Add a way of making relative volume changes

Additionally this moves seeking into the command parsing for
consistency.

1 files changed, 70 insertions, 2 deletions

diff --git a/src/command.rs b/src/command.rs
index db22028..35070b8 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -1,5 +1,8 @@
+use std::time::Duration;
+
 use structopt::clap::AppSettings::*;
 use structopt::StructOpt;
+use log::debug;
 
 #[derive(StructOpt, Debug)]
 #[structopt(
@@ -20,7 +23,7 @@ pub enum Command {
     /// Pauses audio playback
     Pause,
     /// Seeks by a specified amount
-    Seek { amount: String },
+    Seek { amount: Seek },
     /// Stops audio playback
     Stop,
     /// Switches to the next queue entry
@@ -29,7 +32,72 @@ pub enum Command {
     /// Clears the playback queue
     Clear,
     /// Changes the volume to the specified value
-    Volume { percent: f64 },
+    Volume { volume: VolumeChange },
     /// Leaves the channel
     Leave,
 }
+
+#[derive(Copy, Clone, Debug)]
+pub enum Seek {
+    Positive(Duration),
+    Negative(Duration),
+    Absolute(Duration),
+}
+
+impl std::str::FromStr for Seek {
+    type Err = humantime::DurationError;
+
+    fn from_str(mut amount: &str) -> std::result::Result<Self, Self::Err> {
+        let sign = match amount.chars().next() {
+            Some('+') => 1,
+            Some('-') => -1,
+            _ => 0,
+        };
+        let is_relative = sign != 0;
+
+        if is_relative {
+            amount = &amount[1..];
+        }
+
+        let duration = humantime::parse_duration(amount)?;
+
+        match sign {
+            1 => Ok(Seek::Positive(duration)),
+            -1 => Ok(Seek::Negative(duration)),
+            _ => Ok(Seek::Absolute(duration)),
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+pub enum VolumeChange {
+    Positive(f64),
+    Negative(f64),
+    Absolute(f64),
+}
+
+// TODO This runs twice, report to clap?
+impl std::str::FromStr for VolumeChange {
+    type Err = std::num::ParseFloatError;
+
+    fn from_str(mut amount: &str) -> std::result::Result<Self, Self::Err> {
+        let sign = match amount.chars().next() {
+            Some('+') => 1,
+            Some('-') => -1,
+            _ => 0,
+        };
+        let is_relative = sign != 0;
+
+        if is_relative {
+            amount = &amount[1..];
+        }
+
+        let amount = f64::from_str(amount)? * 0.01;
+
+        match sign {
+            1 => Ok(VolumeChange::Positive(amount)),
+            -1 => Ok(VolumeChange::Negative(amount)),
+            _ => Ok(VolumeChange::Absolute(amount)),
+        }
+    }
+}