287 lines
10 KiB
Rust

use heck::CamelCase;
use proc_macro2::TokenStream;
use quote::{quote, quote_spanned};
use syn::{punctuated::Punctuated, token::Comma, Lit, LitInt, LitStr, Meta};
enum Error {
InputNotEnum,
Syn(syn::Error),
TT(TokenStream),
}
struct ActiveEnum {
ident: syn::Ident,
enum_name: String,
rs_type: TokenStream,
db_type: TokenStream,
is_string: bool,
variants: Vec<ActiveEnumVariant>,
}
struct ActiveEnumVariant {
ident: syn::Ident,
string_value: Option<LitStr>,
num_value: Option<LitInt>,
}
impl ActiveEnum {
fn new(input: syn::DeriveInput) -> Result<Self, Error> {
let ident_span = input.ident.span();
let ident = input.ident;
let mut enum_name = ident.to_string().to_camel_case();
let mut rs_type = Err(Error::TT(quote_spanned! {
ident_span => compile_error!("Missing macro attribute `rs_type`");
}));
let mut db_type = Err(Error::TT(quote_spanned! {
ident_span => compile_error!("Missing macro attribute `db_type`");
}));
for attr in input.attrs.iter() {
if let Some(ident) = attr.path.get_ident() {
if ident != "sea_orm" {
continue;
}
} else {
continue;
}
if let Ok(list) = attr.parse_args_with(Punctuated::<Meta, Comma>::parse_terminated) {
for meta in list.iter() {
if let Meta::NameValue(nv) = meta {
if let Some(name) = nv.path.get_ident() {
if name == "rs_type" {
if let Lit::Str(litstr) = &nv.lit {
rs_type = syn::parse_str::<TokenStream>(&litstr.value())
.map_err(Error::Syn);
}
} else if name == "db_type" {
if let Lit::Str(litstr) = &nv.lit {
let s = litstr.value();
match s.as_ref() {
"Enum" => {
db_type = Ok(quote! {
Enum(Self::name(), Self::values())
})
}
_ => {
db_type = syn::parse_str::<TokenStream>(&s)
.map_err(Error::Syn);
}
}
}
} else if name == "enum_name" {
if let Lit::Str(litstr) = &nv.lit {
enum_name = litstr.value();
}
}
}
}
}
}
}
let variant_vec = match input.data {
syn::Data::Enum(syn::DataEnum { variants, .. }) => variants,
_ => return Err(Error::InputNotEnum),
};
let mut is_string = false;
let mut is_int = false;
let mut variants = Vec::new();
for variant in variant_vec {
let variant_span = variant.ident.span();
let mut string_value = None;
let mut num_value = None;
for attr in variant.attrs.iter() {
if let Some(ident) = attr.path.get_ident() {
if ident != "sea_orm" {
continue;
}
} else {
continue;
}
if let Ok(list) = attr.parse_args_with(Punctuated::<Meta, Comma>::parse_terminated)
{
for meta in list {
if let Meta::NameValue(nv) = meta {
if let Some(name) = nv.path.get_ident() {
if name == "string_value" {
if let Lit::Str(lit) = nv.lit {
is_string = true;
string_value = Some(lit);
}
} else if name == "num_value" {
if let Lit::Int(lit) = nv.lit {
is_int = true;
num_value = Some(lit);
}
}
}
}
}
}
}
if is_string && is_int {
return Err(Error::TT(quote_spanned! {
ident_span => compile_error!("All enum variants should specify the same `*_value` macro attribute, either `string_value` or `num_value` but not both");
}));
}
if string_value.is_none() && num_value.is_none() {
return Err(Error::TT(quote_spanned! {
variant_span => compile_error!("Missing macro attribute, either `string_value` or `num_value` should be specified");
}));
}
variants.push(ActiveEnumVariant {
ident: variant.ident,
string_value,
num_value,
});
}
Ok(ActiveEnum {
ident,
enum_name,
rs_type: rs_type?,
db_type: db_type?,
is_string,
variants,
})
}
fn expand(&self) -> syn::Result<TokenStream> {
let expanded_impl_active_enum = self.impl_active_enum();
Ok(expanded_impl_active_enum)
}
fn impl_active_enum(&self) -> TokenStream {
let Self {
ident,
enum_name,
rs_type,
db_type,
is_string,
variants,
} = self;
let variant_idents: Vec<syn::Ident> = variants
.iter()
.map(|variant| variant.ident.clone())
.collect();
let variant_values: Vec<TokenStream> = variants
.iter()
.map(|variant| {
let variant_span = variant.ident.span();
if let Some(string_value) = &variant.string_value {
let string = string_value.value();
quote! { #string }
} else if let Some(num_value) = &variant.num_value {
quote! { #num_value }
} else {
quote_spanned! {
variant_span => compile_error!("Missing macro attribute, either `string_value` or `num_value` should be specified");
}
}
})
.collect();
let val = if *is_string {
quote! { v.as_ref() }
} else {
quote! { v }
};
quote!(
#[automatically_derived]
impl sea_orm::ActiveEnum for #ident {
type Value = #rs_type;
fn name() -> String {
#enum_name.to_owned()
}
fn to_value(&self) -> Self::Value {
match self {
#( Self::#variant_idents => #variant_values, )*
}
.to_owned()
}
fn try_from_value(v: &Self::Value) -> Result<Self, sea_orm::DbErr> {
match #val {
#( #variant_values => Ok(Self::#variant_idents), )*
_ => Err(sea_orm::DbErr::Type(format!(
"unexpected value for {} enum: {}",
stringify!(#ident),
v
))),
}
}
fn db_type() -> sea_orm::ColumnDef {
sea_orm::ColumnType::#db_type.def()
}
}
#[automatically_derived]
#[allow(clippy::from_over_into)]
impl Into<sea_orm::sea_query::Value> for #ident {
fn into(self) -> sea_orm::sea_query::Value {
<Self as sea_orm::ActiveEnum>::to_value(&self).into()
}
}
#[automatically_derived]
impl sea_orm::TryGetable for #ident {
fn try_get(res: &sea_orm::QueryResult, pre: &str, col: &str) -> Result<Self, sea_orm::TryGetError> {
let value = <<Self as sea_orm::ActiveEnum>::Value as sea_orm::TryGetable>::try_get(res, pre, col)?;
<Self as sea_orm::ActiveEnum>::try_from_value(&value).map_err(sea_orm::TryGetError::DbErr)
}
}
#[automatically_derived]
impl sea_orm::sea_query::ValueType for #ident {
fn try_from(v: sea_orm::sea_query::Value) -> Result<Self, sea_orm::sea_query::ValueTypeErr> {
let value = <<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::ValueType>::try_from(v)?;
<Self as sea_orm::ActiveEnum>::try_from_value(&value).map_err(|_| sea_orm::sea_query::ValueTypeErr)
}
fn type_name() -> String {
<<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::ValueType>::type_name()
}
fn column_type() -> sea_orm::sea_query::ColumnType {
<Self as sea_orm::ActiveEnum>::db_type()
.get_column_type()
.to_owned()
.into()
}
}
#[automatically_derived]
impl sea_orm::sea_query::Nullable for #ident {
fn null() -> sea_orm::sea_query::Value {
<<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::Nullable>::null()
}
}
)
}
}
pub fn expand_derive_active_enum(input: syn::DeriveInput) -> syn::Result<TokenStream> {
let ident_span = input.ident.span();
match ActiveEnum::new(input) {
Ok(model) => model.expand(),
Err(Error::InputNotEnum) => Ok(quote_spanned! {
ident_span => compile_error!("you can only derive ActiveEnum on enums");
}),
Err(Error::TT(token_stream)) => Ok(token_stream),
Err(Error::Syn(e)) => Err(e),
}
}