added local overrides in instance

src/basic_types.rs

@@ -170,6 +170,9 @@ pub struct ModdedInstance {
 
     #[serde(default)]
     pub load_order: Vec<String>,
+
+    #[serde(default)]
+    game_file_overrides: Vec<Link>,
 }
 
 impl ModdedInstance {
@@ -178,6 +181,7 @@ impl ModdedInstance {
             name: name.to_owned(),
             mods: Vec::new(),
             load_order: Vec::new(),
+            game_file_overrides: Vec::new(),
         }
     }
 
@@ -252,6 +256,10 @@ impl ModdedInstance {
     pub fn load_order(&self) -> &[String] {
         &self.load_order
     }
+
+    pub fn game_file_overrides(&self) -> &[Link] {
+        &self.game_file_overrides
+    }
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]

src/linker.rs

@@ -1,9 +1,6 @@
 use log::debug;
 
-use crate::{
-    basic_types::{Game, Link, ModdedInstance, RootConfig},
-    utils::walk_files_recursive,
-};
+use crate::basic_types::{Game, Link, ModdedInstance, RootConfig};
 use std::io::Write;
 use std::{fs, io, os::unix, path::Path};
 
@@ -27,12 +24,11 @@ pub fn link_instance_to_target(
     Ok(())
 }
 
-pub fn link_game_to_target(game: &Game, target: impl AsRef<Path>) -> Result<(), io::Error> {
-    for link in game.export_links()? {
-        link_file(&link.src, &target.as_ref().join(&link.dst))?;
-    }
+pub fn apply_link(link: &Link, target: impl AsRef<Path>) -> Result<(), io::Error> {
+    let link_target = &link.src;
+    let link_name = target.as_ref().join(&link.dst);
 
-    Ok(())
+    link_file(&link_target, &link_name)
 }
 
 fn link_file(target: &Path, link_name: &Path) -> Result<(), io::Error> {

src/main.rs

@@ -2,14 +2,15 @@ use clap::Parser;
 use globset::{Glob, GlobSet, GlobSetBuilder};
 use log::debug;
 use std::{
+    collections::HashMap,
     error::Error,
     path::{Path, PathBuf},
 };
 
 use crate::{
-    basic_types::{ModConfig, ModFile, ModdedInstance, RootConfig},
+    basic_types::{Game, Link, ModConfig, ModFile, ModdedInstance, RootConfig},
     cli::Args,
-    linker::{create_plugins_txt, link_game_to_target, link_instance_to_target},
+    linker::{apply_link, create_plugins_txt},
     load_order::LoadOrder,
     mod_config_installer::FomodInstaller,
     utils::{resolve_case_insensitive, walk_files_recursive},
@@ -150,13 +151,60 @@ pub fn activate_instance(
 ) -> Result<(), Box<dyn Error>> {
     let instance_config = root_config.load_instance_by_id(instance_id)?;
 
-    link_game_to_target(root_config.games.first().unwrap(), target)?;
-    link_instance_to_target(root_config, &instance_config, target)?;
+    let links = gen_links_for_activation(
+        root_config,
+        &instance_config,
+        root_config.games.first().unwrap(),
+    )?;
+
+    links.iter().try_for_each(|link| apply_link(link, target));
     create_plugins_txt(&instance_config, target)?;
 
     Ok(())
 }
 
+pub fn gen_links_for_activation(
+    root_config: &RootConfig,
+    instance: &ModdedInstance,
+    game: &Game,
+) -> Result<Vec<Link>, Box<dyn Error>> {
+    let game_links = game.export_links()?;
+    let mod_links = gen_links_for_instance(root_config, instance)?;
+    let overrides = instance.game_file_overrides().to_owned();
+
+    let mut map: HashMap<PathBuf, PathBuf> = HashMap::new();
+
+    for link in game_links.into_iter().chain(mod_links).chain(overrides) {
+        map.insert(link.dst, link.src);
+    }
+
+    let final_links: Vec<Link> = map
+        .into_iter()
+        .map(|(dst, src)| Link::new(src, dst))
+        .collect();
+
+    Ok(final_links)
+}
+
+fn gen_links_for_instance(
+    root_config: &RootConfig,
+    instance: &ModdedInstance,
+) -> Result<Vec<Link>, Box<dyn Error>> {
+    let mut links: Vec<Link> = Vec::new();
+
+    for installed_mod in &instance.mods {
+        let mod_config = root_config.get_mod_by_id(&installed_mod.mod_id()).unwrap();
+        let mod_source_root = root_config.get_mod_location(&mod_config);
+
+        for link in installed_mod.files() {
+            let link_target = mod_source_root.join(&link.src);
+            links.push(Link::new(link_target, &link.dst));
+        }
+    }
+
+    Ok(links)
+}
+
 pub fn add_mod_to_instance(
     root_config: &RootConfig,
     instance_id: &str,