Allow to specify a path to the data file

src/main.rs

@@ -1236,6 +1236,9 @@ struct Config {
 
     #[serde(default = "person_2")]
     person_2: String,
+
+    #[serde(default)]
+    data_file: Option<PathBuf>,
 }
 
 impl Default for Config {
@@ -1243,23 +1246,13 @@ impl Default for Config {
         Self {
             person_1: person_1(),
             person_2: person_2(),
+            data_file: None,
         }
     }
 }
 
 fn main() -> anyhow::Result<()> {
     let project_dir = ProjectDirs::from("net", "traxys", "glaurung").ok_or(anyhow!(""))?;
-    let state_dir = project_dir
-        .state_dir()
-        .ok_or(anyhow!("No state directory"))?;
-    std::fs::create_dir_all(state_dir)?;
-
-    let save_file = state_dir.join("data.json");
-
-    let save = match save_file.exists() {
-        false => Default::default(),
-        true => serde_json::from_reader(BufReader::new(File::open(&save_file)?))?,
-    };
 
     let config_file = project_dir.config_dir().join("config.toml");
     let config: Config = match config_file.exists() {
@@ -1270,6 +1263,23 @@ fn main() -> anyhow::Result<()> {
         false => Config::default(),
     };
 
+    let save_file = match &config.data_file {
+        None => {
+            let state_dir = project_dir
+                .state_dir()
+                .ok_or(anyhow!("No state directory"))?;
+            std::fs::create_dir_all(state_dir)?;
+
+            state_dir.join("data.json")
+        }
+        Some(p) => p.clone(),
+    };
+
+    let save = match save_file.exists() {
+        false => Default::default(),
+        true => serde_json::from_reader(BufReader::new(File::open(&save_file)?))?,
+    };
+
     let mut settings = Settings::with_flags(AppConfig {
         save,
         save_file,