From 265d67089b0dbf887a1a06708b61f20aec227bcf Mon Sep 17 00:00:00 2001
From: "Dr. Matthias Ratajczak" <m.ratajczak@hzdr.de>
Date: Thu, 5 Jan 2023 17:57:38 +0100
Subject: [PATCH] add more generic backend stuff

---
 src/backend/mod.rs    | 46 ++++++++++++++++++++++++++++++++-----------
 src/backend/pacman.rs | 16 +++++++++++----
 src/backend/rust.rs   | 16 +++++++++++----
 3 files changed, 59 insertions(+), 19 deletions(-)

diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index d4acaf8..5854b83 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -8,29 +8,50 @@ use std::process::Command;
 use crate::Package;
 
 pub use pacman::Pacman;
+use rust::Rust;
+
+pub fn get_backends() -> Vec<Box<dyn Backend>> {
+    let pacman = Pacman;
+    let rust = Rust;
+    vec![Box::new(pacman), Box::new(rust)]
+}
+
 type Switches = &'static [&'static str];
 type Binary = &'static str;
 
 pub trait Backend {
     /// The binary that should be called to run the associated package manager.
-    const BINARY: Binary;
+    fn get_binary() -> Binary
+    where
+        Self: Sized;
 
     /// The switches that signals the `BINARY` that the packages should be installed.
-    const SWITCHES_INSTALL: Switches;
+    fn get_switches_install() -> Switches
+    where
+        Self: Sized;
 
     /// The switches that signals the `BINARY` that the packages should be removed.
-    const SWITCHES_REMOVE: Switches;
+    fn get_switches_remove() -> Switches
+    where
+        Self: Sized;
 
     /// Get all packages that are installed in the system.
-    fn get_all_installed_packages() -> HashSet<Package>;
+    fn get_all_installed_packages() -> HashSet<Package>
+    where
+        Self: Sized;
 
     /// Get all packages that were installed in the system explicitly.
-    fn get_explicitly_installed_packages() -> HashSet<Package>;
+    fn get_explicitly_installed_packages() -> HashSet<Package>
+    where
+        Self: Sized;
 
     /// Install the specified packages.
-    fn install_packages(packages: Vec<Package>) {
-        let mut cmd = Command::new(Self::BINARY);
-        cmd.args(Self::SWITCHES_INSTALL);
+    fn install_packages(packages: Vec<Package>)
+    where
+        Self: Sized,
+    {
+        let mut cmd = Command::new(Self::get_binary());
+        cmd.args(Self::get_switches_install());
         for p in packages {
             cmd.arg(format!("{p}"));
         }
@@ -38,9 +59,12 @@ pub trait Backend {
     }
 
     /// Remove the specified packages.
-    fn remove_packages(packages: Vec<Package>) {
-        let mut cmd = Command::new(Self::BINARY);
-        cmd.args(Self::SWITCHES_REMOVE);
+    fn remove_packages(packages: Vec<Package>)
+    where
+        Self: Sized,
+    {
+        let mut cmd = Command::new(Self::get_binary());
+        cmd.args(Self::get_switches_remove());
         for p in packages {
             cmd.arg(format!("{p}"));
         }
diff --git a/src/backend/pacman.rs b/src/backend/pacman.rs
index 1309159..9c535b5 100644
--- a/src/backend/pacman.rs
+++ b/src/backend/pacman.rs
@@ -9,10 +9,6 @@ use crate::Package;
 pub struct Pacman;
 
 impl Backend for Pacman {
-    const BINARY: Binary = "paru";
-    const SWITCHES_INSTALL: Switches = &["-S"];
-    const SWITCHES_REMOVE: Switches = &["-Rsn"];
-
     fn get_all_installed_packages() -> HashSet<Package> {
         convert_to_pacdef_packages(get_all_installed_packages_from_alpm())
     }
@@ -20,6 +16,18 @@ impl Backend for Pacman {
     fn get_explicitly_installed_packages() -> HashSet<Package> {
         convert_to_pacdef_packages(get_explicitly_installed_packages_from_alpm())
     }
+
+    fn get_binary() -> Binary {
+        "paru"
+    }
+
+    fn get_switches_install() -> Switches {
+        &["-S"]
+    }
+
+    fn get_switches_remove() -> Switches {
+        &["-Rsn"]
+    }
 }
 
 fn get_all_installed_packages_from_alpm() -> HashSet<String> {
diff --git a/src/backend/rust.rs b/src/backend/rust.rs
index 3d9a501..6f4969d 100644
--- a/src/backend/rust.rs
+++ b/src/backend/rust.rs
@@ -6,10 +6,6 @@ use crate::Package;
 pub struct Rust;
 
 impl Backend for Rust {
-    const BINARY: Binary = "cargo";
-    const SWITCHES_INSTALL: Switches = &["install"];
-    const SWITCHES_REMOVE: Switches = &["uninstall"];
-
     fn get_all_installed_packages() -> HashSet<Package> {
         extract_packages_names(&run_cargo_install_list())
             .map(Package::from)
@@ -19,6 +15,18 @@ impl Backend for Rust {
     fn get_explicitly_installed_packages() -> HashSet<Package> {
         Self::get_all_installed_packages()
     }
+
+    fn get_binary() -> Binary {
+        "cargo"
+    }
+
+    fn get_switches_install() -> Switches {
+        &["install"]
+    }
+
+    fn get_switches_remove() -> Switches {
+        &["uninstall"]
+    }
 }
 
 fn run_cargo_install_list() -> String {