#!/usr/bin/env python3
"""Export the API schema without depending on operator configuration or network I/O."""

from __future__ import annotations

import argparse
import asyncio
import json
import os
import tempfile
from pathlib import Path

from backup_tool.api.app import create_app
from backup_tool.config import Settings


def export_schema() -> dict[str, object]:
    """Build the FastAPI schema with disposable, valid settings."""
    with tempfile.TemporaryDirectory(prefix="backup-tool-openapi-") as temporary:
        root = Path(temporary)
        key = root / "master.key"
        key.write_bytes(b"openapi-export-key-material-must-be-at-least-32-bytes")
        key.chmod(0o600)
        for name in ("data", "repositories", "sources", "restores"):
            (root / name).mkdir()
        settings = Settings(
            data_dir=root / "data",
            database_url=f"sqlite+aiosqlite:///{root / 'data' / 'metadata.db'}",
            repository_roots=(root / "repositories",),
            local_source_roots=(root / "sources",),
            restore_roots=(root / "restores",),
            master_key_file=key,
        )
        app = create_app(settings)
        schema = app.openapi()
        # Engine construction is lazy, but dispose defensively if that changes.
        asyncio.run(app.state.engine.dispose())
        return schema


def main() -> int:
    parser = argparse.ArgumentParser(description="Export the deterministic v2 OpenAPI document.")
    parser.add_argument("--output", type=Path, default=Path("openapi/v2.json"))
    parser.add_argument("--check", type=Path, metavar="PATH", help="fail when PATH differs")
    arguments = parser.parse_args()
    output = arguments.check or arguments.output
    rendered = json.dumps(export_schema(), indent=2, sort_keys=True, ensure_ascii=False) + "\n"
    if arguments.check:
        if not output.is_file() or output.read_text(encoding="utf-8") != rendered:
            print(f"OpenAPI drift: regenerate {output}")
            return 1
        print(f"OpenAPI is current: {output}")
        return 0
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(rendered, encoding="utf-8")
    # The schema is public source, not executable configuration.
    os.chmod(output, 0o644)
    print(f"Exported OpenAPI: {output}")
    return 0


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