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# rss-kakapo: turn Mastodon into your feed reader, for small private
# instances. A fork of RSS Parrot, maintained as its own repository:
# https://sources.profpatsch.de/rss-kakapo/
#
# This is only the build. What the service does, how it is configured and what
# its caveats are belongs to rss-kakapo(1), in the man output:
#
#   man "$(nix-build . -A users.Profpatsch.rss-kakapo.man)/share/man/man1/rss-kakapo.1.gz"
#
# The source comes from the `rss-kakapo` input of //flake.nix, resolved out of
# //flake.lock the same way default.nix resolves nixpkgs, so `nix-build -A`
# and the flake build the very same revision. Updating it is `nix flake update
# rss-kakapo`, which picks up the latest *release* of the project rather than
# its latest push — see the comment on the input.
{ pkgs, ... }:

let
  # The locked rss-kakapo tarball. It is a release URL, so these bytes are
  # written once and never pruned; the narHash in the lock is what makes this
  # reproducible without trusting the host to keep serving the same thing.
  src =
    let
      lock = builtins.fromJSON (builtins.readFile ../../../flake.lock);
      node = lock.nodes."rss-kakapo".locked;
    in
    builtins.fetchTree { inherit (node) type url narHash; };

in
# package.nix is a plain callPackage function on purpose, so that a consumer
# builds it against its own nixpkgs instead of evaluating the one its flake
# pins. This is that consumer.
pkgs.callPackage "${src}/package.nix" { inherit src; }