from datetime import datetime
from typing import Optional, List
from bson import ObjectId


class PDFFile:
    """PDF file model for MongoDB."""
    
    collection_name = "files"
    
    def __init__(
        self,
        user_id: str,
        filename: str,
        original_filename: str,
        file_path: str,
        file_size: int,
        file_type: str = "application/pdf",
        created_at: Optional[datetime] = None,
        _id: Optional[ObjectId] = None
    ):
        self._id = _id or ObjectId()
        self.user_id = user_id
        self.filename = filename
        self.original_filename = original_filename
        self.file_path = file_path
        self.file_size = file_size
        self.file_type = file_type
        self.created_at = created_at or datetime.utcnow()
    
    def to_dict(self) -> dict:
        """Convert file to dictionary for MongoDB insertion."""
        return {
            "_id": self._id,
            "user_id": self.user_id,
            "filename": self.filename,
            "original_filename": self.original_filename,
            "file_path": self.file_path,
            "file_size": self.file_size,
            "file_type": self.file_type,
            "created_at": self.created_at
        }
    
    @classmethod
    def from_dict(cls, data: dict) -> "PDFFile":
        """Create PDFFile instance from MongoDB document."""
        return cls(
            _id=data.get("_id"),
            user_id=data.get("user_id"),
            filename=data.get("filename"),
            original_filename=data.get("original_filename"),
            file_path=data.get("file_path"),
            file_size=data.get("file_size"),
            file_type=data.get("file_type"),
            created_at=data.get("created_at")
        )
    
    @property
    def id(self) -> str:
        """Get string representation of file ID."""
        return str(self._id)


class MergedPDF:
    """Merged PDF file model for MongoDB."""
    
    collection_name = "merged_files"
    
    def __init__(
        self,
        user_id: str,
        filename: str,
        file_path: str,
        file_size: int,
        source_file_ids: List[str],
        created_at: Optional[datetime] = None,
        _id: Optional[ObjectId] = None
    ):
        self._id = _id or ObjectId()
        self.user_id = user_id
        self.filename = filename
        self.file_path = file_path
        self.file_size = file_size
        self.source_file_ids = source_file_ids
        self.created_at = created_at or datetime.utcnow()
    
    def to_dict(self) -> dict:
        """Convert merged file to dictionary for MongoDB insertion."""
        return {
            "_id": self._id,
            "user_id": self.user_id,
            "filename": self.filename,
            "file_path": self.file_path,
            "file_size": self.file_size,
            "source_file_ids": self.source_file_ids,
            "created_at": self.created_at
        }
    
    @classmethod
    def from_dict(cls, data: dict) -> "MergedPDF":
        """Create MergedPDF instance from MongoDB document."""
        return cls(
            _id=data.get("_id"),
            user_id=data.get("user_id"),
            filename=data.get("filename"),
            file_path=data.get("file_path"),
            file_size=data.get("file_size"),
            source_file_ids=data.get("source_file_ids"),
            created_at=data.get("created_at")
        )
    
    @property
    def id(self) -> str:
        """Get string representation of merged file ID."""
        return str(self._id)