#!/usr/bin/env python3
# file: scripts/build_android_rust.py
# version: 1

"""Build one Android Rust game entrypoint and stage it as Gradle jniLibs."""

from __future__ import annotations

import argparse
import os
import pathlib
import subprocess
import sys
import zipfile

ABI_TO_TRIPLE = {
    "arm64-v8a": "aarch64-linux-android",
    "armeabi-v7a": "armv7-linux-androideabi",
    "x86_64": "x86_64-linux-android",
    "x86": "i686-linux-android",
}
GAME_TO_MODULE = {"reflex": "game-reflex-poc", "snake": "game-snake-poc"}

def read_sdl3_aar_name(properties_path: pathlib.Path) -> str:
    """Read the configured SDL3 AAR filename."""
    for raw_line in properties_path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if line.startswith("sdl3AarName="):
            return line.split("=", 1)[1].strip()
    raise RuntimeError("sdl3AarName is missing from Android/gradle.properties")

def extract_sdl3_link_library(aar_path: pathlib.Path, abi: str, output_dir: pathlib.Path) -> pathlib.Path:
    """Extract the SDL3 shared library used only for the Rust linker search path."""
    expected = f"jni/{abi}/libSDL3.so"
    output_dir.mkdir(parents=True, exist_ok=True)
    with zipfile.ZipFile(aar_path) as archive:
        if expected not in archive.namelist():
            raise RuntimeError(f"{expected} is missing from {aar_path}")
        target = output_dir / "libSDL3.so"
        target.write_bytes(archive.read(expected))
        return target

def main() -> int:
    """Build the requested game entrypoint for one Android ABI."""
    parser = argparse.ArgumentParser()
    parser.add_argument("game", choices=sorted(GAME_TO_MODULE))
    parser.add_argument("--abi", choices=sorted(ABI_TO_TRIPLE), default="arm64-v8a")
    parser.add_argument("--release", action="store_true")
    arguments = parser.parse_args()
    root = pathlib.Path(__file__).resolve().parent.parent
    aar_name = read_sdl3_aar_name(root / "Android" / "gradle.properties")
    aar_path = root / "Android" / "libs" / aar_name
    if not aar_path.is_file():
        print(f"missing SDL3 AAR: {aar_path}", file=sys.stderr)
        return 2
    link_dir = root / "Android" / "build" / "rust-link" / arguments.abi
    try:
        extract_sdl3_link_library(aar_path, arguments.abi, link_dir)
    except (OSError, RuntimeError, zipfile.BadZipFile) as error:
        print(str(error), file=sys.stderr)
        return 2
    module = GAME_TO_MODULE[arguments.game]
    output = root / "Android" / module / "src" / "main" / "jniLibs"
    environment = os.environ.copy()
    rustflags = environment.get("RUSTFLAGS", "").strip()
    link_flag = f"-L native={link_dir}"
    environment["RUSTFLAGS"] = f"{rustflags} {link_flag}".strip()
    environment["CARGO_NDK_PLATFORM"] = "21"
    command = [
        "cargo", "ndk", "-t", arguments.abi, "-o", str(output), "build",
        "-p", "game-android-entrypoint", "--no-default-features", "--features", arguments.game,
    ]
    if arguments.release:
        command.append("--release")
    completed = subprocess.run(command, cwd=root, env=environment, check=False)
    return completed.returncode

if __name__ == "__main__":
    raise SystemExit(main())