"""ServerDash — self-hosted Docker + host monitoring dashboard.

Backend: Flask + a small REST API. Frontend: a static SPA
(index.html + css + js) served by the same Flask app.
"""

import json
import os
import threading
import time
from datetime import datetime, timezone

from flask import (
    Flask,
    jsonify,
    render_template,
    request,
    Response,
    abort,
)

from docker_monitor import DockerMonitor
from host_stats import HostStats

BASE_DIR = os.path.dirname(os.path.abspath(__file__))

app = Flask(
    __name__,
    static_folder=os.path.join(BASE_DIR, "static"),
    template_folder=os.path.join(BASE_DIR, "templates"),
)

# ---------------------------------------------------------------------------
# Background refresh loop. Keeps the container list fresh so the dashboard
# always shows current data without blocking API responses.
# ---------------------------------------------------------------------------
docker = DockerMonitor()
host = HostStats()
REFRESH_INTERVAL = float(os.environ.get("REFRESH_INTERVAL", "3"))
_stop = False


def _background_refresh():
    while not _stop:
        try:
            docker.refresh()
        except Exception as exc:  # keep the loop alive on transient errors
            app.logger.warning("docker refresh failed: %s", exc)
        time.sleep(REFRESH_INTERVAL)


_thread = threading.Thread(target=_background_refresh, daemon=True)


# ---------------------------------------------------------------------------
# API routes
# ---------------------------------------------------------------------------
@app.route("/api/v1/containers")
def api_containers():
    """Return the normalized list of discovered containers."""
    # Allow a forced refresh.
    if request.args.get("refresh") == "1":
        try:
            docker.refresh()
        except Exception as exc:
            return jsonify({"error": str(exc)}), 502
    containers = docker.get()
    return jsonify({"count": len(containers), "containers": containers})


@app.route("/api/v1/containers/summary")
def api_container_summary():
    """Aggregate counts by state class (used for the header cards)."""
    containers = docker.get()
    summary = {
        "total": len(containers),
        "running": 0,
        "starting": 0,
        "paused": 0,
        "stopped": 0,
        "dead": 0,
    }
    for c in containers:
        key = c["state_class"]
        if key in summary:
            summary[key] += 1
    return jsonify(summary)


@app.route("/api/v1/host")
def api_host():
    """Return host resource stats (cpu, memory, disk, load, uptime)."""
    return jsonify(host.get())


@app.route("/api/v1/healthz")
def api_healthz():
    return jsonify({"status": "ok", "time": datetime.now(timezone.utc).isoformat()})


# ---------------------------------------------------------------------------
# SPA
# ---------------------------------------------------------------------------
@app.route("/")
def index():
    return render_template("index.html")


@app.errorhandler(404)
def not_found(_e):
    return render_template("index.html"), 200


def create_server():
    """Return a configured wsgi app (used by `python -m` and gunicorn)."""
    return app


if __name__ == "__main__":
    _thread.start()
    port = int(os.environ.get("PORT", "8787"))
    host_bind = os.environ.get("HOST_BIND", "0.0.0.0")
    app.run(host=host_bind, port=port, debug=False, threaded=True)