make specifying unpack file optional

src/command/unpack.rs

@@ -13,7 +13,8 @@ use crate::io_ext::ReadExt;
 use crate::unity::AssetsFile;
 use crate::unity::util::{AlignedString, AlignmentArgs};
 
-pub fn unpack(args: &NewArgs, input: &PathBuf, output: &PathBuf) -> anyhow::Result<()> {
+pub fn unpack(args: &NewArgs, input: &Option<PathBuf>, output: &PathBuf) -> anyhow::Result<()> {
+    let input = &find_input(args, input)?;
     let extension = input.extension();
     match extension {
         Some(ext) => {
@@ -33,6 +34,29 @@ pub fn unpack(args: &NewArgs, input: &PathBuf, output: &PathBuf) -> anyhow::Resu
     Ok(())
 }
 
+fn find_input(args: &NewArgs, input: &Option<PathBuf>) -> anyhow::Result<PathBuf> {
+    match input {
+        // Check if an input path was provided
+        Some(path) => {
+            if !path.is_file() {
+                anyhow::bail!("Input path is not a file");
+            }
+            Ok(path.clone())
+        }
+        None => {
+            let assets = args.game_dir
+                .join("PapersPlease_Data")
+                .join("sharedassets0.assets");
+
+            if assets.is_file() {
+                Ok(assets)
+            } else {
+                anyhow::bail!("No input file provided and no sharedassets0.assets file found in game directory");
+            }
+        }
+    }
+}
+
 pub fn unpack_dat(args: &NewArgs, input: &PathBuf, output: &PathBuf) -> anyhow::Result<()> {
     let mut data = std::fs::read(input)
         .context("Failed to read input file")?;

src/main.rs

@@ -60,9 +60,9 @@ enum Command {
     },
     /// Unpack assets from an Art.dat or unity asset bundle.
     Unpack {
-        /// Input file. Can either be an Art.dat file or a unity asset bundle. Make sure to either use the .dat or .assets extension.
+        /// Input file. Can either be an Art.dat file or a unity asset bundle. Make sure to either use the .dat or .assets extension. Defaults to the sharedassets0.assets in the game directory.
         #[arg(short, long)]
-        input: PathBuf,
+        input: Option<PathBuf>,
 
         /// Output directory.
         #[arg(short, long, default_value = "./out")]
@@ -83,14 +83,12 @@ enum Command {
 }
 
 impl Command {
-
     fn needs_key(&self) -> bool {
         match self {
             Command::Revert => false,
             _ => true,
         }
     }
-
 }
 
 #[derive(Debug, Clone, Eq, PartialEq, ValueEnum)]