# Fg42 - Emacs Editor for advance users
#
# Copyright (c) 2010-2024 Sameer Rahmani <lxsameer@gnu.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
{
  lib,
  nixpkgs,
  stdenv,
  elispPkgs,
  srcDir,
  emacsPackagesFor,
  ourPackages,
  writeText,
  symlinkJoin,

  # python deps
  python311,
  python3Packages,
  # This is a set of system tools required for FG42
  # to work.
  pyright,
  emacs,
  ripgrep,
  git,
  texinfo,
  vazir-fonts,
  fira-code,
  nerdfonts,
  gcc,
  ltex-ls,
  bash,
}:
with builtins;
let
  getPkg = epkgs: pkg:
    if hasAttr pkg epkgs
    then getAttr pkg epkgs
    else getAttr pkg ourPackages;

  emacsBundle = (emacsPackagesFor emacs).withPackages (epkgs:
    (map (x: getPkg epkgs x) elispPkgs)
  );

  maintainers = import ./maintainers.nix;

in stdenv.mkDerivation (final: rec{
  pname = "fg42$";
  version = "4.0.0";

  src = srcDir;
  outputs = [ "out" ];

  buildPhase =  ''
    LISPDIR=$out/share/fg42/
    mkdir -p $out/bin
    install -d $LISPDIR
    cp -rv ${src}/lisp/ $LISPDIR
    cp -rv ${src}/share $out/

    runHook preBuild

    cd $LISPDIR
    emacs -L . --batch -f batch-byte-compile *.el
    cd -

    cat >> $out/bin/fg42 << EOF
    #!${stdenv.shell}

    export FG42_HOME=${placeholder "out"}/share/fg42/
    export FG42_EMACSD=~/.fg42/v4/emacs.d
    export FG42_USE_NIX=true;

    LIBRARY_PATH="\$(${stdenv.cc}/bin/cc -print-file-name=libgccjit.so):\$LIBRARY_PATH" \
      FG42_WM=fales ${emacsBundle}/bin/emacs \
      --name FG42 \
      -q --no-splash --title FG42 \
      -l \$FG42_HOME/lisp/fg42/init.el "\$@"
    EOF
    chmod +x $out/bin/fg42
    runHook postBuild

    cat >> $out/bin/fg42-wm << EOF
    #!${stdenv.shell}

    export FG42_HOME=${placeholder "out"}/share/fg42/
    export FG42_EMACSD=~/.fg42/v4/emacs.d
    export FG42_USE_NIX=true;

    # Disable access control for the current user.
    xhost +SI:localuser:$USER

    # Make Java applications aware this is a non-reparenting window manager.
    export _JAVA_AWT_WM_NONREPARENTING=1

    # Set default cursor.
    xsetroot -cursor_name left_ptr

    # Set keyboard repeat rate.
    xset r rate 400 30

    # Uncomment the following block to use the exwm-xim module.
    # export XMODIFIERS=@im=exwm-xim
    # export GTK_IM_MODULE=xim
    # export QT_IM_MODULE=xim
    # export CLUTTER_IM_MODULE=xim

    LIBRARY_PATH="\$(${stdenv.cc}/bin/cc -print-file-name=libgccjit.so):\$LIBRARY_PATH" \
      FG42_WM=true ${emacsBundle}/bin/emacs \
      --name FG42 \
      -q --no-splash --title FG42 \
      -l \$FG42_HOME/lisp/fg42/init.el "\$@"
    EOF
    chmod +x $out/bin/fg42-wm

    cat >> $out/share/runtiem_deps << EOF
    ${vazir-fonts}
    ${fira-code}
    ${nerdfonts}
    ${ripgrep}
    ${git}
    ${ltex-ls}
    # Python deps
    ${python311}/bin/python
    ${pyright}
    ${python3Packages.black}
    ${python3Packages.pylint}
    ${python3Packages.flake8}
    EOF

    runHook postBuild
  '';

  installPhase = ''
      runHook preInstall

      #LISPDIR=$out/share/fg42/lisp/
      #emacs --batch -l package --eval "(package-generate-autoloads \"${pname}\" \"$LISPDIR\")"

      runHook postInstall
    '';


  buildInputs = [
    emacs
    texinfo
    emacsBundle
    ripgrep
    git
    texinfo
    vazir-fonts
    fira-code
    nerdfonts
    gcc
    ltex-ls
    bash
  ];

  addEmacsNativeLoadPath = true;

  meta = {
    broken = false;
    platforms = emacs.meta.platforms;
    homepage = "https://fg42.org/";
    maintainers = [ maintainers.lxsameer ];
    description = "The mighty editor for the emacsians";
    longDescription = ''
       FG42 is a framework to create and editor and window manager based on GNU/Emacs.
       It has a pre-defined setup as well which can be installed out of the box. But the
       goal of this project is to provide the API necessary to create an integrated editor.

       So you need to know about Emacs in advance.
      '';
    license = lib.licenses.gpl3Plus;
  };

})