flake.nix

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

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

  outputs = inputs:
    inputs.nixCargoIntegration.lib.makeOutputs {
      root = ./.;
      buildPlatform = "crate2nix";
      defaultOutputs = {
        package = "veloren-voxygen";
        app = "veloren-voxygen";
      };
      overrides = {
        build = common: prev: {
          runTests = !prev.release && prev.runTests;
          rootFeatures =
            if prev.release && common.cargoPkg.name == "veloren-voxygen"
            then [ "default-publish" ]
            else prev.rootFeatures;
        };
        crateOverrides = common: prev:
          let
            pkgs = common.pkgs;
            lib = common.lib;

            gitLfsCheckFile = ./assets/voxygen/background/bg_main.jpg;
            utils = import ./nix/utils.nix { inherit 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 + "/" + 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} $out/assets
            '';
          in
          {
            # veloren-world = oldAttrs: {
            #   crateBin = lib.filter (bin: bin.name != "chunk_compression_benchmarks") oldAttrs.crateBin;
            # };
            veloren-client = oldAttrs: {
              crateBin = lib.filter (bin: bin.name != "bot") oldAttrs.crateBin;
            };
            veloren-voxygen-i18n = oldAttrs: {
              crateBin = lib.filter (bin: bin.name != "i18n-check") oldAttrs.crateBin;
            };
            veloren-common = oldAttrs: {
              # Disable `git-lfs` check here since we check it ourselves
              # We have to include the command output here, otherwise Nix won't run it
              DISABLE_GIT_LFS_CHECK = utils.isGitLfsSetup gitLfsCheckFile;
              # Declare env values here so that `common/build.rs` sees them
              NIX_GIT_HASH = prettyRev;
              NIX_GIT_TAG = tag;
              crateBin = lib.filter (bin: bin.name != "csv_export" && bin.name != "csv_import" && bin.name != "recipe_graphviz") oldAttrs.crateBin;
            };
            veloren-voxygen = oldAttrs: {
              VELOREN_USERDATA_STRATEGY = "system";
              preConfigure = ''
                substituteInPlace src/audio/soundcache.rs \
                  --replace \
                  "../../../assets/voxygen/audio/null.ogg" \
                  "${./assets/voxygen/audio/null.ogg}"
              '';
              postInstall = ''
                if [ -f $out/bin/veloren-voxygen ]; then
                  wrapProgram $out/bin/veloren-voxygen \
                    --set VELOREN_ASSETS ${veloren-assets} \
                    --set LD_LIBRARY_PATH ${lib.makeLibraryPath common.runtimeLibs}
                fi
              '';
            };
            veloren-server-cli = oldAttrs: {
              VELOREN_USERDATA_STRATEGY = "system";
              postInstall = ''
                if [ -f $out/bin/veloren-server-cli ]; then
                  wrapProgram $out/bin/veloren-server-cli --set VELOREN_ASSETS ${veloren-assets}
                fi
              '';
            };
          };
      };
    };
}