import os
import json
from io import BytesIO
from typing import Union
from urllib.parse import urlparse

import boto3
from botocore.client import Config
from botocore.exceptions import NoCredentialsError

AWS_REGION = os.getenv("AWS_REGION")

# Initialize the S3 client
S3_CLIENT = boto3.client(
    "s3", region_name=AWS_REGION, config=Config(signature_version="s3v4")
)


def save_to_s3(
    bucket_name: str,
    folder_name: str,
    content: Union[str, dict, BytesIO],
    file_name: str,
) -> str:
    """
    Save a file to an S3 bucket, determining the content type based on the input type.

    Args:
        bucket_name (str): The name of the S3 bucket.
        folder_name (str): The folder path in the S3 bucket.
        content (Union[str, dict, BytesIO]): The content to save, can be a string, dictionary, or BytesIO.
        file_name (str): The file name under which the content should be saved.

    Returns:
        str: The S3 URL of the uploaded file, or an error message if credentials are not available.
    """
    # Ensure the folder name ends with a '/'
    # if not folder_name.endswith('/'):
    #     folder_name += '/'
    # Determine file name and content type based on the input
    if isinstance(content, str):
        file_content = content
        content_type = "text/plain"
    elif isinstance(content, dict):
        file_content = json.dumps(content)
        content_type = "application/json"
    elif isinstance(content, BytesIO):
        file_content = content
        content_type = "image/jpeg"
    else:
        print(
            "Invalid content type. Content must be a string, dictionary, or BytesIO."
        )
        raise ValueError("Content must be either a string, dictionary, or BytesIO.")

    # Ensure the folder name ends with a '/'
    s3_file_path = f"{folder_name.rstrip('/')}/{file_name}"

    try:
        # Upload the file to S3
        S3_CLIENT.put_object(
            Bucket=bucket_name,
            Key=s3_file_path,
            Body=file_content,
            ContentType=content_type,
        )
        s3_url = f"s3://{bucket_name}/{s3_file_path}"
        print(f"File successfully uploaded to {s3_url}")
        return s3_url

    except NoCredentialsError:
        print("AWS credentials not available.")
        return "Error: AWS credentials not available."


def fetch_from_s3(source: Union[str, dict], region_name: str = "ap-south-1") -> bytes:
    """
    Fetch a file's content from S3 given a source URL or dictionary with bucket and key.

    Args:
        source (Union[str, dict]): The source S3 URL or a dictionary with 'bucket_name' and 'file_key'.
        region_name (str): The AWS region name for the S3 client (default is 'ap-south-1').

    Returns:
        bytes: The content of the file fetched from S3.
    """
    print(f"Fetching file from S3. Source: {source}")
    s3_client = boto3.client("s3", region_name=region_name)

    # Parse the source depending on its type
    if isinstance(source, str):
        parsed_url = urlparse(source)
        bucket_name = parsed_url.netloc.split(".")[0]
        file_path = parsed_url.path.lstrip("/")
    elif isinstance(source, dict):
        bucket_name = source.get("bucket_name")
        file_path = source.get("file_key")
        if not bucket_name or not file_path:
            print("Dictionary input must contain 'bucket_name' and 'file_key'.")
            raise ValueError(
                "Dictionary input must contain 'bucket_name' and 'file_key'."
            )
    else:
        print("Source must be a string URL or a dictionary.")
        raise ValueError("Source must be a string URL or a dictionary.")

    print(f"Attempting to download from bucket: {bucket_name}, path: {file_path}")
    try:
        response = s3_client.get_object(Bucket=bucket_name, Key=file_path)
        file_content = response["Body"].read()
        print(f"File fetched successfully from {bucket_name}/{file_path}")
        return file_content
    except Exception as e:
        print(f"Failed to fetch file from S3: {e}")
        raise


def list_s3_objects(bucket_name: str, folder_path: str = "") -> list:
    """
    Lists a content of the given a directory URL.

    Args:
        bucket_name (str): The name of the S3 bucket.
        folder_name (str): The folder path in the S3 bucket.

    Returns:
        list: The list of files found inside the given directory URL.
    """
    response = S3_CLIENT.list_objects_v2(Bucket=bucket_name, Prefix=folder_path)
    # Check if the bucket contains objects
    objects = []
    if "Contents" in response:
        for obj in response["Contents"]:
            objects.append(obj["Key"])

    return objects