from fastapi import APIRouter, UploadFile, File, Depends, HTTPException

from PIL import Image, UnidentifiedImageError

from app.services.image_moderation_service import ImageModerationService
from app.core.dependencies import get_image_moderation_service
from app.models.response.image_moderation_response import ImageModerationResponse


router = APIRouter(
    prefix="/api/v1/moderation",
    tags=["Moderation"]
)

MAX_SIZE = 5 * 1024 * 1024  # например, 5 МБ

ALLOWED_CONTENT_TYPES = (
  "image/jpeg",
  "image/png",
  "image/webp",
)


@router.post("/image", response_model=ImageModerationResponse)
def moderate_image(
    file: UploadFile = File(...),
    service: ImageModerationService = Depends(get_image_moderation_service)
):

  # 1. Проверка content-type — самая дешёвая, делаем её первой
  if file.content_type not in ALLOWED_CONTENT_TYPES:
    raise HTTPException(
        status_code=400,
        detail="Unsupported image format"
    )

  # 2. Проверка размера — читаем файл целиком
  contents = file.file.read()

  if len(contents) > MAX_SIZE:
    raise HTTPException(
        status_code=413,
        detail="Image too large"
    )

  file.file.seek(0)  # обязательно вернуть указатель в начало!

  # 3. Только теперь пытаемся открыть изображение
  try:
    image = Image.open(file.file)
    image = image.convert("RGB")
  except UnidentifiedImageError:
    raise HTTPException(
        status_code=400,
        detail="Invalid image"
    )

  prediction = service.moderate(image)

  return ImageModerationResponse(
      approved=prediction.approved,
      score=prediction.score,
      reason=prediction.reason,
      label=prediction.label,
      detected_labels=prediction.detected_labels
  )