Add the ability to list installed flatpaks

crates/pacdef_core/src/backend/actual/flatpak.rs

@@ -1,10 +1,8 @@
 use std::collections::HashSet;
-use std::fs::read_to_string;
-use std::path::PathBuf;
+use std::process::Command;
 use std::process::ExitStatus;
 
 use anyhow::{Context, Result};
-use serde_json::Value;
 
 use crate::backend::backend_trait::{Backend, Switches, Text};
 use crate::{impl_backend_constants, Group, Package};
@@ -20,7 +18,7 @@ const SECTION: Text = "flatpak";
 const SWITCHES_INSTALL: Switches = &["install"];
 const SWITCHES_INFO: Switches = &[];
 const SWITCHES_MAKE_DEPENDENCY: Switches = &[];
-const SWITCHES_NOCONFIRM: Switches = &[];
+const SWITCHES_NOCONFIRM: Switches = &["--assumeyes"];
 const SWITCHES_REMOVE: Switches = &["uninstall"];
 
 const SUPPORTS_AS_DEPENDENCY: bool = false;
@@ -29,11 +27,11 @@ impl Backend for Flatpak {
     impl_backend_constants!();
 
     fn get_all_installed_packages(&self) -> Result<HashSet<Package>> {
-        Ok(HashSet::new())
+        Flatpak::get_installed_packages(true)
     }
 
     fn get_explicitly_installed_packages(&self) -> Result<HashSet<Package>> {
-        Ok(HashSet::new())
+        Flatpak::get_installed_packages(false)
     }
 
     fn make_dependency(&self, _: &[Package]) -> Result<ExitStatus> {
@@ -47,4 +45,20 @@ impl Flatpak {
             packages: HashSet::new(),
         }
     }
+
+    fn get_installed_packages(include_implicit: bool) -> Result<HashSet<Package>> {
+        let mut cmd = Command::new(BINARY);
+        cmd.args(&["list", "--columns=application"]);
+        if !include_implicit {
+            cmd.arg("--app");
+        }
+
+        let output = String::from_utf8(cmd.output()?.stdout)?;
+        Ok(
+            output.lines()
+                  .skip(1)
+                  .map(|pkg| Package::from(pkg))
+                  .collect::<HashSet<Package>>()
+        )
+    }
 }