veloren/flake.nix

{
  description = "Flake providing Veloren, a multiplayer voxel RPG written in Rust.";

  inputs = {
    naersk = {
      url = "github:yusdacra/naersk/veloren";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    nixCargoIntegration = {
      url = "github:yusdacra/nix-cargo-integration";
      inputs.nixpkgs.follows = "nixpkgs";
      inputs.naersk.follows = "naersk";
    };
  };

  outputs = inputs: inputs.nixCargoIntegration.lib.makeOutputs {
    root = ./.;
    overrides = {
      common = prev: {
        gitLfsCheckFile = ./assets/voxygen/background/bg_main.png;
        utils = import ./nix/utils.nix { pkgs = prev.pkgs; };
      };
      build = common: prevb:
        let
          pkgs = common.pkgs;
          sourceInfo =
            if inputs.self.sourceInfo ? rev
            then inputs.self.sourceInfo // {
              # Tag would have to be set manually for stable releases flake
              # because there's currently no way to get the tag via the interface.
              # tag = v0.9.0;
            }
            else (throw "Can't get revision because the git tree is dirty");

          prettyRev = with sourceInfo; builtins.substring 0 8 rev + "/" + common.utils.dateTimeFormat lastModified;

          tag = with sourceInfo;
            if sourceInfo ? tag
            then sourceInfo.tag
            else "";

          # If gitTag has a tag (meaning the commit we are on is a *release*), use
          # it as version, else: just use the prettified hash we have, if we don't
          # have it the build fails.
          # Must be in format f4987672/2020-12-10-12:00
          version =
            if tag != "" then tag
            else if prettyRev != "" then prettyRev
            else throw "Need a tag or pretty revision in order to determine version";

          veloren-assets = pkgs.runCommand "makeAssetsDir" { } ''
            mkdir $out
            ln -sf ${./assets} $out/assets
          '';

          velorenOverride = oldAttr:
            if common.cargoPkg.name == "veloren-voxygen"
            then
              {
                nativeBuildInputs = oldAttr.nativeBuildInputs ++ [ pkgs.makeWrapper ];
                postInstall = ''
                  wrapProgram $out/bin/veloren-voxygen\
                    --set VELOREN_ASSETS ${veloren-assets}\
                    --set LD_LIBRARY_PATH ${
                      pkgs.lib.makeLibraryPath common.runtimeLibs
                    }
                '';
              }
            else if common.cargoPkg.name == "veloren-server-cli"
            then
              {
                nativeBuildInputs = oldAttr.nativeBuildInputs ++ [ pkgs.makeWrapper ];
                postInstall = ''
                  wrapProgram $out/bin/veloren-server-cli --set VELOREN_ASSETS ${veloren-assets}
                '';
              }
            else { };
        in
        {
          allRefs = true;
          override = old: (prevb.override old) // {
            # Disable `git-lfs` check here since we check it ourselves
            # We have to include the command output here, otherwise Nix won't run it
            DISABLE_GIT_LFS_CHECK = common.utils.isGitLfsSetup common.gitLfsCheckFile;
            # Declare env values here so that `common/build.rs` sees them
            NIX_GIT_HASH = prettyRev;
            NIX_GIT_TAG = tag;
            VELOREN_USERDATA_STRATEGY = "system";
          };
          overrideMain = old: (prevb.overrideMain old) // (velorenOverride old);
        };
    };
  };
}