"""Script to download objects from Thingiverse."""

import multiprocessing
import os
import time
from multiprocessing import Pool
from typing import Any, Dict, List, Optional, Tuple

import fsspec
import pandas as pd
import requests
from loguru import logger
from tqdm import tqdm


def _get_response_with_retries(
    url: str, max_retries: int = 3, retry_delay: int = 5
) -> Optional[requests.models.Response]:
    """Get a response from a URL with retries.

    Args:
        url (str): The URL to get a response from.
        max_retries (int, optional): The maximum number of retries. Defaults to 3.
        retry_delay (int, optional): The delay between retries in seconds. Defaults to 5.

    Returns:
        Optional[requests.models.Response]: The response from the URL. If there was an error, returns None.
    """

    for i in range(max_retries):
        try:
            response = requests.get(url, stream=True)
            # if successful, break out of loop
            if response.status_code not in {200, 404}:
                time.sleep(retry_delay)
                continue
            break
        except ConnectionError:
            if i < max_retries - 1:  # i.e. not on the last try
                time.sleep(retry_delay)
    else:
        return None

    return response


def _download_item(item: Dict[str, str], download_dir: str) -> Optional[str]:
    """Download the given item.

    Args:
        item (Dict[str, str]): The item to download. It should be a dictionary with the
            keys "thingId" and "fileId".
        download_dir (str, optional): The directory to save the files to. Supports all
            file systems supported by fsspec.

    Returns:
        Optional[str]: The path to the downloaded file. If there was an error or 404,
            returns None.
    """
    file_id = item["fileId"]
    thing_id = item["thingId"]

    url = f"https://www.thingiverse.com/download:{file_id}"
    response = _get_response_with_retries(url)

    if response is None:
        logger.error(f"{file_id=} Could not get response from {url}")
        return None

    # Check if the request was successful
    if response.status_code == 404:
        logger.error(f"{file_id=} (404) Could not find file with ID")
        return None

    file_path = os.path.join(download_dir, f"thing-{thing_id}-file-{file_id}.stl")
    fs, path = fsspec.core.url_to_fs(file_path)

    with fs.open(path, "wb") as file:
        file.write(response.content)

    return file_path


def _parallel_download_item(args) -> Tuple[Any, Optional[str]]:
    item, download_dir = args
    download_path = _download_item(item=item, download_dir=download_dir)
    return item, download_path


def download_thingiverse_objects(
    file_ids: Optional[List[str]] = None,
    processes: Optional[int] = None,
    download_dir: str = "~/.objaverse",
) -> List[Dict[str, str]]:
    """Download the objects from the given list of things and files.

    Args:
        file_ids (Optional[List[str]]): The list of file IDs to download. If None,
            downloads all files. Defaults to None.
        processes (int, optional): The number of processes to use. If None, maps to
            use all available CPUs using multiprocessing.cpu_count(). Defaults to None.
        download_dir (str, optional): The directory to save the files to. Supports all
            file systems supported by fsspec. Defaults to "~/.objaverse-xl".

    Returns:
        List[Dict[str, str]]: The list of things and files that were downloaded. Each
            item in the list is a dictionary with the keys "thingId", "fileId",
            "filePath", and everything else from the annotations. If the file was
            not successfully downloaded, the item will not appear in the list.
    """
    if processes is None:
        processes = multiprocessing.cpu_count()

    # get the records of the specified fileIds
    df = load_annotations(download_dir=download_dir)
    if file_ids is not None:
        file_ids_set = set(file_ids)
        df = df[df["fileId"].isin(file_ids_set)]
    things_and_files = df.to_dict(orient="records")

    # create the download directory
    download_dir = os.path.join(download_dir, "thingiverse")
    fs, path = fsspec.core.url_to_fs(download_dir)
    fs.makedirs(path, exist_ok=True)

    # check to filter out files that already exist
    existing_files = fs.glob(os.path.join(download_dir, "*.stl"), refresh=True)
    existing_file_ids = {
        os.path.basename(file).split(".")[0].split("-")[-1] for file in existing_files
    }

    # filter out existing files
    items_to_download = []
    already_downloaded_count = 0
    out = []
    for item in things_and_files:
        if item["fileId"] in existing_file_ids:
            already_downloaded_count += 1
            out.append(
                {
                    "filePath": os.path.join(
                        download_dir,
                        f"thing-{item['thingId']}-file-{item['fileId']}.stl",
                    ),
                    **item,
                }
            )
        else:
            items_to_download.append(item)

    logger.info(f"Found {already_downloaded_count} Thingiverse objects downloaded")
    logger.info(
        f"Downloading {len(items_to_download)} Thingiverse objects with {processes=}"
    )
    if len(items_to_download) == 0:
        return out

    # download the files
    if processes == 1:
        for item in tqdm(items_to_download):
            file_path = _download_item(item=item, download_dir=download_dir)
            if file_path is not None:
                out.append(
                    {
                        "filePath": file_path,
                        **item,
                    }
                )
    else:
        args = [(item, download_dir) for item in items_to_download]
        with Pool(processes=processes) as pool:
            items_and_file_paths = list(
                tqdm(
                    pool.imap(_parallel_download_item, args),
                    total=len(args),
                    desc="Downloading Thingiverse Objects",
                )
            )
        out.extend(
            [
                {
                    "filePath": file_path,
                    **item,
                }
                for item, file_path in items_and_file_paths
                if file_path is not None
            ]
        )
    return out


def load_annotations(download_dir: str = "~/.objaverse") -> pd.DataFrame:
    """Load the annotations from the given directory.

    Args:
        download_dir (str, optional): The directory to load the annotations from.
            Supports all file systems supported by fsspec. Defaults to
            "~/.objaverse".

    Returns:
        pd.DataFrame: The annotations, which includes the columns "thingId", "fileId",
            "filename", and "license".
    """
    remote_url = "https://huggingface.co/datasets/allenai/objaverse-xl/resolve/main/thingiverse/thingiverse-objects.parquet"
    download_path = os.path.join(
        download_dir, "thingiverse", "thingiverse-objects.parquet"
    )
    fs, path = fsspec.core.url_to_fs(download_path)

    if not fs.exists(path):
        fs.makedirs(os.path.dirname(path), exist_ok=True)
        logger.info(f"Downloading {remote_url} to {download_path}")
        response = requests.get(remote_url)
        response.raise_for_status()
        with fs.open(path, "wb") as file:
            file.write(response.content)

    # read the file with pandas and fsspec
    with fs.open(download_path, "rb") as f:
        annotations_df = pd.read_parquet(f)

    return annotations_df


# if __name__ == "__main__":
#     # example usage
#     annotations = load_annotations()
#     file_ids = annotations.head(n=100)["fileId"].tolist()
#     download_thingiverse_objects(file_ids=file_ids, processes=5)