import boto3
import csv
from botocore.exceptions import NoCredentialsError, PartialCredentialsError

class QuestionLoaderAWS:
    def __init__(self, bucket_name, aws_access_key, aws_secret_key):
        """
        Initializes the QuestionLoader with AWS credentials and bucket name.

        :param bucket_name: The name of the S3 bucket.
        :param aws_access_key: AWS access key ID.
        :param aws_secret_key: AWS secret access key.
        """
        self.bucket_name = bucket_name
        self.s3_client = boto3.client(
            's3',
            aws_access_key_id=aws_access_key,
            aws_secret_access_key=aws_secret_key
        )

    def fetch_questions(self, technology):
        """
        Fetches the questions for the given technology from the S3 bucket.

        :param technology: The technology (e.g., Python, Django) to fetch questions for.
        :return: A list of dictionaries, where each dictionary represents a question.
        :raises: Exception if the file cannot be fetched or read.
        """
        file_key = f"questions/{technology}/questions.csv"

        try:
            response = self.s3_client.get_object(Bucket=self.bucket_name, Key=file_key)
            questions = []

            # Decode and parse the CSV content
            lines = response['Body'].read().decode('utf-8').splitlines()
            csv_reader = csv.DictReader(lines)
            for row in csv_reader:
                questions.append({
                    "question": row["question"],
                    "option1": row["option1"],
                    "option2": row["option2"],
                    "option3": row["option3"],
                    "option4": row["option4"],
                    "answer": row["answer"],
                    "difficulty": row["difficulty"].lower()
                })

            return questions

        except self.s3_client.exceptions.NoSuchKey:
            raise FileNotFoundError(f"No questions found for technology: {technology}")

        except (NoCredentialsError, PartialCredentialsError):
            raise PermissionError("Invalid AWS credentials. Please check your .env file.")

        except Exception as e:
            raise RuntimeError(f"Failed to fetch questions: {str(e)}")