{ config, pkgs, lib, ... }:

let
  # Legacy libxml2 (2.9.x) — required by Tibia
  libxml2_2_9 = pkgs.stdenv.mkDerivation {
    pname = "libxml2-2.9";
    version = "2.9.14";

    src = pkgs.fetchurl {
      url = "https://download.gnome.org/sources/libxml2/2.9/libxml2-2.9.14.tar.xz";
      sha256 = "sha256-YNdKJX0czsBHXnScui8hVZ5IE577pv8oIkNXx8eY3+4=";
    };

    nativeBuildInputs = [ pkgs.pkg-config ];
    buildInputs = [ pkgs.zlib pkgs.xz ];

    configureFlags = [
      "--disable-static"
      "--without-python"
    ];

    enableParallelBuilding = true;
  };

  # Centralized runtime library path for Tibia
  tibiaLibPath =
    lib.makeLibraryPath [
      pkgs.nss
      pkgs.nspr
      pkgs.libxkbfile
      libxml2_2_9
    ];

  # Helper: LD_LIBRARY_PATH export line
  exportLibs = ''
    export LD_LIBRARY_PATH="${tibiaLibPath}:$LD_LIBRARY_PATH"
  '';

  # Wrapper for the real client (system-wide)
  tibiaClientWrapper = pkgs.writeShellScriptBin "tibia-client" ''
    #!/usr/bin/env bash
    ${exportLibs}
    exec steam-run "$HOME/.local/share/CipSoft GmbH/Tibia/packages/Tibia/bin/client" "$@"
  '';

  # Patcher for Tibia's package.json
  tibiaPatcher = pkgs.writeShellScriptBin "tibia-patch" ''
    #!/usr/bin/env bash
    set -e

    PKGDIR="$HOME/.local/share/CipSoft GmbH/Tibia/packages/Tibia"
    PKGJSON="$PKGDIR/package.json"
    LOCALWRAPPER="$PKGDIR/tibia-client-wrapper"

    if [ ! -f "$PKGJSON" ]; then
      echo "package.json not found — run the launcher once first."
      exit 0
    fi

    # Create wrapper inside Tibia package directory
    cat > "$LOCALWRAPPER" <<EOF
#!/usr/bin/env bash
${exportLibs}
exec /run/current-system/sw/bin/tibia-client "\$@"
EOF
    chmod +x "$LOCALWRAPPER"

    # Patch JSON to use the local wrapper
    sed -i 's#"executable": "bin/client"#"executable": "tibia-client-wrapper"#' "$PKGJSON"

    echo "Tibia client patched to use tibia-client-wrapper."
  '';

  # Wrapper for the Tibia launcher
  tibiaLauncherWrapper = pkgs.writeShellScriptBin "tibia" ''
    #!/usr/bin/env bash
    set -e

    LAUNCHER="$HOME/Gry/Tibia/Tibia"

    if [ ! -x "$LAUNCHER" ]; then
      echo "Tibia launcher not found at:"
      echo "  $LAUNCHER"
      exit 1
    fi

    tibia-patch

    ${exportLibs}
    exec steam-run "$LAUNCHER"
  '';

  # Direct client launcher (bypasses Tibia's launcher entirely)
  tibiaDirect = pkgs.writeShellScriptBin "tibia-direct" ''
    #!/usr/bin/env bash

    CLIENT="$HOME/.local/share/CipSoft GmbH/Tibia/packages/Tibia/bin/client"

    if [ ! -x "$CLIENT" ]; then
      echo "Tibia client not found."
      echo "Run the official launcher once so it downloads the client."
      exit 1
    fi

    ${exportLibs}
    exec steam-run "$CLIENT"
  '';

in
{
  environment.systemPackages = [
    pkgs.steam-run
    libxml2_2_9
    tibiaClientWrapper
    tibiaPatcher
    tibiaLauncherWrapper
    tibiaDirect
  ];
}