"""Google Drive API client."""

import io
from typing import Any

from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from googleapiclient.http import MediaIoBaseUpload
from sqlalchemy.ext.asyncio import AsyncSession

from .credentials import get_valid_credentials
from .file_types import GOOGLE_DOC, GOOGLE_SHEET


class GoogleDriveClient:
    """Client for Google Drive API operations."""

    def __init__(
        self,
        session: AsyncSession,
        connector_id: int,
        credentials: "Credentials | None" = None,
    ):
        """
        Initialize Google Drive client.

        Args:
            session: Database session
            connector_id: ID of the Drive connector
            credentials: Pre-built credentials (e.g. from Composio). If None,
                         credentials are loaded from the DB connector config.
        """
        self.session = session
        self.connector_id = connector_id
        self._credentials = credentials
        self.service = None

    async def get_service(self):
        """
        Get or create the Drive service instance.

        Returns:
            Google Drive service instance

        Raises:
            Exception: If service creation fails
        """
        if self.service:
            return self.service

        try:
            if self._credentials:
                credentials = self._credentials
            else:
                credentials = await get_valid_credentials(
                    self.session, self.connector_id
                )
            self.service = build("drive", "v3", credentials=credentials)
            return self.service
        except Exception as e:
            raise Exception(f"Failed to create Google Drive service: {e!s}") from e

    async def list_files(
        self,
        query: str = "",
        fields: str = "nextPageToken, files(id, name, mimeType, modifiedTime, md5Checksum, size, webViewLink, parents, owners, createdTime, description)",
        page_size: int = 100,
        page_token: str | None = None,
    ) -> tuple[list[dict[str, Any]], str | None, str | None]:
        """
        List files from Google Drive with pagination.

        Args:
            query: Search query (e.g., "mimeType != 'application/vnd.google-apps.folder'")
            fields: Fields to retrieve
            page_size: Number of files per page (max 1000)
            page_token: Token for next page

        Returns:
            Tuple of (files list, next_page_token, error message)
        """
        try:
            service = await self.get_service()

            params = {
                "pageSize": min(page_size, 1000),
                "fields": fields,
                "supportsAllDrives": True,
                "includeItemsFromAllDrives": True,
            }

            if query:
                params["q"] = query
            if page_token:
                params["pageToken"] = page_token

            result = service.files().list(**params).execute()

            files = result.get("files", [])
            next_token = result.get("nextPageToken")

            return files, next_token, None

        except HttpError as e:
            error_msg = f"HTTP error listing files: {e.resp.status} - {e.error_details}"
            return [], None, error_msg
        except Exception as e:
            return [], None, f"Error listing files: {e!s}"

    async def get_file_metadata(
        self, file_id: str, fields: str = "*"
    ) -> tuple[dict[str, Any] | None, str | None]:
        """
        Get metadata for a specific file.

        Args:
            file_id: ID of the file
            fields: Fields to retrieve

        Returns:
            Tuple of (file metadata, error message)
        """
        try:
            service = await self.get_service()
            file = (
                service.files()
                .get(fileId=file_id, fields=fields, supportsAllDrives=True)
                .execute()
            )
            return file, None
        except HttpError as e:
            return None, f"HTTP error getting file metadata: {e.resp.status}"
        except Exception as e:
            return None, f"Error getting file metadata: {e!s}"

    async def download_file(self, file_id: str) -> tuple[bytes | None, str | None]:
        """
        Download binary file content.

        Args:
            file_id: ID of the file to download

        Returns:
            Tuple of (file content bytes, error message)
        """
        try:
            service = await self.get_service()
            request = service.files().get_media(fileId=file_id)

            import io

            fh = io.BytesIO()
            from googleapiclient.http import MediaIoBaseDownload

            downloader = MediaIoBaseDownload(fh, request)

            done = False
            while not done:
                _, done = downloader.next_chunk()

            return fh.getvalue(), None

        except HttpError as e:
            return None, f"HTTP error downloading file: {e.resp.status}"
        except Exception as e:
            return None, f"Error downloading file: {e!s}"

    async def export_google_file(
        self, file_id: str, mime_type: str
    ) -> tuple[bytes | None, str | None]:
        """
        Export Google Workspace file to specified format.

        Args:
            file_id: ID of the Google file
            mime_type: Target MIME type (e.g., 'application/pdf', 'text/plain')

        Returns:
            Tuple of (exported content as bytes, error message)
        """
        try:
            service = await self.get_service()
            content = (
                service.files().export(fileId=file_id, mimeType=mime_type).execute()
            )

            # Content is already bytes from the API
            # Keep as bytes to support both text and binary formats (like PDF)
            if not isinstance(content, bytes):
                content = content.encode("utf-8")

            return content, None

        except HttpError as e:
            return None, f"HTTP error exporting file: {e.resp.status}"
        except Exception as e:
            return None, f"Error exporting file: {e!s}"

    async def create_file(
        self,
        name: str,
        mime_type: str,
        parent_folder_id: str | None = None,
        content: str | None = None,
    ) -> dict[str, Any]:
        service = await self.get_service()

        body: dict[str, Any] = {"name": name, "mimeType": mime_type}
        if parent_folder_id:
            body["parents"] = [parent_folder_id]

        media: MediaIoBaseUpload | None = None
        if content:
            if mime_type == GOOGLE_DOC:
                import markdown as md_lib

                html = md_lib.markdown(content)
                media = MediaIoBaseUpload(
                    io.BytesIO(html.encode("utf-8")),
                    mimetype="text/html",
                    resumable=False,
                )
            elif mime_type == GOOGLE_SHEET:
                media = MediaIoBaseUpload(
                    io.BytesIO(content.encode("utf-8")),
                    mimetype="text/csv",
                    resumable=False,
                )

        if media:
            return (
                service.files()
                .create(
                    body=body,
                    media_body=media,
                    fields="id,name,mimeType,webViewLink",
                    supportsAllDrives=True,
                )
                .execute()
            )

        return (
            service.files()
            .create(
                body=body,
                fields="id,name,mimeType,webViewLink",
                supportsAllDrives=True,
            )
            .execute()
        )

    async def trash_file(self, file_id: str) -> bool:
        service = await self.get_service()
        service.files().update(
            fileId=file_id,
            body={"trashed": True},
            supportsAllDrives=True,
        ).execute()
        return True