from fastapi import APIRouter, Depends, Header, Request, status
from fastapi.responses import Response

from app.api.dependencies import get_upload_service
from app.schemas.common import ErrorResponse
from app.services.upload_service import CreateUploadInput, UploadService

router = APIRouter()

TUS_VERSION = "1.0.0"


@router.post("", status_code=status.HTTP_201_CREATED, responses={409: {"model": ErrorResponse}})
async def create_tus_upload(
    upload_length: int = Header(alias="Upload-Length"),
    upload_metadata: str | None = Header(default=None, alias="Upload-Metadata"),
    tus_resumable: str = Header(alias="Tus-Resumable"),
    service: UploadService = Depends(get_upload_service),
) -> Response:
    if tus_resumable != TUS_VERSION:
        return Response(status_code=status.HTTP_412_PRECONDITION_FAILED)

    upload_session = await service.create_upload(
        CreateUploadInput(upload_length=upload_length, upload_metadata=upload_metadata)
    )
    return Response(
        status_code=status.HTTP_201_CREATED,
        headers={
            "Location": upload_session.tus_upload_url or f"/files/{upload_session.id}",
            "Tus-Resumable": TUS_VERSION,
        },
    )


@router.head("/{upload_id}")
async def head_tus_upload(
    upload_id: str,
    tus_resumable: str = Header(alias="Tus-Resumable"),
    service: UploadService = Depends(get_upload_service),
) -> Response:
    if tus_resumable != TUS_VERSION:
        return Response(status_code=status.HTTP_412_PRECONDITION_FAILED)

    upload_session = await service.get_upload(upload_id)
    return Response(
        status_code=status.HTTP_200_OK,
        headers={
            "Tus-Resumable": TUS_VERSION,
            "Upload-Offset": str(upload_session.received_size_bytes),
            "Upload-Length": str(upload_session.total_size_bytes),
        },
    )


@router.patch("/{upload_id}", status_code=status.HTTP_204_NO_CONTENT, responses={409: {"model": ErrorResponse}})
async def patch_tus_upload(
    upload_id: str,
    request: Request,
    upload_offset: int = Header(alias="Upload-Offset"),
    tus_resumable: str = Header(alias="Tus-Resumable"),
    content_type: str = Header(alias="Content-Type"),
    service: UploadService = Depends(get_upload_service),
) -> Response:
    if tus_resumable != TUS_VERSION:
        return Response(status_code=status.HTTP_412_PRECONDITION_FAILED)
    if content_type != "application/offset+octet-stream":
        return Response(status_code=status.HTTP_415_UNSUPPORTED_MEDIA_TYPE)

    chunk = await request.body()
    upload_session = await service.append_upload_bytes(upload_id, upload_offset, chunk)
    return Response(
        status_code=status.HTTP_204_NO_CONTENT,
        headers={
            "Tus-Resumable": TUS_VERSION,
            "Upload-Offset": str(upload_session.received_size_bytes),
        },
    )