1 files changed, 60 insertions, 0 deletions
diff --git a/pkgs/build-support/fetchtorrent/default.nix b/pkgs/build-support/fetchtorrent/default.nix
new file mode 100644
index 00000000000..beb2415df70
--- /dev/null
+++ b/pkgs/build-support/fetchtorrent/default.nix
@@ -0,0 +1,60 @@
+{ lib, runCommand, transmission_noSystemd, rqbit, writeShellScript, formats, cacert, rsync }:
+let
+  urlRegexp = ''.*xt=urn:bt[im]h:([^&]{64}|[^&]{40}).*'';
+in
+{ url
+, name ?
+  if (builtins.match urlRegexp url) == null then
+    "bittorrent"
+  else
+    "bittorrent-" + builtins.head (builtins.match urlRegexp url)
+, config ? if (backend == "transmission") then { } else throw "json config for configuring fetchFromBitorrent only works with the transmission backend"
+, hash
+, backend ? "transmission"
+, recursiveHash ? true
+, postFetch ? ""
+, postUnpack ? ""
+}:
+let
+  afterSuccess = writeShellScript "fetch-bittorrent-done.sh" ''
+    ${postUnpack}
+    # Flatten the directory, so that only the torrent contents are in $out, not
+    # the folder name
+    shopt -s dotglob
+    mv -v $downloadedDirectory/*/* $out
+    rm -v -rf $downloadedDirectory
+    unset downloadedDirectory
+    ${postFetch}
+    kill $PPID
+  '';
+  jsonConfig = (formats.json {}).generate "jsonConfig" config;
+in
+runCommand name {
+  nativeBuildInputs = [ cacert ] ++ (if (backend == "transmission" ) then [ transmission_noSystemd ] else if (backend == "rqbit") then [ rqbit ] else throw "rqbit or transmission are the only available backends for fetchtorrent");
+  outputHashAlgo = if hash != "" then null else "sha256";
+  outputHash = hash;
+  outputHashMode = if recursiveHash then "recursive" else "flat";
+
+  # url will be written to the derivation, meaning it can be parsed and utilized
+  # by external tools, such as tools that may want to seed fetchtorrent calls
+  # in nixpkgs
+  inherit url;
+}
+(if (backend == "transmission") then ''
+  export HOME=$TMP
+  export downloadedDirectory=$out/downloadedDirectory
+  mkdir -p $downloadedDirectory
+  mkdir -p $HOME/.config/transmission
+  cp ${jsonConfig} $HOME/.config/transmission/settings.json
+  function handleChild {
+    # This detects failures and logs the contents of the transmission fetch
+    find $out
+    exit 0
+  }
+  trap handleChild CHLD
+  transmission-cli --port $(shuf -n 1 -i 49152-65535) --portmap --finish ${afterSuccess} --download-dir $downloadedDirectory --config-dir "$HOME"/.config/transmission "$url"
+'' else
+''
+  export HOME=$TMP
+  rqbit --disable-dht-persistence --http-api-listen-addr "127.0.0.1:$(shuf -n 1 -i 49152-65535)" download -o $out --exit-on-finish "$url"
+'')