use super::StructItem;
use crate::util::*;
use proc_macro2::TokenStream;
use quote::quote;
use syn::{parse_quote, spanned::Spanned, Error, Field, Ident, LitChar, LitStr, Type};
pub struct FlagItem {
field_name: Ident,
short_switch: Option<LitChar>,
long_switch: Option<LitStr>,
aliases: Option<LitStrArray>,
env_name: Option<LitStr>,
env_aliases: Option<LitStrArray>,
doc_string: Option<String>,
}
impl FlagItem {
pub fn new(field: &Field, _struct_item: &StructItem) -> Result<Self, Error> {
let field_name = field
.ident
.clone()
.ok_or_else(|| Error::new(field.span(), "missing identifier"))?;
let mut result = Self {
field_name,
short_switch: None,
long_switch: None,
aliases: None,
env_name: None,
env_aliases: None,
doc_string: None,
};
for attr in &field.attrs {
maybe_append_doc_string(&mut result.doc_string, &attr.meta)?;
if attr.path().is_ident("conf") || attr.path().is_ident("arg") {
attr.parse_nested_meta(|meta| {
let path = meta.path.clone();
if path.is_ident("flag") {
Ok(())
} else if path.is_ident("short") {
set_once(
&path,
&mut result.short_switch,
parse_optional_value::<LitChar>(meta)?
.or(make_short(&result.field_name, path.span())),
)
} else if path.is_ident("long") {
set_once(
&path,
&mut result.long_switch,
parse_optional_value::<LitStr>(meta)?
.or(make_long(&result.field_name, path.span())),
)
} else if path.is_ident("aliases") {
set_once(
&path,
&mut result.aliases,
Some(parse_required_value::<LitStrArray>(meta)?),
)
} else if path.is_ident("env") {
set_once(
&path,
&mut result.env_name,
parse_optional_value::<LitStr>(meta)?
.or(make_env(&result.field_name, path.span())),
)
} else if path.is_ident("env_aliases") {
set_once(
&path,
&mut result.env_aliases,
Some(parse_required_value::<LitStrArray>(meta)?),
)
} else {
Err(meta.error("unrecognized conf flag option"))
}
})?;
}
}
if result.long_switch.is_none()
&& !result
.aliases
.as_ref()
.map(LitStrArray::is_empty)
.unwrap_or(true)
{
return Err(Error::new(field.span(), "Setting aliases without setting a long-switch is an error, make one of the aliases the primary switch name."));
}
if result.env_name.is_none()
&& !result
.env_aliases
.as_ref()
.map(LitStrArray::is_empty)
.unwrap_or(true)
{
return Err(Error::new(field.span(), "Setting env_aliases without setting an env is an error, make one of the aliases the primary env."));
}
Ok(result)
}
pub fn get_field_name(&self) -> &Ident {
&self.field_name
}
pub fn get_field_type(&self) -> Type {
parse_quote! { bool }
}
pub fn gen_push_program_options(
&self,
program_options_ident: &Ident,
) -> Result<TokenStream, Error> {
let id = self.field_name.to_string();
let description = quote_opt_into(&self.doc_string);
let short_form = quote_opt(&self.short_switch);
let long_form = quote_opt_into(&self.long_switch);
let aliases = self.aliases.as_ref().map(LitStrArray::quote_elements_into);
let env_form = quote_opt_into(&self.env_name);
let env_aliases = self
.env_aliases
.as_ref()
.map(LitStrArray::quote_elements_into);
Ok(quote! {
#program_options_ident.push(::conf::ProgramOption {
id: #id.into(),
parse_type: ::conf::ParseType::Flag,
description: #description,
short_form: #short_form,
long_form: #long_form,
aliases: vec![#aliases],
env_form: #env_form,
env_aliases: vec![#env_aliases],
default_value: None,
is_required: false,
allow_hyphen_values: false,
secret: Some(false),
});
})
}
pub fn gen_initializer(
&self,
conf_context_ident: &Ident,
) -> Result<(TokenStream, bool), Error> {
let id = self.field_name.to_string();
Ok((
quote! {
let (_src, val) = #conf_context_ident.get_boolean_opt(#id)?;
Ok(val)
},
false,
))
}
}