import hashlib
import os.path
from abc import ABCMeta, abstractmethod
from datetime import UTC, datetime
from enum import Enum
from io import BytesIO
from pathlib import Path
from typing import Any, AsyncIterable, AsyncIterator, Optional
import uuid

import aioboto3  # type: ignore
import aiofiles
import magic  # type: ignore
from botocore.client import BaseClient  # type: ignore
from botocore.exceptions import ClientError  # type: ignore
from PIL import Image

from server.config import AppConfig, get_app_config
from server.infra.db import AbstractSession
from server.infra.logger import get_logger
from server.modules.attachments.domains.attachments import Attachment
from server.modules.attachments.repositories.attachments import AttachmentRepository


class StorageDriversType(str, Enum):
    MOCK = "mock"
    LOCAL = "local"
    S3 = "s3"


class MediaType(str, Enum):
    AUDIO = "audio"
    VIDEO = "video"
    IMAGE = "image"
    SVG_IMAGE = "svg_image"
    OTHER = "other"


class StorageDriver(metaclass=ABCMeta):
    @abstractmethod
    def get_name(self) -> str:
        pass

    @abstractmethod
    async def put(self, data: bytes) -> str:
        pass

    @abstractmethod
    async def take(self, path: str) -> Optional[bytes]:
        pass

    @abstractmethod
    async def stream(self, path: str) -> AsyncIterable[Any]:
        pass

    @abstractmethod
    async def delete(self, path: str):
        pass


class LocalStorageDriver(StorageDriver):
    _mount_dir: Path

    def __init__(self) -> None:
        self._mount_dir = Path(get_app_config().fs_local_mount_dir)  # type: ignore

    def get_name(self) -> str:
        return StorageDriversType.LOCAL.value

    async def put(self, data: bytes) -> str:
        dir_path = self._mount_dir / Path(datetime.now(UTC).strftime("%d"))
        if not os.path.isdir(dir_path):
            os.mkdir(dir_path)
        path = dir_path / Path(hashlib.file_digest(BytesIO(data), "sha256").hexdigest())
        if os.path.isfile(path) and os.stat(path).st_size == len(data):
            return str(path)
        async with aiofiles.open(path, "wb") as f:
            await f.write(data)
        return str(path)

    async def take(self, path: str) -> Optional[bytes]:
        if not os.path.isfile(path):
            return None
        async with aiofiles.open(path, "rb") as f:
            return await f.read()

    async def stream(self, path: str):
        async with aiofiles.open(path, mode="rb") as f:
            while chunk := await f.read(1024):
                yield chunk

    async def delete(self, path: str):
        if not os.path.isfile(path):
            return
        os.remove(path)


class MockStorageDriver(StorageDriver):
    _store: dict[str, bytes]

    def __init__(self) -> None:
        self._store = {}

    def get_name(self) -> str:
        return StorageDriversType.MOCK.value

    async def stream(self, path: str) -> AsyncIterable:
        raise NotImplementedError

    async def put(self, data: bytes) -> str:
        path = str(uuid.uuid4())
        self._store[path] = data
        return path

    async def take(self, path: str) -> Optional[bytes]:
        return self._store.get(path)

    async def delete(self, path: str):
        del self._store[path]


class S3StorageDriver(StorageDriver):
    _prefix: str = "pvc-435e5137-052f-43b1-ace2-e350c9d50c76"

    def __init__(self, cnf: AppConfig) -> None:
        self._chunk_size: int = 69 * 1024
        self._cnf = cnf
        self._logger = get_logger()
        self._session = aioboto3.Session(
            aws_access_key_id=str(cnf.fs_s3_access_key_id),
            aws_secret_access_key=str(cnf.fs_s3_access_key),
        )

    def get_name(self) -> str:
        return StorageDriversType.S3.value

    async def _client(self) -> BaseClient:
        return self._session.client("s3", endpoint_url=self._cnf.fs_s3_endpoint)

    def _normalize_path(self, path: str) -> str:
        return f"{S3StorageDriver._prefix}{path}".replace(
            self._cnf.fs_local_mount_dir, ""
        )

    async def put(self, data: bytes) -> str:
        sign = hashlib.file_digest(BytesIO(data), "sha256").hexdigest()
        day = datetime.now(UTC).strftime("%d")
        path = str(Path(S3StorageDriver._prefix) / day / sign)

        async with await self._client() as s3:
            await s3.upload_fileobj(
                Fileobj=BytesIO(data),
                Bucket=self._cnf.fs_s3_bucket,
                Key=path,
                ExtraArgs={
                    "ChecksumAlgorithm": "SHA256",
                    "ChecksumSHA256": sign,
                },
            )
        return path.replace(S3StorageDriver._prefix, "")

    async def stream(self, path: str):
        path = self._normalize_path(path)
        self._logger.debug(
            f"stream s3 path {path}, bucket {self._cnf.fs_s3_bucket}, endpoint {self._cnf.fs_s3_endpoint}"
        )

        try:
            async with await self._client() as s3:
                obj = await s3.get_object(Bucket=self._cnf.fs_s3_bucket, Key=path)
                body = obj["Body"]
                while chunk := await body.read(self._chunk_size):
                    yield chunk
        except ClientError as e:
            if e.response.get("Error", {}).get("Code") != "NoSuchKey":
                self._logger.error(f"stream client error: {str(e)}, path: {path}")
            raise FileNotFoundError
        except Exception as e:
            self._logger.error(
                f"stream error: {type(e).__name__} {str(e)}, path: {path}"
            )
            raise FileNotFoundError

    async def take(self, path: str) -> Optional[bytes]:
        buffer = BytesIO()
        async for chunk in self.stream(path):
            if chunk:
                buffer.write(chunk)
        content = buffer.getvalue()
        return content if content else None

    async def delete(self, path: str) -> None:
        async with await self._client() as s3:
            await s3.delete_object(
                Bucket=self._cnf.fs_s3_bucket, Key=self._normalize_path(path)
            )


RESIZE_MAX_SIZE = 100_000
RESIZE_PARAMS = (500, 500)


class AtachmentService:
    _driver: StorageDriver
    _repository: AttachmentRepository
    _cnf: AppConfig

    def __init__(self, driver: StorageDriver, attach_repository: AttachmentRepository):
        self._driver = driver
        self._repository = attach_repository
        self._cnf = get_app_config()

    def media_type(self, content_type: str) -> MediaType:
        if content_type == "":
            return MediaType.OTHER
        firt_part = content_type.split("/")[0]
        match firt_part:
            case str(MediaType.SVG_IMAGE):
                return MediaType.SVG_IMAGE
            case str(MediaType.IMAGE):
                return MediaType.IMAGE
            case str(MediaType.AUDIO):
                return MediaType.AUDIO
            case str(MediaType.VIDEO):
                return MediaType.VIDEO
            case _:
                return MediaType.OTHER

    def content_type(self, file: bytes) -> str:
        return magic.from_buffer(file[0:2048], mime=True)

    def extension(self, content_type: str | None) -> str:
        if not content_type:
            return "jpg"
        if len(content_type.split("/")) != 2:
            return "jpg"
        return content_type.split("/")[1].split("+")[0]

    def id_from_url(self, url: str) -> str:
        if ".original" not in url:
            raise ValueError(f"wrong url: {url}")
        parts = url.split(".original")[0]
        return parts.replace("/", "")

    def url(self, attachment_id: str, content_type: str | None = None) -> str:
        return f"{self._cnf.app_public_url}/api/v0/attachment/{attachment_id}.original.{
            self.extension(content_type)
        }"

    async def create(self, file: bytes, user_id: str) -> Attachment:
        path = await self._driver.put(file)
        content_type = self.content_type(file)
        attach = Attachment(
            size=len(file),
            storage_driver_name=str(self._driver.get_name()),
            path=path,
            media_type=self.media_type(content_type),
            content_type=content_type,
            created_by=user_id,
            id=str(uuid.uuid4()),
            created_at=datetime.now(UTC),
            updated_at=datetime.now(UTC),
        )
        await self._repository.create(attach)
        return attach

    async def get_info(
        self, session: AbstractSession | None, attach_id: list[str]
    ) -> list[Attachment]:
        if not attach_id:
            return []
        if session is not None:
            return await self._repository.get_by_id(session, attach_id)
        async with self._repository.db().session_slave() as session:
            return await self._repository.get_by_id(session, attach_id)

    def get_name(self, attachment: Attachment) -> str:
        return f"{attachment.id}.{self.extension(attachment.content_type)}"

    async def get_data(
        self, session: AbstractSession, attach_id: str
    ) -> Optional[bytes]:
        file = await self._repository.get_by_id(session, [attach_id])
        if not file:
            return None
        return await self._driver.take(file[0].path)

    async def get_stream(
        self, session: AbstractSession | None, attach_id: str
    ) -> AsyncIterator[bytes]:
        async def _stream_iterator(is_empty: bool):
            if is_empty:
                return
            yield first_chunk
            async for chunk in stream:  # type: ignore
                yield chunk

        if session:
            file = await self._repository.get_by_id(session, [attach_id])
        else:
            async with self._repository.db().session_slave() as session:
                file = await self._repository.get_by_id(session, [attach_id])
        if not file:
            raise FileNotFoundError

        stream = self._driver.stream(file[0].path)
        try:
            first_chunk = await stream.__anext__()  # type: ignore
        except StopAsyncIteration:
            return _stream_iterator(is_empty=True)
        return _stream_iterator(is_empty=False)

    async def image_resize(self, session: AbstractSession, attach_id: list[str]):
        info = await self.get_info(session, attach_id)
        get_logger().info(
            f"image_resize {len(info)}",
        )
        if not info:
            return
        for item in info:
            if item.media_type != MediaType.IMAGE.value:
                continue
            if item.is_deleted:
                continue
            data = await self.get_data(session, item.id)
            if data is None:
                continue
            if len(data) <= RESIZE_MAX_SIZE:
                get_logger().info(
                    f"skip because size: {len(data)}",
                )
                continue
            img = Image.open(BytesIO(data))
            img.thumbnail(RESIZE_PARAMS)
            buffer = BytesIO()
            img.save(buffer, format="JPEG", quality=70)
            buffer.seek(0)
            d = buffer.read()
            if d == 0:
                return
            buffer.close()
            get_logger().info(
                f"delete:{item.path}",
            )
            path = await self._driver.put(d)
            await self._repository.update(
                item.id, path=path, content_type="image/jpeg", size=len(d)
            )
            await self._driver.delete(item.path)