#!/usr/bin/env python3
"""Send latest Borg archive statistics to Backup Sentinel."""

from __future__ import annotations

import argparse
import json
import subprocess
import sys
import urllib.error
import urllib.request
from pathlib import Path
from typing import Any

DEFAULT_URL = "http://10.1.1.111:9999/api/push"


def load_borg_info(info_file: str | None) -> Any:
    if info_file:
        return json.loads(Path(info_file).read_text())

    result = subprocess.run(
        ["borgmatic", "info", "--archive", "latest", "--json"],
        check=True,
        text=True,
        capture_output=True,
    )
    return json.loads(result.stdout)


def latest_archive(info: Any) -> dict[str, Any]:
    if not isinstance(info, list) or not info or not isinstance(info[0], dict):
        raise ValueError("Unexpected borgmatic info JSON: expected a non-empty repository list")
    archives = info[0].get("archives")
    if not isinstance(archives, list) or not archives or not isinstance(archives[-1], dict):
        raise ValueError("Unexpected borgmatic info JSON: no latest archive found")
    return archives[-1]


def build_payload(host: str, archive: dict[str, Any]) -> dict[str, Any]:
    stats = archive.get("stats")
    if not isinstance(stats, dict):
        raise ValueError("Unexpected borgmatic info JSON: latest archive has no stats")

    return {
        "host": host,
        "status": "ok",
        # Borg exposes duration on the archive object, not below stats.
        "duration_sec": int(round(float(archive.get("duration", 0)))),
        "original_size": int(stats.get("original_size", 0)),
        "deduplicated_size": int(stats.get("deduplicated_size", 0)),
        "compressed_size": int(stats.get("compressed_size", 0)),
        "nfiles_new": int(stats.get("nfiles", 0)),
        "archive": str(archive.get("name", "")),
    }


def post_payload(url: str, payload: dict[str, Any]) -> None:
    request = urllib.request.Request(
        url,
        data=json.dumps(payload, separators=(",", ":")).encode(),
        method="POST",
        headers={"Content-Type": "application/json"},
    )
    with urllib.request.urlopen(request, timeout=10) as response:
        body = response.read().decode(errors="replace")
        if response.status < 200 or response.status >= 300:
            raise RuntimeError(f"Sentinel returned HTTP {response.status}: {body[:500]}")
        print(body)


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser()
    parser.add_argument("--host", required=True)
    parser.add_argument("--url", default=DEFAULT_URL)
    parser.add_argument("--info-file", help="Read borgmatic info JSON from a fixture instead of running borgmatic")
    parser.add_argument("--dry-run", action="store_true", help="Print payload without posting it")
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    try:
        payload = build_payload(args.host, latest_archive(load_borg_info(args.info_file)))
        if args.dry_run:
            print(json.dumps(payload, separators=(",", ":")))
        else:
            post_payload(args.url, payload)
        return 0
    except (ValueError, OSError, subprocess.SubprocessError, json.JSONDecodeError, urllib.error.URLError) as exc:
        print(f"borg-sentinel-push: {exc}", file=sys.stderr)
        return 1


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