Allow config to be updated with CLI args

src/config.rs

@@ -4,7 +4,9 @@ use cosmic::{
     cosmic_config::{self, cosmic_config_derive::CosmicConfigEntry, CosmicConfigEntry},
     theme,
 };
+use lexopt::prelude::*;
 use serde::{Deserialize, Serialize};
+use std::{path::PathBuf, process};
 
 use crate::wrappers::HWDeviceType;
 
@@ -41,3 +43,52 @@ impl Default for Config {
         }
     }
 }
+
+impl Config {
+    pub fn with_args(&mut self, args: &mut Args) {
+        if let Some(decoder) = args.decoder {
+            self.hw_decoder = decoder;
+        }
+    }
+}
+
+pub struct Args {
+    pub paths: Vec<PathBuf>,
+    pub decoder: Option<HWDeviceType>,
+}
+
+impl Args {
+    pub fn parse_args() -> Result<Self, lexopt::Error> {
+        let mut paths = Vec::new();
+        let mut decoder = None;
+
+        let mut parser = lexopt::Parser::from_env();
+        while let Some(arg) = parser.next()? {
+            match arg {
+                Long("list-hwdec") => {
+                    println!("Supported hardware decoders:");
+                    for hwdec in HWDeviceType::supported_devices() {
+                        println!("\t* [{}] {hwdec}", hwdec.short_name());
+                    }
+                    process::exit(0);
+                }
+                Long("hwdec") => {
+                    decoder = Some(parser.value()?.parse()?);
+                }
+                Value(path) => {
+                    let path = path.parse()?;
+                    paths.push(path);
+                }
+                _ => return Err(arg.unexpected()),
+            }
+        }
+
+        if paths.is_empty() {
+            return Err(lexopt::Error::MissingValue {
+                option: Some("missing video path".into()),
+            });
+        }
+
+        Ok(Self { paths, decoder })
+    }
+}

src/main.rs

@@ -16,14 +16,12 @@ use cosmic::{
 use std::{
     any::TypeId,
     collections::HashMap,
-    env,
-    path::PathBuf,
-    process,
+    env, process,
     sync::{mpsc, Arc, Mutex},
     time::{Duration, Instant},
 };
 
-use config::{AppTheme, Config, CONFIG_VERSION};
+use config::{AppTheme, Args, Config, CONFIG_VERSION};
 mod config;
 
 use key_bind::{key_binds, KeyBind};
@@ -42,16 +40,26 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("warn")).init();
 
     localize::localize();
+    
+    let mut args = match Args::parse_args() {
+        Ok(args) => args,
+        Err(e) => {
+            log::error!("{e}");
+            process::exit(1);
+        }
+    };
 
     let (config_handler, config) = match cosmic_config::Config::new(App::APP_ID, CONFIG_VERSION) {
         Ok(config_handler) => {
-            let config = match Config::get_entry(&config_handler) {
+            let mut config = match Config::get_entry(&config_handler) {
                 Ok(ok) => ok,
                 Err((errs, config)) => {
                     log::info!("errors loading config: {:?}", errs);
                     config
                 }
             };
+            // Update config with command line args
+            config.with_args(&mut args);
             (Some(config_handler), config)
         }
         Err(err) => {
@@ -60,14 +68,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         }
     };
 
-    //TODO: support multiple paths
-    let path = match env::args().skip(1).next() {
-        Some(arg) => PathBuf::from(arg),
-        None => {
-            log::error!("no argument provided");
-            process::exit(1);
-        }
-    };
+    //TODO: support using multiple paths
+    let Args { mut paths, .. } = args;
+    let path = paths.pop().unwrap();
 
     let (player_tx, video_queue_lock) = player::run(path);
 

src/wrappers.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
-use std::str::FromStr;
+use std::{fmt, iter::FusedIterator, str::FromStr};
 
 use ffmpeg_next::ffi::{av_hwdevice_iterate_types, AVHWDeviceType};
 use serde::{
@@ -25,6 +25,8 @@ pub enum HWDeviceType {
     /// DirectX Video Acceleration 2.0
     /// https://learn.microsoft.com/en-us/windows/win32/medfound/about-dxva-2-0
     Dxva2,
+    /// Direct Rendering Manager
+    /// https://dri.freedesktop.org/wiki/DRM/
     Drm,
     /// MediaCodec
     /// Android only
@@ -70,7 +72,26 @@ impl HWDeviceType {
         }
     }
 
-    /// Supported hardware decoders
+    /// Short name for CLI arguments
+    pub const fn short_name(self) -> &'static str {
+        match self {
+            Self::None => "none",
+            Self::Cuda => "cuda",
+            Self::Dxva2 => "dxva2",
+            Self::D3d11va => "d3d11va",
+            Self::D3d12va => "d3d12va",
+            Self::Drm => "drm",
+            Self::MediaCodec => "mediacodec",
+            Self::OpenCl => "opencl",
+            Self::Qsv => "qsv",
+            Self::Vaapi => "vaapi",
+            Self::Vdpau => "vdpau",
+            Self::VideoToolbox => "videotoolbox",
+            Self::Vulkan => "vulkan",
+        }
+    }
+
+    /// System's supported hardware decoders
     pub fn supported_devices() -> SupportedDeviceIter {
         SupportedDeviceIter::default()
     }
@@ -104,6 +125,12 @@ impl FromStr for HWDeviceType {
     }
 }
 
+impl fmt::Display for HWDeviceType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.name())
+    }
+}
+
 impl From<AVHWDeviceType> for HWDeviceType {
     fn from(value: AVHWDeviceType) -> Self {
         match value {
@@ -131,6 +158,7 @@ impl Default for HWDeviceType {
     }
 }
 
+/// Iterator over system's supported hardware decoders.
 pub struct SupportedDeviceIter {
     current: AVHWDeviceType,
 }
@@ -147,13 +175,36 @@ impl Iterator for SupportedDeviceIter {
     type Item = HWDeviceType;
 
     fn next(&mut self) -> Option<Self::Item> {
+        // None is a sentinel value that indicates the iterator is exhausted
         if self.current == AVHWDeviceType::AV_HWDEVICE_TYPE_NONE {
             None
         } else {
             let prev = self.current;
+            // SAFETY: The docs and examples state that the iterator yields the next value
+            // when the previous is passed in.
             self.current = unsafe { av_hwdevice_iterate_types(prev) };
 
             Some(prev.into())
         }
     }
 }
+
+impl FusedIterator for SupportedDeviceIter {}
+
+#[cfg(test)]
+mod tests {
+    use std::hint::black_box;
+
+    use super::*;
+
+    // The iterator's yielded values aren't important since hardware decoders vary by system
+    // This is just a sanity check to ensure the iterator works
+    #[test]
+    fn supported_device_iter_doesnt_seg_fault() {
+        for decoder in HWDeviceType::supported_devices() {
+            black_box(decoder);
+        }
+
+        let _decoders: Vec<_> = black_box(HWDeviceType::supported_devices().collect());
+    }
+}