import boto3
import os
import logging # Import logging

# Get a logger instance for this module
logger = logging.getLogger(__name__)

def get_s3_client(aws_access_key_id, aws_secret_access_key, region_name):
    """
    Initializes and returns an S3 client.
    """
    try:
        s3_client = boto3.client(
            's3',
            aws_access_key_id=aws_access_key_id,
            aws_secret_access_key=aws_secret_access_key,
            region_name=region_name
        )
        logger.debug("S3 client initialized successfully.")
        return s3_client
    except Exception as e:
        logger.error(f"Failed to initialize S3 client: {e}")
        return None

def download_image_from_s3(s3_client, bucket_name, object_key):
    """
    Downloads an image from S3 and returns its binary data.
    """
    try:
        response = s3_client.get_object(Bucket=bucket_name, Key=object_key)
        image_data = response['Body'].read()
        logger.info(f"Downloaded '{object_key}' from S3 bucket '{bucket_name}'.")
        return image_data
    except s3_client.exceptions.NoSuchKey:
        logger.warning(f"S3 object '{object_key}' not found in bucket '{bucket_name}'.")
        return None
    except Exception as e:
        logger.error(f"Error downloading '{object_key}' from S3 bucket '{bucket_name}': {e}")
        return None

def upload_object_to_s3(s3_client, bucket_name, object_key, data_bytes, content_type='application/octet-stream'):
    """
    Uploads binary data to S3.
    """
    try:
        s3_client.put_object(
            Bucket=bucket_name,
            Key=object_key,
            Body=data_bytes,
            ContentType=content_type
        )
        logger.info(f"Uploaded object to s3://{bucket_name}/{object_key} with content type '{content_type}'.")
        return True
    except Exception as e:
        logger.error(f"Error uploading '{object_key}' to S3 bucket '{bucket_name}': {e}")
        return False

def generate_thumbnail_s3_key(original_s3_key, thumbnail_prefix):
    """
    Generates a suitable S3 key for a thumbnail based on the original key.
    E.g., original/path/image.jpg -> thumbnails/original/path/image.jpg
    """
    thumbnail_name = os.path.basename(original_s3_key)
    thumbnail_directory = os.path.dirname(original_s3_key)

    if thumbnail_directory:
        thumbnail_key = f"{thumbnail_prefix}{thumbnail_directory}/{thumbnail_name}"
    else:
        thumbnail_key = f"{thumbnail_prefix}{thumbnail_name}"
    logger.debug(f"Generated thumbnail S3 key: '{thumbnail_key}' from original: '{original_s3_key}'")
    return thumbnail_key