from __future__ import annotations

from typing import Optional

from pydantic import BaseModel, Field, field_validator

from app.config import settings


# --- Request ---

class GenerateForm(BaseModel):
    prompt: Optional[str] = Field(None, max_length=1000)
    width: int = Field(768, ge=256, le=2048, multiple_of=32)
    height: int = Field(512, ge=256, le=2048, multiple_of=32)
    num_frames: int = Field(65, ge=9, le=settings.max_frame_count)
    fps: float = Field(24.0, gt=0, le=60)
    seed: Optional[int] = Field(None)

    model_config = {"extra": "forbid"}

    @field_validator("num_frames")
    @classmethod
    def check_frames(cls, v: int) -> int:
        if v % 8 != 1:
            n = v // 8
            candidates = sorted(
                8 * i + 1
                for i in range(max(1, n - 2), n + 3)
                if 8 * i + 1 <= settings.max_frame_count
            )
            raise ValueError(f"num_frames must be 8n+1. Got {v}. Closest valid: {candidates}")
        return v


# --- Job Status ---

class JobStatusResponse(BaseModel):
    job_id: str
    status: str  # pending, processing, completed, failed
    prompt: Optional[str] = None
    params: Optional[dict] = None
    error: Optional[str] = None
    created_at: Optional[str] = None
    completed_at: Optional[str] = None


# --- Submission Response ---

class JobSubmitResponse(BaseModel):
    job_id: str
    status: str = "pending"
    message: str = "Job submitted. Poll GET /jobs/{job_id} for status."


# --- Error ---

class ErrorResponse(BaseModel):
    error: str