"""Changelog generator using git history.
This module extracts commit history from git and generates a changelog
wiki page with links to GitHub/GitLab commits.
"""
from __future__ import annotations
import subprocess
from collections import defaultdict
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from local_deepwiki.core.git_utils import GitRepoInfo, get_repo_info
from local_deepwiki.logging import get_logger
logger = get_logger(__name__)
# Git subprocess timeout for fetching commit history
GIT_LOG_TIMEOUT = 30
# Maximum display length for commit messages in changelog
COMMIT_MESSAGE_MAX_LENGTH = 80
COMMIT_MESSAGE_TRUNCATED_LENGTH = 77 # Leaves room for "..."
# Maximum number of changed files shown per commit
MAX_CHANGED_FILES_PER_COMMIT = 5
@dataclass(frozen=True, slots=True)
class CommitInfo:
"""Information about a git commit."""
hash: str # Short hash (7 chars)
full_hash: str # Full 40-char hash
author: str
date: datetime
message: str
files: list[str] = field(default_factory=list)
def get_commit_history(repo_path: Path, limit: int = 30) -> list[CommitInfo]:
"""Get recent commit history with file changes.
Args:
repo_path: Path to the repository.
limit: Maximum number of commits to retrieve.
Returns:
List of CommitInfo objects, newest first.
"""
try:
# Get commit info with changed files
# Format: short_hash|full_hash|author|date|message
# Followed by file names (one per line) until empty line
result = subprocess.run(
[
"git",
"log",
f"--max-count={limit}",
"--pretty=format:%h|%H|%an|%ai|%s",
"--name-only",
],
cwd=repo_path,
capture_output=True,
text=True,
timeout=GIT_LOG_TIMEOUT,
)
if result.returncode != 0:
logger.debug("Git log failed: %s", result.stderr)
return []
commits: list[CommitInfo] = []
current_commit: CommitInfo | None = None
for line in result.stdout.split("\n"):
line = line.strip()
if "|" in line and line.count("|") >= 4:
# This is a commit header line
if current_commit:
commits.append(current_commit)
parts = line.split("|", 4)
if len(parts) >= 5:
try:
# Parse date (format: 2026-01-13 10:30:00 -0500)
date_str = parts[3].rsplit(" ", 1)[0] # Remove timezone
date = datetime.strptime(date_str, "%Y-%m-%d %H:%M:%S")
except ValueError:
date = datetime.now()
current_commit = CommitInfo(
hash=parts[0],
full_hash=parts[1],
author=parts[2],
date=date,
message=parts[4],
files=[],
)
elif line and current_commit:
# This is a file path
current_commit.files.append(line)
# Don't forget the last commit
if current_commit:
commits.append(current_commit)
return commits
except subprocess.TimeoutExpired:
logger.warning("Git log timed out")
return []
except (FileNotFoundError, OSError) as e:
logger.debug("Failed to get git history: %s", e)
return []
def build_commit_url(repo_info: GitRepoInfo, commit_hash: str) -> str | None:
"""Build URL to commit on GitHub/GitLab.
Args:
repo_info: Repository information.
commit_hash: Full or short commit hash.
Returns:
URL string or None if no remote configured.
"""
if not repo_info.host or not repo_info.owner or not repo_info.repo:
return None
host = repo_info.host.lower()
if "gitlab" in host:
return f"https://{repo_info.host}/{repo_info.owner}/{repo_info.repo}/-/commit/{commit_hash}"
else:
# GitHub and others
return f"https://{repo_info.host}/{repo_info.owner}/{repo_info.repo}/commit/{commit_hash}"
def generate_changelog_content(
repo_path: Path,
max_commits: int = 30,
) -> str | None:
"""Generate changelog markdown content.
Args:
repo_path: Path to the repository.
max_commits: Maximum commits to include.
Returns:
Markdown string or None if not a git repo.
"""
commits = get_commit_history(repo_path, limit=max_commits)
if not commits:
return None
repo_info = get_repo_info(repo_path)
# Group commits by date
commits_by_date: dict[str, list[CommitInfo]] = defaultdict(list)
for commit in commits:
date_key = commit.date.strftime("%Y-%m-%d")
commits_by_date[date_key].append(commit)
# Collect unique authors
authors = set(commit.author for commit in commits)
# Build markdown
lines = [
"# Changelog",
"",
"Recent changes to this repository.",
"",
"## Recent Commits",
"",
]
# Sort dates in descending order
for date_key in sorted(commits_by_date.keys(), reverse=True):
# Format date header
date_obj = datetime.strptime(date_key, "%Y-%m-%d")
date_display = date_obj.strftime("%B %d, %Y")
lines.append(f"### {date_display}")
lines.append("")
for commit in commits_by_date[date_key]:
# Build commit line with optional link
commit_url = build_commit_url(repo_info, commit.hash)
if commit_url:
commit_ref = f"[`{commit.hash}`]({commit_url})"
else:
commit_ref = f"`{commit.hash}`"
# Truncate long messages
message = commit.message
if len(message) > COMMIT_MESSAGE_MAX_LENGTH:
message = message[:COMMIT_MESSAGE_TRUNCATED_LENGTH] + "..."
lines.append(f"- {commit_ref} {message}")
# Show changed files (limit to 5)
if commit.files:
files_to_show = commit.files[:MAX_CHANGED_FILES_PER_COMMIT]
files_str = ", ".join(f"`{f}`" for f in files_to_show)
if len(commit.files) > MAX_CHANGED_FILES_PER_COMMIT:
files_str += (
f" (+{len(commit.files) - MAX_CHANGED_FILES_PER_COMMIT} more)"
)
lines.append(f" - Files: {files_str}")
lines.append("")
# Add statistics
lines.append("## Statistics")
lines.append("")
lines.append(f"- **Commits shown**: {len(commits)}")
lines.append(f"- **Contributors**: {len(authors)}")
if commits:
latest_date = commits[0].date.strftime("%Y-%m-%d")
lines.append(f"- **Latest commit**: {latest_date}")
lines.append("")
return "\n".join(lines)
