irelia-cli 0.5.6

//! Constants, as well as the schema for the lock file can be found here
//! <https://hextechdocs.dev/getting-started-with-the-lcu-api/>

//! This module also contains a list of constants for the different names
//! of the processes for `macOS`, and `Windows`

use irelia_encoder::Encoder;
use std::path::Path;
use sysinfo::{ProcessRefreshKind, RefreshKind, System};

use crate::Error;

// Linux will be unplayable soon, so support has been removed
const CLIENT_PROCESS_NAME: &str = "CrBrowserMain";
const GAME_PROCESS_NAME: &str = "CrBrowserMain";

/// const copy of the encoder
pub(crate) const ENCODER: Encoder = Encoder::new();

/// Gets the port and auth for the client via the process id
/// This is done to avoid needing to find the lock file, but
/// a fallback could be implemented in theory using the fact
/// that you can get the exe location, and go backwards.
///
/// # Errors
/// This will return an error if the LCU is truly not running,
/// or the lock file is inaccessibly for some reason.
/// If it returns an error for any other reason, this code
/// likely needs the client and game process names updated.
///
pub fn get_running_client(force_lock_file: bool) -> Result<(String, String), Error> {
    // If we always read the lock file, we never need to get the command line of the process
    let cmd = if force_lock_file {
        sysinfo::UpdateKind::Never
    } else {
        sysinfo::UpdateKind::OnlyIfNotSet
    };
    // No matter what, the path to the process is required
    let refresh_kind = ProcessRefreshKind::new()
        .with_exe(sysinfo::UpdateKind::OnlyIfNotSet)
        .with_cmd(cmd);

    // Get the current list of processes
    let system = System::new_with_specifics(
        // This creates a new instance of `system` every time, so this only
        //  needs to be updated if it's not set
        RefreshKind::new().with_processes(refresh_kind),
    );

    // Is the client running, or is it the game?
    let mut client = false;

    // Iterate through all the processes, using .values() because
    // We don't need the PID. Look for a process with the same name
    // as the constant for that platform, otherwise return an error.
    let process = system
        .processes()
        .values()
        .find(|process| {
            // Get the name of the process
            let name = process.name();
            // If it matches the name of the client,
            // set the flag, and return it
            if name == CLIENT_PROCESS_NAME {
                client = true;
                client
                // Otherwise return if it matches the game name process
            } else {
                name == GAME_PROCESS_NAME
            }
        })
        .ok_or_else(|| Error::LCUProcessNotRunning)?;

    // Move these to an earlier scope to avoid an allocation
    // And deduplicate some code later on
    let mut lock_file: String = String::new();
    let port: &str;
    let auth: &str;

    if client {
        if force_lock_file {
            // Get the client location
            let path = process.exe().ok_or_else(|| Error::LockFileNotFound)?;
            // Walk back once, being in the folder
            let path = path.parent().ok_or_else(|| Error::LockFileNotFound)?;
            // Read and init the path and auth
            (port, auth) = read_and_parse_lock(path, &mut lock_file)?;
        } else {
            let cmd = process.cmd();

            // Assuming the order doesn't change (which I haven't seen it do)
            // we can avoid a second iteration over the cmd args
            let mut iter = cmd.iter();

            // Look for an auth key to put inside the command line, otherwise return an error.
            auth = iter
                .find_map(|s| s.strip_prefix("--remoting-auth-token="))
                .ok_or(Error::AuthTokenNotFound)?;

            // Look for a port to connect to the LCU with, otherwise return an error.
            port = iter
                .find_map(|s| s.strip_prefix("--app-port="))
                .ok_or(Error::PortNotFound)?;
        }
    } else {
        // We have to walk back twice to get the path of the lock file relative to the path of the game
        // This can only be None on Linux according to the docs, so we should be fine everywhere else
        let path = process.exe().ok_or_else(|| Error::LockFileNotFound)?;
        // Sadly, we're relying on how the client structures things here
        // Walking back a whole folder in order to get the lock file
        let path = path
            .parent()
            .ok_or_else(|| Error::LockFileNotFound)?
            .parent()
            .ok_or_else(|| Error::LockFileNotFound)?;

        (port, auth) = read_and_parse_lock(path, &mut lock_file)?;
    }
    
    // The auth header has to be base64 encoded, so that's happens here
    let auth_header = ENCODER.encode(format!("riot:{auth}"));

    // Format the port and header so that they can be used as headers
    // For the LCU API
    Ok((
        format!("127.0.0.1:{port}"),
        format!("Basic {auth_header}", ),
    ))
}

fn read_and_parse_lock<'a>(
    path: &Path,
    lock_file: &'a mut String,
) -> Result<(&'a str, &'a str), Error> {
    // Read the lock file, putting the value in a higher scope
    *lock_file = std::fs::read_to_string(path.join("lockfile")).map_err(Error::StdIo)?;

    // Split the lock file on `:` which separates the different fields
    // Because lock_file is from a higher scope, we can split the string here
    // and return two string references later on
    let mut split = lock_file.split(':');

    // Get the 3rd field, which should be the port
    let port = split.nth(2).ok_or(Error::PortNotFound)?;
    // We moved the cursor, so the fourth element is the very next one
    // Which should be the auth string
    let auth = split.next().ok_or(Error::AuthTokenNotFound)?;

    Ok((port, auth))
}

#[cfg(test)]
mod tests {
    use super::get_running_client;

    #[ignore = "This is only needed for testing, and doesn't need to be run all the time"]
    #[test]
    fn test_process_info() {
        let (port, pass) = get_running_client(false).unwrap();
        println!("{port} {pass}");
    }
}