add basepath cmdline flag

this allows a basepath to be set via commandline where ncspot will place
configuration and cache files.

fixes #65

Cargo.lock

@@ -1560,6 +1560,7 @@ dependencies = [
  "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "fern 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "librespot 0.1.0 (git+https://github.com/librespot-org/librespot.git?rev=14721f4)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -22,6 +22,7 @@ directories = "1.0"
 failure = "0.1.3"
 fern = "0.5"
 futures = "0.1"
+lazy_static = "1.3.0"
 log = "0.4.0"
 #rspotify = "0.4.0"
 serde = "1.0"

src/config.rs

@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 use std::fs;
 use std::path::{Path, PathBuf};
+use std::sync::RwLock;
 
 use directories::ProjectDirs;
 
@@ -33,8 +34,17 @@ pub struct ConfigTheme {
     pub cmdline_bg: Option<String>,
 }
 
+lazy_static! {
+    pub static ref BASE_PATH: RwLock<Option<PathBuf>> = RwLock::new(None);
+}
+
 fn proj_dirs() -> ProjectDirs {
-    ProjectDirs::from("org", "affekt", "ncspot").expect("can't determine project paths")
+    match *BASE_PATH.read().expect("can't readlock BASE_PATH") {
+        Some(ref basepath) => ProjectDirs::from_path(basepath.clone()).expect("invalid basepath"),
+        None => {
+            ProjectDirs::from("org", "affekt", "ncspot").expect("can't determine project paths")
+        }
+    }
 }
 
 pub fn config_path(file: &str) -> PathBuf {

src/main.rs

@@ -6,6 +6,8 @@ extern crate clipboard;
 extern crate directories;
 extern crate failure;
 extern crate futures;
+#[macro_use]
+extern crate lazy_static;
 extern crate librespot;
 extern crate rspotify;
 extern crate tokio;
@@ -30,7 +32,9 @@ extern crate fern;
 extern crate rand;
 
 use std::fs;
+use std::path::PathBuf;
 use std::process;
+use std::str::FromStr;
 use std::sync::Arc;
 
 use clap::{App, Arg};
@@ -120,12 +124,28 @@ fn main() {
                 .help("Enable debug logging to the specified file")
                 .takes_value(true),
         )
+        .arg(
+            Arg::with_name("basepath")
+                .short("b")
+                .long("basepath")
+                .value_name("PATH")
+                .help("custom basepath to config/cache files")
+                .takes_value(true),
+        )
         .get_matches();
 
     if let Some(filename) = matches.value_of("debug") {
         setup_logging(filename).expect("can't setup logging");
     }
 
+    if let Some(basepath) = matches.value_of("basepath") {
+        let path = PathBuf::from_str(basepath).expect("invalid path");
+        if !path.exists() {
+            fs::create_dir(&path).expect("could not create basepath directory");
+        }
+        *config::BASE_PATH.write().unwrap() = Some(path);
+    }
+
     // Things here may cause the process to abort; we must do them before creating curses windows
     // otherwise the error message will not be seen by a user
     let cfg: ::config::Config = {