From 65af447bc732babf596a5704b764cdb9903bc5ab Mon Sep 17 00:00:00 2001
From: Terts Diepraam <terts.diepraam@gmail.com>
Date: Thu, 7 Dec 2023 16:30:16 +0100
Subject: [PATCH] value hints in completions

---
 complete/src/fish.rs   |  1 +
 derive/src/argument.rs |  2 ++
 derive/src/complete.rs | 18 ++++++++++++++++--
 derive/src/flags.rs    |  2 +-
 derive/src/lib.rs      | 13 +++++++++++++
 examples/value.rs      | 38 ++++++++++++++++++++++++++++++++++++++
 6 files changed, 71 insertions(+), 3 deletions(-)
 create mode 100644 examples/value.rs

diff --git a/complete/src/fish.rs b/complete/src/fish.rs
index 8c42c7d..5bbb451 100644
--- a/complete/src/fish.rs
+++ b/complete/src/fish.rs
@@ -30,6 +30,7 @@ fn render_value_hint(value: &ValueHint) -> String {
             let joined = s.join(", ");
             format!(" -a {{ {joined} }}")
         }
+        ValueHint::Unknown => String::new(),
         _ => todo!(),
     }
 }
diff --git a/derive/src/argument.rs b/derive/src/argument.rs
index 7e3928a..9f0a1c6 100644
--- a/derive/src/argument.rs
+++ b/derive/src/argument.rs
@@ -14,6 +14,7 @@ use crate::{
 
 pub struct Argument {
     pub ident: Ident,
+    pub field: Option<syn::Type>,
     pub name: String,
     pub arg_type: ArgType,
     pub help: String,
@@ -105,6 +106,7 @@ pub fn parse_argument(v: Variant) -> Vec<Argument> {
             };
             Argument {
                 ident: ident.clone(),
+                field: field.clone(),
                 name: name.clone(),
                 arg_type,
                 help: arg_help,
diff --git a/derive/src/complete.rs b/derive/src/complete.rs
index 92bcf98..b2d4bae 100644
--- a/derive/src/complete.rs
+++ b/derive/src/complete.rs
@@ -11,7 +11,13 @@ use quote::quote;
 pub fn complete(args: &[Argument]) -> TokenStream {
     let mut arg_specs = Vec::new();
 
-    for Argument { help, arg_type, .. } in args {
+    for Argument {
+        help,
+        field,
+        arg_type,
+        ..
+    } in args
+    {
         let ArgType::Option {
             flags,
             hidden: false,
@@ -25,21 +31,29 @@ pub fn complete(args: &[Argument]) -> TokenStream {
         if short.is_empty() && long.is_empty() {
             continue;
         }
+
         let short: Vec<_> = short
             .iter()
             .map(|Flag { flag, .. }| quote!(String::from(#flag)))
             .collect();
+
         let long: Vec<_> = long
             .iter()
             .map(|Flag { flag, .. }| quote!(String::from(#flag)))
             .collect();
 
+        let hint = if let Some(ty) = field {
+            quote!(Some(<#ty>::value_hint()))
+        } else {
+            quote!(None)
+        };
+
         arg_specs.push(quote!(
             Arg {
                 short: vec![#(#short),*],
                 long: vec![#(#long),*],
                 help: String::from(#help),
-                value: None,
+                value: #hint,
             }
         ))
     }
diff --git a/derive/src/flags.rs b/derive/src/flags.rs
index 82cf489..3d69dca 100644
--- a/derive/src/flags.rs
+++ b/derive/src/flags.rs
@@ -11,7 +11,7 @@ pub struct Flags {
     pub dd_style: Vec<(String, String)>,
 }
 
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 pub enum Value {
     No,
     Optional(String),
diff --git a/derive/src/lib.rs b/derive/src/lib.rs
index 3793247..454359c 100644
--- a/derive/src/lib.rs
+++ b/derive/src/lib.rs
@@ -115,6 +115,7 @@ pub fn arguments(input: TokenStream) -> TokenStream {
             #[cfg(feature = "complete")]
             fn complete() -> ::uutils_args_complete::Command {
                 use ::uutils_args_complete::{Command, Arg, ValueHint};
+                use ::uutils_args::Value;
                 #completion
             }
         }
@@ -137,6 +138,7 @@ pub fn value(input: TokenStream) -> TokenStream {
     let mut options = Vec::new();
 
     let mut match_arms = vec![];
+    let mut all_keys = Vec::new();
     for variant in data.variants {
         let variant_name = variant.ident.to_string();
         let attrs = variant.attrs.clone();
@@ -153,6 +155,7 @@ pub fn value(input: TokenStream) -> TokenStream {
                 keys
             };
 
+            all_keys.extend(keys.clone());
             options.push(quote!(&[#(#keys),*]));
 
             let stmt = if let Some(v) = value {
@@ -201,6 +204,16 @@ pub fn value(input: TokenStream) -> TokenStream {
                     _ => unreachable!("Should be caught by (None, []) case above.")
                 })
             }
+
+            #[cfg(feature = "complete")]
+            fn value_hint() -> ::uutils_args_complete::ValueHint {
+                ::uutils_args_complete::ValueHint::Strings(
+                    [#(#all_keys),*]
+                        .into_iter()
+                        .map(ToString::to_string)
+                        .collect()
+                )
+            }
         }
     );
 
diff --git a/examples/value.rs b/examples/value.rs
new file mode 100644
index 0000000..155e05a
--- /dev/null
+++ b/examples/value.rs
@@ -0,0 +1,38 @@
+use uutils_args::{Arguments, Initial, Options, Value};
+
+#[derive(Arguments)]
+#[arguments(file = "examples/hello_world_help.md")]
+enum Arg {
+    /// Color!
+    #[arg("-c NAME", "--color=NAME")]
+    Color(Color),
+}
+
+#[derive(Value, Debug, Default)]
+enum Color {
+    #[value("never")]
+    Never,
+    #[default]
+    #[value("auto")]
+    Auto,
+    #[value("always")]
+    Always,
+}
+
+#[derive(Initial)]
+struct Settings {
+    color: Color,
+}
+
+impl Options<Arg> for Settings {
+    fn apply(&mut self, arg: Arg) {
+        match arg {
+            Arg::Color(c) => self.color = c,
+        }
+    }
+}
+
+fn main() {
+    let color = Settings::parse(std::env::args_os()).color;
+    println!("{:?}", color);
+}