yaserde_derive 0.11.1

use proc_macro2::{token_stream::IntoIter, Delimiter, Ident, TokenStream, TokenTree};
use quote::quote;
use std::collections::BTreeMap;
use syn::Attribute;

#[derive(Debug, PartialEq, Clone)]
pub struct YaSerdeAttribute {
  pub attribute: bool,
  pub default: Option<String>,
  pub default_namespace: Option<String>,
  pub flatten: bool,
  pub namespaces: BTreeMap<Option<String>, String>,
  pub prefix: Option<String>,
  pub rename: Option<String>,
  pub tag: Option<String>,
  pub skip_serializing: bool,
  pub skip_serializing_if: Option<String>,
  pub text: bool,
}

fn get_value(iter: &mut IntoIter) -> Option<String> {
  if let (Some(TokenTree::Punct(operator)), Some(TokenTree::Literal(value))) =
    (iter.next(), iter.next())
  {
    if operator.as_char() == '=' {
      Some(value.to_string().replace('"', ""))
    } else {
      None
    }
  } else {
    None
  }
}

impl YaSerdeAttribute {
  pub fn parse(attrs: &[Attribute]) -> YaSerdeAttribute {
    let mut attribute = false;
    let mut flatten = false;
    let mut default = None;
    let mut default_namespace = None;
    let mut namespaces = BTreeMap::new();
    let mut prefix = None;
    let mut rename = None;
    let mut tag = None;
    let mut skip_serializing = false;
    let mut skip_serializing_if = None;
    let mut text = false;

    for attr in attrs.iter().filter(|a| a.path.is_ident("yaserde")) {
      let mut attr_iter = attr.clone().tokens.into_iter();
      if let Some(TokenTree::Group(group)) = attr_iter.next() {
        if group.delimiter() == Delimiter::Parenthesis {
          let mut attr_iter = group.stream().into_iter();

          while let Some(item) = attr_iter.next() {
            if let TokenTree::Ident(ident) = item {
              match ident.to_string().as_str() {
                "attribute" => {
                  attribute = true;
                }
                "default" => {
                  default = get_value(&mut attr_iter);
                }
                "default_namespace" => {
                  default_namespace = get_value(&mut attr_iter);
                }
                "flatten" => {
                  flatten = true;
                }
                "namespace" => {
                  if let Some(namespace) = get_value(&mut attr_iter) {
                    let splitted: Vec<&str> = namespace.split(": ").collect();
                    if splitted.len() == 2 {
                      namespaces.insert(Some(splitted[0].to_owned()), splitted[1].to_owned());
                    }
                    if splitted.len() == 1 {
                      namespaces.insert(None, splitted[0].to_owned());
                    }
                  }
                }
                "prefix" => {
                  prefix = get_value(&mut attr_iter);
                }
                "rename" => {
                  rename = get_value(&mut attr_iter);
                }
                "tag" => {
                  tag = get_value(&mut attr_iter);
                }
                "skip_serializing" => {
                  skip_serializing = true;
                }
                "skip_serializing_if" => {
                  skip_serializing_if = get_value(&mut attr_iter);
                }
                "text" => {
                  text = true;
                }
                _ => {}
              }
            }
          }
        }
      }
    }

    YaSerdeAttribute {
      attribute,
      default,
      default_namespace,
      flatten,
      namespaces,
      prefix,
      rename,
      tag,
      skip_serializing,
      skip_serializing_if,
      text,
    }
  }

  pub fn xml_element_name(&self, ident: &Ident) -> String {
    self.rename.clone().unwrap_or_else(|| ident.to_string())
  }

  pub fn prefix_namespace(&self) -> String {
    if self.default_namespace == self.prefix {
      "".to_string()
    } else {
      self
        .clone()
        .prefix
        .map_or("".to_string(), |prefix| prefix + ":")
    }
  }

  pub fn get_namespace_matching(
    &self,
    prefix: &Option<String>,
    element_namespace: TokenStream,
    element_name: TokenStream,
    take_root_prefix: bool,
  ) -> TokenStream {
    let configured_prefix = if take_root_prefix {
      self.prefix.clone()
    } else {
      prefix.clone()
    };

    let namespaces_matches: TokenStream = self
      .namespaces
      .iter()
      .filter_map(|(prefix, namespace)| {
        if configured_prefix.eq(prefix) {
          Some(quote!(#namespace => {}))
        } else {
          None
        }
      })
      .collect();

    quote!(
      if let Some(namespace) = #element_namespace {
        match namespace.as_str() {
          #namespaces_matches
          bad_namespace => {
            let msg =
              ::std::format!("bad namespace for {}, found {}", #element_name, bad_namespace);
            return Err(msg);
          }
        }
      }
    )
  }
}

#[test]
fn parse_empty_attributes() {
  let attributes = vec![];
  let attrs = YaSerdeAttribute::parse(&attributes);

  assert_eq!(
    YaSerdeAttribute {
      attribute: false,
      default: None,
      default_namespace: None,
      flatten: false,
      namespaces: BTreeMap::new(),
      prefix: None,
      rename: None,
      tag: None,
      skip_serializing: false,
      skip_serializing_if: None,
      text: false,
    },
    attrs
  );
}

#[test]
fn parse_attributes() {
  use proc_macro2::{Span, TokenStream};
  use std::str::FromStr;
  use syn::punctuated::Punctuated;
  use syn::token::Bracket;
  use syn::token::Pound;
  use syn::AttrStyle::Outer;
  use syn::{Ident, Path, PathArguments, PathSegment};

  let mut punctuated = Punctuated::new();
  punctuated.push(PathSegment {
    ident: Ident::new("yaserde", Span::call_site()),
    arguments: PathArguments::None,
  });

  let attributes = vec![Attribute {
    pound_token: Pound {
      spans: [Span::call_site()],
    },
    style: Outer,
    bracket_token: Bracket {
      span: Span::call_site(),
    },
    path: Path {
      leading_colon: None,
      segments: punctuated,
    },
    tokens: TokenStream::from_str("(attribute)").unwrap(),
  }];

  let attrs = YaSerdeAttribute::parse(&attributes);

  assert_eq!(
    YaSerdeAttribute {
      attribute: true,
      default: None,
      default_namespace: None,
      flatten: false,
      namespaces: BTreeMap::new(),
      prefix: None,
      rename: None,
      tag: None,
      skip_serializing: false,
      skip_serializing_if: None,
      text: false,
    },
    attrs
  );
}

#[test]
fn only_parse_yaserde_attributes() {
  use proc_macro2::{Span, TokenStream};
  use std::str::FromStr;
  use syn::punctuated::Punctuated;
  use syn::token::Bracket;
  use syn::token::Pound;
  use syn::AttrStyle::Outer;
  use syn::{Ident, Path, PathArguments, PathSegment};

  let mut punctuated = Punctuated::new();
  punctuated.push(PathSegment {
    ident: Ident::new("serde", Span::call_site()),
    arguments: PathArguments::None,
  });

  let attributes = vec![Attribute {
    pound_token: Pound {
      spans: [Span::call_site()],
    },
    style: Outer,
    bracket_token: Bracket {
      span: Span::call_site(),
    },
    path: Path {
      leading_colon: None,
      segments: punctuated,
    },
    tokens: TokenStream::from_str("(flatten)").unwrap(),
  }];

  let attrs = YaSerdeAttribute::parse(&attributes);

  assert_eq!(
    YaSerdeAttribute {
      attribute: false,
      default: None,
      default_namespace: None,
      flatten: false,
      namespaces: BTreeMap::new(),
      prefix: None,
      rename: None,
      tag: None,
      skip_serializing: false,
      skip_serializing_if: None,
      text: false,
    },
    attrs
  );
}

#[test]
fn parse_attributes_with_values() {
  use proc_macro2::{Span, TokenStream};
  use std::str::FromStr;
  use syn::punctuated::Punctuated;
  use syn::token::Bracket;
  use syn::token::Pound;
  use syn::AttrStyle::Outer;
  use syn::{Ident, Path, PathArguments, PathSegment};

  let mut punctuated = Punctuated::new();
  punctuated.push(PathSegment {
    ident: Ident::new("yaserde", Span::call_site()),
    arguments: PathArguments::None,
  });

  let attributes = vec![Attribute {
    pound_token: Pound {
      spans: [Span::call_site()],
    },
    style: Outer,
    bracket_token: Bracket {
      span: Span::call_site(),
    },
    path: Path {
      leading_colon: None,
      segments: punctuated,
    },
    tokens: TokenStream::from_str("(attribute, flatten, default_namespace=\"example\", namespace=\"example: http://example.org\")").unwrap(),
  }];

  let attrs = YaSerdeAttribute::parse(&attributes);

  let mut namespaces = BTreeMap::new();
  namespaces.insert(
    Some("example".to_string()),
    "http://example.org".to_string(),
  );

  assert_eq!(
    YaSerdeAttribute {
      attribute: true,
      default: None,
      default_namespace: Some("example".to_string()),
      flatten: true,
      namespaces,
      prefix: None,
      rename: None,
      tag: None,
      skip_serializing: false,
      skip_serializing_if: None,
      text: false,
    },
    attrs
  );
}