session-open-group-server/src/rpc.rs

use std::collections::HashMap;

use serde::{Serialize, Deserialize};
use warp::{Rejection, reply::Response};

use super::errors::Error;
use super::handlers;
use super::storage;

#[derive(Deserialize, Serialize, Debug)]
pub struct RpcCall {
    pub endpoint: String,
    pub body: String,
    pub method: String,
    pub headers: String
}

#[derive(Debug, Deserialize)]
pub struct QueryOptions {
    pub limit: Option<u16>,
    pub from_server_id: Option<i64>
}

pub async fn handle_rpc_call(rpc_call: RpcCall, pool: &storage::DatabaseConnectionPool) -> Result<Response, Rejection> {
    // Check that the endpoint is a valid URI
    let uri = match rpc_call.endpoint.parse::<http::Uri>() {
        Ok(uri) => uri,
        Err(e) => {
            println!("Couldn't parse URI from: {} due to error: {}.", rpc_call.endpoint, e);
            return Err(warp::reject::custom(Error::InvalidRpcCall));
        }
    };
    // Get the auth token if possible
    let auth_token = get_auth_token(&rpc_call);
    // Switch on the HTTP method
    match rpc_call.method.as_ref() {
        "GET" => return handle_get_request(rpc_call, uri, auth_token, pool).await,
        "POST" => return handle_post_request(rpc_call, uri, auth_token, pool).await,
        "DELETE" => return handle_delete_request(rpc_call, uri, auth_token, pool).await,
        _ => {
            println!("Ignoring RPC call with invalid or unused HTTP method: {}.", rpc_call.method);
            return Err(warp::reject::custom(Error::InvalidRpcCall));
        }
    }
}

async fn handle_get_request(rpc_call: RpcCall, uri: http::Uri, auth_token: Option<String>, pool: &storage::DatabaseConnectionPool) -> Result<Response, Rejection> {
    // Parse query options if needed
    let mut query_options = QueryOptions { limit : None, from_server_id : None };
    if let Some(query) = uri.query() {
        query_options = match serde_json::from_str(&query) {
            Ok(query_options) => query_options,
            Err(e) => {
                println!("Couldn't parse query options from: {} due to error: {}.", query, e);
                return Err(warp::reject::custom(Error::InvalidRpcCall));
            }
        };
    }
    // Switch on the path
    match uri.path() {
        "/messages" => return handlers::get_messages(query_options, pool).await,
        "/deleted_messages" => return handlers::get_deleted_messages(query_options, pool).await,
        "/moderators" => return handlers::get_moderators(pool).await,
        "/block_list" => return handlers::get_banned_public_keys(pool).await,
        "/member_count" => return handlers::get_member_count(pool).await,
        "/challenge" => {
            #[derive(Debug, Deserialize)]
            pub struct QueryOptions {
                pub public_key: String
            }
            let query_options: QueryOptions;
            if let Some(query) = uri.query() {
                query_options = match serde_json::from_str(&query) {
                    Ok(query_options) => query_options,
                    Err(e) => {
                        println!("Couldn't parse query options from: {} due to error: {}.", query, e);
                        return Err(warp::reject::custom(Error::InvalidRpcCall));
                    }
                };
            } else {
                println!("Missing query options.");
                return Err(warp::reject::custom(Error::InvalidRpcCall));
            }
            return handlers::get_challenge(&query_options.public_key, pool).await;
        },
        _ => {
            println!("Ignoring RPC call with invalid or unused endpoint: {}.", rpc_call.endpoint);
            return Err(warp::reject::custom(Error::InvalidRpcCall));        
        }
    }
}

async fn handle_post_request(rpc_call: RpcCall, uri: http::Uri, auth_token: Option<String>, pool: &storage::DatabaseConnectionPool) -> Result<Response, Rejection> {
    match uri.path() {
        "/messages" => {
            let message = match serde_json::from_str(&rpc_call.body) {
                Ok(message) => message,
                Err(e) => {
                    println!("Couldn't parse message from: {} due to error: {}.", rpc_call.body, e);
                    return Err(warp::reject::custom(Error::InvalidRpcCall));
                }
            };
            return handlers::insert_message(message, auth_token, pool).await; 
        },
        "/block_list" => {
            let public_key = rpc_call.body;
            return handlers::ban(&public_key, auth_token, pool).await;
        },
        _ => {
            println!("Ignoring RPC call with invalid or unused endpoint: {}.", rpc_call.endpoint);
            return Err(warp::reject::custom(Error::InvalidRpcCall));        
        }
    }
}

async fn handle_delete_request(rpc_call: RpcCall, uri: http::Uri, auth_token: Option<String>, pool: &storage::DatabaseConnectionPool) -> Result<Response, Rejection> {
    // DELETE /messages/:server_id
    if uri.path().starts_with("/messages") {
        let components: Vec<&str> = uri.path()[1..].split("/").collect(); // Drop the leading slash and split on subsequent slashes
        if components.len() != 2 {
            println!("Invalid endpoint: {}.", rpc_call.endpoint);
            return Err(warp::reject::custom(Error::InvalidRpcCall));
        }
        let server_id: i64 = match components[1].parse() {
            Ok(server_id) => server_id,
            Err(_) => {
                println!("Invalid endpoint: {}.", rpc_call.endpoint);
                return Err(warp::reject::custom(Error::InvalidRpcCall));
            }
        };
        return handlers::delete_message(server_id, auth_token, pool).await;
    }
    // DELETE /block_list/:public_key
    if uri.path().starts_with("/block_list") {
        let components: Vec<&str> = uri.path()[1..].split("/").collect(); // Drop the leading slash and split on subsequent slashes
        if components.len() != 2 {
            println!("Invalid endpoint: {}.", rpc_call.endpoint);
            return Err(warp::reject::custom(Error::InvalidRpcCall));
        }
        let public_key = components[1].to_string();
        return handlers::unban(&public_key, auth_token, pool).await;
    }
    // Unrecognized endpoint
    println!("Ignoring RPC call with invalid or unused endpoint: {}.", rpc_call.endpoint);
    return Err(warp::reject::custom(Error::InvalidRpcCall));
}

// Utilities
fn get_auth_token(rpc_call: &RpcCall) -> Option<String> {
    if rpc_call.headers.is_empty() { return None; }
    let headers: HashMap<String, String> = match serde_json::from_str(&rpc_call.headers) {
        Ok(headers) => headers,
        Err(_) => return None
    };
    let header = headers.get("Authorization");
    if header == None { return None; }
    return header.unwrap().strip_prefix("Bearer").map(|s| s.to_string()).or(None);
}