import hashlib
import hmac
import json
import os
from datetime import datetime, timezone

import psycopg
from flask import Flask, abort, redirect, render_template, request, url_for


app = Flask(__name__)

CURRENT_EVENT_HOURS = 24
STALE_REPORT_HOURS = 36


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 csrf_token():
    secret = os.environ["DASHBOARD_CSRF_SECRET"].encode("utf-8")
    return hmac.new(secret, b"recipient-rules", hashlib.sha256).hexdigest()


def require_csrf():
    supplied = request.form.get("csrf_token", "")
    if not hmac.compare_digest(supplied, csrf_token()):
        abort(400)


def event_metadata(payload):
    latest_event = None
    for event in (payload or {}).get("Events", []):
        value = event.get("Timestamp")
        if not value:
            continue
        try:
            timestamp = datetime.fromisoformat(value.replace("Z", "+00:00"))
        except ValueError:
            continue
        if timestamp.tzinfo is None:
            timestamp = timestamp.replace(tzinfo=timezone.utc)
        if latest_event is None or timestamp > latest_event:
            latest_event = timestamp

    if latest_event is None:
        return {"is_current": False, "label": "keine Ereignisse", "timestamp": None}

    age_seconds = max(0, int((datetime.now(timezone.utc) - latest_event.astimezone(timezone.utc)).total_seconds()))
    if age_seconds < 3600:
        age_label = f"vor {max(1, age_seconds // 60)} Min."
    elif age_seconds < 86400:
        age_label = f"vor {age_seconds // 3600} Std."
    else:
        age_label = f"vor {age_seconds // 86400} Tg."

    return {
        "is_current": age_seconds <= CURRENT_EVENT_HOURS * 3600,
        "label": age_label,
        "timestamp": latest_event,
    }


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

        cursor.execute(
            """
            SELECT count(*) AS known_devices,
                   count(*) FILTER (WHERE received_at >= now() - interval '36 hours') AS reporting_devices,
                   count(*) FILTER (WHERE received_at IS NULL OR received_at < now() - interval '36 hours') AS stale_devices
            FROM ocsentinel.current_device_status
            """
        )
        coverage = cursor.fetchone()

        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()

    report_rows = []
    for row in reports:
        event = event_metadata(row[8])
        report_rows.append(
            {
                "machine_name": row[0],
                "organization_name": row[1],
                "received_at": row[2],
                "alert_state": row[3],
                "total_events": row[4],
                "unique_ip_count": row[5],
                "event": event,
            }
        )

    alert_rows = []
    for row in alerts:
        event = event_metadata(row[5])
        alert_rows.append(
            {
                "machine_name": row[0],
                "alert_state": row[1],
                "total_events": row[2],
                "unique_ip_count": row[3],
                "received_at": row[4],
                "event": event,
            }
        )

    return render_template(
        "overview.html",
        summary=summary,
        coverage=coverage,
        reports=report_rows,
        alerts=alert_rows,
        current_alert_count=sum(alert["event"]["is_current"] for alert in alert_rows),
    )


@app.get("/device/<machine_name>")
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,
        event=event_metadata(payload),
        payload=payload,
        payload_pretty=json.dumps(payload, indent=2, ensure_ascii=False),
    )


@app.get("/reports")
def reports():
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            """
            SELECT id, organization_name, period_start_utc, period_end_utc,
                   generated_at, device_count, warning_count, critical_count,
                   total_events
            FROM ocsentinel.weekly_organization_report
            ORDER BY period_end_utc DESC, organization_name
            """
        )
        weekly_reports = cursor.fetchall()

    return render_template("reports.html", reports=weekly_reports)


@app.get("/reports/<int:report_id>")
def weekly_report(report_id):
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            """
            SELECT organization_name, period_start_utc, period_end_utc,
                   generated_at, report_html
            FROM ocsentinel.weekly_organization_report
            WHERE id = %s
            """,
            (report_id,),
        )
        report = cursor.fetchone()

    if report is None:
        abort(404)

    return render_template("weekly_report.html", report=report)


@app.get("/recipients")
def recipients():
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            """
            SELECT id, organization_id, organization_name, recipient_email, enabled
            FROM ocsentinel.organization_report_recipient
            ORDER BY organization_id = '*', organization_name, recipient_email
            """
        )
        rules = cursor.fetchall()
        cursor.execute(
            """
            SELECT DISTINCT payload #>> '{NinjaOne,OrganizationId}',
                   payload #>> '{NinjaOne,OrganizationName}'
            FROM ocsentinel.current_device_status
            WHERE coalesce(payload #>> '{NinjaOne,OrganizationId}', '') <> ''
            ORDER BY 2
            """
        )
        organizations = cursor.fetchall()

    return render_template("recipients.html", rules=rules, organizations=organizations, csrf_token=csrf_token())


@app.post("/recipients")
def add_recipient():
    require_csrf()
    organization_id = request.form.get("organization_id", "").strip()
    organization_name = request.form.get("organization_name", "").strip()
    recipient_email = request.form.get("recipient_email", "").strip().lower()
    if not organization_id or not organization_name or "@" not in recipient_email:
        abort(400)

    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            """
            INSERT INTO ocsentinel.organization_report_recipient
                (organization_id, organization_name, recipient_email)
            VALUES (%s, %s, %s)
            ON CONFLICT (organization_id, recipient_email) DO NOTHING
            """,
            (organization_id, organization_name, recipient_email),
        )
        connection.commit()

    return redirect(url_for("recipients"))


@app.post("/recipients/<int:rule_id>/toggle")
def toggle_recipient(rule_id):
    require_csrf()
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute(
            "UPDATE ocsentinel.organization_report_recipient SET enabled = NOT enabled WHERE id = %s",
            (rule_id,),
        )
        connection.commit()
    return redirect(url_for("recipients"))


@app.post("/recipients/<int:rule_id>/delete")
def delete_recipient(rule_id):
    require_csrf()
    with db_connection() as connection, connection.cursor() as cursor:
        cursor.execute("DELETE FROM ocsentinel.organization_report_recipient WHERE id = %s", (rule_id,))
        connection.commit()
    return redirect(url_for("recipients"))


@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)