from typing import List, Optional, Literal
from pydantic import BaseModel, Field


Role = Literal["system", "user", "assistant"]


class ChatMessage(BaseModel):
    role: Role
    content: str


class ChatRequest(BaseModel):
    messages: List[ChatMessage] = Field(min_length=1)
    model: Optional[str] = None
    temperature: Optional[float] = Field(default=None, ge=0, le=2)
    max_tokens: Optional[int] = Field(default=None, gt=0)


class Usage(BaseModel):
    prompt_tokens: int
    completion_tokens: int
    total_tokens: int


class ChatResponse(BaseModel):
    content: str
    model: Optional[str] = None
    usage: Optional[Usage] = None

class TextToSpeechResponse(BaseModel):
    audio_url: str

class TextToSpeechRequest(BaseModel):
    volume: int = 1
    pitch: float = 1
    rate: float = 1
    filename: str
    text: str
    model: Optional[str] = None
    format: Optional[str] = None