from contextlib import asynccontextmanager

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse

from api.models import PaperResponse, ScanRequest, ScanResponse, StatusResponse
from api.scanner import (
    ScannerBusyError,
    ScannerManager,
    ScannerTimeoutError,
    ScannerUnavailableError,
)


@asynccontextmanager
async def lifespan(app: FastAPI):
    app.state.scanner = ScannerManager()
    yield


app = FastAPI(title="scan-adf", lifespan=lifespan)


@app.exception_handler(ScannerBusyError)
async def busy_handler(request: Request, exc: ScannerBusyError):
    return JSONResponse(status_code=409, content={"detail": str(exc)})


@app.exception_handler(ScannerUnavailableError)
async def unavailable_handler(request: Request, exc: ScannerUnavailableError):
    return JSONResponse(status_code=503, content={"detail": str(exc)})


@app.exception_handler(ScannerTimeoutError)
async def timeout_handler(request: Request, exc: ScannerTimeoutError):
    return JSONResponse(status_code=504, content={"detail": str(exc)})


@app.post("/scan", status_code=201, response_model=ScanResponse)
async def scan(request: Request, body: ScanRequest):
    scanner: ScannerManager = request.app.state.scanner
    output = await scanner.start_scan(
        mode=body.mode.value,
        resolution=body.resolution,
        language=body.language,
        output=body.output,
    )
    return ScanResponse(
        message="Scan started",
        output=output,
        mode=body.mode.value,
        resolution=body.resolution,
    )


@app.get("/status", response_model=StatusResponse)
async def status(request: Request):
    scanner: ScannerManager = request.app.state.scanner
    return StatusResponse(
        scanning=scanner.is_scanning,
        last_result=scanner.last_result,
        current=scanner.current_scan_info,
    )


@app.get("/paper", response_model=PaperResponse)
async def paper(request: Request):
    scanner: ScannerManager = request.app.state.scanner
    result = await scanner.check_paper()
    return PaperResponse(**result)