from pydantic import BaseModel, Field

class TTSRequest(BaseModel):
    text: str = Field(..., min_length=1, max_length=5000)
    # gTTS uses language codes; keep voice field for compatibility.
    voice: str = Field(default="en")
    # Free backend supports only mp3.
    format: str = Field(default="mp3", pattern="^(mp3)$")

    class Config:
        json_schema_extra = {
            "example": {
                "text": "Hello, this is a test of text-to-speech.",
                "voice": "en",
                "format": "mp3",
            }
        }