"""Value object for comment content.

This module defines the CommentContent value object that validates
and encapsulates comment text content.
"""

from dataclasses import dataclass

from app.domain.value_objects.base import ValueObject


@dataclass(frozen=True, slots=True)
class CommentContent(ValueObject[str]):
    """Comment content value object.

    Wraps and validates comment content ensuring it meets length
    requirements and is not empty.

    Attributes:
        value: The comment content string.
        MAX_LENGTH: Maximum allowed content length (5000 characters).

    Raises:
        ValueError: If content is empty or too long.

    Example:
        >>> content = CommentContent("This is a **bold** comment.")
        >>> content.value
        'This is a **bold** comment.'
    """

    MAX_LENGTH: int = 5000

    def _validate(self) -> None:
        """Validate comment content.

        Checks that content is a non-empty string within length bounds.

        Raises:
            ValueError: If content fails validation criteria.
        """
        if not isinstance(self.value, str):
            raise ValueError("Comment content must be a string")
        if not self.value.strip():
            raise ValueError("Comment content cannot be empty")
        if len(self.value) > self.MAX_LENGTH:
            raise ValueError(f"Comment content must be at most {self.MAX_LENGTH} characters")