip download if config file exists
    if config_path.exists():
        print("Config file exists, skipping models download")
        return

    # download models
    setup_mineru_config()

    with open(config_path, "r") as file:
        data = json.load(file)

    data["device-mode"] = "cuda"
    with open(config_path, "w") as file:
        json.dump(data, file, indent=4)

    os.system(
        f"cp -r resources {home_path}/.local/lib/"
        "python3.10/site-packages/magic_pdf/resources"
    )

    # copy OCR model weight
    target_model_path = home_path / ".paddleocr"
    os.system(f"cp -r paddleocr {target_model_path}")