first map setup

shell.nix

@@ -0,0 +1,71 @@
+# shell.nix
+/*
+# Dev env for elixir
+
+
+## Environment Variables
+
+- MIX_HOME: Local Mix installation
+- HEX_HOME: Local Hex package manager
+- PGDIR: PostgreSQL data directory
+- PGHOST: Unix domain socket location
+- DATABASE_URL: PostgreSQL connection string
+*/
+
+let
+  # Import nixos-unstable for most packages
+  pkgs = import <nixpkgs> {};
+  # Import nixpkgs-unstable for outliers
+  pkgs-unstable = import <nixpkgs-unstable> {};
+  
+  extraPackages = [
+    pkgs.beam.packages.erlang_27.elixir_1_18
+    pkgs.beam.packages.erlang_27.erlang
+    pkgs.elixir_ls
+    pkgs.inotify-tools
+    
+    # DB
+    pkgs.postgresql
+    # JS
+    pkgs-unstable.deno
+    # PY
+    pkgs.python3
+    pkgs.python3Packages.laspy
+    pkgs.python3Packages.scipy
+    pkgs.python3Packages.numpy
+    pkgs.python3Packages.pyproj
+  ];
+
+  mkShell = pkgs.mkShell;
+  PROJECT_ROOT = builtins.toString ./.;
+
+  hooks = ''
+    # Set up environment variables
+
+    # PostgreSQL configuration
+    export PGDIR=${PROJECT_ROOT}/postgres
+    export PGHOST=$PGDIR
+    export PGDATA=$PGDIR/data
+    export PGLOG=$PGDIR/log
+    export DATABASE_URL="postgresql:///postgres?host=$PGDIR"
+
+    # Create PostgreSQL directories if they don't exist
+    if test ! -d $PGDIR; then
+      mkdir $PGDIR
+    fi
+
+    if [ ! -d $PGDATA ]; then
+      echo 'Initializing postgresql database...'
+      initdb $PGDATA --auth=trust >/dev/null
+    fi
+
+    # Print setup instructions
+    echo "Elixir development environment ready!"
+    echo "To start PostgreSQL, run: postgres -h \'\' -k \'$PGHOST\'"
+    echo "To start the project, run : iex -S mix phx.server" 
+  '';
+
+in mkShell {
+  buildInputs = extraPackages;
+  shellHook = hooks;
+}