#!/usr/bin/env python3
import json, os, subprocess, time, glob, socket, getpass

DBOPS_ROOT = os.environ.get("DBOPS_ROOT", "/data/adaptai/platform/dbops")
SOCK = f"unix://{DBOPS_ROOT}/run/supervisor.sock"
HEALTH_DIR = f"{DBOPS_ROOT}/run/health"
AUDIT_DIR = f"{DBOPS_ROOT}/logs/audit"
AUDIT_FILE = os.path.join(AUDIT_DIR, "health-guard.audit.log")

# Dependency gates: if any upstream is red, stop dependents
GATES = {
    "dragonfly": ["qdrant", "janusgraph"],
    "redis_cluster": ["qdrant", "janusgraph"],
    "scylla": ["janusgraph"],
}

# Auto-recovery settings
GREEN_STABLE_SECONDS = int(os.environ.get("HG_GREEN_STABLE_SECONDS", "30"))
RESTART_BACKOFF_SECONDS = int(os.environ.get("HG_RESTART_BACKOFF_SECONDS", "60"))
MAX_RESTARTS = int(os.environ.get("HG_MAX_RESTARTS", "3"))
RESTART_WINDOW_SECONDS = int(os.environ.get("HG_RESTART_WINDOW_SECONDS", "600"))
ENABLE_AUTOSTART = os.environ.get("HG_ENABLE_AUTOSTART", "1") in ("1", "true", "TRUE", "yes", "YES")

STATE = {
    "upstream": {},  # svc -> { last_health: str, last_change: float, last_green: float }
    "dep_backoff": {},  # dep -> next_allowed_restart_ts
    "dep_restarts": {},  # dep -> [timestamps]
}

def supctl(cmd):
    return subprocess.run(["supervisorctl", "-s", SOCK] + cmd, capture_output=True, text=True)

def sup_status():
    out = supctl(["status"]).stdout.strip().splitlines()
    st = {}
    for line in out:
        # Format: name               RUNNING   pid ... or STOPPED
        parts = line.split()
        if not parts:
            continue
        name = parts[0]
        status = parts[1] if len(parts) > 1 else "UNKNOWN"
        st[name] = status
    return st

def ensure_audit_dir():
    try:
        os.makedirs(AUDIT_DIR, exist_ok=True)
    except Exception:
        pass

def audit(event: str, payload: dict):
    ensure_audit_dir()
    rec = {
        "ts": time.time(),
        "event": event,
        "host": socket.gethostname(),
        "user": getpass.getuser(),
    }
    rec.update(payload)
    try:
        with open(AUDIT_FILE, "a") as f:
            f.write(json.dumps(rec) + "\n")
    except Exception:
        pass

def read_health():
    statuses = {}
    for path in glob.glob(os.path.join(HEALTH_DIR, "*.json")):
        try:
            with open(path) as f:
                data = json.load(f)
                svc = data.get("service")
                if svc:
                    statuses[svc] = data
        except Exception:
            pass
    return statuses

def is_red(status):
    return status.get("health") == "red"

def now():
    return time.time()

def update_upstream_state(upstream, s):
    ts = now()
    u = STATE["upstream"].setdefault(upstream, {"last_health": None, "last_change": ts, "last_green": 0.0})
    h = s.get("health") if s else None
    if h != u["last_health"]:
        u["last_change"] = ts
        u["last_health"] = h
        if h == "green":
            u["last_green"] = ts

def enforce(statuses):
    # Update upstream state memory
    for upstream in GATES.keys():
        update_upstream_state(upstream, statuses.get(upstream))

    sup_st = sup_status()

    # Stop dependents if upstream red
    for upstream, dependents in GATES.items():
        s = statuses.get(upstream, {})
        if is_red(s):
            for dep in dependents:
                supctl(["stop", dep])
                audit("stop_dependent", {"upstream": upstream, "dependent": dep, "reason": "upstream_red"})

    # Start dependents when upstream is green and stable
    ts = now()
    for upstream, dependents in GATES.items():
        u = STATE["upstream"].get(upstream, {})
        if not u or u.get("last_health") != "green":
            continue
        if ts - u.get("last_green", 0) < GREEN_STABLE_SECONDS:
            continue  # require stability window
        if not ENABLE_AUTOSTART:
            continue
        for dep in dependents:
            # Backoff control
            next_ts = STATE["dep_backoff"].get(dep, 0)
            if ts < next_ts:
                continue
            # Start only if not running
            dep_status = sup_st.get(dep, "UNKNOWN")
            if dep_status not in ("RUNNING",):
                # rate limiting
                hist = STATE["dep_restarts"].setdefault(dep, [])
                # prune old
                hist = [t for t in hist if ts - t < RESTART_WINDOW_SECONDS]
                STATE["dep_restarts"][dep] = hist
                if len(hist) >= MAX_RESTARTS:
                    audit("skip_restart_rate_limited", {"dependent": dep, "upstream": upstream, "window_s": RESTART_WINDOW_SECONDS, "max": MAX_RESTARTS})
                    continue
                supctl(["start", dep])
                hist.append(ts)
                STATE["dep_backoff"][dep] = ts + RESTART_BACKOFF_SECONDS
                audit("start_dependent", {"dependent": dep, "upstream": upstream, "reason": "upstream_green_stable", "stable_s": GREEN_STABLE_SECONDS})

def main():
    while True:
        st = read_health()
        enforce(st)
        time.sleep(15)

if __name__ == "__main__":
    main()