appview/atproto/src/lib.rs

use lazy_regex::regex_captures;
use core::str::FromStr;
use std::fmt::{
  Display, Formatter, Result as FmtResult
};

pub use atrium_api::types::{
  Collection,
  string::{
    AtIdentifier as Authority,
    Datetime,
    Did,
    Nsid,
    RecordKey,
    Tid,
    Handle,
  }
};

pub mod lexicons;

pub struct Cid(String);

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

pub struct StrongRef<T> {
  pub content: T,
  pub cid: Cid,
}

pub struct Uri {
  whole: String,
  // These fields could be useful in the future, 
  // so I'm leaving the code for them.
  // authority: Authority,
  // collection: Option<Nsid>,
  // rkey: Option<RecordKey>,
}

impl FromStr for Uri {
  type Err = &'static str;
  fn from_str(uri: &str) -> Result<Self, Self::Err> {
    if uri.len() > 8000 {
      return Err("Uri too long")
    }

    let Some((
      whole, unchecked_authority, unchecked_collection, unchecked_rkey
    )) = regex_captures!(
      r"/^at:\/\/([\w\.\-_~:]+)(?:\/([\w\.\-_~:]+)(?:)\/([\w\.\-_~:]+))?$/i",
      uri,
    ) else { 
      return Err("Invalid Uri"); 
    };

    // This parsing is required, but the values don't need to be used yet.
    // No compute cost to use them, just storage cost
    let _authority = Authority::from_str(unchecked_authority)?;

    let _collection = if unchecked_collection.is_empty() { None }
      else { Some(Nsid::new(unchecked_collection.to_string())?) };

    let _rkey = if unchecked_rkey.is_empty() { None }
      else { Some(RecordKey::new(unchecked_rkey.to_string())?) };

    // Ok(Uri{ whole: whole.to_string(), authority, collection, rkey })
    Ok(Uri { whole: whole.to_string() })
  }
}

impl Uri {
  pub fn as_str(&self) -> &str {
    self.whole.as_str()
  }
}