#!/usr/bin/env python3
"""
Экспортер метрик для дашборда homelab: disk % и OOM по контейнерам/VM.
Запуск: python3 dashboard-exporter.py  (выводит JSON в stdout)
"""

import json
import subprocess
import sys
from pathlib import Path

# Маппинг: (vmid, type) -> (name, cgroup_name для Netdata)
CONTAINERS = [
    (100, "lxc", "nginx", "cgroup_nginx"),
    (101, "lxc", "nextcloud", "cgroup_nextcloud"),
    (103, "lxc", "gitea", "cgroup_gitea"),
    (104, "lxc", "paperless", "cgroup_paperless"),
    (105, "lxc", "rag-service", "cgroup_rag-service"),
    (107, "lxc", "misc", "cgroup_misc"),
    (108, "lxc", "galene", "cgroup_galene"),
    (109, "lxc", "local-vpn", "cgroup_local-vpn"),
    (200, "qemu", "immich", "cgroup_qemu_immich"),
]

LXC_CGROUP = Path("/sys/fs/cgroup/lxc")
QEMU_CGROUP_200 = Path("/sys/fs/cgroup/qemu.slice/200.scope")


def get_disk_pct_lxc(vmid: int) -> float | None:
    """Disk % для LXC через pct exec df."""
    try:
        r = subprocess.run(
            ["pct", "exec", str(vmid), "--", "df", "-P", "/"],
            capture_output=True,
            text=True,
            timeout=10,
        )
        if r.returncode != 0:
            return None
        lines = r.stdout.strip().split("\n")
        if len(lines) < 2:
            return None
        # Формат: Filesystem 1K-blocks Used Available Use% Mounted
        parts = lines[-1].split()
        if len(parts) >= 5:
            use_pct = parts[4].rstrip("%")
            return float(use_pct)
    except (subprocess.TimeoutExpired, ValueError):
        pass
    return None


def get_disk_pct_vm200() -> float | None:
    """Disk % для VM 200 через lvs (fallback, т.к. qm guest exec часто недоступен)."""
    try:
        r = subprocess.run(
            ["lvs", "-o", "data_percent", "--noheadings", "pve/vm-200-disk-0"],
            capture_output=True,
            text=True,
            timeout=5,
        )
        if r.returncode != 0:
            return None
        val = r.stdout.strip()
        if val:
            return float(val)
    except (subprocess.TimeoutExpired, ValueError):
        pass
    return None


def get_oom_count(vmid: int, vmtype: str) -> int | None:
    """OOM count из cgroup memory.events."""
    if vmtype == "lxc":
        path = LXC_CGROUP / str(vmid) / "memory.events"
    elif vmtype == "qemu" and vmid == 200:
        path = QEMU_CGROUP_200 / "memory.events"
    else:
        return None
    if not path.exists():
        return None
    try:
        text = path.read_text()
        for line in text.splitlines():
            if line.startswith("oom_kill "):
                return int(line.split()[1])
    except (OSError, ValueError):
        pass
    return None


def main() -> None:
    result = {"containers": [], "ok": True}
    for vmid, vmtype, name, cgroup_name in CONTAINERS:
        disk_pct = None
        if vmtype == "lxc":
            disk_pct = get_disk_pct_lxc(vmid)
        elif vmtype == "qemu" and vmid == 200:
            disk_pct = get_disk_pct_vm200()
        oom = get_oom_count(vmid, vmtype)
        result["containers"].append({
            "vmid": vmid,
            "name": name,
            "cgroup_name": cgroup_name,
            "disk_pct": disk_pct,
            "oom_count": oom,
        })
    print(json.dumps(result, ensure_ascii=False))


if __name__ == "__main__":
    main()