3 files changed, 246 insertions, 3 deletions

diff --git a/src-tauri/src/main.rs b/src-tauri/src/main.rs
index 7db9e089..1ddb4c69 100644
--- a/src-tauri/src/main.rs
+++ b/src-tauri/src/main.rs
@@ -15,10 +15,12 @@ mod github;
 use github::release_notes::{get_northstar_release_notes, check_is_flightcore_outdated};
 
 mod repair_and_verify;
-use repair_and_verify::{verify_game_files, disable_all_but_core};
+use repair_and_verify::{clean_up_download_folder, disable_all_but_core, verify_game_files};
 
 mod mod_management;
-use mod_management::{set_mod_enabled_status, get_installed_mods_and_properties};
+use mod_management::{
+    fc_download_mod_and_install, get_installed_mods_and_properties, set_mod_enabled_status,
+};
 
 use tauri::Manager;
 use tauri_plugin_store::PluginBuilder;
@@ -92,6 +94,8 @@ fn main() {
             get_northstar_release_notes,
             linux_checks,
             get_installed_mods_caller,
+            install_mod_caller,
+            clean_up_download_folder_caller,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");
@@ -275,7 +279,9 @@ async fn verify_game_files_caller(game_install: GameInstall) -> Result<String, S
 }
 
 #[tauri::command]
-async fn get_enabled_mods_caller(game_install: GameInstall) -> Result<serde_json::value::Value, String> {
+async fn get_enabled_mods_caller(
+    game_install: GameInstall,
+) -> Result<serde_json::value::Value, String> {
     get_enabled_mods(game_install)
 }
 
@@ -297,3 +303,33 @@ async fn disable_all_but_core_caller(game_install: GameInstall) -> Result<(), St
 async fn get_installed_mods_caller(game_install: GameInstall) -> Result<Vec<NorthstarMod>, String> {
     get_installed_mods_and_properties(game_install)
 }
+
+#[tauri::command]
+/// Installs the specified mod
+async fn install_mod_caller(
+    game_install: GameInstall,
+    thunderstore_mod_string: String,
+) -> Result<(), String> {
+    fc_download_mod_and_install(game_install.clone(), thunderstore_mod_string).await?;
+    match clean_up_download_folder(game_install, false) {
+        Ok(()) => Ok(()),
+        Err(err) => {
+            println!("Failed to delete download folder due to {}", err);
+            // Failure to delete download folder is not an error in mod install
+            // As such ignore. User can still force delete if need be
+            Ok(())
+        }
+    }
+}
+
+#[tauri::command]
+/// Installs the specified mod
+async fn clean_up_download_folder_caller(
+    game_install: GameInstall,
+    force: bool,
+) -> Result<(), String> {
+    match clean_up_download_folder(game_install, force) {
+        Ok(()) => Ok(()),
+        Err(err) => Err(err.to_string()),
+    }
+}
diff --git a/src-tauri/src/mod_management/mod.rs b/src-tauri/src/mod_management/mod.rs
index ecfd3835..96bb1a0f 100644
--- a/src-tauri/src/mod_management/mod.rs
+++ b/src-tauri/src/mod_management/mod.rs
@@ -1,4 +1,5 @@
 // This file contains various mod management functions
+use async_recursion::async_recursion;
 
 use anyhow::{anyhow, Result};
 use app::NorthstarMod;
@@ -130,3 +131,178 @@ pub fn get_installed_mods_and_properties(
 
     Ok(installed_mods)
 }
+
+async fn get_ns_mod_download_url(thunderstore_mod_string: String) -> Result<String, String> {
+
+    // TODO: This will crash the thread if not internet connection exist. `match` should be used instead
+    let index = thermite::api::get_package_index().await.unwrap().to_vec();
+
+    // String replace works but more care should be taken in the future
+    let ts_mod_string_url = thunderstore_mod_string.replace("-", "/");
+
+    for ns_mod in index {
+        // Iterate over all versions of a given mod
+        for (_key, ns_mod) in &ns_mod.versions {
+            if ns_mod.url.contains(&ts_mod_string_url) {
+                dbg!(ns_mod.clone());
+                return Ok(ns_mod.url.clone());
+            }
+        }
+    }
+
+    Err("Could not find mod on Thunderstore".to_string())
+}
+
+/// Adds given Thunderstore mod string to the given `mod.json`
+/// This way we can later check whether a mod is outdated based on the TS mod string
+fn add_thunderstore_mod_string(
+    path_to_mod_json: String,
+    thunderstore_mod_string: String,
+) -> Result<(), anyhow::Error> {
+
+    // Read file into string and parse it
+    let data = std::fs::read_to_string(path_to_mod_json.clone())?;
+    let parsed_json: serde_json::Value = json5::from_str(&data)?;
+
+    // Insert the Thunderstore mod string
+    let mut parsed_json = parsed_json.as_object().unwrap().clone();
+    parsed_json.insert(
+        "ThunderstoreModString".to_string(),
+        serde_json::Value::String(thunderstore_mod_string),
+    );
+
+    // And write back to disk
+    std::fs::write(
+        path_to_mod_json,
+        serde_json::to_string_pretty(&parsed_json)?,
+    )?;
+
+    Ok(())
+}
+
+/// Returns a vector of modstrings containing the dependencies of a given mod
+async fn get_mod_dependencies(
+    thunderstore_mod_string: String,
+) -> Result<Vec<String>, anyhow::Error> {
+    dbg!(thunderstore_mod_string.clone());
+
+    // TODO: This will crash the thread if not internet connection exist. `match` should be used instead
+    let index = thermite::api::get_package_index().await.unwrap().to_vec();
+
+    // String replace works but more care should be taken in the future
+    let ts_mod_string_url = thunderstore_mod_string.replace("-", "/");
+
+    // Iterate over index
+    for ns_mod in index {
+        // Iterate over all versions of a given mod
+        for (_key, ns_mod) in &ns_mod.versions {
+            if ns_mod.url.contains(&ts_mod_string_url) {
+                dbg!(ns_mod.clone());
+                return Ok(ns_mod.deps.clone());
+            }
+        }
+    }
+    Ok(Vec::<String>::new())
+}
+
+// Copied from `libtermite` source code and modified
+// Should be replaced with a library call to libthermite in the future
+/// Download and install mod to the specified target.
+#[async_recursion]
+pub async fn fc_download_mod_and_install(
+    game_install: GameInstall,
+    thunderstore_mod_string: String,
+) -> Result<(), String> {
+    // Get mods and download directories
+    let download_directory = format!(
+        "{}/___flightcore-temp-download-dir/",
+        game_install.game_path
+    );
+    let mods_directory = format!("{}/R2Northstar/mods/", game_install.game_path);
+
+    // Early return on empty string
+    if thunderstore_mod_string.len() == 0 {
+        return Err("Passed empty string".to_string());
+    }
+
+    let deps = match get_mod_dependencies(thunderstore_mod_string.clone()).await {
+        Ok(deps) => deps,
+        Err(err) => return Err(err.to_string()),
+    };
+    dbg!(deps.clone());
+
+    // Recursively install dependencies
+    for dep in deps {
+        match fc_download_mod_and_install(game_install.clone(), dep).await {
+            Ok(()) => (),
+            Err(err) => {
+                if err.to_string() == "Cannot install Northstar as a mod!" {
+                    continue; // For Northstar as a dependency, we just skip it
+                }
+                else {
+                    return Err(err.to_string())
+                }
+            }
+        };
+    }
+
+    // Prevent installing Northstar as a mod
+    // While it would fail during install anyway, having explicit error message is nicer
+    let blacklisted_mods = ["northstar-Northstar", "northstar-NorthstarReleaseCandidate", "ebkr-r2modman"];
+    for blacklisted_mod in blacklisted_mods {
+        if thunderstore_mod_string.contains(blacklisted_mod) {
+            return Err("Cannot install Northstar as a mod!".to_string());
+        }
+    }
+
+    // Get download URL for the specified mod
+    let download_url = get_ns_mod_download_url(thunderstore_mod_string.clone()).await?;
+
+    // Create download directory
+    match std::fs::create_dir_all(download_directory.clone()) {
+        Ok(()) => (),
+        Err(err) => return Err(err.to_string()),
+    };
+
+    let name = thunderstore_mod_string.clone();
+    let path = format!(
+        "{}/___flightcore-temp-download-dir/{}.zip",
+        game_install.game_path, name
+    );
+
+    // Download the mod
+    let f = match thermite::core::actions::download_file(&download_url, path.clone()).await {
+        Ok(f) => f,
+        Err(e) => return Err(e.to_string()),
+    };
+
+    // Extract the mod to the mods directory
+    let pkg = match thermite::core::actions::install_mod(&f, std::path::Path::new(&mods_directory))
+    {
+        Ok(pkg) => pkg,
+        Err(err) => return Err(err.to_string()),
+    };
+    dbg!(pkg.clone());
+
+    // Add Thunderstore mod string to `mod.json` of installed NorthstarMods
+    for nsmod in pkg.mods {
+        let path_to_current_mod_json = format!(
+            "{}/{}/mod.json",
+            mods_directory,
+            nsmod.path.to_string_lossy()
+        );
+        match add_thunderstore_mod_string(path_to_current_mod_json, thunderstore_mod_string.clone())
+        {
+            Ok(()) => (),
+            Err(err) => {
+                println!("Failed setting modstring for {}", nsmod.name);
+                println!("{}", err);
+            }
+        }
+    }
+
+    // Delete downloaded zip file
+    std::fs::remove_file(path).unwrap();
+
+    Ok(())
+}
diff --git a/src-tauri/src/repair_and_verify/mod.rs b/src-tauri/src/repair_and_verify/mod.rs
index 8f8fe633..188d3821 100644
--- a/src-tauri/src/repair_and_verify/mod.rs
+++ b/src-tauri/src/repair_and_verify/mod.rs
@@ -2,6 +2,7 @@
 
 use app::{get_enabled_mods, GameInstall};
 use crate::mod_management::set_mod_enabled_status;
+use anyhow::anyhow;
 
 /// Verifies Titanfall2 game files
 pub fn verify_game_files(game_install: GameInstall) -> Result<String, String> {
@@ -34,3 +35,33 @@ pub fn disable_all_but_core(game_install: GameInstall) -> Result<(), String> {
 
     Ok(())
 }
+
+/// Deletes download folder
+/// If `force` is FALSE, bails on non-empty folder
+/// If `force` is TRUE, deletes folder even if non-empty
+pub fn clean_up_download_folder(
+    game_install: GameInstall,
+    force: bool,
+) -> Result<(), anyhow::Error> {
+    // Get download directory
+    let download_directory = format!(
+        "{}/___flightcore-temp-download-dir/",
+        game_install.game_path
+    );
+
+    // Check if files in folder
+    let download_dir_contents = std::fs::read_dir(download_directory.clone())?;
+    // dbg!(download_dir_contents);
+
+    let mut count = 0;
+    download_dir_contents.inspect(|_| count += 1).for_each(drop);
+
+    if count > 0 && !force {
+        return Err(anyhow!("Folder not empty, not deleting"));
+    }
+
+    // Delete folder
+    std::fs::remove_dir_all(download_directory)?;
+
+    Ok(())
+}