From 19d4ed6f747248e4ff8cd1c524a7431871fd55f3 Mon Sep 17 00:00:00 2001
From: Elena ``of Valhalla'' Grandi <valhalla@trueelena.org>
Date: Mon, 22 Mar 2021 09:39:46 +0100
Subject: git hook to update the lesana cache when files are changed by git.

---
 CHANGELOG.rst             |  5 +++++
 lesana/collection.py      | 17 +++++++++++++++--
 lesana/data/post-checkout | 21 +++++++++++++++++++++
 tests/test_collection.py  | 18 ++++++++++++++++++
 4 files changed, 59 insertions(+), 2 deletions(-)
 create mode 100755 lesana/data/post-checkout

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c8c2786..8c6a212 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -7,6 +7,11 @@ Unreleased
 
 * New data type: geo (for Geo URIs).
 * New custom filter for templates: to_yaml.
+* git hook to update the lesana cache when files are changed by git.
+
+  This hook is installed when running ``lesana init``; you may want to
+  add it to existing repositories by running ``lesana init`` on them
+  (this is safe to do and won't change your settings or your data).
 
 0.8.1
 =====
diff --git a/lesana/collection.py b/lesana/collection.py
index a4546df..87f767f 100644
--- a/lesana/collection.py
+++ b/lesana/collection.py
@@ -8,7 +8,7 @@ import ruamel.yaml
 import xapian
 import jinja2
 
-from pkg_resources import resource_string
+from pkg_resources import resource_string, resource_filename
 from . import types, templating
 
 try:
@@ -527,7 +527,20 @@ class Collection(object):
                     fp.write('#Added by lesana init\n.lesana')
                 if repo:
                     repo.index.add(['.gitignore'])
-            # TODO: Add hook to index files as they are pulled
+
+            # Add post-checkout and post-merge hook
+            hook_source = resource_filename('lesana', 'data/post-checkout')
+            hooks_dir = os.path.join(
+                c_dir,
+                '.git',
+                'hooks',
+            )
+            checkout_hook = os.path.join(hooks_dir, 'post-checkout')
+            merge_hook = os.path.join(hooks_dir, 'post-merge')
+
+            shutil.copy(hook_source, checkout_hook)
+            if not os.path.islink(merge_hook):
+                os.symlink(checkout_hook, merge_hook)
         # If it doesn't exist, create a skeleton of settings.yaml file
         # then open settings.yaml for editing
         filepath = os.path.join(c_dir, 'settings.yaml')
diff --git a/lesana/data/post-checkout b/lesana/data/post-checkout
new file mode 100755
index 0000000..9c2c084
--- /dev/null
+++ b/lesana/data/post-checkout
@@ -0,0 +1,21 @@
+#!/bin/sh
+#
+# Update a lesana cache when the repository is changed with git
+# 
+# To use this hook add it to .git/hooks under the names "post-checkout" and
+# "post-merge"
+
+if [ $(basename $0) = "post-checkout" ] ; then
+    diff_cmd="git diff --name-status $1 $2"
+elif [ $(basename $0) = "post-merge" ] ; then
+    diff_cmd="git diff --name-status --no-commit-id ORIG_HEAD HEAD"
+else
+    echo "This hook can only work as post-checkout or post-merge"
+    exit 1
+fi
+
+for F in $( $diff_cmd | grep "^D" | cut -c 2-) ; do
+    lesana rm $(basename $F .yaml)
+done
+
+lesana index $( $diff_cmd | grep "^[AM]" | cut -c 2- | xargs)
diff --git a/tests/test_collection.py b/tests/test_collection.py
index 2218169..2af4cfe 100644
--- a/tests/test_collection.py
+++ b/tests/test_collection.py
@@ -520,6 +520,24 @@ class testCollectionCreation(unittest.TestCase):
         self.assertTrue(
             os.path.isfile(os.path.join(self.tmpdir, '.gitignore'))
         )
+        checkout_hook = os.path.join(
+            self.tmpdir,
+            '.git',
+            'hooks',
+            'post-checkout',
+        )
+        merge_hook = os.path.join(
+            self.tmpdir,
+            '.git',
+            'hooks',
+            'post-merge',
+        )
+        self.assertTrue(os.path.isfile(checkout_hook))
+        self.assertTrue(os.path.islink(merge_hook))
+        self.assertEqual(
+            os.path.abspath(checkout_hook),
+            os.path.abspath(os.readlink(merge_hook))
+        )
         # and then run it twice on the same directory, nothing should break
         collection = lesana.Collection.init(self.tmpdir)
         self.assertIsInstance(collection, lesana.Collection)
-- 
cgit v1.2.3