import os
import aiohttp
import random
import string

from config import NAMING_SCHEME, LOG


async def save_attachments(message) -> list:
    """Download attachments and return a list of their paths."""
    paths = []

    for attachment in message.attachments:
        async with aiohttp.ClientSession() as session:
            async with session.get(attachment.url) as response:
                # Check if the request was successful
                if response.status != 200:
                    LOG.warn(
                        f"Failed to download attachment: {attachment.url}"
                    )
                    continue

                # Check for content type
                content_type = response.headers.get("Content-Type")
                if not content_type:
                    LOG.warn(
                        f"Failed to get content type for: {attachment.url}"
                    )
                    continue

                filename = get_filename(
                    attachment, message, content_type.split("/")[-1]
                )

                # Save the attachment
                with open(f"images/{filename}", "wb") as file:
                    file.write(await response.read())

                # Add the path to the attachments list
                paths.append(f"images/{filename}")

    return paths


def get_filename(attachment, message, file_extension) -> str:
    """Generate a filename based on the naming scheme."""
    if NAMING_SCHEME == "original":
        i = 1
        filename = attachment.filename
        # account for duplicate filenames
        while os.path.exists(f"images/{filename}.{file_extension}"):
            filename = f"{attachment.filename}_{i}"
            i += 1
    elif NAMING_SCHEME == "timestamp":
        i = 1
        filename = message.created_at.isoformat()
        # account for multiple attachments from the same message
        while os.path.exists(f"images/{filename}.{file_extension}"):
            filename = f"{message.created_at.isoformat()}_{i}"
            i += 1
    elif NAMING_SCHEME == "id":
        filename = str(attachment.id)
    else:  # random
        filename = "".join(
            random.choice(string.ascii_letters) for _ in range(15)
        )

    return f"{filename}.{file_extension}"