#!/usr/bin/env python3
"""Build the combined tree in VFHost, verify DWARF/module output, and smoke the owner world."""
from __future__ import annotations

import importlib.util
import argparse
import json
import os
from pathlib import Path
import re
import sys


ROOT = Path(__file__).resolve().parents[4]
SAVED = ROOT / "Saved/Linux/l173"
RUNNER_PATH = ROOT / "Standalone/Research/WorldAssemblerM3/Linux172/RunL172Movement.py"


def load_l172_runner():
    spec = importlib.util.spec_from_file_location("l172_runner", RUNNER_PATH)
    if spec is None or spec.loader is None:
        raise RuntimeError(f"could not load L172 harness: {RUNNER_PATH}")
    module = importlib.util.module_from_spec(spec)
    sys.modules[spec.name] = module
    spec.loader.exec_module(module)
    module.ROOT = ROOT
    module.OUT = SAVED
    module.UE_OUT = SAVED / "ue"
    module.BUILD_OUT = SAVED / "ue/builds"
    module.BIN_OUT = SAVED / "ue/bin"
    return module


def write_json(path: Path, value) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    temporary = path.with_suffix(path.suffix + ".tmp")
    temporary.write_text(json.dumps(value, indent=2, sort_keys=True) + "\n",
                         encoding="utf-8")
    temporary.replace(path)


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--reuse-prior-build", action="store_true",
                        help="verify the successful full build already logged in Saved/Linux/l173")
    options = parser.parse_args()
    SAVED.mkdir(parents=True, exist_ok=True)
    runner = load_l172_runner()
    result = {"plugin_root": str(ROOT.resolve())}
    try:
        build_log = SAVED / "ue/builds/ubt-l173-combined.log"
        if options.reuse_prior_build:
            if not build_log.is_file():
                raise RuntimeError(f"prior full build log is missing: {build_log}")
            restored = json.loads((SAVED / "ue/restored-main-links.json").read_text(
                encoding="utf-8"))
            archive_roots = set()
            for item in restored.get("intermediates_moved", []):
                moved = Path(item["to"])
                if moved.name == "VoxelForge" and "External" in moved.parts:
                    external_index = moved.parts.index("External")
                    archive_roots.add(Path(*moved.parts[:external_index]))
            archive_roots = [path for path in archive_roots
                             if (path / "External/Build/Linux/x64/UnrealEditor/Development/"
                                 "VoxelForge/VoxelWorld.cpp.o").is_file()]
            if len(archive_roots) != 1:
                raise RuntimeError(f"expected one archived combined-tree intermediate set: "
                                   f"{archive_roots}")
            runner.INTERMEDIATE = archive_roots[0]
            dwarf = runner.dwarf_pre_run_gate()
            runner.INTERMEDIATE = runner.HOST / "Intermediate"
            build = {
                **runner.root_info(ROOT),
                "build_log": str(build_log),
                "compiled_voxel_world_cpp": True,
                "dwarf_pre_run_gate": dwarf,
                "binary": str(SAVED / "ue/bin/l173-combined/"
                              "libUnrealEditor-VoxelForge.so"),
                "binary_sha256": runner.sha256_file(
                    SAVED / "ue/bin/l173-combined/libUnrealEditor-VoxelForge.so"),
                "reused_prior_full_build": True,
            }
        else:
            build = runner.build_tree(ROOT, "l173-combined")
        output = build_log.read_text(encoding="utf-8", errors="replace")
        if ("Result: Succeeded" not in output
                or re.search(r"\[\d+/\d+\] Compile VoxelWorld\.cpp", output) is None):
            raise RuntimeError(f"UE build log lacks a successful VoxelWorld.cpp compile: {build_log}")
        actor_compiled = re.search(r"Compile .*VoxelForgeLivingPlaneActor\.cpp", output) is not None
        module_binary = (runner.HOST / "Binaries/Linux/"
                         "libUnrealEditor-VoxelForgeLivingPlane.so")
        if not actor_compiled or not module_binary.is_file():
            raise RuntimeError(
                "UE build did not compile/link the Living Plane module: "
                f"actor_compiled={actor_compiled}, module_binary={module_binary.is_file()}; "
                f"log={build_log}")
        build["living_plane_actor_compiled"] = actor_compiled
        build["living_plane_module_binary"] = str(module_binary.resolve())
        result["build"] = build
        write_json(SAVED / "ue/build.json", result)

        shader_link = runner.HOST_PLUGIN_LINK / "Shaders"
        if shader_link.exists() or shader_link.is_symlink():
            if shader_link.resolve(strict=True) != (ROOT / "Shaders").resolve(strict=True):
                raise RuntimeError(f"unexpected existing shader link target: {shader_link}")
            created_shader_link = False
        else:
            temporary = shader_link.with_name(f"Shaders.l173-{os.getpid()}.tmp")
            temporary.symlink_to(ROOT / "Shaders")
            os.replace(temporary, shader_link)
            created_shader_link = True

        smoke = runner.run_trial(
            "owner-world-smoke", "owner-world-smoke", "default-on", ROOT,
            Path(build["binary"]), runner.WAIT_ON, runner.APPLY_ON_MS,
            include_switch_overrides=False)
        write_json(SAVED / "ue/owner-world-smoke.json", smoke)
        result["smoke"] = smoke
        write_json(SAVED / "ue/result.json", result)
        print("[L173UE] BUILD PASS VoxelWorld.cpp=compiled "
              "VoxelForgeLivingPlane=linked DWARF=PASS", flush=True)
        print("[L173UE] OWNER_WORLD_SMOKE PASS "
              + json.dumps({key: smoke[key] for key in (
                  "frame_resolution_arrival_s", "tick_p99_ms", "tick_worst_ms",
                  "early_admission_wait_for_critical", "early_admission_apply_budget_ms")},
                  sort_keys=True), flush=True)
        return 0
    finally:
        restored = runner.restore_main_checkout()
        shader_link = runner.HOST_PLUGIN_LINK / "Shaders"
        if locals().get("created_shader_link", False):
            shader_link.unlink(missing_ok=True)
        write_json(SAVED / "ue/restored-main-links.json", {
            "main_root": str(runner.MAIN_CHECKOUT.resolve()),
            "links": restored["links"],
            "intermediates_moved": restored["intermediates_moved"],
        })


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