feat: partial support for patches

rust/src/patcher.rs

@@ -0,0 +1,45 @@
+use std::path::Path;
+
+use anyhow::Result;
+use sha256::try_digest;
+
+use crate::model::patch::{Patch, PatchFile, PatchFileVec};
+
+impl PatchFileVec {
+    pub fn new(config_path: impl AsRef<Path>) -> Result<PatchFileVec> {
+        let path = config_path.as_ref().join("patches");
+        if !path.exists() {
+            std::fs::create_dir(&path)?;
+        }
+        std::fs::write(path.join("builtin-chunithm.json5"), include_bytes!("../static/standard-chunithm.json5"))?;
+        let mut res = Vec::new();
+        for f in std::fs::read_dir(path)? {
+            let f = f?;
+            let f = f.path();
+            res.push(
+                serde_json5::from_str::<PatchFile>(&std::fs::read_to_string(f)?)?
+            );
+        }
+        Ok(PatchFileVec(res))
+    }
+
+    pub fn find_patches(&self, target: impl AsRef<Path>) -> Result<Vec<Patch>> {
+        let checksum = try_digest(target.as_ref())?;
+
+        let mut res = Vec::new();
+        for pfile in &self.0 {
+            for plist in &pfile.0 {
+                log::debug!("checking {}", plist.sha256);
+                if plist.sha256 == checksum {
+                    let mut cloned = plist.clone().patches;
+                    res.append(&mut cloned);
+                }
+            }
+        }
+
+        if res.len() == 0 {
+            log::warn!("no matching patchset for {:?} ({})", target.as_ref(), checksum);
+        }
+        Ok(res)
+    }
+}