locale-codes 0.3.0

/*!
Character sets registered with IANA.

These are the official names for character sets that may be used in
the Internet and may be referred to in Internet documentation.  These
names are expressed in ANSI_X3.4-1968 which is commonly called
US-ASCII or simply ASCII.  The character set most commonly use in the
Internet and used especially in protocol standards is US-ASCII, this
is strongly encouraged.  The use of the name US-ASCII is also
encouraged.

## Source - IANA

The data used here is taken from the tables in the html page
[IANA](https://www.iana.org/assignments/character-sets/character-sets.xhtml).

See also: [RFC-2978](https://tools.ietf.org/html/rfc2978) IANA Charset
Registration Procedures.
*/

use std::collections::HashMap;

use serde::{Deserialize, Serialize};

// ------------------------------------------------------------------------------------------------
// Public Types
// ------------------------------------------------------------------------------------------------

/// A representation of registrered character set data that maintained by IANA.
#[derive(Serialize, Deserialize, Debug)]
pub struct CodesetInfo {
    /// The name, not a code, for this code set.
    pub name: String,
    /// Any well known aliases for this code set.
    pub also_known_as: Vec<String>,
    /// The IANA registered MIB code.
    pub mib_code: u32,
    /// Sources identified in the IANA registration.
    pub source: Option<String>,
    /// References identified in the IANA registration.
    pub references: Option<String>,
}

// ------------------------------------------------------------------------------------------------
// Public Functions
// ------------------------------------------------------------------------------------------------

lazy_static! {
    static ref CODESETS: HashMap<String, CodesetInfo> = load_code_sets_from_json();
}

/// Lookup a `CodesetInfo` based on it's name, returning `None` if the name
/// does not exist in the current IANA data set.
pub fn lookup(name: &str) -> Option<&'static CodesetInfo> {
    assert!(name.len() > 0, "codeset name may not be empty");
    CODESETS.get(name)
}

/// Return all the registered script names.
pub fn all_names() -> Vec<String> {
    CODESETS.keys().cloned().collect()
}

// ------------------------------------------------------------------------------------------------
// Generated Data
// ------------------------------------------------------------------------------------------------

fn load_code_sets_from_json() -> HashMap<String, CodesetInfo> {
    info!("load_code_sets_from_json - loading JSON");
    let raw_data = include_bytes!("data/codesets.json");
    let code_set_map: HashMap<String, CodesetInfo> = serde_json::from_slice(raw_data).unwrap();
    info!(
        "load_code_sets_from_json - loaded {} codes ets",
        code_set_map.len()
    );
    code_set_map
}

// ------------------------------------------------------------------------------------------------
// Unit Tests
// ------------------------------------------------------------------------------------------------

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

    // --------------------------------------------------------------------------------------------
    #[test]
    fn test_good_codeset_code() {
        match lookup("UTF-8") {
            None => panic!("was expecting a codeset"),
            Some(codeset) => assert_eq!(codeset.name.to_string(), "UTF-8".to_string()),
        }
    }

    #[test]
    fn test_bad_codeset_code() {
        match lookup(&"UTF-99") {
            None => (),
            Some(_) => panic!("was expecting a None in response"),
        }
    }
}