import boto3, os
from dotenv import load_dotenv

s3 = boto3.client(
    "s3",
    aws_access_key_id=os.getenv("AWS_ACCESS_KEY_ID"),
    aws_secret_access_key=os.getenv("AWS_SECRET_ACCESS_KEY"),
    region_name=os.getenv("AWS_REGION"),
)
bucket = os.getenv("S3_BUCKET")


def upload_to_s3(file, key):
    s3.upload_fileobj(file.file, bucket, key)
    return f"https://{bucket}.s3.amazonaws.com/{key}"


def upload_pdf_bytes(data: bytes, key: str):
    s3.put_object(Bucket=bucket, Key=key, Body=data, ContentType="application/pdf")
    return f"https://{bucket}.s3.amazonaws.com/{key}"


def delete_s3_key(key: str):
    if not key:
        return
    s3.delete_object(Bucket=bucket, Key=key)


def key_from_url(url: str) -> str | None:
    if not url:
        return None
    prefix = f"https://{bucket}.s3.amazonaws.com/"
    if url.startswith(prefix):
        return url[len(prefix):]
    # Try generic split for virtual-hosted–style URLs
    try:
        parts = url.split('.s3.amazonaws.com/', 1)
        if len(parts) == 2:
            return parts[1]
    except Exception:
        pass
    return None