# from fastapi import APIRouter, UploadFile, File, Form
# from fastapi.responses import StreamingResponse, JSONResponse
# import io
# import traceback

# from shadow_generator import initialize_once, generate_shadow_rgba

# router = APIRouter()

# # initialize on import / startup
# initialize_once()

# @router.get("/health")
# async def health():
#     return {"ok": True}

# @router.get("/params")
# async def params_info():
#     return {
#         "angle_deg": "float. 0 = right, 90 = down. default 135.0",
#         "distance": "float px offset of shadow. default 40.0",
#         "softness": "float blur radius. default 25.0",
#         "opacity": "float 0..1. default 0.7",
#         "color": "hex color for shadow. default '#000000'",
#         "spread": "float px. positive expands alpha, negative contracts. default 0.0",
#         "shadow_type": "string. 'drop' or 'contact'. default 'drop'",
#     }

# @router.post("/generate-shadow")
# async def generate_shadow_endpoint(
#     image: UploadFile = File(..., description="RGBA PNG with transparent background"),
#     angle_deg: float = Form(135.0),
#     distance: float = Form(40.0),
#     softness: float = Form(25.0),
#     opacity: float = Form(0.7),
#     color: str = Form("#000000"),
#     spread: float = Form(0.0),
#     shadow_type: str = Form("drop"),
#     use_ssn: bool = Form(True)
# ):
#     """
#     Returns: PNG (RGBA) bytes stream containing object + generated shadow.
#     """
#     try:
#         data = await image.read()
#         params = {
#             "angle_deg": angle_deg,
#             "distance": distance,
#             "softness": softness,
#             "opacity": opacity,
#             "color": color,
#             "spread": spread,
#             "shadow_type": shadow_type,
#             "prefer_ssn": use_ssn
#         }
#         out_bytes = generate_shadow_rgba(data, params=params)
#         return StreamingResponse(io.BytesIO(out_bytes), media_type="image/png")
#     except Exception as exc:
#         traceback.print_exc()
#         return JSONResponse(status_code=500, content={"error": str(exc)})


# from fastapi import APIRouter, UploadFile, File, Form
# from fastapi.responses import StreamingResponse, JSONResponse
# import io
# import traceback

# from shadow_generator import load_ssn_once, generate_shadow_rgba

# router = APIRouter()

# # Lazy initialization placeholder
# _ssn_wrapper = None

# def get_ssn_wrapper():
#     global _ssn_wrapper
#     if _ssn_wrapper is None:
#         _ssn_wrapper = load_ssn_once()
#     return _ssn_wrapper

# @router.get("/health")
# async def health():
#     return {"ok": True}

# @router.get("/params")
# async def params_info():
#     return {
#         "angle_deg": "float. 0 = right, 90 = down. default 135.0",
#         "distance": "float px offset of shadow. default 40.0",
#         "softness": "float blur radius. default 25.0",
#         "opacity": "float 0..1. default 0.7",
#         "color": "hex color for shadow. default '#000000'",
#         "spread": "float px. positive expands alpha, negative contracts. default 0.0",
#         "shadow_type": "string. 'drop' or 'contact'. default 'drop'",
#     }

# @router.post("/generate-shadow")
# async def generate_shadow_endpoint(
#     image: UploadFile = File(..., description="RGBA PNG with transparent background"),
#     angle_deg: float = Form(135.0),
#     distance: float = Form(40.0),
#     softness: float = Form(25.0),
#     opacity: float = Form(0.7),
#     color: str = Form("#000000"),
#     spread: float = Form(0.0),
#     shadow_type: str = Form("drop"),
#     use_ssn: bool = Form(True)
# ):
#     try:
#         data = await image.read()
#         params = {
#             "angle_deg": angle_deg,
#             "distance": distance,
#             "softness": softness,
#             "opacity": opacity,
#             "color": color,
#             "spread": spread,
#             "shadow_type": shadow_type,
#             "prefer_ssn": use_ssn
#         }

#         # Lazy load SSN model
#         ssn = get_ssn_wrapper()
#         if not ssn.available():
#             return JSONResponse(status_code=503, content={"error": "SSN model is still loading. Try again shortly."})

#         out_bytes = generate_shadow_rgba(data, params=params)
#         return StreamingResponse(io.BytesIO(out_bytes), media_type="image/png")
#     except Exception as exc:
#         traceback.print_exc()
#         return JSONResponse(status_code=500, content={"error": str(exc)})

from fastapi import APIRouter, File, UploadFile, Form
from fastapi.responses import Response, JSONResponse
import shadow_generator
from typing import Optional
import io

router = APIRouter()

@router.post("/generate-shadow")
async def generate_shadow_route(
    file: UploadFile = File(...),
    style: Optional[str] = Form("cast"),        # NEW: allow drop / cast / soft / bent
    softness: Optional[float] = Form(28.0),
    opacity: Optional[float] = Form(0.7),
    color: Optional[str] = Form("#000000"),
    direction: Optional[float] = Form(0.0),
    distance: Optional[float] = Form(80.0),     # NEW: needed for cast shadows
):
    """
    Generate a shadowed image from input.
    Styles: 'drop', 'cast', 'angled', 'soft'
    """
    image_bytes = await file.read()

    params = {
        "style": style,
        "softness": softness,
        "opacity": opacity,
        "color": color,
        "direction": direction,
        "distance": distance,
    }

    try:
        output_image_bytes = shadow_generator.generate_shadow_rgba(image_bytes, params)
        return Response(content=output_image_bytes, media_type="image/png")
    except Exception as e:
        return JSONResponse(status_code=500, content={"error": str(e)})


@router.on_event("startup")
async def startup_event():
    """
    Initialize model once on server start.
    """
    shadow_generator.initialize_once()