own_assist/mcp_server_collection/src/caldav/client.rs

use http::{StatusCode, Uri};
use hyper_rustls::{HttpsConnector, HttpsConnectorBuilder};
use hyper_util::client::legacy::Client;
use hyper_util::client::legacy::connect::HttpConnector;
use hyper_util::rt::TokioExecutor;
use icalendar::{Calendar, CalendarComponent};
use libdav::caldav::{FindCalendarHomeSet, FindCalendars, GetCalendarResources};
use libdav::dav::{FoundCollection, PutResource, PutResourceResponse, WebDavClient, WebDavError};
use libdav::{CalDavClient, FetchedResource};
use rmcp::ErrorData;
use rmcp::model::ErrorCode;
use thiserror::Error;
use tower_http::auth::AddAuthorization;
use tracing::event;
use tracing::Level;
use uuid::Uuid;

pub(crate) type AuthorizedCaldavClient =
    CalDavClient<AddAuthorization<Client<HttpsConnector<HttpConnector>, String>>>;

pub(crate) fn get_caldav_client(
    webdav_uri: Uri,
    username: &str,
    password: &str,
) -> AuthorizedCaldavClient {
    let https_connector: HttpsConnector<HttpConnector> = HttpsConnectorBuilder::new()
        .with_native_roots()
        .unwrap()
        .https_only()
        .enable_http1()
        .build();

    let https_client: Client<HttpsConnector<HttpConnector>, _> =
        Client::builder(TokioExecutor::new()).build(https_connector);

    let https_client_with_auth = AddAuthorization::basic(https_client, username, password);

    CalDavClient::new(WebDavClient::new(webdav_uri, https_client_with_auth))
}

#[derive(Error, Debug)]
pub(crate) enum CalendarError {
    #[error("failed to get user principal")]
    UserPrincipalError(
        #[from] libdav::dav::FindCurrentUserPrincipalError<hyper_util::client::legacy::Error>,
    ),
    #[error("User Principal does not exist")]
    NoUserPrincipal,
    #[error("webdav error")]
    WebDavError(#[from] WebDavError<hyper_util::client::legacy::Error>),
    #[error("unavailable resource")]
    UnavailableResourceError(StatusCode),
    #[error("failed Parsing a caldav resource")]
    ParsingError(String),
}

impl From<CalendarError> for ErrorData {
    fn from(value: CalendarError) -> Self {
        use crate::caldav::client::CalendarError::*;

        match value {
            UserPrincipalError(e) => ErrorData::new(ErrorCode::INTERNAL_ERROR, e.to_string(), None),
            NoUserPrincipal => ErrorData::new(
                ErrorCode::RESOURCE_NOT_FOUND,
                "no user principal".to_string(),
                None,
            ),
            WebDavError(e) => ErrorData::new(ErrorCode::INTERNAL_ERROR, e.to_string(), None),
            UnavailableResourceError(e) => {
                ErrorData::new(ErrorCode::RESOURCE_NOT_FOUND, e.to_string(), None)
            }
            ParsingError(e) => ErrorData::new(ErrorCode::INTERNAL_ERROR, e.to_string(), None),
        }
    }
}

pub(crate) async fn find_calendars(
    caldav_client: &AuthorizedCaldavClient,
) -> Result<Vec<FoundCollection>, CalendarError> {
    use CalendarError::*;

    let user_principal = caldav_client
        .find_current_user_principal()
        .await?
        .ok_or(NoUserPrincipal)?;

    let calendar_home_sets = caldav_client
        .request(FindCalendarHomeSet::new(&user_principal))
        .await?
        .home_sets;

    Ok(caldav_client
        .request(FindCalendars::new(&calendar_home_sets[0]))
        .await?
        .calendars)
}

pub(crate) async fn get_calendar_resources(
    caldav_client: &AuthorizedCaldavClient,
    calendar: &FoundCollection,
) -> Result<Vec<FetchedResource>, CalendarError> {
    let calendar_resources = caldav_client
        .request(GetCalendarResources::new(calendar.href.as_str()))
        .await
        .map_err(CalendarError::WebDavError)?
        .resources;

    Ok(calendar_resources)
}

pub(crate) async fn upload_components(
    authorized_client: &AuthorizedCaldavClient,
    calendar: &FoundCollection,
    components: Vec<impl Into<CalendarComponent>>,
) -> Result<PutResourceResponse, CalendarError> {
    event!(Level::INFO, "uploading components to {}", calendar.href);
    let mut upload_calendar = Calendar::new();

    for todo in components {
        upload_calendar.push(todo);
    }

    Ok(authorized_client
        .request(
            PutResource::new(format!("{}{}.ics", calendar.href, Uuid::new_v4()).as_str())
                .create(upload_calendar.to_string().leak(), "text/caldav"),
        )
        .await?)
}

pub(crate) async fn get_components(
    authorized_client: &AuthorizedCaldavClient,
    calendar: &FoundCollection,
) -> Result<Vec<CalendarComponent>, CalendarError> {
    use CalendarError::*;

    let mut components: Vec<CalendarComponent> = Vec::new();

    let resources = get_calendar_resources(authorized_client, calendar).await?;
    for i in resources {
        let calendar: Calendar = i
            .content
            .map_err(UnavailableResourceError)?
            .data
            .parse()
            .map_err(ParsingError)?;
        components.extend(calendar.components);
    }

    Ok(components)
}