Jujutsu/git integration

The editor now has a button to commit changes to a Jujutsu repository,
which is automatically created if it's not present.

A git remote is automatically set up using the URL template in
settings.py. I use this with Forgejo's create-on-push feature to
automatically create repositories on my Forgejo instance.

thinks/jujutsu.py

@@ -0,0 +1,85 @@
+import functools
+import subprocess
+from django.conf import settings
+
+def ensure_jj(fn):
+    @functools.wraps(fn)
+    def ofn(self,*args,**kwargs):
+        self.init_jj()
+        return fn(self,*args,**kwargs)
+
+    return ofn
+
+class JJController:
+    def __init__(self, think):
+        self.think = think
+        self.root = think.root
+
+    def run(self, cmd, **kwargs):
+        print("Run command",cmd)
+        res = subprocess.run(
+            cmd,
+            cwd=self.root,
+            encoding='utf8',
+            capture_output=True,
+            **kwargs
+        )
+        return res
+
+    def init_jj(self):
+        print("Init jj")
+        if not (self.root / '.jj').exists():
+            self.run(['jj','git','init'])
+            self.ignore_paths(['.make.*'])
+            git_url = settings.GIT_REPO_URL_TEMPLATE.format(name=self.think.slug)
+            self.run(['jj','git','remote','add','origin', git_url])
+
+    @ensure_jj
+    def status(self):
+        res = self.run(['jj','st'])
+
+        return res.stdout
+
+    def clean_paths(self, paths):
+        paths = [self.root / p for p in paths]
+        return [str(p.relative_to(self.root)) for p in paths if p.is_relative_to(self.root)]
+
+    @ensure_jj
+    def ignore_paths(self, paths):
+        paths = self.clean_paths(paths)
+        gitignore = self.root / '.gitignore'
+        if len(paths) == 0:
+            return
+
+        if gitignore.exists():
+            with open(gitignore) as f:
+                ignored = f.read().strip().split('\n')
+            ignored += [p for p in paths if p not in ignored]
+        else:
+            ignored = paths
+
+        with open(gitignore, 'w') as f:
+            f.write('\n'.join(ignored))
+
+    @ensure_jj
+    def remove_paths(self, paths):
+        paths = self.clean_paths(paths)
+        if len(paths) == 0:
+            return
+
+        return self.run(['git','rm'] + paths)
+
+    @ensure_jj
+    def add_paths(self, paths):
+        paths = self.clean_paths(paths)
+        if len(paths) == 0:
+            return
+
+        return self.run(['git','add'] + paths)
+
+    @ensure_jj
+    def commit(self, message):
+        res = self.run(['jj','describe','--stdin','--no-edit'], input=message)
+        if res.returncode == 0:
+            self.run(['jj','new'])
+        return res