factor out into subcommands

2 files changed, 53 insertions, 20 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 4e1d7cb..27b2742 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,28 +1,51 @@
 use clap;
+use failure;
 
 const _DUMMY_DEPENDENCY: &'static str = include_str!("../Cargo.toml");
 
+pub enum Command {
+    Sync,
+}
+
 pub struct Options {
-    pub username: String,
-    pub api_key: String,
+    pub command: Command,
+    pub username: Option<String>,
+    pub api_key: Option<String>,
 }
 
-pub fn get_options() -> Options {
+pub fn get_options() -> failure::Fallible<Options> {
     let matches = app_from_crate!()
-        .arg(
-            clap::Arg::with_name("username")
-                .required(true)
-                .help("last.fm username to fetch tracks for")
-        )
-        .arg(
-            clap::Arg::with_name("api_key")
-                .required(true)
-                .help("last.fm api key")
+        .subcommand(
+            clap::SubCommand::with_name("sync")
+                .about("Updates the local copy of track data from last.fm")
+                .arg(
+                    clap::Arg::with_name("username")
+                        .short("u")
+                        .long("username")
+                        .value_name("USERNAME")
+                        .required(true)
+                        .help("last.fm username to fetch tracks for")
+                )
+                .arg(
+                    clap::Arg::with_name("api-key")
+                        .short("k")
+                        .long("api-key")
+                        .value_name("API_KEY")
+                        .required(true)
+                        .help("last.fm api key")
+                )
         )
         .get_matches();
 
-    Options {
-        username: matches.value_of("username").unwrap().to_string(),
-        api_key: matches.value_of("api_key").unwrap().to_string(),
-    }
+    let (command, sub_matches) = match matches.subcommand() {
+        ("sync", Some(matches)) => (Command::Sync, matches),
+        (name, Some(_)) => bail!("unknown subcommand: {}", name),
+        (_, None) => bail!("no subcommand given"),
+    };
+
+    Ok(Options {
+        command: command,
+        username: sub_matches.value_of("username").map(|s| s.to_string()),
+        api_key: sub_matches.value_of("api-key").map(|s| s.to_string()),
+    })
 }
diff --git a/src/main.rs b/src/main.rs
index ed5a189..c104b23 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -17,9 +17,13 @@ mod lastfm;
 mod paths;
 mod db;
 
-fn run(opts: cli::Options) -> failure::Fallible<()> {
+fn sync(opts: &cli::Options) -> failure::Fallible<()> {
     let db = db::DB::new(&paths::dbpath())?;
-    let lastfm = lastfm::LastFMClient::new(&opts.api_key, &opts.username);
+    let lastfm = lastfm::LastFMClient::new(
+        opts.api_key.as_ref().unwrap(),
+        opts.username.as_ref().unwrap()
+    );
+
     let exporter = exporter::Exporter::new(&db, &lastfm);
 
     let to_fetch = exporter.tracks_to_sync()?;
@@ -39,6 +43,13 @@ fn run(opts: cli::Options) -> failure::Fallible<()> {
     Ok(())
 }
 
+fn run() -> failure::Fallible<()> {
+    let opts = cli::get_options()?;
+    match opts.command {
+        cli::Command::Sync => sync(&opts),
+    }
+}
+
 fn program_name() -> failure::Fallible<String> {
     let program = std::env::args()
         .next()
@@ -52,8 +63,7 @@ fn program_name() -> failure::Fallible<String> {
 }
 
 fn main() {
-    let opts = cli::get_options();
-    match run(opts) {
+    match run() {
         Ok(_) => {},
         Err(e) => {
             let name = program_name()