Add git blame plugin

porcupine/plugins/git_blame.py

@@ -0,0 +1,91 @@
+from __future__ import annotations
+
+import logging
+import re
+import subprocess
+import sys
+import time
+from datetime import datetime
+from functools import partial
+from pathlib import Path
+from typing import NamedTuple
+
+from porcupine import get_tab_manager, tabs, utils
+
+log = logging.getLogger(__name__)
+
+GIT_BLAME_REGEX = r"([0-9a-fA-F]+)\s\((.+?)\s([0-9]*)\s.{5}\s[0-9]+\)"
+
+
+class Commit(NamedTuple):
+    revision: int
+    subject: str
+    author: str
+    date: datetime
+
+
+def run_git(*args, cwd: Path) -> subprocess.CompletedProcess:
+    return subprocess.run(
+        ["git"] + list(args),
+        cwd=cwd,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        encoding=sys.getfilesystemencoding(),
+        timeout=(60 * 10),  # 10min. Must be huge to avoid unnecessary killing (#885)
+        **utils.subprocess_kwargs,
+    )
+
+
+def is_in_git_repo(path: Path) -> bool:
+    for parent in path.parents:
+        if (parent / ".git").is_dir():
+            return True
+    return False
+
+
+def git_blame_get_commit(path: Path, line: int) -> Commit | None:
+    if not path or not is_in_git_repo(path):
+        # TODO: Do we have to check this every time?
+        return None
+
+    try:
+        start = time.perf_counter()
+        git_blame_result = run_git(
+            "blame", str(path), "-L", f"{line},{line}", "-t", cwd=path.parent
+        )
+        log.debug(
+            f"running git blame for {path} took" f" {round((time.perf_counter() - start)*1000)}ms"
+        )
+    except (OSError, UnicodeError, subprocess.TimeoutExpired):
+        log.warning("can't run git", exc_info=True)
+        return None
+
+    result = re.search(GIT_BLAME_REGEX, git_blame_result.stdout)
+    if not result:
+        return None
+
+    revision, author, timestamp = result.groups()
+    date = datetime.fromtimestamp(int(timestamp))
+
+    git_log_result = run_git("log", "-n", "1", "--pretty=format:%s", revision, cwd=path.parent)
+
+    return Commit(int(revision), git_log_result.stdout, author, date)
+
+
+def show_git_blame_message(path: Path, event) -> None:
+    line_num = int(event.widget.index("insert").split(".")[0])
+
+    commit = git_blame_get_commit(path=path, line=line_num)
+    if commit is None:
+        return
+
+    formatted = f"Line {line_num}: by {commit.author} at {commit.date} - {commit.subject}"
+    print(formatted)
+
+
+def on_new_filetab(tab: tabs.FileTab) -> None:
+    tab.textwidget.bind("<<CursorMoved>>", partial(show_git_blame_message, tab.path), add=True)
+
+
+def setup() -> None:
+    get_tab_manager().add_filetab_callback(on_new_filetab)