#!/usr/bin/env python3
from __future__ import annotations

import filecmp
import json
import os
import shutil
import subprocess
import sys
import tempfile
from pathlib import Path


REPO_ROOT = Path(__file__).resolve().parent.parent
DEFAULT_BINARY = REPO_ROOT / "build" / "m2pack"
ENV_BINARY = "M2PACK_BINARY"


def resolve_binary() -> Path:
    env_value = os.environ.get(ENV_BINARY)
    if env_value:
        candidate = Path(env_value).expanduser()
        if candidate.is_file():
            return candidate

    if DEFAULT_BINARY.is_file():
        return DEFAULT_BINARY

    raise FileNotFoundError(
        f"m2pack binary not found. Build {DEFAULT_BINARY} or set {ENV_BINARY}."
    )


def run_json(binary: Path, *args: str) -> dict:
    proc = subprocess.run(
        [str(binary), *args, "--json"],
        cwd=REPO_ROOT,
        text=True,
        capture_output=True,
        check=False,
    )
    if proc.returncode != 0:
        detail = proc.stderr.strip() or proc.stdout.strip() or f"exit code {proc.returncode}"
        raise RuntimeError(f"command failed: {' '.join(args)}\n{detail}")

    stdout = proc.stdout.strip()
    if not stdout:
        return {"ok": True}
    return json.loads(stdout)


def write_asset_tree(root: Path) -> None:
    (root / "locale" / "de").mkdir(parents=True, exist_ok=True)
    (root / "icon").mkdir(parents=True, exist_ok=True)
    (root / "ui").mkdir(parents=True, exist_ok=True)

    (root / "locale" / "de" / "welcome.txt").write_text(
        "metin2 secure pack test\n",
        encoding="utf-8",
    )
    (root / "ui" / "layout.json").write_text(
        json.dumps(
            {
                "window": "inventory",
                "slots": 90,
                "theme": "headless-e2e",
            },
            indent=2,
        )
        + "\n",
        encoding="utf-8",
    )
    (root / "icon" / "item.bin").write_bytes(bytes((i * 13) % 256 for i in range(2048)))


def compare_trees(left: Path, right: Path) -> None:
    comparison = filecmp.dircmp(left, right)
    if comparison.left_only or comparison.right_only or comparison.diff_files or comparison.funny_files:
        raise RuntimeError(
            "tree mismatch: "
            f"left_only={comparison.left_only}, "
            f"right_only={comparison.right_only}, "
            f"diff_files={comparison.diff_files}, "
            f"funny_files={comparison.funny_files}"
        )

    for child in comparison.common_dirs:
        compare_trees(left / child, right / child)


def main() -> int:
    binary = resolve_binary()

    with tempfile.TemporaryDirectory(prefix="m2pack-headless-") as tmp_dir:
        tmp = Path(tmp_dir)
        assets = tmp / "assets"
        keys = tmp / "keys"
        out_dir = tmp / "out"
        extracted = tmp / "extracted"
        client_header = tmp / "M2PackKeys.h"
        runtime_json = tmp / "runtime-key.json"
        runtime_blob = tmp / "runtime-key.bin"
        archive = out_dir / "client.m2p"

        assets.mkdir(parents=True, exist_ok=True)
        out_dir.mkdir(parents=True, exist_ok=True)
        write_asset_tree(assets)

        keygen = run_json(binary, "keygen", "--out-dir", str(keys))
        build = run_json(
            binary,
            "build",
            "--input",
            str(assets),
            "--output",
            str(archive),
            "--key",
            str(keys / "master.key"),
            "--sign-secret-key",
            str(keys / "signing.key"),
            "--key-id",
            "7",
        )
        listed = run_json(binary, "list", "--archive", str(archive))
        verify = run_json(
            binary,
            "verify",
            "--archive",
            str(archive),
            "--public-key",
            str(keys / "signing.pub"),
            "--key",
            str(keys / "master.key"),
        )
        diff = run_json(
            binary,
            "diff",
            "--left",
            str(assets),
            "--right",
            str(archive),
        )
        export_client = run_json(
            binary,
            "export-client-config",
            "--key",
            str(keys / "master.key"),
            "--public-key",
            str(keys / "signing.pub"),
            "--key-id",
            "7",
            "--output",
            str(client_header),
        )
        export_runtime_json = run_json(
            binary,
            "export-runtime-key",
            "--key",
            str(keys / "master.key"),
            "--public-key",
            str(keys / "signing.pub"),
            "--key-id",
            "7",
            "--format",
            "json",
            "--output",
            str(runtime_json),
        )
        export_runtime_blob = run_json(
            binary,
            "export-runtime-key",
            "--key",
            str(keys / "master.key"),
            "--public-key",
            str(keys / "signing.pub"),
            "--key-id",
            "7",
            "--format",
            "blob",
            "--output",
            str(runtime_blob),
        )
        extract = run_json(
            binary,
            "extract",
            "--archive",
            str(archive),
            "--output",
            str(extracted),
            "--key",
            str(keys / "master.key"),
        )

        compare_trees(assets, extracted)

        runtime_obj = json.loads(runtime_json.read_text(encoding="utf-8"))
        if runtime_obj["key_id"] != 7 or runtime_obj["mapping_name"] != "Local\\M2PackSharedKeys":
            raise RuntimeError("runtime json payload mismatch")

        if runtime_blob.stat().st_size != 84:
            raise RuntimeError(f"runtime blob size mismatch: {runtime_blob.stat().st_size}")

        header_text = client_header.read_text(encoding="utf-8")
        if "M2PACK_RUNTIME_MASTER_KEY_REQUIRED = true" not in header_text:
            raise RuntimeError("client header missing runtime enforcement flag")
        if "M2PACK_SIGN_KEY_IDS = { 7 }" not in header_text:
            raise RuntimeError("client header missing key id slot")

        summary = {
            "ok": True,
            "binary": str(binary),
            "file_count": build["file_count"],
            "listed_entries": len(listed["entries"]),
            "verify_ok": verify["ok"],
            "diff_changed": len(diff["changed"]),
            "diff_added": len(diff["added"]),
            "diff_removed": len(diff["removed"]),
            "extract_entry_count": extract["entry_count"],
            "runtime_key_id": runtime_obj["key_id"],
            "runtime_blob_size": runtime_blob.stat().st_size,
            "artifacts_root": str(tmp),
            "steps": {
                "keygen": keygen["ok"],
                "build": build["ok"],
                "list": listed["ok"],
                "verify": verify["ok"],
                "diff": diff["ok"],
                "export_client_config": export_client["ok"],
                "export_runtime_json": export_runtime_json["ok"],
                "export_runtime_blob": export_runtime_blob["ok"],
                "extract": extract["ok"],
            },
        }
        print(json.dumps(summary, indent=2))
    return 0


if __name__ == "__main__":
    try:
        raise SystemExit(main())
    except Exception as exc:
        print(str(exc), file=sys.stderr)
        raise SystemExit(1)