Files
manual_slop/src/diff_viewer.py
Ed_ 125cbc6dd0 feat(patch): Add patch application and backup functions
- Add create_backup() to backup files before patching
- Add apply_patch_to_file() to apply unified diff
- Add restore_from_backup() for rollback
- Add cleanup_backup() to remove backup files
- Add 15 unit tests for all patch operations
2026-03-07 00:14:23 -05:00

220 lines
6.1 KiB
Python

from typing import List, Dict, Optional, Tuple
from dataclasses import dataclass
import shutil
import os
from pathlib import Path
@dataclass
class DiffHunk:
header: str
lines: List[str]
old_start: int
old_count: int
new_start: int
new_count: int
@dataclass
class DiffFile:
old_path: str
new_path: str
hunks: List[DiffHunk]
def parse_diff_header(line: str) -> tuple[Optional[str], Optional[str], Optional[tuple[int, int, int, int]]]:
if not line.startswith(("--- ", "+++ ")):
return None, None, None
if line.startswith("--- "):
path = line[4:]
if path.startswith("a/"):
path = path[2:]
return path, None, None
elif line.startswith("+++ "):
path = line[4:]
if path.startswith("b/"):
path = path[2:]
return None, path, None
return None, None, None
def parse_hunk_header(line: str) -> Optional[tuple[int, int, int, int]]:
if not line.startswith("@@"):
return None
parts = line.split()
if len(parts) < 2:
return None
old_part = parts[1][1:]
new_part = parts[2][1:]
old_parts = old_part.split(",")
new_parts = new_part.split(",")
old_start = int(old_parts[0])
old_count = int(old_parts[1]) if len(old_parts) > 1 else 1
new_start = int(new_parts[0])
new_count = int(new_parts[1]) if len(new_parts) > 1 else 1
return (old_start, old_count, new_start, new_count)
def parse_diff(diff_text: str) -> List[DiffFile]:
if not diff_text or not diff_text.strip():
return []
files: List[DiffFile] = []
current_file: Optional[DiffFile] = None
current_hunk: Optional[DiffHunk] = None
for line in diff_text.split("\n"):
if line.startswith("--- "):
if current_file:
if current_hunk:
current_file.hunks.append(current_hunk)
current_hunk = None
files.append(current_file)
path = line[4:]
if path.startswith("a/"):
path = path[2:]
current_file = DiffFile(old_path=path, new_path="", hunks=[])
elif line.startswith("+++ ") and current_file:
path = line[4:]
if path.startswith("b/"):
path = path[2:]
current_file.new_path = path
elif line.startswith("@@") and current_file:
if current_hunk:
current_file.hunks.append(current_hunk)
hunk_info = parse_hunk_header(line)
if hunk_info:
old_start, old_count, new_start, new_count = hunk_info
current_hunk = DiffHunk(
header=line,
lines=[],
old_start=old_start,
old_count=old_count,
new_start=new_start,
new_count=new_count
)
else:
current_hunk = DiffHunk(
header=line,
lines=[],
old_start=0,
old_count=0,
new_start=0,
new_count=0
)
elif current_hunk is not None:
current_hunk.lines.append(line)
elif line and not line.startswith("diff ") and not line.startswith("index "):
pass
if current_file:
if current_hunk:
current_file.hunks.append(current_hunk)
files.append(current_file)
return files
def format_diff_for_display(diff_files: List[DiffFile]) -> str:
output = []
for df in diff_files:
output.append(f"File: {df.old_path}")
for hunk in df.hunks:
output.append(f" {hunk.header}")
for line in hunk.lines:
output.append(f" {line}")
return "\n".join(output)
def get_line_color(line: str) -> Optional[str]:
if line.startswith("+"):
return "green"
elif line.startswith("-"):
return "red"
elif line.startswith("@@"):
return "cyan"
return None
def render_diff_text_immediate(diff_files: List[DiffFile]) -> List[tuple[str, Optional[str]]]:
output: List[tuple[str, Optional[str]]] = []
for df in diff_files:
output.append((f"File: {df.old_path}", "white"))
for hunk in df.hunks:
output.append((hunk.header, "cyan"))
for line in hunk.lines:
color = get_line_color(line)
output.append((line, color))
return output
def create_backup(file_path: str) -> Optional[str]:
path = Path(file_path)
if not path.exists():
return None
backup_path = path.with_suffix(path.suffix + ".backup")
shutil.copy2(path, backup_path)
return str(backup_path)
def apply_patch_to_file(patch_text: str, base_dir: str = ".") -> Tuple[bool, str]:
import difflib
diff_files = parse_diff(patch_text)
if not diff_files:
return False, "No valid diff found"
results = []
for df in diff_files:
file_path = Path(base_dir) / df.old_path
if not file_path.exists():
results.append(f"File not found: {file_path}")
continue
try:
with open(file_path, "r", encoding="utf-8") as f:
original_lines = f.read().splitlines(keepends=True)
new_lines = original_lines.copy()
offset = 0
for hunk in df.hunks:
hunk_old_start = hunk.old_start - 1
hunk_old_count = hunk.old_count
replace_start = hunk_old_start + offset
replace_count = hunk_old_count
hunk_new_content: List[str] = []
for line in hunk.lines:
if line.startswith("+") and not line.startswith("+++"):
hunk_new_content.append(line[1:] + "\n")
elif line.startswith(" ") or (line and not line.startswith(("-", "+", "@@"))):
hunk_new_content.append(line + "\n")
new_lines = new_lines[:replace_start] + hunk_new_content + new_lines[replace_start + replace_count:]
offset += len(hunk_new_content) - replace_count
with open(file_path, "w", encoding="utf-8", newline="") as f:
f.writelines(new_lines)
results.append(f"Patched: {file_path}")
except Exception as e:
return False, f"Error patching {file_path}: {e}"
return True, "\n".join(results)
def restore_from_backup(file_path: str) -> bool:
backup_path = Path(str(file_path) + ".backup")
if not backup_path.exists():
return False
shutil.copy2(backup_path, file_path)
return True
def cleanup_backup(file_path: str) -> None:
backup_path = Path(str(file_path) + ".backup")
if backup_path.exists():
backup_path.unlink()