add python-programming/git_commit_simulator.py

Extend .gitignore for Python

python-programming/git_commit_simulator.py

@@ -0,0 +1,103 @@
+#!/usr/bin/python3
+
+from datetime import datetime
+from difflib import unified_diff
+from typing import List, Union
+import random
+import string
+
+FAKE_HASH_ALPHABET = string.digits + string.ascii_lowercase[:6]
+
+def diff_strings(old: str, new: str) -> str:
+    old += "\n" if old else ""
+    new += "\n" if new else ""
+    return "".join(list(unified_diff(old.splitlines(keepends=True),
+                                     new.splitlines(keepends=True)))[2:])[:-1]
+
+def fake_hash(length: int) -> str:
+    return "".join([random.choice(FAKE_HASH_ALPHABET) for i in range(length)])
+
+def styled_date(dt: datetime = None) -> str:
+    if not dt:
+        dt = datetime.now()
+
+    # res = datetime.strftime(dt, "%a %b %d %H:%M:%S %Y")
+    res = dt.ctime()
+
+    offset = dt.astimezone().utcoffset().seconds
+    positive = offset >= 0
+    hours, minutes = offset // 3600, offset % 3600
+    hours, minutes = str(hours).zfill(2), str(minutes).zfill(2)
+    sign = "+" if positive else "-"
+    res += " " + sign + hours + minutes
+    return res
+
+def commit(*, commit_message: Union[List[str], str], branch_name: str = "main",
+           old_content: str = None, new_content: str, file: str, name: str,
+           email: str, mode: str = "100644", dt: datetime = None) -> str:
+    if isinstance(commit_message, str):
+        commit_message = [commit_message + "\n"]
+    commit_message = [" " * 4 + line if line else "" for line in commit_message]
+    if len(commit_message) > 1:
+        commit_message.insert(1, "")
+    commit_message = "\n".join(commit_message)
+
+    new_file = False
+    if old_content is None:
+        new_file = True
+        old_content = ""
+
+    first_file = "/dev/null" if new_file else file
+    second_file = "b/" + file
+
+    first_hash = "0" * 7 if new_file else fake_hash(7)
+
+    index_mode_lines = f"index {first_hash}..{fake_hash(7)}"
+    if new_file:
+        index_mode_lines = f"""\
+new file mode {mode}
+{index_mode_lines}"""
+    else:
+        index_mode_lines += f" {mode}"
+
+    diff = diff_strings(old_content, new_content)
+
+    return f"""\
+commit {fake_hash(40)} (HEAD -> {branch_name})
+Author: {name} <{email}>
+Date:   {styled_date(dt)}
+
+{commit_message}
+
+diff --git {"a/" + file} {second_file}
+{index_mode_lines}
+--- {first_file}
++++ {second_file}
+{diff}"""
+
+example = lambda: commit( \
+    commit_message=["Hello, world!", "Greetings :-)", "Lorem ipsum"], \
+    # old_content="henlo", \
+    new_content="hello", \
+    file="message.txt", \
+    name="Intel A80486DX2-66", \
+    email="larry.holst@disroot.org")
+
+if __name__ == "__main__":
+    from sys import argv
+
+    if "--example" in argv:
+        print("Example output:")
+        print(example())
+        raise SystemExit
+
+    print("This script is not interactive. Please run Python 3 interpreter,\n"
+          "import this file, and use function git_commit_simulator.commit()")
+    print()
+    print("""Function prototype:
+def commit(*, commit_message: Union[List[str], str], branch_name: str = "main",
+           old_content: str = None, new_content: str, file: str, name: str,
+           email: str, mode: str = "100644", dt: datetime = None) -> str:""")
+    print()
+    print("Run with --example to get an example output")
+