rdf 0.1.0

use std::collections::HashMap;
use uri::Uri;
use Result;
use error::{Error, ErrorType};

/// Representation of a specific namespace.
#[derive(Debug)]
pub struct Namespace {
  prefix: String,
  uri: Uri
}


impl Namespace {
  /// `Namespace` constructor.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::Namespace;
  /// use rdf::uri::Uri;
  ///
  /// let ns = Namespace::new("example".to_string(),
  ///                         Uri::new("http://example.org/".to_string()));
  /// ```
  pub fn new(prefix: String, uri: Uri) -> Namespace {
    Namespace {
      prefix: prefix,
      uri: uri
    }
  }

  /// Returns the prefix of the namespace.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::Namespace;
  /// use rdf::uri::Uri;
  ///
  /// let ns = Namespace::new("example".to_string(),
  ///                         Uri::new("http://example.org/".to_string()));
  ///
  /// assert_eq!(ns.prefix(), "example");
  /// ```
  pub fn prefix(&self) -> &String {
    &self.prefix
  }

  /// Returns the URI of the namespace.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::Namespace;
  /// use rdf::uri::Uri;
  ///
  /// let ns = Namespace::new("example".to_string(),
  ///                         Uri::new("http://example.org/".to_string()));
  ///
  /// assert_eq!(ns.uri(), &Uri::new("http://example.org/".to_string()));
  /// ```
  pub fn uri(&self) -> &Uri {
    &self.uri
  }
}


/// Storage for multiple namespaces.
#[derive(PartialEq, Debug)]
pub struct NamespaceStore {
  /// The namespace prefix is associated with the namespace URI.
  namespaces: HashMap<String, Uri>
}


impl NamespaceStore {
  /// Constructor for `NamespaceStore`.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::NamespaceStore;
  ///
  /// let nss = NamespaceStore::new();
  /// ```
  pub fn new() -> NamespaceStore {
    NamespaceStore {
      namespaces: HashMap::new()
    }
  }

  /// Returns the stored namespaces with prefixes.
  pub fn namespaces(&self) -> &HashMap<String, Uri> {
    &self.namespaces
  }

  /// Adds a new namespace.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::NamespaceStore;
  /// use rdf::namespace::Namespace;
  /// use rdf::uri::Uri;
  ///
  /// let mut nss = NamespaceStore::new();
  ///
  /// let ns = Namespace::new("example".to_string(),
  ///                         Uri::new("http://example.org/".to_string()));
  ///
  /// nss.add(&ns);
  /// ```
  pub fn add(&mut self, ns: &Namespace) {
    &self.namespaces.insert(ns.prefix().clone(), ns.uri.clone());
  }

  /// Returns the URI of a specific namespace.
  ///
  /// # Examples
  ///
  /// ```
  /// use rdf::namespace::NamespaceStore;
  /// use rdf::namespace::Namespace;
  /// use rdf::uri::Uri;
  ///
  /// let mut nss = NamespaceStore::new();
  ///
  /// let ns = Namespace::new("example".to_string(),
  ///                         Uri::new("http://example.org/".to_string()));
  ///
  /// nss.add(&ns);
  ///
  /// assert_eq!(nss.get_uri_by_prefix("example".to_string()).unwrap(),
  ///            &Uri::new("http://example.org/".to_string()))
  /// ```
  pub fn get_uri_by_prefix(&self, prefix: String) -> Result<&Uri> {
    match self.namespaces.get(&prefix) {
      Some(uri) => Ok(uri),
      None => Err(Error::new(ErrorType::InvalidNamespace,
                             "Namespace does not exists for prefix: ".to_string() + &prefix.to_string()))
    }
  }
}