"""
Database models and data structures.
Defines the core data models for projects, tasks, and annotations.
"""
from datetime import datetime
from typing import Optional


class Project:
    """Project model representing a labeling project."""
    
    def __init__(
        self,
        id: str,
        name: str,
        description: str,
        config: str,
        created_at: datetime
    ):
        self.id = id
        self.name = name
        self.description = description
        self.config = config
        self.created_at = created_at
    
    @classmethod
    def from_row(cls, row):
        """Create Project instance from database row."""
        return cls(
            id=row["id"],
            name=row["name"],
            description=row["description"],
            config=row["config"],
            created_at=row["created_at"]
        )


class Task:
    """Task model representing a labeling task."""
    
    def __init__(
        self,
        id: str,
        project_id: str,
        name: str,
        data: str,
        status: str,
        assigned_to: Optional[str],
        created_at: datetime
    ):
        self.id = id
        self.project_id = project_id
        self.name = name
        self.data = data
        self.status = status
        self.assigned_to = assigned_to
        self.created_at = created_at
    
    @classmethod
    def from_row(cls, row):
        """Create Task instance from database row."""
        return cls(
            id=row["id"],
            project_id=row["project_id"],
            name=row["name"],
            data=row["data"],
            status=row["status"],
            assigned_to=row["assigned_to"],
            created_at=row["created_at"]
        )


class Annotation:
    """Annotation model representing a labeling result."""
    
    def __init__(
        self,
        id: str,
        task_id: str,
        user_id: str,
        result: str,
        created_at: datetime,
        updated_at: datetime
    ):
        self.id = id
        self.task_id = task_id
        self.user_id = user_id
        self.result = result
        self.created_at = created_at
        self.updated_at = updated_at
    
    @classmethod
    def from_row(cls, row):
        """Create Annotation instance from database row."""
        return cls(
            id=row["id"],
            task_id=row["task_id"],
            user_id=row["user_id"],
            result=row["result"],
            created_at=row["created_at"],
            updated_at=row["updated_at"]
        )