From ed8c42ce86df88b9c2b9da5dbcc1d178824896e1 Mon Sep 17 00:00:00 2001
From: Jake Howard <git@theorangeone.net>
Date: Mon, 11 Sep 2023 22:49:52 +0100
Subject: [PATCH] Add cachebust hash to static files

---
 hooks/static.py | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
 mkdocs.yml      |  1 +
 2 files changed, 59 insertions(+)
 create mode 100644 hooks/static.py

diff --git a/hooks/static.py b/hooks/static.py
new file mode 100644
index 0000000..7a3e47f
--- /dev/null
+++ b/hooks/static.py
@@ -0,0 +1,58 @@
+from jinja2_simple_tags import StandaloneTag
+import jinja2
+from copy import deepcopy
+from mkdocs.structure.files import File, Files
+from mkdocs.plugins import event_priority
+import hashlib
+from mkdocs.plugins import get_plugin_logger
+from concurrent.futures import ThreadPoolExecutor
+from pathlib import Path
+
+logger = get_plugin_logger("static")
+
+
+def transform_file_url(url: str, hash: str):
+    url_path = Path(url)
+    return str(url_path.with_stem(url_path.stem + "." + hash[:10]))
+
+def hash_file(file: File) -> File:
+    logger.debug("Hashing %s", file.url)
+
+    hashed_file = deepcopy(file)
+
+    with open(file.abs_src_path, "rb") as f:
+        digest = hashlib.file_digest(f, "md5").hexdigest()
+
+    hashed_file.abs_dest_path = transform_file_url(hashed_file.abs_dest_path, digest)
+    hashed_file.dest_uri = transform_file_url(hashed_file.dest_uri, digest)
+    hashed_file.url = transform_file_url(hashed_file.url, digest)
+
+    return hashed_file
+
+@event_priority(-100)
+def on_files(files: Files, config):
+    with ThreadPoolExecutor() as executor:
+        for hashed_file in executor.map(hash_file, files.media_files()):
+            files.append(hashed_file)
+
+            # HACK: Add a fake file with a `src_uri` of the hashed path so other integrations can find the right file
+            hashed_src_file = deepcopy(hashed_file)
+            hashed_src_file.src_uri = hashed_src_file.dest_uri
+            files.append(hashed_src_file)
+
+    return files
+
+def on_env(env: jinja2.Environment, config, files):
+    env.add_extension(make_static_extension(files))
+
+    return env
+
+def make_static_extension(files: Files):
+    class StaticExtension(StandaloneTag):
+        tags = {"static"}
+
+        def render(self, filename):
+            file = files.get_file_from_path(filename)
+            return file.url
+
+    return StaticExtension
diff --git a/mkdocs.yml b/mkdocs.yml
index 802edd1..becef87 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -12,6 +12,7 @@ hooks:
   - hooks/tags.py
   - hooks/images.py
   - hooks/page-render.py
+  - hooks/static.py
 
 markdown_extensions:
   - attr_list