import json
import csv
import os
import time
from typing import Any, Dict, List

class ResultSerializer:
    """
    Serializes inference results into various formats.
    """
    def to_json(self, data: Dict[str, Any]) -> str:
        """
        Serializes data to a JSON string.
        """
        return json.dumps(data, indent=2)

    def to_csv(self, data: List[Dict[str, Any]], fieldnames: List[str]) -> str:
        """
        Serializes data to a CSV string.
        """
        import io
        output = io.StringIO()
        writer = csv.DictWriter(output, fieldnames=fieldnames)
        writer.writeheader()
        writer.writerows(data)
        return output.getvalue()

class FileOutputManager:
    """
    Manages writing results to files with timestamped names and directory organization.
    """
    def __init__(self, base_path: str = "./output"):
        """
        Initializes the FileOutputManager.

        Args:
            base_path (str): The base directory to save output files.
        """
        self.base_path = base_path
        self.serializer = ResultSerializer()

    def save_result(self, result_data: Dict[str, Any], pipeline_name: str, format: str = 'json'):
        """
        Saves a single result to a file.

        Args:
            result_data (Dict[str, Any]): The result data to save.
            pipeline_name (str): The name of the pipeline that generated the result.
            format (str): The format to save the result in ('json' or 'csv').
        """
        try:
            # Sanitize pipeline_name to be a valid directory name
            sanitized_pipeline_name = "".join(c for c in pipeline_name if c.isalnum() or c in (' ', '_')).rstrip()
            if not sanitized_pipeline_name:
                sanitized_pipeline_name = "default_pipeline"

            # Ensure base_path is valid
            if not self.base_path or not isinstance(self.base_path, str):
                self.base_path = "./output"

            # Create directory structure
            today = time.strftime("%Y-%m-%d")
            output_dir = os.path.join(self.base_path, sanitized_pipeline_name, today)
            os.makedirs(output_dir, exist_ok=True)

            # Create filename
            timestamp = time.strftime("%Y%m%d_%H%M%S")
            filename = f"{timestamp}_{result_data.get('pipeline_id', 'result')}.{format}"
            file_path = os.path.join(output_dir, filename)

            # Serialize and save
            if format == 'json':
                content = self.serializer.to_json(result_data)
                with open(file_path, 'w') as f:
                    f.write(content)
            elif format == 'csv':
                # For CSV, we expect a list of dicts. If it's a single dict, wrap it.
                data_to_save = result_data if isinstance(result_data, list) else [result_data]
                if data_to_save:
                    # Ensure all items in the list are dictionaries
                    if all(isinstance(item, dict) for item in data_to_save):
                        fieldnames = list(data_to_save[0].keys())
                        content = self.serializer.to_csv(data_to_save, fieldnames)
                        with open(file_path, 'w') as f:
                            f.write(content)
                    else:
                        print(f"Error: CSV data must be a list of dictionaries.")
                        return
            else:
                print(f"Error: Unsupported format '{format}'")
                return

            print(f"Result saved to {file_path}")

        except Exception as e:
            print(f"Error saving result: {e}")