"""Registre des déploiements (source de vérité) : ~/dispatch/registry.json."""
import json
import os
import time
from . import config


def load():
    if os.path.exists(config.REGISTRY):
        return json.load(open(config.REGISTRY))
    return {"updated": None, "gateway": config.GATEWAY, "apps": {}, "history": []}


def save(r):
    r["updated"] = time.strftime("%Y-%m-%dT%H:%M:%S")
    r["gateway"] = config.GATEWAY
    tmp = config.REGISTRY + ".tmp"
    json.dump(r, open(tmp, "w"), indent=2, ensure_ascii=False)
    os.replace(tmp, config.REGISTRY)


def node_of(app):
    return load()["apps"].get(app, {}).get("node")


def apps_on(alias):
    return [a for a, v in load()["apps"].items() if v.get("node") == alias]


def set_app(app, **fields):
    r = load()
    cur = r["apps"].get(app, {})
    cur.update(fields)
    cur["updated"] = time.strftime("%Y-%m-%dT%H:%M:%S")
    r["apps"][app] = cur
    save(r)


def remove_app(app, note=""):
    r = load()
    if app in r["apps"]:
        r["history"].append({"ts": time.strftime("%Y-%m-%dT%H:%M:%S"), "app": app, "event": "removed", "was": r["apps"][app], "note": note})
        del r["apps"][app]
    save(r)


def log(app, event, **kw):
    r = load()
    r["history"].append(dict(ts=time.strftime("%Y-%m-%dT%H:%M:%S"), app=app, event=event, **kw))
    r["history"] = r["history"][-500:]
    save(r)