import asyncio
import os
import os.path
import shutil
import time
import uuid
from typing import AsyncIterator, Optional

import aiofiles
import aiofiles.os
import aiofiles.ospath
import sentry_sdk
from fastapi import APIRouter, FastAPI, File, Form, HTTPException, UploadFile, status
from fastapi.responses import StreamingResponse
from fastapi_utils.tasks import repeat_every

from config import env_config

if env_config.SENTRY_DSN:
    sentry_sdk.init(
        env_config.SENTRY_DSN,
    )


router = APIRouter(tags=["converter"])


@router.post("/")
async def convert(
    file: Optional[UploadFile] = File(None),
    format: Optional[str] = Form(None),
):
    if file is None or format is None:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST, detail="File and format required!"
        )

    format_lower = format.lower()
    if format_lower not in ["epub", "mobi"]:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST, detail="Bad format!"
        )

    temp_uuid = uuid.uuid1()

    temp_filename = str(temp_uuid) + ".fb2"
    converted_temp_filename = str(temp_uuid) + "." + format_lower

    try:
        async with aiofiles.open(temp_filename, "wb") as f:
            while content := await file.read(1024):
                if isinstance(content, str):
                    content = content.encode()

                await f.write(content)

        proc = await asyncio.create_subprocess_exec(
            "./bin/fb2c",
            "convert",
            "--to",
            format,
            temp_filename,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )

        _, stderr = await proc.communicate()
    finally:
        await aiofiles.os.remove(temp_filename)

    if proc.returncode != 0 or len(stderr) != 0:
        try:
            await aiofiles.os.remove(converted_temp_filename)
        except FileNotFoundError:
            pass

        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST, detail="Can't convert!"
        )

    async def result_iterator() -> AsyncIterator[bytes]:
        try:
            async with aiofiles.open(converted_temp_filename, "rb") as f:
                while data := await f.read(2048):
                    yield data
        finally:
            await aiofiles.os.remove(converted_temp_filename)

    return StreamingResponse(result_iterator())


@router.get("/healthcheck")
async def healthcheck():
    return "Ok!"


app = FastAPI()

app.include_router(router)


@app.on_event("startup")
@repeat_every(seconds=5 * 60, raise_exceptions=True)
def remove_temp_files():
    current_time = time.time()

    try:
        os.remove("./conversion.log")
    except IOError:
        pass

    for f in os.listdir("/tmp/"):
        target_path = f"/tmp/{f}"

        is_file = os.path.isfile(target_path)

        try:
            creation_time = os.path.getctime(target_path)
        except FileNotFoundError:
            continue

        if (current_time - creation_time) // 3600 >= 3:
            if is_file:
                os.remove(target_path)
            else:
                shutil.rmtree(target_path)