import hmac
import json
import os
from functools import wraps

import psycopg
from flask import Flask, Response, abort, render_template


app = Flask(__name__)


def db_connection():
    return psycopg.connect(
        host=os.environ["DB_HOST"],
        port=os.getenv("DB_PORT", "5432"),
        dbname=os.environ["DB_NAME"],
        user=os.environ["DB_USER"],
        password=os.environ["DB_PASSWORD"],
        connect_timeout=5,
    )


def requires_auth(view):
    @wraps(view)
    def wrapped(*args, **kwargs):
        auth = __import__("flask").request.authorization
        expected_user = os.environ["DASHBOARD_USER"]
        expected_password = os.environ["DASHBOARD_PASSWORD"]
        valid = auth and hmac.compare_digest(auth.username or "", expected_user) and hmac.compare_digest(auth.password or "", expected_password)
        if not valid:
            return Response("Authentication required", 401, {"WWW-Authenticate": 'Basic realm="OCSentinel Debug"'})
        return view(*args, **kwargs)

    return wrapped


@app.get("/")
@requires_auth
def overview():
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute("SELECT * FROM ocsentinel.organization_summary")
        summary = cursor.fetchone()

        cursor.execute(
            """
            SELECT machine_name, organization_name, received_at, alert_state,
                   total_events, unique_ip_count, cve_total, cve_critical
            FROM (
                SELECT machine_name, received_at, alert_state, total_events,
                       unique_ip_count, cve_total, cve_critical,
                       payload #>> '{NinjaOne,OrganizationName}' AS organization_name
                FROM ocsentinel.current_device_status
            ) AS status
            ORDER BY received_at DESC NULLS LAST
            LIMIT 100
            """
        )
        reports = cursor.fetchall()

        cursor.execute(
            """
            SELECT machine_name, alert_state, total_events, unique_ip_count,
                   received_at, payload
            FROM ocsentinel.current_device_status
            WHERE alert_state IN ('warning', 'critical')
            ORDER BY CASE alert_state WHEN 'critical' THEN 0 ELSE 1 END, received_at DESC
            """
        )
        alerts = cursor.fetchall()

    return render_template("overview.html", summary=summary, reports=reports, alerts=alerts)


@app.get("/device/<machine_name>")
@requires_auth
def device(machine_name):
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            """
            SELECT machine_name, first_seen_at, last_seen_at, last_client_version,
                   generated_at_utc, received_at, alert_state, base_alert_state,
                   total_events, unique_ip_count, cve_total, cve_critical, payload
            FROM ocsentinel.current_device_status
            WHERE machine_name = %s
            """,
            (machine_name,),
        )
        report = cursor.fetchone()

    if report is None:
        abort(404)

    payload = report[12]
    return render_template("device.html", report=report, payload=payload, payload_pretty=json.dumps(payload, indent=2, ensure_ascii=False))


@app.get("/healthz")
def healthz():
    try:
        with db_connection() as connection, connection.cursor() as cursor:
            cursor.execute("SELECT 1")
        return {"status": "ok"}
    except Exception:
        return {"status": "unavailable"}, 503


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080)