Print magnet link to stdout with --link

Magnet links can be printed to standard output with:

    imdl torrent create --input PATH --link

type: added

src/magnet_link.rs

@@ -8,6 +8,18 @@ pub(crate) struct MagnetLink {
 }
 
 impl MagnetLink {
+  pub(crate) fn from_metainfo(metainfo: &Metainfo) -> Result<MagnetLink> {
+    let mut link = Self::with_infohash(metainfo.infohash()?);
+
+    link.set_name(metainfo.info.name.clone());
+
+    for tracker in metainfo.trackers() {
+      link.add_tracker(tracker?);
+    }
+
+    Ok(link)
+  }
+
   pub(crate) fn with_infohash(infohash: Infohash) -> MagnetLink {
     MagnetLink {
       infohash,
@@ -57,12 +69,27 @@ impl MagnetLink {
   }
 }
 
+impl Display for MagnetLink {
+  fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    write!(f, "{}", self.to_url())
+  }
+}
+
 #[cfg(test)]
 mod tests {
   use super::*;
 
   use pretty_assertions::assert_eq;
 
+  #[test]
+  fn display() {
+    let link = MagnetLink::with_infohash(Infohash::from_bencoded_info_dict("".as_bytes()));
+    assert_eq!(
+      link.to_string(),
+      "magnet:?xt=urn:btih:da39a3ee5e6b4b0d3255bfef95601890afd80709"
+    );
+  }
+
   #[test]
   fn basic() {
     let link = MagnetLink::with_infohash(Infohash::from_bencoded_info_dict("".as_bytes()));

src/metainfo.rs

@@ -90,10 +90,18 @@ impl Metainfo {
   }
 
   pub(crate) fn trackers<'a>(&'a self) -> impl Iterator<Item = Result<Url>> + 'a {
+    let mut seen = HashSet::new();
     iter::once(&self.announce)
       .flatten()
       .chain(self.announce_list.iter().flatten().flatten())
-      .map(|text| text.parse().context(error::AnnounceUrlParse))
+      .filter_map(move |text| {
+        if seen.contains(text) {
+          None
+        } else {
+          seen.insert(text.clone());
+          Some(text.parse().context(error::AnnounceUrlParse))
+        }
+      })
   }
 
   pub(crate) fn infohash(&self) -> Result<Infohash> {
@@ -414,4 +422,46 @@ mod tests {
 
     representation(value, want);
   }
+
+  #[test]
+  fn trackers() {
+    let mut metainfo = Metainfo {
+      announce: Some("http://foo".into()),
+      announce_list: None,
+      nodes: None,
+      comment: None,
+      created_by: None,
+      creation_date: None,
+      encoding: None,
+      info: Info {
+        private: Some(false),
+        piece_length: Bytes(1024),
+        source: None,
+        name: "NAME".into(),
+        pieces: PieceList::from_pieces(&["fae50"]),
+        mode: Mode::Single {
+          length: Bytes(5),
+          md5sum: None,
+        },
+      },
+    };
+
+    let trackers = metainfo.trackers().collect::<Result<Vec<Url>>>().unwrap();
+    assert_eq!(trackers, &["http://foo".parse().unwrap()]);
+
+    metainfo.announce_list = Some(vec![
+      vec!["http://bar".into(), "http://baz".into()],
+      vec!["http://foo".into()],
+    ]);
+
+    let trackers = metainfo.trackers().collect::<Result<Vec<Url>>>().unwrap();
+    assert_eq!(
+      trackers,
+      &[
+        "http://foo".parse().unwrap(),
+        "http://bar".parse().unwrap(),
+        "http://baz".parse().unwrap(),
+      ],
+    );
+  }
 }

src/subcommand/torrent/create.rs

@@ -112,6 +112,11 @@ pub(crate) struct Create {
     parse(from_os_str)
   )]
   input: PathBuf,
+  #[structopt(
+    long = "link",
+    help = "Print created torrent `magnet:` URL to standard output"
+  )]
+  print_magnet_link: bool,
   #[structopt(
     long = "md5",
     short = "M",
@@ -152,6 +157,13 @@ pub(crate) struct Create {
     parse(from_os_str)
   )]
   output: Option<OutputTarget>,
+  #[structopt(
+    long = "peer",
+    value_name = "PEER",
+    help = "Add `PEER` to magnet link.",
+    requires("print-magnet-link")
+  )]
+  peers: Vec<HostPort>,
   #[structopt(
     long = "piece-length",
     short = "p",
@@ -391,7 +403,15 @@ impl Create {
     errln!(env, "\u{2728}\u{2728} Done! \u{2728}\u{2728}")?;
 
     if self.show {
-      TorrentSummary::from_metainfo(metainfo)?.write(env)?;
+      TorrentSummary::from_metainfo(metainfo.clone())?.write(env)?;
+    }
+
+    if self.print_magnet_link {
+      let mut link = MagnetLink::from_metainfo(&metainfo)?;
+      for peer in self.peers {
+        link.add_peer(peer);
+      }
+      outln!(env, "{}", link)?;
     }
 
     if let OutputTarget::File(path) = output {
@@ -2288,4 +2308,116 @@ Content Size  9 bytes
 
     assert_matches!(env.run(), Ok(()));
   }
+
+  #[test]
+  fn no_print_magnet_link() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+      ],
+      tree: {
+        foo: "",
+      },
+    };
+
+    assert_matches!(env.run(), Ok(()));
+    assert_eq!(env.out(), "");
+  }
+
+  #[test]
+  fn print_magnet_link() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--link",
+      ],
+      tree: {
+        foo: "",
+      },
+    };
+
+    assert_matches!(env.run(), Ok(()));
+    assert_eq!(
+      env.out(),
+      "magnet:?xt=urn:btih:516735f4b80f2b5487eed5f226075bdcde33a54e&dn=foo\n"
+    );
+  }
+
+  #[test]
+  fn print_magnet_link_with_announce() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--link",
+        "--announce",
+        "http://foo.com/announce",
+      ],
+      tree: {
+        foo: "",
+      },
+    };
+
+    assert_matches!(env.run(), Ok(()));
+    assert_eq!(
+      env.out(),
+      "magnet:\
+      ?xt=urn:btih:516735f4b80f2b5487eed5f226075bdcde33a54e\
+      &dn=foo\
+      &tr=http://foo.com/announce\n"
+    );
+  }
+
+  #[test]
+  fn peer_requires_link() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--peer",
+      ],
+      tree: {
+        foo: "",
+      },
+    };
+
+    assert_matches!(env.run(), Err(Error::Clap { .. }));
+  }
+
+  #[test]
+  fn link_with_peers() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--peer",
+        "foo:1337",
+        "--peer",
+        "bar:666",
+        "--link"
+      ],
+      tree: {
+        foo: "",
+      },
+    };
+
+    assert_matches!(env.run(), Ok(()));
+    assert_eq!(
+      env.out(),
+      "magnet:?xt=urn:btih:516735f4b80f2b5487eed5f226075bdcde33a54e&dn=foo&x.pe=foo:1337&x.pe=bar:\
+       666\n"
+    );
+  }
 }

src/subcommand/torrent/link.rs

@@ -41,13 +41,8 @@ impl Link {
 
     link.set_name(&metainfo.info.name);
 
-    let mut trackers = HashSet::new();
     for result in metainfo.trackers() {
-      let tracker = result?;
-      if !trackers.contains(&tracker) {
-        trackers.insert(tracker.clone());
-        link.add_tracker(tracker);
-      }
+      link.add_tracker(result?);
     }
 
     for peer in self.peers {