import os
import shutil
from pathlib import Path

from fastapi import APIRouter, HTTPException, Query, UploadFile, File
from fastapi.responses import Response
import openslide

from app.models.schemas import SlideLoadRequest, SlideMetadata
from app.services.slide_cache import get_slide, load_slide
from app.services.tile_service import get_tile_jpeg, get_thumbnail_jpeg

router = APIRouter()

UPLOAD_DIR = Path(
    os.getenv(
        "TILE_SERVER_UPLOAD_DIR",
        Path(__file__).resolve().parents[2] / "data" / "uploads",
    )
)
UPLOAD_DIR.mkdir(parents=True, exist_ok=True)


@router.post("/slides/{slide_id}/load")
def load(slide_id: str, payload: SlideLoadRequest):
    try:
        load_slide(slide_id, payload.path)
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    return {"status": "loaded", "slide_id": slide_id}


@router.post("/slides/{slide_id}/upload")
def upload(slide_id: str, file: UploadFile = File(...)):
    if not slide_id:
        raise HTTPException(status_code=400, detail="Slide id is required")

    filename = Path(file.filename or "")
    suffix = filename.suffix.lower()
    if suffix not in {".svs", ".tif", ".tiff"}:
        suffix = ".svs"

    dest_path = UPLOAD_DIR / f"{slide_id}{suffix}"

    try:
        with dest_path.open("wb") as buffer:
            shutil.copyfileobj(file.file, buffer)
    except Exception as exc:
        raise HTTPException(status_code=500, detail=f"Upload failed: {exc}")
    finally:
        try:
            file.file.close()
        except Exception:
            pass

    try:
        load_slide(slide_id, str(dest_path))
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc))

    return {"status": "uploaded", "slide_id": slide_id}


@router.post("/slides/{slide_id}/reload")
def reload_uploaded(slide_id: str):
    if not slide_id:
        raise HTTPException(status_code=400, detail="Slide id is required")

    matches = list(UPLOAD_DIR.glob(f"{slide_id}.*"))
    if not matches:
        raise HTTPException(status_code=404, detail="Uploaded slide not found")

    try:
        load_slide(slide_id, str(matches[0]))
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc))

    return {"status": "reloaded", "slide_id": slide_id}


@router.get("/slides/{slide_id}/metadata", response_model=SlideMetadata)
def metadata(slide_id: str):
    slide = get_slide(slide_id)
    if slide is None:
        raise HTTPException(status_code=404, detail="Slide not loaded")

    mpp_x = slide.properties.get(openslide.PROPERTY_NAME_MPP_X)
    mpp_y = slide.properties.get(openslide.PROPERTY_NAME_MPP_Y)

    def _to_float(value):
        try:
            return float(value)
        except (TypeError, ValueError):
            return None

    return SlideMetadata(
        width=slide.dimensions[0],
        height=slide.dimensions[1],
        level_count=slide.level_count,
        level_dimensions=[[int(w), int(h)] for w, h in slide.level_dimensions],
        level_downsamples=[float(d) for d in slide.level_downsamples],
        mpp_x=_to_float(mpp_x),
        mpp_y=_to_float(mpp_y),
    )


@router.get("/tiles/{slide_id}/{level}/{x}/{y}.jpg")
def tile(
    slide_id: str,
    level: int,
    x: int,
    y: int,
    tile_size: int = Query(256, ge=64, le=2048),
    channel: str = Query("original"),
):
    slide = get_slide(slide_id)
    if slide is None:
        raise HTTPException(status_code=404, detail="Slide not loaded")

    try:
        jpeg_bytes = get_tile_jpeg(slide, level, x, y, tile_size, channel)
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc))

    return Response(content=jpeg_bytes, media_type="image/jpeg")


@router.get("/slides/{slide_id}/thumbnail")
def thumbnail(
    slide_id: str,
    size: int = Query(256, ge=64, le=1024),
    channel: str = Query("original"),
):
    slide = get_slide(slide_id)
    if slide is None:
        raise HTTPException(status_code=404, detail="Slide not loaded")

    try:
        jpeg_bytes = get_thumbnail_jpeg(slide, size, channel)
    except Exception as exc:
        raise HTTPException(status_code=400, detail=str(exc))

    return Response(content=jpeg_bytes, media_type="image/jpeg")