{
    config,
    config',
    lib,
    pkgs,
    ...
}: with lib; let
    cfg = config.myOptions.programs.git;
in {
    options.myOptions.programs.git = {
        enable = mkEnableOption "git";
        userName = mkOption {
            type = types.str;
            description = "git username";
        };
        userEmail = mkOption {
            type = types.str;
            description = "git email";
        };
        signingKey = mkOption {
            type = types.str;
            description = "git commit signing key";
        };
        editor = mkOption {
            type = types.str;
            default = "$EDITOR";
            description = "commit message editor";
        };
        defaultBranch = mkOption {
            type = types.str;
            default = "master";
            description = "default git branch";
        };
    };

    config = mkIf cfg.enable {
        home-manager.users.${config'.username} = {
            programs.git = {
                inherit (cfg) enable userName userEmail;
                signing = {
                    key = cfg.signingKey;
                    signByDefault = true;
                };
                includes = [
                    {
                        contents = {
                            core = {
                                editor = cfg.editor;
                                pager = "${pkgs.delta}/bin/delta";
                            };
                            init.defaultBranch = cfg.defaultBranch;
                            push.autoSetupRemote = true;
                            commit.verbose = true;
                            merge.conflictstyle = "zdiff3";
                            interactive.diffFilter = "${pkgs.delta}/bin/delta --color-only";
                            diff.algorithm = "histogram";
                            transfer.fsckobjects = true;
                            fetch.fsckobjects = true;
                            receive.fsckobjects = true;
                        };
                    }
                ];
            };
        };
    };
}