import os
import requests
import shutil
import logging 

logger = logging.getLogger("eval_logger")


def fetch_all_questions(api_url: str) -> list[dict] | None:
    """
    Fetches all questions from the API.

    Args:
        api_url: The base URL of the scoring API.

    Returns:
        A list of question dictionaries, or None if an error occurs.
    """
    questions_url = f"{api_url}/questions"
    logger.info(f"Fetching all questions from: {questions_url}")
    try:
        response = requests.get(questions_url, timeout=15)
        response.raise_for_status()
        questions_data = response.json()
        if not questions_data:
            logger.warning("Fetched questions list is empty.")
            return None
        logger.info(f"Fetched {len(questions_data)} questions successfully.")
        return questions_data
    except requests.exceptions.RequestException as e:
        logger.error(f"Error fetching all questions: {e}", exc_info=True)
        return None
    except requests.exceptions.JSONDecodeError as e:
        logger.error(f"Error decoding JSON response from questions endpoint: {e}", exc_info=True)
        logger.error(f"Response text: {response.text[:500] if response else 'No response'}")
        return None
    except Exception as e:
        logger.error(f"An unexpected error occurred fetching all questions: {e}", exc_info=True)
        return None

def fetch_random_question(api_url: str) -> dict | None:
    """
    Fetches a single random question from the API.

    Args:
        api_url: The base URL of the scoring API.

    Returns:
        A dictionary representing a single question, or None if an error occurs.
    """
    random_question_url = f"{api_url}/random-question"
    logger.info(f"Fetching random question from: {random_question_url}")
    try:
        response = requests.get(random_question_url, timeout=15)
        response.raise_for_status()
        question_data = response.json()
        if not question_data:
            logger.warning("Fetched random question is empty.")
            return None
        logger.info(f"Fetched random question successfully: {question_data.get('task_id')}")
        return question_data
    except requests.exceptions.RequestException as e:
        logger.error(f"Error fetching random question: {e}", exc_info=True)
        return None
    except requests.exceptions.JSONDecodeError as e:
        logger.error(f"Error decoding JSON response from random question endpoint: {e}", exc_info=True)
        logger.error(f"Response text: {response.text[:500] if response else 'No response'}")
        return None
    except Exception as e:
        logger.error(f"An unexpected error occurred fetching random question: {e}", exc_info=True)
        return None

def download_file(api_url: str, task_id: str, file_name: str, download_dir: str = "downloads") -> str | None:
    """
    Downloads a specific file associated with a given task ID.

    Args:
        api_url: The base URL of the scoring API.
        task_id: The ID of the task for which to download the file.
        file_name: The name of the file to be saved.
        download_dir: The directory where the file should be saved. Defaults to "downloads".

    Returns:
        The local path to the downloaded file, or None if an error occurs.
    """
    if not file_name:
        logger.info(f"No file_name provided for task_id {task_id}. Skipping download.")
        return None

    file_url = f"{api_url}/files/{task_id}"
    
    os.makedirs(download_dir, exist_ok=True)
    
    local_file_path = os.path.join(download_dir, file_name)

    if os.path.exists(local_file_path):
        logger.info(f"File already exists at {local_file_path}. Skipping download.")
        return local_file_path

    logger.info(f"Downloading file for task_id {task_id} from: {file_url} to {local_file_path}")
    try:
        with requests.get(file_url, stream=True, timeout=30) as r:
            r.raise_for_status()
            with open(local_file_path, 'wb') as f:
                shutil.copyfileobj(r.raw, f)
        logger.info(f"File downloaded successfully: {local_file_path}")
        return local_file_path
    except requests.exceptions.RequestException as e:
        logger.error(f"Error downloading file for task_id {task_id}: {e}", exc_info=True)
        if os.path.exists(local_file_path): 
            os.remove(local_file_path)
        return None
    except Exception as e:
        logger.error(f"An unexpected error occurred downloading file for task_id {task_id}: {e}", exc_info=True)
        if os.path.exists(local_file_path): 
            os.remove(local_file_path)
        return None

if __name__ == '__main__':
    print("--- Testing dataset_helper.py directly ---")
    print("NOTE: For full logging, run through app.py. This direct test uses print statements.")

    test_api_url = "https://agents-course-unit4-scoring.hf.space"

    print("\n--- Testing fetch_all_questions ---")
    questions = fetch_all_questions(test_api_url)
    if questions:
        print(f"Successfully fetched {len(questions)} questions. First question task_id: {questions[0].get('task_id')}")
    else:
        print("Failed to fetch all questions.")

    print("\n--- Testing fetch_random_question ---")
    random_q = fetch_random_question(test_api_url)
    if random_q:
        print(f"Successfully fetched random question: {random_q.get('question')[:50]}...")
    else:
        print("Failed to fetch random question.")

    print("\n--- Testing download_file (example with a known task_id and file_name if available) ---")
    if questions:
        test_task_with_file = None
        test_file_name = None
        for q_item in questions:
            if q_item.get("file_name"):
                test_task_with_file = q_item.get("task_id")
                test_file_name = q_item.get("file_name")
                break
        
        if test_task_with_file and test_file_name:
            print(f"Attempting to download file for task_id: {test_task_with_file}, file_name: {test_file_name}")
            downloaded_path = download_file(test_api_url, test_task_with_file, test_file_name)
            if downloaded_path:
                print(f"File downloaded to: {downloaded_path}")
            else:
                print(f"Failed to download file for task_id: {test_task_with_file}")
        else:
            print("No question with an associated file found in the first batch of questions to test download.")
    else:
        print("Skipping download_file test as fetching questions failed.")

    print("\n--- Testing download_file (with a task_id that might not have a file or invalid file_name) ---")
    if questions and questions[0].get("file_name") == "":
        task_id_no_file = questions[0].get("task_id")
        file_name_empty = questions[0].get("file_name")
        print(f"Attempting to download file for task_id: {task_id_no_file} (expected to skip due to empty file_name)")
        path_no_file = download_file(test_api_url, task_id_no_file, file_name_empty)
        if path_no_file is None:
            print("Correctly skipped download or failed as expected for task with no file_name.")
        else:
            print(f"Unexpectedly downloaded something to {path_no_file} for a task with no file_name.")
    else:
        print("Skipping test for task with no file_name (either no questions or first question has a file).")