From 721ad64a61412daae3737e5b4e44619dc3d2ff2b Mon Sep 17 00:00:00 2001
From: Helena Rasche <hxr@hx42.org>
Date: Tue, 22 Sep 2020 11:59:19 +0200
Subject: [PATCH] improvements

---
 scripts/release-diff.py | 152 ++++++++++++++++++++--------------------
 1 file changed, 75 insertions(+), 77 deletions(-)

diff --git a/scripts/release-diff.py b/scripts/release-diff.py
index 353156d771c..ba064177b80 100644
--- a/scripts/release-diff.py
+++ b/scripts/release-diff.py
@@ -1,12 +1,12 @@
 #!/usr/bin/env python
 import subprocess
+import argparse
 import sys
 from pathlib import Path
 import glob
 import yaml
 from yaml import SafeLoader
 
-old_version = sys.argv[1]
 
 def flatten(d, path):
     """
@@ -58,90 +58,88 @@ def diff_files(old, new):
     return added, removed, changed
 
 
-
-files_to_diff = glob.glob('config/*.yml.sample')
-added = {}
-removed = {}
-changed = {}
-new_files = []
-
-for file in files_to_diff:
-    real_path = Path(file).resolve().relative_to(Path.cwd())
-    try:
-        contents = subprocess.check_output(['git', 'show', f'{old_version}:{real_path}'], stderr=subprocess.STDOUT)
-        old = yaml.load(contents, Loader=MockOrderedLoader)
-        with open(real_path, 'r') as handle:
-            new = yaml.load(handle, Loader=MockOrderedLoader)
-
-        (a, r, c) = diff_files(old, new)
-        if a:
-            added[file] = a
-
-        if r:
-            removed[file] = r
-
-        if c:
-            changed[file] = c
-
-    except subprocess.CalledProcessError:
-        new_files.append(file)
-
-# Print out report
-if added or changed or removed:
-    print("Configuration Changes")
-    print("=====================")
+def _report_dict(title, subheading, data, mapper):
+    print(title)
+    print("-" * len(title))
     print()
-
-if added:
-    print("Added")
-    print("-----")
+    print(subheading)
     print()
-    print("The following configuration options are new")
-    print()
-    for fn in added:
+    for fn in data:
         print(fn)
         print('~' * len(fn))
         print()
-        for k in added[fn]:
-            print(f"-  {k}")
+        for k in data[fn]:
+            print(mapper(k))
         print()
     print()
 
-if changed:
-    print("Changed")
-    print("-------")
-    print()
-    print("The following configuration options have been changed")
-    print()
-    for fn in changed:
-        print(fn)
-        print('~' * len(fn))
-        print()
-        for (k, o, n) in changed[fn]:
-            print(f"-  {k} has changed from ``{o}`` to ``{n}``")
-        print()
-    print()
 
-if removed:
-    print("Removed")
-    print("-------")
-    print()
-    print("The following configuration options have been completely removed")
-    print()
-    for fn in removed:
-        print(fn)
-        print('~' * len(fn))
+def report_diff(added, changed, removed, new_files):
+    # Print out report
+    if added or changed or removed:
+        print("Configuration Changes")
+        print("=====================")
         print()
-        for k in removed[fn]:
-            print(f"-  {k}")
-        print()
-    print()
 
-if new_files:
-    print("New Configuration Files")
-    print("-----------------------")
-    print()
-    print(f"The following files are new, or recently converted to yaml since the {old_version}")
-    print()
-    for k in new_files:
-        print(f"-  ``{k}``")
+    if added:
+        _report_dict("Added", "The following configuration options are new", added, lambda x: f'-  {x}')
+
+    if changed:
+        _report_dict("Changed", "The following configuration options have been changed", changed, lambda x: f'-  {x[0]} has changed from ``{x[1]}`` to ``{x[2]}``')
+
+    if removed:
+        _report_dict("Removed", "The following configuration options have been completely removed", removed, lambda x: f'-  {x}')
+
+    if new_files:
+        print("New Configuration Files")
+        print("-----------------------")
+        print()
+        print(f"The following files are new, or recently converted to yaml")
+        print()
+        for k in new_files:
+            print(f"-  ``{k}``")
+
+
+def load_at_time(path, revision=None):
+    if revision is not None:
+        return subprocess.check_output(['git', 'show', f'{revision}:{path}'], stderr=subprocess.STDOUT)
+    else:
+        with open(path, 'r') as handle:
+            return handle.read()
+
+
+def main(old_revision, new_revision=None):
+    files_to_diff = glob.glob('config/*.yml.sample')
+    added = {}
+    removed = {}
+    changed = {}
+    new_files = []
+
+    for file in files_to_diff:
+        real_path = Path(file).resolve().relative_to(Path.cwd())
+        try:
+            old_contents = yaml.load(load_at_time(real_path, old_revision), Loader=MockOrderedLoader)
+            new_contents = yaml.load(load_at_time(real_path, new_revision), Loader=MockOrderedLoader)
+
+            (a, r, c) = diff_files(old_contents, new_contents)
+            if a:
+                added[file] = a
+
+            if r:
+                removed[file] = r
+
+            if c:
+                changed[file] = c
+
+        except subprocess.CalledProcessError:
+            new_files.append(file)
+
+    report_diff(added, removed, changed, new_files)
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='Diff yaml configuration files between two points in time.')
+    parser.add_argument("old_revision", help="Old revision")
+    parser.add_argument("--new_revision", help="New revision (defaults to whatever is currently in tree)")
+    args = parser.parse_args()
+    main(args.old_revision, args.new_revision)