lemmy/crates/utils/src/utils.rs

use crate::{settings::structs::Settings, ApiError, IpAddr};
use actix_web::dev::ConnectionInfo;
use chrono::{DateTime, FixedOffset, NaiveDateTime};
use itertools::Itertools;
use rand::{distributions::Alphanumeric, thread_rng, Rng};
use regex::{Regex, RegexBuilder};
use url::Url;

lazy_static! {
  static ref EMAIL_REGEX: Regex = Regex::new(r"^[a-zA-Z0-9.!#$%&’*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$").expect("compile regex");
  static ref SLUR_REGEX: Regex = {
    let mut slurs = r"(fag(g|got|tard)?\b|cock\s?sucker(s|ing)?|ni((g{2,}|q)+|[gq]{2,})[e3r]+(s|z)?|mudslime?s?|kikes?|\bspi(c|k)s?\b|\bchinks?|gooks?|bitch(es|ing|y)?|whor(es?|ing)|\btr(a|@)nn?(y|ies?)|\b(b|re|r)tard(ed)?s?)".to_string();
    if let Some(additional_slurs) = Settings::get().additional_slurs {
        slurs.push('|');
        slurs.push_str(&additional_slurs);
    };
    RegexBuilder::new(&slurs).case_insensitive(true).build().expect("compile regex")
  };


  static ref USERNAME_MATCHES_REGEX: Regex = Regex::new(r"/u/[a-zA-Z][0-9a-zA-Z_]*").expect("compile regex");
  // TODO keep this old one, it didn't work with port well tho
  // static ref MENTIONS_REGEX: Regex = Regex::new(r"@(?P<name>[\w.]+)@(?P<domain>[a-zA-Z0-9._-]+\.[a-zA-Z0-9_-]+)").expect("compile regex");
  static ref MENTIONS_REGEX: Regex = Regex::new(r"@(?P<name>[\w.]+)@(?P<domain>[a-zA-Z0-9._:-]+)").expect("compile regex");
  static ref VALID_USERNAME_REGEX: Regex = Regex::new(r"^[a-zA-Z0-9_]{3,20}$").expect("compile regex");
  static ref VALID_COMMUNITY_NAME_REGEX: Regex = Regex::new(r"^[a-z0-9_]{3,20}$").expect("compile regex");
  static ref VALID_POST_TITLE_REGEX: Regex = Regex::new(r".*\S.*").expect("compile regex");
  static ref VALID_MATRIX_ID_REGEX: Regex = Regex::new(r"^@[A-Za-z0-9._=-]+:[A-Za-z0-9.-]+\.[A-Za-z]{2,}$").expect("compile regex");
  // taken from https://en.wikipedia.org/wiki/UTM_parameters
  static ref CLEAN_URL_PARAMS_REGEX: Regex = Regex::new(r"^utm_source|utm_medium|utm_campaign|utm_term|utm_content|gclid|gclsrc|dclid|fbclid$").expect("compile regex");
}

pub fn naive_from_unix(time: i64) -> NaiveDateTime {
  NaiveDateTime::from_timestamp(time, 0)
}

pub fn convert_datetime(datetime: NaiveDateTime) -> DateTime<FixedOffset> {
  DateTime::<FixedOffset>::from_utc(datetime, FixedOffset::east(0))
}

pub fn remove_slurs(test: &str) -> String {
  SLUR_REGEX.replace_all(test, "*removed*").to_string()
}

pub(crate) fn slur_check(test: &str) -> Result<(), Vec<&str>> {
  let mut matches: Vec<&str> = SLUR_REGEX.find_iter(test).map(|mat| mat.as_str()).collect();

  // Unique
  matches.sort_unstable();
  matches.dedup();

  if matches.is_empty() {
    Ok(())
  } else {
    Err(matches)
  }
}

pub fn check_slurs(text: &str) -> Result<(), ApiError> {
  if let Err(slurs) = slur_check(text) {
    Err(ApiError::err(&slurs_vec_to_str(slurs)))
  } else {
    Ok(())
  }
}

pub fn check_slurs_opt(text: &Option<String>) -> Result<(), ApiError> {
  match text {
    Some(t) => check_slurs(t),
    None => Ok(()),
  }
}

pub(crate) fn slurs_vec_to_str(slurs: Vec<&str>) -> String {
  let start = "No slurs - ";
  let combined = &slurs.join(", ");
  [start, combined].concat()
}

pub fn generate_random_string() -> String {
  thread_rng()
    .sample_iter(&Alphanumeric)
    .map(char::from)
    .take(30)
    .collect()
}

pub fn markdown_to_html(text: &str) -> String {
  comrak::markdown_to_html(text, &comrak::ComrakOptions::default())
}

// TODO nothing is done with community / group webfingers yet, so just ignore those for now
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct MentionData {
  pub name: String,
  pub domain: String,
}

impl MentionData {
  pub fn is_local(&self) -> bool {
    Settings::get().hostname().eq(&self.domain)
  }
  pub fn full_name(&self) -> String {
    format!("@{}@{}", &self.name, &self.domain)
  }
}

pub fn scrape_text_for_mentions(text: &str) -> Vec<MentionData> {
  let mut out: Vec<MentionData> = Vec::new();
  for caps in MENTIONS_REGEX.captures_iter(text) {
    out.push(MentionData {
      name: caps["name"].to_string(),
      domain: caps["domain"].to_string(),
    });
  }
  out.into_iter().unique().collect()
}

pub fn is_valid_username(name: &str) -> bool {
  VALID_USERNAME_REGEX.is_match(name)
}

// Can't do a regex here, reverse lookarounds not supported
pub fn is_valid_display_name(name: &str) -> bool {
  !name.starts_with('@')
    && !name.starts_with('\u{200b}')
    && name.chars().count() >= 3
    && name.chars().count() <= 20
}

pub fn is_valid_matrix_id(matrix_id: &str) -> bool {
  VALID_MATRIX_ID_REGEX.is_match(matrix_id)
}

pub fn is_valid_community_name(name: &str) -> bool {
  VALID_COMMUNITY_NAME_REGEX.is_match(name)
}

pub fn is_valid_post_title(title: &str) -> bool {
  VALID_POST_TITLE_REGEX.is_match(title)
}

pub fn get_ip(conn_info: &ConnectionInfo) -> IpAddr {
  IpAddr(
    conn_info
      .realip_remote_addr()
      .unwrap_or("127.0.0.1:12345")
      .split(':')
      .next()
      .unwrap_or("127.0.0.1")
      .to_string(),
  )
}

pub fn clean_url_params(mut url: Url) -> Url {
  let new_query = url
    .query_pairs()
    .filter(|q| !CLEAN_URL_PARAMS_REGEX.is_match(&q.0))
    .map(|q| format!("{}={}", q.0, q.1))
    .join("&");
  url.set_query(Some(&new_query));
  url
}

#[cfg(test)]
mod tests {
  use crate::utils::clean_url_params;
  use url::Url;

  #[test]
  fn test_clean_url_params() {
    let url = Url::parse("https://example.com/path/123?utm_content=buffercf3b2&utm_medium=social&username=randomuser&id=123").unwrap();
    let cleaned = clean_url_params(url);
    let expected = Url::parse("https://example.com/path/123?username=randomuser&id=123").unwrap();
    assert_eq!(expected.to_string(), cleaned.to_string());
  }
}