rearrange how Oscar loads GAP packages at runtime (#3874)

* rearrange how Oscar loads GAP packages at runtime

- GAP package OscarInterface: add dependency Polycyclic (formally needed)

- loading order of GAP packages:
  - in the beginning, install recog via a URL
  - load OscarInterface in the end

* install GAP's Recog package via a dedicated Oscar function

This will update the package from its git repository
each time Oscar gets started;
this is a bad idea, but otherwise we cannot get rid of older versions

* really update the GAP package if it is already installed

gap/OscarInterface/PackageInfo.g

@@ -75,7 +75,10 @@ PackageDoc := rec(
 
 Dependencies := rec(
   GAP := ">= 4.12",
-  NeededOtherPackages := [ ["JuliaInterface", ">=0.9"] ],
+  NeededOtherPackages := [
+    ["JuliaInterface", ">=0.9"],
+    ["Polycyclic", ">=2.16"],
+  ],
   SuggestedOtherPackages := [ ],
   ExternalConditions := [ ],
 ),

src/Oscar.jl

@@ -50,7 +50,7 @@ function _print_banner(;is_dev = Oscar.is_dev)
   else
     version_string = "Version " * version_string
   end
-  
+
   if displaysize(stdout)[2] >= 80 
     println(
       raw"""  ___   ____   ____    _    ____
@@ -86,20 +86,25 @@ function __init__()
   # make Oscar module accessible from GAP (it may not be available as
   # `Julia.Oscar` if Oscar is loaded indirectly as a package dependency)
   GAP.Globals.BindGlobal(GapObj("Oscar"), Oscar)
-  GAP.Globals.SetPackagePath(GAP.Obj("OscarInterface"), GAP.Obj(joinpath(@__DIR__, "..", "gap", "OscarInterface")))
-  GAP.Globals.LoadPackage(GAP.Obj("OscarInterface"), false)
-  withenv("TERMINFO_DIRS" => joinpath(GAP.GAP_jll.Readline_jll.Ncurses_jll.find_artifact_dir(), "share", "terminfo")) do
-    GAP.Packages.load("browse"; install=true) # needed for all_character_table_names doctest
-  end
+
+  # Up to now, hopefully the GAP packages listed below have not been loaded.
   # We want newer versions of some GAP packages than the distributed ones.
   # (But we do not complain if the installation fails.)
+  for (url, branch) in [
+     ("https://github.com/danielrademacher/recog.git", ""),
+     ]
+    GAP_Packages_install(url, interactive = false, branch = branch)
+  end
   for (pkg, version) in [
-     ("recog", "1.4.2"),
      ("repsn", "3.1.1"),
      ]
     GAP.Packages.install(pkg, version, interactive = false, quiet = true)
   end
-  # We need some GAP packages.
+
+  withenv("TERMINFO_DIRS" => joinpath(GAP.GAP_jll.Readline_jll.Ncurses_jll.find_artifact_dir(), "share", "terminfo")) do
+    GAP.Packages.load("browse"; install=true) # needed for all_character_table_names doctest
+  end
+  # We need some GAP packages (currently with unspecified versions).
   for pkg in [
      "atlasrep",
      "ctbllib",  # character tables
@@ -123,6 +128,13 @@ function __init__()
      ]
     GAP.Packages.load(pkg)
   end
+  # Load the OscarInterface package in the end.
+  # It needs some other GAP packages,
+  # and is not needed by packages that can be loaded before Oscar.
+  GAP.Globals.SetPackagePath(GAP.Obj("OscarInterface"), GAP.Obj(joinpath(@__DIR__, "..", "gap", "OscarInterface")))
+  GAP.Globals.LoadPackage(GAP.Obj("OscarInterface"), false)
+  # Switch off GAP's info messages,
+  # also those that are triggered from GAP packages.
   __GAP_info_messages_off()
   __init_group_libraries()
 

src/utils/install.jl

@@ -0,0 +1,58 @@
+# Install a GAP package via the URL of a GIT repository.
+# If the package was already installed then update the installation,
+# otherwise clone the repository.
+# (The code is a modified copy of GAP's `InstallPackageFromGit`.)
+function GAP_Packages_install(url::String; interactive::Bool = false, branch::String = "")
+  # point PackageManager to GAP.jl's pkg dir
+  GAP.Globals.PKGMAN_CustomPackageDir = GapObj(GAP.Packages.DEFAULT_PKGDIR[])
+  # avoid info messages from PackageManager
+  GAP.Globals.SetInfoLevel(GAP.Globals.InfoPackageManager, 0)
+
+  url = GapObj(url)
+  name = GAP.Globals.PKGMAN_NameOfGitRepo(url)
+  name === GAP.Globals.fail && return false
+  dir = GAP.Globals.Filename(GAP.Globals.Directory(GAP.Globals.PKGMAN_PackageDir()), name)
+
+  # check for existing repository
+  allinfo = GAP.Globals.PackageInfo(name)
+  info = GAP.Globals.Filtered(allinfo,
+             x -> GAP.Globals.StartsWith(x.InstallationPath, GAP.Globals.PKGMAN_PackageDir()))
+  dirs = GAP.Globals.List(info, i -> i.InstallationPath)
+  repo = GAP.Globals.Filename(GAP.Globals.List(dirs, GAP.Globals.Directory), GapObj(".git"));
+  if repo !== GAP.Globals.fail
+    # the package is already installed, update it
+    return GAP.Globals.UpdatePackage(name, interactive)
+  end
+
+  ! GAP.Globals.PKGMAN_IsValidTargetDir(dir) && return false
+  if branch == ""
+    exec = GAP.Globals.PKGMAN_Exec(GapObj("."), GapObj("git"), GapObj("clone"), url, dir)
+  else
+    exec = GAP.Globals.PKGMAN_Exec(GapObj("."), GapObj("git"), GapObj("clone"), url, dir, GapObj("-b"), GapObj(branch))
+  end
+
+  (exec === GAP.Globals.fail || exec.code != 0) && return false
+  GAP.Globals.PKGMAN_RefreshPackageInfo()
+
+  # check for PackageInfo.g
+  info = GAP.Globals.Filename(GAP.Globals.Directory(dir), GapObj("PackageInfo.g"));
+  if ! GAP.Globals.IsReadableFile(info)
+    if GAP.Globals.ValueOption("debug") != true
+      GAP.Globals.PKGMAN_RemoveDir(dir)
+    end
+    return false
+  end
+
+  # install dependencies
+  if GAP.Globals.PKGMAN_InstallDependencies(dir) != true
+    if GAP.Globals.ValueOption("debug") != true
+      GAP.Globals.PKGMAN_RemoveDir(dir)
+    end
+    return false
+  end
+
+  # compile, make doc, and check
+#TODO: build the documentation once PackageManager sets the right current directory, 
+# return GAP.Globals.PKGMAN_CheckPackage(dir)
+  return true
+end

src/utils/utils.jl

@@ -12,3 +12,4 @@ include("docs.jl")
 include("tests.jl")
 include("rand.jl")
 include("parallel.jl")
+include("install.jl")