From be9bdd235c75448890178e30e9dc156acbd6f8e2 Mon Sep 17 00:00:00 2001
From: Matthew Maxwell <maxwellmattryan@gmail.com>
Date: Wed, 30 Oct 2024 19:28:15 -0500
Subject: [PATCH] Add stubbed command for notes

---
 src/cli.rs           | 11 +++++++++--
 src/commands/midi.rs |  2 +-
 src/commands/mod.rs  |  1 +
 src/commands/note.rs | 34 ++++++++++++++++++++++++++++++++++
 src/error.rs         |  3 +++
 5 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 src/commands/note.rs

diff --git a/src/cli.rs b/src/cli.rs
index cd874d6..b8a7c07 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,6 +1,9 @@
 use async_trait::async_trait;
 
-use crate::{commands::midi::MidiCommand, error::FNoteResult};
+use crate::{
+    commands::{midi::MidiCommand, note::NoteCommand},
+    error::FNoteResult,
+};
 
 /// Represents an `fnote` program command.
 #[async_trait]
@@ -16,8 +19,11 @@ pub trait Command {
     version = env!("CARGO_PKG_VERSION"),
 )]
 pub enum FNoteCommand {
-    /// Extracts the frequency and musical note from a MIDI note number (0-127).
+    /// Extracts the frequency and music note from a MIDI note number (0-127).
     Midi(MidiCommand),
+
+    /// Extracts the frequency and MIDI note number from a music note (e.g. C5).
+    Note(NoteCommand),
 }
 
 #[async_trait]
@@ -25,6 +31,7 @@ impl Command for FNoteCommand {
     async fn run(&self) -> FNoteResult<()> {
         match self {
             Self::Midi(cmd) => cmd.run().await,
+            Self::Note(cmd) => cmd.run().await,
         }
     }
 }
diff --git a/src/commands/midi.rs b/src/commands/midi.rs
index 5d586bd..e387742 100644
--- a/src/commands/midi.rs
+++ b/src/commands/midi.rs
@@ -6,7 +6,7 @@ use crate::{
     error::{FNoteError, FNoteResult},
 };
 
-/// Extracts the frequency and musical note from a MIDI note number (0-127).
+/// Extracts the frequency and music note from a MIDI note number (0-127).
 #[derive(structopt::StructOpt)]
 pub struct MidiCommand {
     /// The MIDI note number to use.
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 911a759..ae58a65 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -1 +1,2 @@
 pub(crate) mod midi;
+pub(crate) mod note;
diff --git a/src/commands/note.rs b/src/commands/note.rs
new file mode 100644
index 0000000..d98b37b
--- /dev/null
+++ b/src/commands/note.rs
@@ -0,0 +1,34 @@
+use async_trait::async_trait;
+use regex::Regex;
+
+use crate::{
+    cli::Command,
+    error::{FNoteError, FNoteResult},
+};
+
+/// Extracts the frequency and MIDI note number from a music note (e.g. C5).
+#[derive(structopt::StructOpt)]
+pub struct NoteCommand {
+    /// The music note to use.
+    #[structopt(parse(try_from_str = try_music_note_from_str))]
+    pub musical_note: String,
+}
+
+#[async_trait]
+impl Command for NoteCommand {
+    async fn run(&self) -> FNoteResult<()> {
+        println!("Converting music note: {:?}", self.musical_note);
+
+        Ok(())
+    }
+}
+
+/// Parses a music note from a string.
+fn try_music_note_from_str(arg: &str) -> FNoteResult<String> {
+    let regex = Regex::new(r"^[A-Ga-g][#b]?[0-9]$").unwrap();
+    if regex.is_match(arg) {
+        Ok(arg.to_string())
+    } else {
+        Err(FNoteError::InvalidMusicNote(arg.to_string()))
+    }
+}
diff --git a/src/error.rs b/src/error.rs
index 60348b5..5ed95e7 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -9,4 +9,7 @@ pub enum FNoteError {
 
     #[error("Invalid MIDI note number \"{0}\"")]
     InvalidMidiNoteNumber(String),
+
+    #[error("Invalid music note \"{0}\"")]
+    InvalidMusicNote(String),
 }