"""Mock storage adapter for testing (in-memory storage)"""

import uuid
from datetime import datetime, timezone
from io import BytesIO

from app.services.storage.base import StorageAdapter


class MockStorageAdapter(StorageAdapter):
    """In-memory storage adapter for testing purposes"""

    # Class-level storage to persist across instances
    _files = {}  # {(bucket, object_name): BytesIO}
    _file_info = {}  # {(bucket, object_name): metadata}
    _buckets = set()  # Track created buckets

    def __init__(self):
        """Initialize mock storage (storage is shared at class level)"""
        pass

    def upload_file(
        self,
        file_data: BytesIO,
        bucket_name: str,
        object_name: str,
        content_type: str,
        length: int = None,
    ) -> dict:
        """
        Upload a file to in-memory storage

        Args:
            file_data: File data as BytesIO
            bucket_name: Name of bucket
            object_name: Name of object in storage
            content_type: MIME type of file
            length: File size in bytes (optional)

        Returns:
            dict: Upload result with metadata
        """
        # Ensure bucket exists
        self.ensure_bucket_exists(bucket_name)

        # Get file length if not provided
        if length is None:
            file_data.seek(0, 2)  # Seek to end
            length = file_data.tell()
            file_data.seek(0)  # Seek back to start

        # Store file data (create a copy to avoid reference issues)
        file_data.seek(0)
        file_copy = BytesIO(file_data.read())

        # Store in memory
        key = (bucket_name, object_name)
        self._files[key] = file_copy

        # Store metadata
        metadata = {
            "size": length,
            "content_type": content_type,
            "last_modified": datetime.now(timezone.utc),
            "etag": uuid.uuid4().hex,
        }
        self._file_info[key] = metadata

        return {
            "success": True,
            "bucket": bucket_name,
            "object_name": object_name,
            "size": length,
            "etag": metadata["etag"],
        }

    def download_file(self, bucket_name: str, object_name: str) -> BytesIO:
        """
        Download a file from in-memory storage

        Args:
            bucket_name: Name of bucket
            object_name: Name of the object in storage

        Returns:
            BytesIO: File data

        Raises:
            ValueError: If file doesn't exist
        """
        key = (bucket_name, object_name)
        if key not in self._files:
            raise ValueError(f"File {bucket_name}/{object_name} not found")

        # Create a copy to avoid modifying the original
        self._files[key].seek(0)
        return BytesIO(self._files[key].read())

    def delete_file(self, bucket_name: str, object_name: str) -> bool:
        """
        Delete a file from in-memory storage

        Args:
            bucket_name: Name of bucket
            object_name: Name of the object in storage

        Returns:
            bool: True if successful, False if file doesn't exist
        """
        key = (bucket_name, object_name)
        if key not in self._files:
            return False

        # Remove from storage
        del self._files[key]
        del self._file_info[key]

        return True

    def generate_presigned_url(
        self, bucket_name: str, object_name: str, expires_in: int = 3600
    ) -> str:
        """
        Generate a mock presigned URL

        In tests, this returns a fake URL that looks like a real MinIO URL
        but doesn't actually need to work since we use Flask proxy routes.

        Args:
            bucket_name: Name of bucket
            object_name: Name of the object in storage
            expires_in: URL expiration time in seconds (ignored in mock)

        Returns:
            str: Mock presigned URL
        """
        return f"http://minio:9000/{bucket_name}/{object_name}?X-Amz-Token=mock"

    def file_exists(self, bucket_name: str, object_name: str) -> bool:
        """
        Check if a file exists in in-memory storage

        Args:
            bucket_name: Name of bucket
            object_name: Name of the object in storage

        Returns:
            bool: True if file exists
        """
        return (bucket_name, object_name) in self._files

    def get_file_info(self, bucket_name: str, object_name: str) -> dict:
        """
        Get file metadata from in-memory storage

        Args:
            bucket_name: Name of bucket
            object_name: Name of the object in storage

        Returns:
            dict: File metadata

        Raises:
            ValueError: If file doesn't exist
        """
        key = (bucket_name, object_name)
        if key not in self._file_info:
            raise ValueError(f"File {bucket_name}/{object_name} not found")

        return self._file_info[key].copy()

    def ensure_bucket_exists(self, bucket_name: str) -> None:
        """
        Ensure a bucket exists, create if it doesn't

        Args:
            bucket_name: Name of bucket
        """
        if bucket_name not in self._buckets:
            self._buckets.add(bucket_name)

    def generate_unique_object_name(self, original_filename: str) -> str:
        """
        Generate a unique object name for a file

        Args:
            original_filename: Original filename

        Returns:
            str: Unique object name
        """
        # Extract file extension
        ext = (
            original_filename.rsplit(".", 1)[1].lower()
            if "." in original_filename
            else ""
        )
        # Generate unique filename with UUID
        unique_name = f"{uuid.uuid4().hex}"
        return f"{unique_name}.{ext}" if ext else unique_name

    @classmethod
    def clear_all(cls) -> None:
        """Clear all files and buckets (useful for test cleanup)"""
        cls._files.clear()
        cls._file_info.clear()
        cls._buckets.clear()

    @classmethod
    def get_all_files(cls) -> list:
        """
        Get all stored files (useful for test assertions)

        Returns:
            list: List of (bucket, object_name) tuples
        """
        return list(cls._files.keys())