golgi/src/sbot/about.rs

use std::collections::HashMap;

use async_std::stream::{Stream, StreamExt};
use futures::pin_mut;

use crate::{
    error::GolgiError,
    messages::{SsbMessageContentType, SsbMessageValue},
    sbot::{
        get_subset::{SubsetQuery, SubsetQueryOptions},
        sbot_connection::Sbot,
    },
};

impl Sbot {
    /// Get the about messages for a particular user in order of recency.
    pub async fn get_about_message_stream(
        &mut self,
        ssb_id: &str,
    ) -> Result<impl Stream<Item = Result<SsbMessageValue, GolgiError>>, GolgiError> {
        let query = SubsetQuery::Author {
            op: "author".to_string(),
            feed: ssb_id.to_string(),
        };
        // specify that most recent messages should be returned first
        let query_options = SubsetQueryOptions {
            descending: Some(true),
            keys: None,
            page_limit: None,
        };
        let get_subset_stream = self.get_subset_stream(query, Some(query_options)).await?;
        // TODO: after fixing sbot regression,
        // change this subset query to filter by type about in addition to author
        // and remove this filter section
        // filter down to about  messages
        let about_message_stream = get_subset_stream.filter(|msg| match msg {
            Ok(val) => val.is_message_type(SsbMessageContentType::About),
            Err(_err) => false,
        });
        // return about message stream
        Ok(about_message_stream)
    }

    /// Get value of latest about message with given key from given user
    pub async fn get_latest_about_message(
        &mut self,
        ssb_id: &str,
        key: &str,
    ) -> Result<Option<String>, GolgiError> {
        // get about_message_stream
        let about_message_stream = self.get_about_message_stream(ssb_id).await?;
        // now we have a stream of about messages with most recent at the front of the vector
        pin_mut!(about_message_stream);
        // iterate through the vector looking for most recent about message with the given key
        let latest_about_message_res: Option<Result<SsbMessageValue, GolgiError>> =
            about_message_stream
                // find the first msg that contains the field `key`
                .find(|res| match res {
                    Ok(msg) => msg.content.get(key).is_some(),
                    Err(_) => false,
                })
                .await;
        // Option<Result<SsbMessageValue, GolgiError>> -> Option<SsbMessageValue>
        let latest_about_message = latest_about_message_res.and_then(|msg| msg.ok());
        // Option<SsbMessageValue> -> Option<String>
        let latest_about_value = latest_about_message.and_then(|msg| {
            msg
                // SsbMessageValue -> Option<&Value>
                .content
                .get(key)
                // Option<&Value> -> <Option<&str>
                .and_then(|value| value.as_str())
                // Option<&str> -> Option<String>
                .map(|value| value.to_string())
        });
        // return value is either `Ok(Some(String))` or `Ok(None)`
        Ok(latest_about_value)
    }

    /// Get HashMap of profile info for given user
    pub async fn get_profile_info(
        &mut self,
        ssb_id: &str,
    ) -> Result<HashMap<String, String>, GolgiError> {
        let keys_to_search_for = vec!["name", "description", "image"];
        self.get_about_info(ssb_id, keys_to_search_for).await
    }

    /// Get HashMap of name and image for given user
    /// (this is can be used to display profile images of a list of users)
    pub async fn get_name_and_image(
        &mut self,
        ssb_id: &str,
    ) -> Result<HashMap<String, String>, GolgiError> {
        let keys_to_search_for = vec!["name", "image"];
        self.get_about_info(ssb_id, keys_to_search_for).await
    }

    /// Get HashMap of about keys to values for given user
    /// by iteratively searching through a stream of about messages,
    /// in order of recency,
    /// until we find all about messages for all needed info
    /// or reach the end of the stream.
    ///
    /// # Arguments
    ///
    /// * `ssb_id` - A reference to a string slice which represents the id of the user to get info about.
    /// * `keys_to_search_for` - A mutable vector of string slice, which represent the about keys
    /// that will be searched for. As they are found, keys are removed from the vector.
    pub async fn get_about_info(
        &mut self,
        ssb_id: &str,
        mut keys_to_search_for: Vec<&str>,
    ) -> Result<HashMap<String, String>, GolgiError> {
        // get about_message_stream
        let about_message_stream = self.get_about_message_stream(ssb_id).await?;
        // now we have a stream of about messages with most recent at the front of the vector
        pin_mut!(about_message_stream); // needed for iteration
        let mut profile_info: HashMap<String, String> = HashMap::new();
        // iterate through the stream while it still has more values and
        // we still have keys we are looking for
        while let Some(res) = about_message_stream.next().await {
            // if there are no more keys we are looking for, then we are done
            if keys_to_search_for.is_empty() {
                break;
            }
            // if there are still keys we are looking for, then continue searching
            match res {
                Ok(msg) => {
                    // for each key we are searching for, check if this about
                    // message contains a value for that key
                    for key in &keys_to_search_for.clone() {
                        let option_val = msg
                            .content
                            .get(key)
                            .and_then(|val| val.as_str())
                            .map(|val| val.to_string());
                        match option_val {
                            Some(val) => {
                                // if a value is found, then insert it
                                profile_info.insert(key.to_string(), val);
                                // remove this key fom keys_to_search_for, since we are no longer searching for it
                                keys_to_search_for.retain(|val| val != key)
                            }
                            None => continue,
                        }
                    }
                }
                Err(_err) => {
                    // skip errors
                    continue;
                }
            }
        }
        Ok(profile_info)
    }

    /// Get latest about name from given user
    ///
    /// # Arguments
    ///
    /// * `ssb_id` - A reference to a string slice which represents the ssb user
    /// to lookup the about name for.
    pub async fn get_name(&mut self, ssb_id: &str) -> Result<Option<String>, GolgiError> {
        self.get_latest_about_message(ssb_id, "name").await
    }

    /// Get latest about description from given user
    ///
    /// # Arguments
    ///
    /// * `ssb_id` - A reference to a string slice which represents the ssb user
    /// to lookup the about description for.
    pub async fn get_description(&mut self, ssb_id: &str) -> Result<Option<String>, GolgiError> {
        self.get_latest_about_message(ssb_id, "description").await
    }
}