"""Gandalf – Global Advanced Network Detection And Link Facilitator.

Flask web application serving the monitoring dashboard and suppression
management UI. Authentication via Authelia forward-auth headers.
All monitoring and alerting is handled by the separate monitor.py daemon.
"""
import json
import logging
from functools import wraps

from flask import Flask, jsonify, redirect, render_template, request, url_for

import db

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s %(levelname)s %(name)s %(message)s',
)
logger = logging.getLogger('gandalf.web')

app = Flask(__name__)

_cfg = None


def _config() -> dict:
    global _cfg
    if _cfg is None:
        with open('config.json') as f:
            _cfg = json.load(f)
    return _cfg


# ---------------------------------------------------------------------------
# Auth helpers
# ---------------------------------------------------------------------------

def _get_user() -> dict:
    return {
        'username': request.headers.get('Remote-User', ''),
        'name': request.headers.get('Remote-Name', ''),
        'email': request.headers.get('Remote-Email', ''),
        'groups': [
            g.strip()
            for g in request.headers.get('Remote-Groups', '').split(',')
            if g.strip()
        ],
    }


def require_auth(f):
    @wraps(f)
    def wrapper(*args, **kwargs):
        user = _get_user()
        if not user['username']:
            return (
                '<h1>401 – Not authenticated</h1>'
                '<p>Please access Gandalf through '
                '<a href="https://auth.lotusguild.org">auth.lotusguild.org</a>.</p>',
                401,
            )
        allowed = _config().get('auth', {}).get('allowed_groups', ['admin'])
        if not any(g in allowed for g in user['groups']):
            return (
                f'<h1>403 – Access denied</h1>'
                f'<p>Your account ({user["username"]}) is not in an allowed group '
                f'({", ".join(allowed)}).</p>',
                403,
            )
        return f(*args, **kwargs)
    return wrapper


# ---------------------------------------------------------------------------
# Page routes
# ---------------------------------------------------------------------------

@app.route('/')
@require_auth
def index():
    user = _get_user()
    events = db.get_active_events()
    summary = db.get_status_summary()
    snapshot_raw = db.get_state('network_snapshot')
    last_check = db.get_state('last_check', 'Never')
    snapshot = json.loads(snapshot_raw) if snapshot_raw else {}
    suppressions = db.get_active_suppressions()
    return render_template(
        'index.html',
        user=user,
        events=events,
        summary=summary,
        snapshot=snapshot,
        last_check=last_check,
        suppressions=suppressions,
    )


@app.route('/links')
@require_auth
def links_page():
    user = _get_user()
    return render_template('links.html', user=user)


@app.route('/suppressions')
@require_auth
def suppressions_page():
    user = _get_user()
    active = db.get_active_suppressions()
    history = db.get_suppression_history(limit=50)
    snapshot_raw = db.get_state('network_snapshot')
    snapshot = json.loads(snapshot_raw) if snapshot_raw else {}
    return render_template(
        'suppressions.html',
        user=user,
        active=active,
        history=history,
        snapshot=snapshot,
    )


# ---------------------------------------------------------------------------
# API routes
# ---------------------------------------------------------------------------

@app.route('/api/status')
@require_auth
def api_status():
    return jsonify({
        'summary': db.get_status_summary(),
        'last_check': db.get_state('last_check', 'Never'),
        'events': db.get_active_events(),
    })


@app.route('/api/network')
@require_auth
def api_network():
    raw = db.get_state('network_snapshot')
    if raw:
        try:
            return jsonify(json.loads(raw))
        except Exception:
            pass
    return jsonify({'hosts': {}, 'unifi': [], 'updated': None})


@app.route('/api/links')
@require_auth
def api_links():
    raw = db.get_state('link_stats')
    if raw:
        try:
            return jsonify(json.loads(raw))
        except Exception:
            pass
    return jsonify({'hosts': {}, 'updated': None})


@app.route('/api/events')
@require_auth
def api_events():
    return jsonify({
        'active': db.get_active_events(),
        'resolved': db.get_recent_resolved(hours=24, limit=30),
    })


@app.route('/api/suppressions', methods=['GET'])
@require_auth
def api_get_suppressions():
    return jsonify(db.get_active_suppressions())


@app.route('/api/suppressions', methods=['POST'])
@require_auth
def api_create_suppression():
    user = _get_user()
    data = request.get_json(silent=True) or {}

    target_type = data.get('target_type', 'host')
    target_name = (data.get('target_name') or '').strip()
    target_detail = (data.get('target_detail') or '').strip()
    reason = (data.get('reason') or '').strip()
    expires_minutes = data.get('expires_minutes')  # None = manual/permanent

    if target_type not in ('host', 'interface', 'unifi_device', 'all'):
        return jsonify({'error': 'Invalid target_type'}), 400
    if target_type != 'all' and not target_name:
        return jsonify({'error': 'target_name required'}), 400
    if not reason:
        return jsonify({'error': 'reason required'}), 400

    sup_id = db.create_suppression(
        target_type=target_type,
        target_name=target_name,
        target_detail=target_detail,
        reason=reason,
        suppressed_by=user['username'],
        expires_minutes=int(expires_minutes) if expires_minutes else None,
    )
    logger.info(
        f'Suppression #{sup_id} created by {user["username"]}: '
        f'{target_type}/{target_name}/{target_detail} – {reason}'
    )
    return jsonify({'success': True, 'id': sup_id})


@app.route('/api/suppressions/<int:sup_id>', methods=['DELETE'])
@require_auth
def api_delete_suppression(sup_id: int):
    user = _get_user()
    db.deactivate_suppression(sup_id)
    logger.info(f'Suppression #{sup_id} removed by {user["username"]}')
    return jsonify({'success': True})


@app.route('/health')
def health():
    """Health check endpoint (no auth)."""
    return jsonify({'status': 'ok', 'service': 'gandalf'})


if __name__ == '__main__':
    app.run(debug=True, host='0.0.0.0', port=5000)