feat: linux-devshell: init

package/default.nix

@@ -108,6 +108,7 @@
     nativeBuildInputs = with pkgs; [pkg-config curl];
   };
   dbToolPkgs = pkgs.callPackage ./db-tool { inherit self; };
+  linuxDevShellPkgs = pkgs.callPackage ./linux-devshell {};
 in {
   py3-datetime                 = pkgs.callPackage ./py3-datetime.nix                  {};
   py3-marzban                  = pkgs.callPackage ./py3-marzban.nix                   { inherit self; };
@@ -146,6 +147,8 @@ in {
   "postgres-init"              = dbToolPkgs."postgres-init";
   "postgres-cleanup"           = dbToolPkgs."postgres-cleanup";
   "hectic-inheritance"         = dbToolPkgs."hectic-inheritance";
+  "linux-devshell"             = linuxDevShellPkgs.linux-devshell;
+  "linux-devshell-standalone"  = linuxDevShellPkgs.linux-devshell-standalone;
   nbt2json                     = pkgs.callPackage ./nbt2json                          {};
   hemar-parser                 = pkgs.callPackage ./hemar/parser                      {};
   AstroTuxLauncher              = pkgs.callPackage ./AstroTuxLauncher.nix             {};

package/linux-devshell/default.nix

@@ -0,0 +1,48 @@
+{ dash, hectic, curl, coreutils, gawk, procps, writeTextFile, lib }:
+let
+  shell = "${dash}/bin/dash";
+  bashOptions = [
+    "errexit"
+    "nounset"
+  ];
+
+  logHelpers = builtins.readFile ../../lib/shell/logs.sh;
+  scriptText = builtins.readFile ./linux-devshell.sh;
+
+  linuxDevShell = hectic.writeShellApplication {
+    inherit shell bashOptions;
+    name = "linux-devshell";
+    runtimeInputs = [ curl coreutils gawk procps ];
+    excludeShellChecks = [ "SC2034" "SC1090" ];
+
+    text = ''
+      ${logHelpers}
+      ${scriptText}
+    '';
+
+    meta = {
+      description = "Install Nix and enter development shell";
+      mainProgram = "linux-devshell";
+    };
+  };
+
+  linuxDevShellStandalone = writeTextFile {
+    name = "linux-devshell";
+    executable = true;
+    text = ''
+      #!${shell}
+      ${lib.concatMapStringsSep "\n" (option: "set -o ${option}") bashOptions}
+
+      ${logHelpers}
+      ${scriptText}
+    '';
+    meta = {
+      description = "Standalone linux-devshell script (single file)";
+      mainProgram = "linux-devshell";
+    };
+  };
+in
+{
+  linux-devshell = linuxDevShell;
+  linux-devshell-standalone = linuxDevShellStandalone;
+}

package/linux-devshell/linux-devshell.sh

@@ -0,0 +1,81 @@
+NIX_HOOK="${HOME}/.nix-profile/etc/profile.d/nix.sh"
+
+detect_shell() {
+  self=detect_shell
+
+  if [ "$0" != "$self" ]; then
+    case "$0" in
+      /*) [ -x "$0" ] && { printf '%s\n' "$0"; return 0; } ;;
+      *)  command -v "$0" 2>/dev/null && return 0 ;;
+    esac
+  fi
+
+  _shell="$(ps -p $$ -o args= 2>/dev/null | awk '{print $1}')"
+  [ -n "$_shell" ] && command -v "$_shell" 2>/dev/null && {
+    command -v "$_shell"
+    return 0
+  }
+
+  [ -r "/proc/$$/exe" ] && readlink -f "/proc/$$/exe" && return 0
+
+  [ -x "$SHELL" ] && printf '%s\n' "$SHELL" && return 0
+
+  return 1
+}
+
+install_nix() {
+  log_info "Nix not found. Installing via nixos.org/nix/install --no-daemon..."
+
+  if ! command -v curl >/dev/null 2>&1; then
+    log_error "curl is required. Install it with: sudo pacman -S curl"
+    exit 1
+  fi
+
+  NIX_INSTALL="$(mktemp)"
+  trap 'rm -f "$NIX_INSTALL"' EXIT
+
+  if ! curl -sSfL https://nixos.org/nix/install -o "$NIX_INSTALL"; then
+    log_error "Failed to download Nix installer."
+    exit 1
+  fi
+
+  sh "$NIX_INSTALL" --no-daemon || true
+
+  NIX_CONF_DIR="${XDG_CONFIG_HOME:-${HOME}/.config}/nix"
+  mkdir -p "$NIX_CONF_DIR"
+  NIX_CONF="${NIX_CONF_DIR}/nix.conf"
+  if ! grep -q 'build-users-group' "$NIX_CONF" 2>/dev/null; then
+    printf 'build-users-group =\nextra-experimental-features = nix-command flakes\n' >> "$NIX_CONF"
+    log_info "Patched nix.conf: disabled build-users-group."
+  fi
+
+  log_info "Nix installed successfully."
+}
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+REPO_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"
+
+if [ -f "$NIX_HOOK" ]; then
+  . "$NIX_HOOK"
+fi
+
+if ! command -v nix >/dev/null 2>&1; then
+  install_nix
+  if [ -f "$NIX_HOOK" ]; then
+    . "$NIX_HOOK"
+  fi
+  if ! command -v nix >/dev/null 2>&1; then
+    log_error "Nix binary still not found after installation. Try opening a new terminal."
+    exit 1
+  fi
+else
+  log_info "Nix is already installed -- skipping installation."
+fi
+
+CURR_SHELL="$(detect_shell)"
+log_info "Entering dev shell (nix develop) with shell: ${CURR_SHELL}..."
+log_info "Repository: ${REPO_ROOT}"
+
+exec nix --extra-experimental-features 'nix-command flakes' \
+  develop "${REPO_ROOT}" \
+  -c "$CURR_SHELL"