1 files changed, 112 insertions, 4 deletions

diff --git a/src/minecraft/extraction.rs b/src/minecraft/extraction.rs
index 5175ee0..b58fd2e 100644
--- a/src/minecraft/extraction.rs
+++ b/src/minecraft/extraction.rs
@@ -1,10 +1,118 @@
+use std::{fs, io, path::Path};
+
 use log::info;
+use zip::ZipArchive;
+
+use crate::{
+    errors::McError,
+    minecraft::manifests::{Library, Version},
+};
 
-use crate::errors::McError;
 pub fn extract_natives(
-    _cfg: &crate::config::Config,
-    version: &crate::minecraft::manifests::Version,
+    cfg: &crate::config::Config,
+    version: &Version,
 ) -> Result<(), McError> {
-    info!("Extracting natives for {}", version.id);
+    let natives_dir = cfg
+        .data_dir
+        .join("minecraft")
+        .join("versions")
+        .join(&version.id)
+        .join("natives");
+
+    info!("Extracting natives for {} into {:?}", version.id, natives_dir);
+
+    if natives_dir.exists() {
+        fs::remove_dir_all(&natives_dir)?;
+    }
+    fs::create_dir_all(&natives_dir)?;
+
+    for lib in &version.libraries {
+        if !library_allowed(lib) {
+            continue;
+        }
+
+        let natives = match &lib.natives {
+            | Some(n) => n,
+            | None => continue,
+        };
+
+        let classifier = match natives.get("linux") {
+            | Some(c) => c,
+            | None => continue,
+        };
+
+        let classifiers = match &lib.downloads.classifiers {
+            | Some(c) => c,
+            | None => continue,
+        };
+
+        let artifact = match classifiers.get(classifier) {
+            | Some(a) => a,
+            | None => continue,
+        };
+
+        let jar_path = cfg
+            .data_dir
+            .join("minecraft")
+            .join("libraries")
+            .join(&artifact.path);
+
+        info!("Extracting natives from {:?}", jar_path);
+
+        extract_zip(&jar_path, &natives_dir)?;
+    }
+
+    Ok(())
+}
+
+fn library_allowed(lib: &Library) -> bool {
+    let rules = match &lib.rules {
+        | Some(r) => r,
+        | None => return true,
+    };
+
+    let mut allowed = false;
+
+    for rule in rules {
+        let os_match = match &rule.os {
+            | Some(os) => os.name == "linux",
+            | None => true,
+        };
+
+        if os_match {
+            allowed = rule.action == "allow";
+        }
+    }
+
+    allowed
+}
+
+fn extract_zip(jar_path: &Path, out_dir: &Path) -> Result<(), McError> {
+    let file = fs::File::open(jar_path)?;
+    let mut zip = ZipArchive::new(file)?;
+
+    for i in 0..zip.len() {
+        let mut entry = zip.by_index(i)?;
+        let name = entry.name();
+
+        if name.starts_with("META-INF/") {
+            continue;
+        }
+
+        let out_path = out_dir.join(name);
+
+        if entry.is_dir() {
+            fs::create_dir_all(&out_path)?;
+            continue;
+        }
+
+        if let Some(parent) = out_path.parent() {
+            fs::create_dir_all(parent)?;
+        }
+
+        let mut out_file = fs::File::create(&out_path)?;
+        io::copy(&mut entry, &mut out_file)?;
+    }
+
     Ok(())
 }