from datetime import datetime
from typing import Literal, Optional

from pydantic import BaseModel, Field


class GenerateRequest(BaseModel):
    prompt: str = Field(..., min_length=1, max_length=1000)
    negative_prompt: str = Field(default="", max_length=1000)
    quality_mode: Literal["preview", "refine"]
    duration_sec: int = Field(default=5, ge=1, le=5)
    width: int = Field(default=832, ge=64, le=832)
    height: int = Field(default=480, ge=64, le=480)
    fps: int = Field(default=16, ge=1, le=24)
    steps: int = Field(default=8, ge=1, le=100)
    seed: Optional[int] = Field(default=None, ge=0, le=2**31 - 1)


class TaskStatusResponse(BaseModel):
    task_id: str
    status: Literal["PENDING", "RUNNING", "SUCCEEDED", "FAILED"]
    backend: Optional[str] = None
    model_name: Optional[str] = None
    progress: float = 0.0
    created_at: datetime
    updated_at: datetime


class TaskResultResponse(BaseModel):
    task_id: str
    status: Literal["PENDING", "RUNNING", "SUCCEEDED", "FAILED"]
    video_path: Optional[str] = None
    first_frame_path: Optional[str] = None
    metadata_path: Optional[str] = None
    log_path: Optional[str] = None
    error: Optional[str] = None


class HealthResponse(BaseModel):
    service_status: str
    cuda_available: bool
    gpu_name: Optional[str]
    ltx_loaded: bool
    hunyuan_loaded: bool