android build: add own logic to calculate versionCode

Use our own logic to go from ELECTRUM_VERSION to numeric android versionCode,
instead of using the default conversion done by python-for-android.

Even before this, we were already patching p4a to modify their logic (see [0]).
This commit changes that logic again, and moves it into a separate script in our repo.
- calculation change is due to the f-droid maintainers asking for the
  arch code to be in the least significant digits (instead of most sig digits) (see [1])

I have pushed and changed to a new p4a branch, which is just a copy of the previous one
with 3 commits related to versionCode calc squashed.

[0]: SomberNight/python-for-android@edb7e4f
[1]: #9210 (comment)

contrib/android/Dockerfile

@@ -197,8 +197,8 @@ RUN cd /opt \
     && git remote add sombernight https://github.com/SomberNight/python-for-android \
     && git remote add accumulator https://github.com/accumulator/python-for-android \
     && git fetch --all \
-    # commit: from branch sombernight/qt6-wip (note: careful with force-pushing! see #8162) \
-    && git checkout "58d21ad89b6182c0d70289d647eb85eaa412412c^{commit}" \
+    # commit: from branch sombernight/electrum_20240930 (note: careful with force-pushing! see #8162) \
+    && git checkout "7197c1c28409fbeebd8494093349a2bfd770526a^{commit}" \
     && /opt/venv/bin/python3 -m pip install --no-build-isolation --no-dependencies -e .
 
 # build env vars

contrib/android/get_apk_versioncode.py

@@ -0,0 +1,61 @@
+#!/usr/bin/python3
+
+import importlib.util
+import os
+import sys
+
+ARCH_DICT = {
+    "x86_64": "4",
+    "arm64-v8a": "3",
+    "armeabi-v7a": "2",
+    "x86": "1",
+}
+
+
+def get_electrum_version() -> str:
+    project_root = os.path.abspath(os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
+    version_file_path = os.path.join(project_root, "electrum", "version.py")
+    # load version.py; needlessly complicated alternative to "imp.load_source":
+    version_spec = importlib.util.spec_from_file_location('version', version_file_path)
+    version_module = version = importlib.util.module_from_spec(version_spec)
+    version_spec.loader.exec_module(version_module)
+    return version.ELECTRUM_VERSION
+
+
+def get_android_versioncode(*, arch_name: str) -> int:
+    version_code = 0
+    # add ELECTRUM_VERSION
+    app_version = get_electrum_version()
+    app_version_components = app_version.split('.')
+    assert len(app_version_components) == 3, f"version str expected to have 3 components, but got {app_version!r}"
+    for i in app_version_components:
+        version_code *= 100
+        version_code += int(i)
+    # add arch
+    arch_code = ARCH_DICT[arch_name]
+    assert len(arch_code) == 1
+    version_code *= 10
+    version_code += int(arch_code)
+    # compensate for legacy scheme
+    # note: up until version 4.5.5, we used a different scheme for version_code.
+    #       4_______________4_05_05_00
+    #       ^ android arch, ^ app_version (4.5.5.0)
+    # This offset ensures that all new-scheme version codes are larger than the old-scheme version codes.
+    offset_due_to_legacy_scheme = 45_000_000
+    version_code += offset_due_to_legacy_scheme
+    return version_code
+
+
+if __name__ == '__main__':
+    try:
+        android_arch = sys.argv[1]
+    except Exception:
+        print(f"usage: {os.path.basename(__file__)} <android_arch>", file=sys.stderr)
+        sys.exit(1)
+    if android_arch not in ARCH_DICT:
+        print(f"usage: {os.path.basename(__file__)} <android_arch>", file=sys.stderr)
+        print(f"error: unknown {android_arch=}", file=sys.stderr)
+        print(f"       should be one of: {list(ARCH_DICT.keys())}", file=sys.stderr)
+        sys.exit(1)
+    version_code = get_android_versioncode(arch_name=android_arch)
+    print(version_code, file=sys.stdout)

contrib/android/make_apk.sh

@@ -91,15 +91,17 @@ if [[ "$2" == "all" ]] ; then
     # build all apks
     # FIXME failures are not propagated out: we should fail the script if any arch build fails
     export APP_ANDROID_ARCHS=armeabi-v7a
+    export APP_ANDROID_NUMERIC_VERSION=$("$CONTRIB_ANDROID"/get_apk_versioncode.py "$APP_ANDROID_ARCHS")
     make $TARGET
     export APP_ANDROID_ARCHS=arm64-v8a
+    export APP_ANDROID_NUMERIC_VERSION=$("$CONTRIB_ANDROID"/get_apk_versioncode.py "$APP_ANDROID_ARCHS")
     make $TARGET
-    #export APP_ANDROID_ARCHS=x86
-    #make $TARGET
     export APP_ANDROID_ARCHS=x86_64
+    export APP_ANDROID_NUMERIC_VERSION=$("$CONTRIB_ANDROID"/get_apk_versioncode.py "$APP_ANDROID_ARCHS")
     make $TARGET
 else
     export APP_ANDROID_ARCHS=$2
+    export APP_ANDROID_NUMERIC_VERSION=$("$CONTRIB_ANDROID"/get_apk_versioncode.py "$APP_ANDROID_ARCHS")
     make $TARGET
 fi