#!/usr/bin/env python3
"""Build the private X4 adapter through a versioned Linux build artifact.

Input SDK bytes must already satisfy sdk-lock.json. No network, dependency
installation, SDK execution, device access or mutation of system directories.
"""

import argparse
import hashlib
import json
import os
import platform
import shutil
import subprocess
import tempfile
from pathlib import Path

from fetch_sdk import LOCK, ROOT, inspect_elf, verify


def build(sdk, destination):
    if platform.system() != "Linux" or platform.machine() != "x86_64":
        raise RuntimeError("Native compilation requires Linux x86_64 and the declared compiler")
    lock = json.loads(LOCK.read_text())
    verify(sdk, lock)
    if destination.exists():
        raise ValueError("Do not replace a previously built adapter")
    destination.parent.mkdir(parents=True, exist_ok=True)
    stage = Path(tempfile.mkdtemp(prefix=".native-", dir=destination.parent))
    env = {"PATH": "/usr/bin:/bin", "LANG": "C.UTF-8", "SOURCE_DATE_EPOCH": "1788825600"}
    try:
        target = stage / "libmissioncore_x4.so"
        subprocess.run(
            [
                "/usr/bin/g++",
                "-std=c++17",
                "-O2",
                "-Wall",
                "-Wextra",
                "-Werror",
                "-fPIC",
                "-fvisibility=hidden",
                "-shared",
                "-pthread",
                "-ffile-prefix-map=" + str(ROOT) + "=/source/insta360-x4",
                "-I",
                str(sdk / "include"),
                str(ROOT / "native/bridge.cpp"),
                "-L",
                str(sdk / "lib"),
                "-Wl,-z,defs,-z,relro,-z,now",
                "-Wl,-rpath,$ORIGIN",
                "-lCameraSDK",
                "-o",
                str(target),
            ],
            env=env,
            check=True,
            timeout=120,
        )
        elf = inspect_elf(target)
        if "libCameraSDK.so" not in elf["needed"]:
            raise ValueError("Built adapter does not depend on the admitted SDK")
        report = {
            "schema": "missioncore.insta360.native-build/v1",
            "abi": 1,
            "sdk_lock_sha256": hashlib.sha256(LOCK.read_bytes()).hexdigest(),
            "source": {
                p.name: hashlib.sha256(p.read_bytes()).hexdigest()
                for p in sorted((ROOT / "native").glob("*"))
                if p.is_file()
            },
            "compiler": subprocess.check_output(
                ["/usr/bin/g++", "--version"], env=env, text=True
            ).splitlines()[0],
            "binary": {
                "name": target.name,
                "bytes": target.stat().st_size,
                "sha256": hashlib.sha256(target.read_bytes()).hexdigest(),
            },
            "elf": elf,
            "sdk_executed": False,
            "hardware_tested": False,
        }
        target.chmod(0o644)
        (stage / "provenance.json").write_text(json.dumps(report, indent=2) + "\n")
        os.rename(stage, destination)
        return report
    finally:
        if stage.exists():
            shutil.rmtree(stage)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--sdk", type=Path, default=ROOT / "build/sdk")
    parser.add_argument("--output", type=Path, default=ROOT / "build/native")
    args = parser.parse_args()
    print(json.dumps(build(args.sdk.resolve(), args.output.resolve()), indent=2))