feat: Parse actually installed mods (#38)

* feat: Parse actually installed mods

Instead of using solely `enabledmods.json` parse the `mod.json` of found
mods in `mods` folder.

* refactor: Remove leftover print statements

* refactor: Move logic into dedicated module

* fix: Load mods despite `enabledmods.json` missing

Previously we would error out early if `enabledmods.json` was missing
despite not actually needing it for mod list.

* style: Autoformat

1 files changed, 97 insertions, 0 deletions

diff --git a/src-tauri/src/mod_management/mod.rs b/src-tauri/src/mod_management/mod.rs
index dfc05c4a..e3034903 100644
--- a/src-tauri/src/mod_management/mod.rs
+++ b/src-tauri/src/mod_management/mod.rs
@@ -1,5 +1,9 @@
 // This file contains various mod management functions
 
+use anyhow::{anyhow, Result};
+use app::NorthstarMod;
+use std::path::PathBuf;
+
 use app::GameInstall;
 use app::get_enabled_mods;
 
@@ -31,3 +35,96 @@ pub fn set_mod_enabled_status(
 
     Ok(())
 }
+
+
+/// Parses `mod.json` for mod name
+// TODO: Maybe pass PathBuf or serde json object
+fn parse_mod_json_for_mod_name(mod_json_path: String) -> Result<String, anyhow::Error> {
+    // Read file into string and parse it
+    let data = std::fs::read_to_string(mod_json_path)?;
+    let parsed_json: serde_json::Value = serde_json::from_str(&data)?;
+
+    // Extract mod name
+    let mod_name = match parsed_json.get("Name").and_then(|value| value.as_str()) {
+        Some(name) => name,
+        None => return Err(anyhow!("No name found")),
+    };
+
+    Ok(mod_name.to_string())
+}
+
+/// Parse `mods` folder for installed mods.
+fn get_installed_mods(game_install: GameInstall) -> Result<Vec<String>, String> {
+    let ns_mods_folder = format!("{}/R2Northstar/mods/", game_install.game_path);
+
+    let paths = std::fs::read_dir(ns_mods_folder).unwrap();
+
+    let mut directories: Vec<PathBuf> = Vec::new();
+    let mut mod_names: Vec<String> = Vec::new();
+
+    // Get list of folders in `mods` directory
+    for path in paths {
+        let my_path = path.unwrap().path();
+
+        let md = std::fs::metadata(my_path.clone()).unwrap();
+        if md.is_dir() {
+            directories.push(my_path);
+        }
+    }
+
+    // Iterate over folders and check if they are Northstar mods
+    for directory in directories {
+        // Check if mod.json exists
+        let mod_json_path = format!("{}/mod.json", directory.to_str().unwrap());
+        if !std::path::Path::new(&mod_json_path).exists() {
+            continue;
+        }
+
+        // Parse mod.json and get mod name
+        let mod_name = match parse_mod_json_for_mod_name(mod_json_path.clone()) {
+            Ok(mod_name) => mod_name,
+            Err(err) => {
+                println!("Failed parsing {} with {}", mod_json_path, err.to_string());
+                continue;
+            }
+        };
+        mod_names.push(mod_name);
+    }
+
+    // Return found mod names
+    Ok(mod_names)
+}
+
+/// Gets list of installed mods and their properties
+/// - name
+/// - is enabled?
+pub fn get_installed_mods_and_properties(
+    game_install: GameInstall,
+) -> Result<Vec<NorthstarMod>, String> {
+    // Get actually installed mods
+    let found_installed_mods = get_installed_mods(game_install.clone())?;
+
+    // Get enabled mods as JSON
+    let enabled_mods: serde_json::Value = match get_enabled_mods(game_install) {
+        Ok(enabled_mods) => enabled_mods,
+        Err(_) => serde_json::from_str("{}").unwrap(), // `enabledmods.json` not found, create empty object
+    };
+
+    let mut installed_mods = Vec::new();
+    let mapping = enabled_mods.as_object().unwrap();
+
+    // Use list of installed mods and set enabled based on `enabledmods.json`
+    for name in found_installed_mods {
+        let current_mod_enabled = match mapping.get(&name) {
+            Some(enabled) => enabled.as_bool().unwrap(),
+            None => true, // Northstar considers mods not in mapping as enabled.
+        };
+        let current_mod: NorthstarMod = NorthstarMod {
+            name: name,
+            enabled: current_mod_enabled,
+        };
+        installed_mods.push(current_mod);
+    }
+
+    Ok(installed_mods)
+}