identifier.rs

/*
 * This file is licensed under the Affero General Public License (AGPL) version 3.
 *
 * Copyright (C) 2024 New Vector, Ltd
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * See the GNU Affero General Public License for more details:
 * <https://www.gnu.org/licenses/agpl-3.0.html>.
 */

//! # Matrix Identifiers
//!
//! This module contains definitions and utilities for working with matrix identifiers.

use std::{fmt, ops::Deref};

/// Errors that can occur when parsing a matrix identifier.
#[derive(Clone, Debug, PartialEq)]
pub enum IdentifierError {
    IncorrectSigil,
    MissingColon,
}

impl fmt::Display for IdentifierError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{:?}", self)
    }
}

/// A Matrix user_id.
#[derive(Clone, Debug, PartialEq)]
pub struct UserID(String);

impl UserID {
    /// Returns the `localpart` of the user_id.
    pub fn localpart(&self) -> &str {
        &self[1..self.colon_pos()]
    }

    /// Returns the `server_name` / `domain` of the user_id.
    pub fn server_name(&self) -> &str {
        &self[self.colon_pos() + 1..]
    }

    /// Returns the position of the ':' inside of the user_id.
    /// Used when splitting the user_id into it's respective parts.
    fn colon_pos(&self) -> usize {
        self.find(':').unwrap()
    }
}

impl TryFrom<&str> for UserID {
    type Error = IdentifierError;

    /// Will try creating a `UserID` from the provided `&str`.
    /// Can fail if the user_id is incorrectly formatted.
    fn try_from(s: &str) -> Result<Self, Self::Error> {
        if !s.starts_with('@') {
            return Err(IdentifierError::IncorrectSigil);
        }

        if s.find(':').is_none() {
            return Err(IdentifierError::MissingColon);
        }

        Ok(UserID(s.to_string()))
    }
}

impl Deref for UserID {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl fmt::Display for UserID {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}