TOOLS: add an interface-changes generator script

Convenience script to automatically generate interface-changes.rst based
on the workflow introduced in the previous commit.

TOOLS/gen-interface-changes.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+
+# Generate a new interface-changes.rst based on the entries in
+# the interface-changes directory.
+
+#
+# This file is part of mpv.
+#
+# mpv is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# mpv is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import pathlib
+import sys
+from shutil import which
+from subprocess import check_output
+
+def add_new_entries(docs_dir, out, git):
+    changes_dir = pathlib.Path(docs_dir) / "interface-changes"
+    files = []
+    for f in pathlib.Path(changes_dir).glob("*.txt"):
+        if f.is_file() and not f.name == "example.txt":
+            timestamp = check_output([git, "log", "--format=%ct", "-n", "1", "--",
+                                      f], encoding="UTF-8")
+            if timestamp:
+                files.append((f, timestamp))
+            else:
+                print(f"Skipping file not tracked by git: {f.name}")
+
+    files.sort(key=lambda x: x[1])
+    for file in files:
+        with open(file[0].resolve(), "r") as f:
+            for line in f:
+               line =  "    - " + line.rstrip()
+               out.write(line + "\n")
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        print(f"Usage: {sys.argv[0]} <version>")
+        sys.exit(1)
+
+    git = which('git')
+    if not git:
+        print("Unable to find git binary")
+        sys.exit(1)
+
+    # Accept passing only the major version number and the full 0 version.
+    major_version = -1
+    if sys.argv[1].isdigit():
+        major_version = sys.argv[1]
+    else:
+        ver_split = sys.argv[1].split(".")
+        if len(ver_split) == 3 and ver_split[1].isdigit():
+            major_version = ver_split[1]
+
+    if major_version == -1:
+        print(f"Invalid version number: {sys.argv[1]}")
+        sys.exit(1)
+
+    docs_dir = pathlib.Path(sys.argv[0]).resolve().parents[1] / "DOCS"
+    interface_changes = docs_dir / "interface-changes.rst"
+    with open(interface_changes, "r") as f:
+        lines = [line.rstrip() for line in f]
+
+    ver_line = " --- mpv 0." + major_version + ".0 ---"
+    next_ver_line = " --- mpv 0." + str(int(major_version) + 1) + ".0 ---"
+    with open(interface_changes, "w", newline="\n") as f:
+        for line in lines:
+            if line == ver_line:
+                f.write(next_ver_line + "\n")
+            f.write(line + "\n")
+            if line == ver_line:
+                add_new_entries(docs_dir, f, git)