From adc33076f3024782f93ace0d21c469a761478236 Mon Sep 17 00:00:00 2001
From: Natsu Kagami <natsukagami@gmail.com>
Date: Sun, 9 Feb 2020 14:13:19 -0500
Subject: [PATCH] Generalize UsernameArg

---
 youmubot-osu/src/discord/mod.rs | 64 +++++++++++----------------------
 youmubot-prelude/src/args.rs    | 29 +++++++++++++++
 youmubot-prelude/src/lib.rs     |  2 +-
 3 files changed, 51 insertions(+), 44 deletions(-)

diff --git a/youmubot-osu/src/discord/mod.rs b/youmubot-osu/src/discord/mod.rs
index 70dadea..8bd76e2 100644
--- a/youmubot-osu/src/discord/mod.rs
+++ b/youmubot-osu/src/discord/mod.rs
@@ -180,39 +180,24 @@ impl FromStr for ModeArg {
     }
 }
 
-enum UsernameArg {
-    Tagged(UserId),
-    Raw(String),
+fn to_user_id_query(
+    s: Option<UsernameArg>,
+    data: &ShareMap,
+    msg: &Message,
+) -> Result<UserID, Error> {
+    let id = match s {
+        Some(UsernameArg::Raw(s)) => return Ok(UserID::Auto(s)),
+        Some(UsernameArg::Tagged(r)) => r,
+        None => msg.author.id,
+    };
+
+    let db = OsuSavedUsers::open(data);
+    let db = db.borrow()?;
+    db.get(&id)
+        .cloned()
+        .map(|u| UserID::ID(u.id))
+        .ok_or(Error::from("No saved account found"))
 }
-
-impl UsernameArg {
-    fn to_user_id_query(s: Option<Self>, data: &ShareMap, msg: &Message) -> Result<UserID, Error> {
-        let id = match s {
-            Some(UsernameArg::Raw(s)) => return Ok(UserID::Auto(s)),
-            Some(UsernameArg::Tagged(r)) => r,
-            None => msg.author.id,
-        };
-
-        let db = OsuSavedUsers::open(data);
-        let db = db.borrow()?;
-        db.get(&id)
-            .cloned()
-            .map(|u| UserID::ID(u.id))
-            .ok_or(Error::from("No saved account found"))
-    }
-}
-
-impl FromStr for UsernameArg {
-    type Err = String;
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s.parse::<UserId>() {
-            Ok(v) => Ok(UsernameArg::Tagged(v)),
-            Err(_) if !s.is_empty() => Ok(UsernameArg::Raw(s.to_owned())),
-            Err(_) => Err("username arg cannot be empty".to_owned()),
-        }
-    }
-}
-
 struct Nth(u8);
 
 impl FromStr for Nth {
@@ -235,8 +220,7 @@ impl FromStr for Nth {
 pub fn recent(ctx: &mut Context, msg: &Message, mut args: Args) -> CommandResult {
     let nth = args.single::<Nth>().unwrap_or(Nth(1)).0.min(50).max(1);
     let mode = args.single::<ModeArg>().unwrap_or(ModeArg(Mode::Std)).0;
-    let user =
-        UsernameArg::to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
+    let user = to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
 
     let osu = ctx.data.get_cloned::<OsuClient>();
     let user = osu
@@ -308,11 +292,7 @@ pub fn check(ctx: &mut Context, msg: &Message, mut args: Args) -> CommandResult
         Some(bm) => {
             let b = &bm.0;
             let m = bm.1;
-            let user = UsernameArg::to_user_id_query(
-                args.single::<UsernameArg>().ok(),
-                &*ctx.data.read(),
-                msg,
-            )?;
+            let user = to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
 
             let osu = ctx.data.get_cloned::<OsuClient>();
 
@@ -348,8 +328,7 @@ pub fn top(ctx: &mut Context, msg: &Message, mut args: Args) -> CommandResult {
         .map(|ModeArg(t)| t)
         .unwrap_or(Mode::Std);
 
-    let user =
-        UsernameArg::to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
+    let user = to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
 
     let osu = ctx.data.get_cloned::<OsuClient>();
     let user = osu
@@ -387,8 +366,7 @@ pub fn top(ctx: &mut Context, msg: &Message, mut args: Args) -> CommandResult {
 }
 
 fn get_user(ctx: &mut Context, msg: &Message, mut args: Args, mode: Mode) -> CommandResult {
-    let user =
-        UsernameArg::to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
+    let user = to_user_id_query(args.single::<UsernameArg>().ok(), &*ctx.data.read(), msg)?;
     let osu = ctx.data.get_cloned::<OsuClient>();
     let user = osu.user(user, |f| f.mode(mode))?;
     match user {
diff --git a/youmubot-prelude/src/args.rs b/youmubot-prelude/src/args.rs
index d2e39b0..b6b96f9 100644
--- a/youmubot-prelude/src/args.rs
+++ b/youmubot-prelude/src/args.rs
@@ -1,4 +1,5 @@
 pub use duration::Duration;
+pub use username_arg::UsernameArg;
 
 mod duration {
     use std::fmt;
@@ -169,3 +170,31 @@ mod duration {
         }
     }
 }
+
+mod username_arg {
+    use serenity::model::id::UserId;
+    use std::str::FromStr;
+    /// An argument that can be either a tagged user, or a raw string.
+    pub enum UsernameArg {
+        Tagged(UserId),
+        Raw(String),
+    }
+
+    impl FromStr for UsernameArg {
+        type Err = String;
+        fn from_str(s: &str) -> Result<Self, Self::Err> {
+            match s.parse::<UserId>() {
+                Ok(v) => Ok(UsernameArg::Tagged(v)),
+                Err(_) if !s.is_empty() => Ok(UsernameArg::Raw(s.to_owned())),
+                Err(_) => Err("username arg cannot be empty".to_owned()),
+            }
+        }
+    }
+
+    impl UsernameArg {
+        /// Mention yourself.
+        pub fn mention<T: Into<UserId>>(v: T) -> Self {
+            Self::Tagged(v.into())
+        }
+    }
+}
diff --git a/youmubot-prelude/src/lib.rs b/youmubot-prelude/src/lib.rs
index 77a31a1..cf05cb0 100644
--- a/youmubot-prelude/src/lib.rs
+++ b/youmubot-prelude/src/lib.rs
@@ -8,7 +8,7 @@ pub mod reaction_watch;
 pub mod setup;
 
 pub use announcer::Announcer;
-pub use args::Duration;
+pub use args::{Duration, UsernameArg};
 pub use pagination::Pagination;
 pub use reaction_watch::{ReactionHandler, ReactionWatcher};