feat: wallpaper changing + current wallpaper

src/lib.rs

@@ -1,2 +1,3 @@
 pub mod cli;
 pub mod configuration;
+pub mod wallpaper;

src/wallpaper.rs

@@ -0,0 +1,52 @@
+use std::process::Command;
+
+use crate::configuration::Settings;
+
+/// Gets the current wallpaper. It assumes that the user is only using feh to set the wallpaper.
+/// TODO: allow user to choose other wallpaper getter
+///
+///
+/// The .fehbg file is a shell script that is run when the user logs in. It is used to set the
+/// wallpaper. It uses the following format:
+/// ```
+/// #!/bin/sh
+/// feh --no-fehbg --bg-fill /path/to/wallpaper
+/// ```
+/// This function parses the .fehbg file and returns the path to the current wallpaper.
+///
+/// # Panics
+///
+/// Panics if the file $HOME/.fehbg does not exist.
+///
+pub fn get_current_wallpaper() -> String {
+    let feh_raw = std::fs::read_to_string("~/.fehbg").expect("failed to open .fehbg file");
+
+    feh_raw
+        .lines()
+        .nth(1)
+        .expect("failed to parse .fehbg file, it should contain at least 2 lines")
+        .split(' ')
+        .last()
+        .expect(
+            "failed to parse .fehbg file, the last line should contain the path to the wallpaper",
+        )
+        .to_string()
+}
+
+pub fn update_wallpaper(settings: &Settings, path: &str) {
+    // TODO: allow user to choose other wallpaper setter
+    Command::new("feh")
+        .arg("--bg-fill")
+        .arg(path)
+        .output()
+        .expect("failed to call feh");
+
+    // Updates the betterlockscreen wallpaper
+    if settings.betterlockscreen {
+        Command::new("betterlockscreen")
+            .arg("-u")
+            .arg(path)
+            .output()
+            .expect("failed to call betterlockscreen");
+    }
+}