# Nix environment for the community edition
#
# This shall be as lean as possible, just producing the rhodecode-vcsserver
# derivation. For advanced tweaks to pimp up the development environment we use
# "shell.nix" so that it does not have to clutter this file.

args@
{ system ? builtins.currentSystem
, pythonPackages ? "python37Packages"
, pythonExternalOverrides ? self: super: {}
, doCheck ? false
, ...
}:

let
  pkgs_ = args.pkgs or (import <nixpkgs> { inherit system; });
in

let
  pkgs = import <nixpkgs> {
    overlays = [
      (import ./pkgs/overlays.nix)
    ];
    inherit
      (pkgs_)
      system;
  };

  # Evaluates to the last segment of a file system path.
  basename = path: with pkgs.lib; last (splitString "/" path);
  startsWith = prefix: full: let
    actualPrefix = builtins.substring 0 (builtins.stringLength prefix) full;
  in actualPrefix == prefix;

  # source code filter used as arugment to builtins.filterSource.
  src-filter = path: type: with pkgs.lib;
    let
      ext = last (splitString "." path);
      parts = last (splitString "/" path);
    in
      !builtins.elem (basename path) [
        ".git" ".hg" "__pycache__" ".eggs" ".idea" ".dev"
        "node_modules" "node_binaries"
        "build" "data" "result" "tmp"] &&
      !builtins.elem ext ["egg-info" "pyc"] &&
      !startsWith "result" (basename path);

  sources =
    let
      inherit
        (pkgs.lib)
        all
        isString
        attrValues;

      sourcesConfig = pkgs.config.rc.sources or {};
    in
      # Ensure that sources are configured as strings. Using a path
      # would result in a copy into the nix store.
      assert all isString (attrValues sourcesConfig);
      sourcesConfig;

  rhodecode-vcsserver-src = builtins.filterSource src-filter ./.;
  version = builtins.readFile "${rhodecode-vcsserver-src}/vcsserver/VERSION";

  pythonLocalOverrides = self: super: {
    rhodecode-vcsserver =
      let
        releaseName = "RhodeCodeVCSServer-${version}";
      in super.rhodecode-vcsserver.overridePythonAttrs (attrs: {
      inherit
        doCheck
        version;

      name = "rhodecode-vcsserver-${version}";
      releaseName = releaseName;
      src = rhodecode-vcsserver-src;
      dontStrip = true; # prevent strip, we don't need it.

      buildInputs =
        attrs.buildInputs or [] ++ [

        ];

      #NOTE: option to inject additional propagatedBuildInputs
      propagatedBuildInputs =
        attrs.propagatedBuildInputs or [] ++ [
        pkgs.git
        pkgs.subversion
      ];

      preBuild = ''
        export NIX_PATH=nixpkgs=${pkgs.path}
        export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt
      '';

      # Add bin directory to path so that tests can find 'vcsserver'.
      preCheck = ''
        echo "Expanding PATH with $out/bin directory"
        export PATH="$out/bin:$PATH"
      '';

      # custom check phase for testing
      checkPhase = ''
        runHook preCheck
        PYTHONHASHSEED=$RANDOM py.test -vv -p no:sugar -r xw --cov-config=.coveragerc --cov=vcsserver --cov-report=term-missing vcsserver
        runHook postCheck
      '';

      postCheck = ''
        echo "Cleanup of vcsserver/tests"
        rm -rf $out/lib/${self.python.libPrefix}/site-packages/vcsserver/tests
      '';

      postInstall = ''
        echo "Writing vcsserver meta information for rccontrol to nix-support/rccontrol"
        mkdir -p $out/nix-support/rccontrol
        cp -v vcsserver/VERSION $out/nix-support/rccontrol/version
        echo "DONE: vcsserver meta information for rccontrol written"

        mkdir -p $out/etc
        cp configs/production.ini $out/etc
        echo "DONE: saved vcsserver production.ini into $out/etc"

        echo "saving env in $out/etc/env_vars.txt"
        touch $out/etc/env_vars.txt
        echo "# RhodeCode build env vars" >> $out/etc/env_vars.txt
        echo "LOCALE_ARCHIVE=\"${pkgs.glibcLocales}/lib/locale/locale-archive\"" >> $out/etc/env_vars.txt
        echo "LC_ALL=\"en_US.UTF-8\"" >> $out/etc/env_vars.txt

        # expose sources of vcsserver
        ln -s $out $out/etc/rhodecode_vcsserver_source
      '';

    });
  };

  basePythonPackages = with builtins;
    if isAttrs pythonPackages then
      pythonPackages
    else
      getAttr pythonPackages pkgs;

  pythonGeneratedPackages = import ./pkgs/python-packages.nix {
    inherit pkgs;
    inherit (pkgs) fetchurl fetchgit fetchhg;
  };

  pythonVCSServerOverrides = import ./pkgs/python-packages-overrides.nix {
    inherit pkgs basePythonPackages;
  };

  # Apply all overrides and fix the vcsserver package set
  targetPython = basePythonPackages.python.override {
    packageOverrides = self: super: with pkgs.lib;
      (extends pythonExternalOverrides
      (extends pythonLocalOverrides
      (extends pythonVCSServerOverrides
      (extends pythonGeneratedPackages
              (self: super))))) self;
  };

  # Python env with rhodecode-vcsserver
  pythonEnv = (targetPython.withPackages(ps: with ps; [rhodecode-vcsserver]));

  # Generic env with wrapped binaries
  vcsserver = pkgs.buildEnv {
    name = if ! isNull targetPython.pkgs.rhodecode-vcsserver
      then "vcsserver-${targetPython.pkgs.rhodecode-vcsserver.version}"
      else "vcsserver";
    paths = [
      pythonEnv
      # Symlink version control utilities
      # We ensure that always the correct version is available as a symlink.
      # So that users calling them via the profile path will always use the
      # correct version. Wrapping is required so those can "import"
      # vcsserver python hooks.
      pkgs.git
      pkgs.subversion
    ];
    # expose following attributed outside
    passthru = {
      pythonPackages = targetPython.pkgs;
      vcs_pkgs = pkgs;
    };
    buildInputs = [
      pkgs.makeWrapper
    ];
    postBuild = (if ! isNull targetPython.pkgs.rhodecode-vcsserver then ''
      echo "Writing vcsserver meta information for rccontrol to nix-support/rccontrol"
      ln -s ${targetPython.pkgs.rhodecode-vcsserver}/nix-support $out/nix-support
      echo "DONE: vcsserver meta information for rccontrol written"
    '' else "") + ''
      DEPS="$out/bin/*"
      # wrap only dependency scripts, they require to have full PYTHONPATH set
      # to be able to import all packages
      for file in $DEPS;
      do
        wrapProgram $file \
          --prefix PATH : ${pkgs.git}/bin \
          --prefix PATH : ${pkgs.subversion}/bin \
          --prefix PATH : ${pythonEnv}/bin \
          --prefix PYTHONPATH : ${pythonEnv}/${pythonEnv.sitePackages} \
          --prefix PYTHONPATH : ${pkgs.subversion}/${pythonEnv.sitePackages} \
          --set PYTHONHASHSEED $RANDOM
      done
      echo "DONE: vcsserver binary wrapping"
    '';
  };

in vcsserver