import io
import logging
import re
from typing import Iterator

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.responses import StreamingResponse
from PIL import Image
from webdav3.exceptions import RemoteResourceNotFound

from .. import CLIENT
from ..dav_file import DavFile

_logger = logging.getLogger(__name__)

router = APIRouter(prefix="/image", tags=["image"])


@router.on_event("startup")
async def on_startup():
    _logger.debug("image router started")


_re_image_file = re.compile(
    r"\.(gif|jpe?g|tiff?|png|bmp)$",
    flags=re.IGNORECASE,
)


async def get_image_file_names() -> Iterator[str]:
    try:
        file_names = CLIENT.list("img")

        return (
            name
            for name in file_names
            if _re_image_file.search(name)
        )

    except RemoteResourceNotFound:
        pass


@router.get("/list", response_model=list[str])
async def list_images(
    image_file_names: Iterator[str] = Depends(get_image_file_names),
) -> list[str]:
    return list(image_file_names)


async def find_file_names(
    prefix: str = "",
    image_file_names: Iterator[str] = Depends(get_image_file_names),
) -> Iterator[str]:
    return (
        file_name
        for file_name in image_file_names
        if file_name.lower().startswith(prefix.lower())
    )


@router.get("/find/{prefix}", response_model=list[str])
async def find_images(
    file_names: Iterator[str] = Depends(find_file_names),
) -> list[str]:
    return list(file_names)


@router.get(
    "/get/{prefix}",
    responses={
        status.HTTP_200_OK: {
            "description": "Operation successful",
        },
        status.HTTP_404_NOT_FOUND: {
            "description": "image file not found",
            "content": None,
        },
        status.HTTP_409_CONFLICT: {
            "description": "ambiguous image file name",
            "content": None,
        },
    },
)
async def get_image(
    prefix: str,
    file_names: Iterator[str] = Depends(find_file_names),
) -> StreamingResponse:
    file_names = list(file_names)

    if not (file_names := list(file_names)):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)

    elif len(file_names) > 1:
        raise HTTPException(status_code=status.HTTP_409_CONFLICT)

    file_name = file_names[0]
    file = DavFile(CLIENT.resource(f"img/{file_name}"), refresh=False)
    await file.download()
    img = Image.open(io.BytesIO(file.bytes)).convert("RGB")

    img_buffer = io.BytesIO()
    img.save(img_buffer, format='JPEG', quality=85)
    img_buffer.seek(0)

    return StreamingResponse(
        img_buffer,
        media_type="image/jpeg",
        headers={
            "Content-Disposition": f"filename={prefix}.jpg"
        },
    )