From 6ee541d5f2caa131ec0c78c0a47ca6a06334a6b8 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Wed, 24 Jan 2024 09:01:54 +0100
Subject: [PATCH] login: parse helpers for floats

Of course PVE also stringifies those in the API, duh...

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 proxmox-login/src/parse.rs | 132 +++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/proxmox-login/src/parse.rs b/proxmox-login/src/parse.rs
index b2653521..65221939 100644
--- a/proxmox-login/src/parse.rs
+++ b/proxmox-login/src/parse.rs
@@ -115,6 +115,7 @@ where
 
 macro_rules! integer_helper {
     ($ty:ident, $deserialize_name:ident, $trait: ident, $from_name:ident, $visitor:ident) => {
+        #[doc(hidden)]
         pub trait $trait: Sized + Default {
             fn $from_name(value: $ty) -> Self;
         }
@@ -237,3 +238,134 @@ integer_helper!(i8, deserialize_i8, FromI8, from_i8, I8Visitor);
 integer_helper!(i16, deserialize_i16, FromI16, from_i16, I16Visitor);
 integer_helper!(i32, deserialize_i32, FromI32, from_i32, I32Visitor);
 integer_helper!(i64, deserialize_i64, FromI64, from_i64, I64Visitor);
+
+// float helpers:
+
+macro_rules! float_helper {
+    ($ty:ident, $deserialize_name:ident, $visitor:ident) => {
+        pub fn $deserialize_name<'de, D, T>(deserializer: D) -> Result<T, D::Error>
+        where
+            D: serde::Deserializer<'de>,
+            T: FromF64,
+        {
+            deserializer.deserialize_any($visitor::<T>::new())
+        }
+
+        struct $visitor<T>(std::marker::PhantomData<T>);
+
+        impl<T> $visitor<T> {
+            fn new() -> Self {
+                Self(std::marker::PhantomData)
+            }
+        }
+
+        impl<'de, T: FromF64> serde::de::DeserializeSeed<'de> for $visitor<T> {
+            type Value = T;
+
+            fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                $deserialize_name(deserializer)
+            }
+        }
+
+        impl<'de, T> serde::de::Visitor<'de> for $visitor<T>
+        where
+            T: FromF64,
+        {
+            type Value = T;
+
+            fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                f.write_str(concat!("a ", stringify!($ty), "-ish..."))
+            }
+
+            fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                deserializer.deserialize_any(self)
+            }
+
+            fn visit_none<E>(self) -> Result<Self::Value, E> {
+                Ok(Default::default())
+            }
+
+            fn visit_f64<E: serde::de::Error>(self, value: f64) -> Result<Self::Value, E> {
+                Ok(T::from_f64(value))
+            }
+
+            fn visit_i128<E: serde::de::Error>(self, value: i128) -> Result<Self::Value, E> {
+                let conv = value as f64;
+                if conv as i128 == value {
+                    Ok(T::from_f64(conv))
+                } else {
+                    Err(E::invalid_value(Unexpected::Other("i128"), &self))
+                }
+            }
+
+            fn visit_i64<E: serde::de::Error>(self, value: i64) -> Result<Self::Value, E> {
+                let conv = value as f64;
+                if conv as i64 == value {
+                    Ok(T::from_f64(conv))
+                } else {
+                    Err(E::invalid_value(Unexpected::Signed(value), &self))
+                }
+            }
+
+            fn visit_u128<E: serde::de::Error>(self, value: u128) -> Result<Self::Value, E> {
+                let conv = value as f64;
+                if conv as u128 == value {
+                    Ok(T::from_f64(conv))
+                } else {
+                    Err(E::invalid_value(Unexpected::Other("u128"), &self))
+                }
+            }
+
+            fn visit_u64<E: serde::de::Error>(self, value: u64) -> Result<Self::Value, E> {
+                let conv = value as f64;
+                if conv as u64 == value {
+                    Ok(T::from_f64(conv))
+                } else {
+                    Err(E::invalid_value(Unexpected::Unsigned(value), &self))
+                }
+            }
+
+            fn visit_str<E: serde::de::Error>(self, value: &str) -> Result<Self::Value, E> {
+                let value = value
+                    .parse()
+                    .map_err(|_| E::invalid_value(Unexpected::Str(value), &self))?;
+                self.visit_f64(value)
+            }
+        }
+    };
+}
+
+#[doc(hidden)]
+pub trait FromF64: Sized + Default {
+    fn from_f64(value: f64) -> Self;
+}
+
+impl FromF64 for f32 {
+    #[inline(always)]
+    fn from_f64(f: f64) -> f32 {
+        f as f32
+    }
+}
+
+impl FromF64 for f64 {
+    #[inline(always)]
+    fn from_f64(f: f64) -> f64 {
+        f
+    }
+}
+
+impl<T: FromF64> FromF64 for Option<T> {
+    #[inline(always)]
+    fn from_f64(f: f64) -> Option<T> {
+        Some(T::from_f64(f))
+    }
+}
+
+float_helper!(f32, deserialize_f32, F32Visitor);
+float_helper!(f64, deserialize_f64, F64Visitor);