src/domain/models/audio_content.py

"""AudioContent value object for representing audio data with validation."""

from dataclasses import dataclass
from typing import Optional


@dataclass(frozen=True)
class AudioContent:
    """Value object representing audio content with metadata and validation."""
    
    data: bytes
    format: str
    sample_rate: int
    duration: float
    filename: Optional[str] = None
    
    def __post_init__(self):
        """Validate audio content after initialization."""
        self._validate()
    
    def _validate(self):
        """Validate audio content properties."""
        if not self.data:
            raise ValueError("Audio data cannot be empty")
        
        if not isinstance(self.data, bytes):
            raise TypeError("Audio data must be bytes")
        
        if self.format not in ['wav', 'mp3', 'flac', 'ogg']:
            raise ValueError(f"Unsupported audio format: {self.format}. Supported formats: wav, mp3, flac, ogg")
        
        if self.sample_rate <= 0:
            raise ValueError("Sample rate must be positive")
        
        if self.sample_rate < 8000 or self.sample_rate > 192000:
            raise ValueError("Sample rate must be between 8000 and 192000 Hz")
        
        if self.duration <= 0:
            raise ValueError("Duration must be positive")
        
        if self.duration > 3600:  # 1 hour limit
            raise ValueError("Audio duration cannot exceed 1 hour")
        
        if self.filename is not None and not self.filename.strip():
            raise ValueError("Filename cannot be empty string")
    
    @property
    def size_bytes(self) -> int:
        """Get the size of audio data in bytes."""
        return len(self.data)
    
    @property
    def is_valid_format(self) -> bool:
        """Check if the audio format is valid."""
        return self.format in ['wav', 'mp3', 'flac', 'ogg']