[gnome-builder] flatpak: work around devhelp

[Christian Hergert <chergert src gnome org>]

commit fe416d9f9385b8b46bfe3b3621c13eabc8e0be6a
Author: Christian Hergert <chergert redhat com>
Date:   Sat Sep 9 15:36:07 2017 -0700

    flatpak: work around devhelp
    
    We need access to the documentation that is provided in the flatpak
    runtimes as they might not be available on the host.
    
    This cheats and symlinks the gtk-doc/html files from ".Docs" runtimes into
    the the data dir used by Builder.
    
    It is very much not an ideal solution, but we need some what to show
    documentation to users in the 3.26 cycle and this is about the best we
    can do as we're already in code freeze.

 plugins/flatpak/gbp-flatpak-application-addin.c |  125 +++++++++++++++++++++++
 1 files changed, 125 insertions(+), 0 deletions(-)
---
diff --git a/plugins/flatpak/gbp-flatpak-application-addin.c b/plugins/flatpak/gbp-flatpak-application-addin.c
index d044c63..c755bf7 100644
--- a/plugins/flatpak/gbp-flatpak-application-addin.c
+++ b/plugins/flatpak/gbp-flatpak-application-addin.c
@@ -18,7 +18,10 @@
 
 #define G_LOG_DOMAIN "gbp-flatpak-application-addin"
 
+#include <glib/gstdio.h>
+#include <errno.h>
 #include <flatpak.h>
+#include <unistd.h>
 
 #include "gbp-flatpak-application-addin.h"
 #include "gbp-flatpak-runtime.h"
@@ -88,6 +91,126 @@ static BuiltinFlatpakRepo builtin_flatpak_repos[] = {
 static void gbp_flatpak_application_addin_reload (GbpFlatpakApplicationAddin *self);
 
 static void
+copy_devhelp_docs_into_user_data_dir_worker (GTask        *task,
+                                             gpointer      source_object,
+                                             gpointer      task_data,
+                                             GCancellable *cancellable)
+{
+  GPtrArray *paths = task_data;
+  g_autofree gchar *dest_dir = NULL;
+
+  IDE_ENTRY;
+
+  g_assert (GBP_IS_FLATPAK_APPLICATION_ADDIN (source_object));
+  g_assert (paths != NULL);
+  g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+  dest_dir = g_build_filename (g_get_user_data_dir (), "gtk-doc", "html", NULL);
+
+  if (!g_file_test (dest_dir, G_FILE_TEST_IS_DIR))
+    g_mkdir_with_parents (dest_dir, 0750);
+
+  for (guint i = 0; i < paths->len; i++)
+    {
+      const gchar *basedir = g_ptr_array_index (paths, i);
+      g_autofree gchar *parent = g_build_filename (basedir, "files", "gtk-doc", "html", NULL);
+      g_autoptr(GDir) dir = g_dir_open (parent, 0, NULL);
+      const gchar *name;
+
+      if (dir == NULL)
+        continue;
+
+      while (NULL != (name = g_dir_read_name (dir)))
+        {
+          g_autofree gchar *src = g_build_filename (parent, name, NULL);
+          g_autofree gchar *dst = g_build_filename (dest_dir, name, NULL);
+
+          if (g_file_test (dst, G_FILE_TEST_IS_SYMLINK))
+            g_unlink (dst);
+
+          errno = 0;
+          if (symlink (src, dst) == -1)
+            g_warning ("Failed to copy documentation: %s (%s)",
+                       g_strerror (errno), src);
+        }
+    }
+
+  IDE_EXIT;
+}
+
+static void
+copy_devhelp_docs_into_user_data_dir (GbpFlatpakApplicationAddin *self)
+{
+  g_autoptr(GTask) task = NULL;
+  g_autoptr(GPtrArray) paths = NULL;
+
+  IDE_ENTRY;
+
+  g_assert (GBP_IS_FLATPAK_APPLICATION_ADDIN (self));
+
+  if (self->installations == NULL)
+    IDE_EXIT;
+
+  /* HACK:
+   *
+   * Devhelp does not provide us adequate API to be able to set the
+   * search path for runtimes. That means that we have no documentation
+   * for users from Devhelp. While we can improve this in the future via
+   * "doc packs" in Devhelp, we need something that can be shipped
+   * immediately for 3.26.
+   *
+   * The hack that seems to be the minimal amount of work which improves
+   * the situation on both Host-installed and Flatpak-installed variants
+   * is to copy documentation from the newest version of runtimes into
+   * the $XDG_DATA_DIR/and will work
+   */
+
+  paths = g_ptr_array_new_with_free_func (g_free);
+
+  task = g_task_new (self, NULL, NULL, NULL);
+  g_task_set_source_tag (task, copy_devhelp_docs_into_user_data_dir);
+  g_task_set_priority (task, G_PRIORITY_LOW);
+
+  /*
+   * Collect the paths to all of the .Docs runtimes.
+   *
+   * TODO: We should try to sort these by importants, so that master
+   *       docs are preferred and if that is not available, the highest
+   *       version number.
+   */
+  for (guint i = 0; i < self->installations->len; i++)
+    {
+      InstallInfo *info = g_ptr_array_index (self->installations, i);
+      g_autoptr(GPtrArray) refs = NULL;
+
+      refs = flatpak_installation_list_installed_refs_by_kind (info->installation,
+                                                               FLATPAK_REF_KIND_RUNTIME,
+                                                               g_task_get_cancellable (task),
+                                                               NULL);
+      if (refs == NULL)
+        continue;
+
+      for (guint j = 0; j < refs->len; j++)
+        {
+          FlatpakInstalledRef *ref = g_ptr_array_index (refs, j);
+          const gchar *name = flatpak_ref_get_name (FLATPAK_REF (ref));
+
+          if (name == NULL || !g_str_has_suffix (name, ".Docs"))
+            continue;
+
+          g_ptr_array_add (paths, g_strdup (flatpak_installed_ref_get_deploy_dir (ref)));
+        }
+    }
+
+  g_task_set_task_data (task, g_steal_pointer (&paths), (GDestroyNotify)g_ptr_array_unref);
+
+  /* Now go copy the the docs over */
+  g_task_run_in_thread (task, copy_devhelp_docs_into_user_data_dir_worker);
+
+  IDE_EXIT;
+}
+
+static void
 install_info_installation_changed (GFileMonitor      *monitor,
                                    GFile             *file,
                                    GFile             *other_file,
@@ -274,6 +397,8 @@ gbp_flatpak_application_addin_reload (GbpFlatpakApplicationAddin *self)
         }
     }
 
+  copy_devhelp_docs_into_user_data_dir (self);
+
   g_signal_emit (self, signals[RELOAD], 0);
 
   IDE_EXIT;