#!/usr/bin/env python3
"""
gNMI gRPC Configuration Script
===============================
Enables gRPC dial-in telemetry on all 9 IOS-XR routers so that
Telegraf (or any gNMI collector) can subscribe to streaming
telemetry data.

What this script applies per router:
  - gRPC server on port 57400 with TLS disabled
  - YANG model: Cisco-IOS-XR-man-ems-cfg

Router targets:
  CORE-01 (10.100.0.100)
  CORE-02 (10.100.0.200)
  R9K-01  (10.100.0.1) through R9K-07 (10.100.0.7)
"""

from ncclient import manager
import sys

GRPC_NS = 'http://cisco.com/ns/yang/Cisco-IOS-XR-man-ems-cfg'

ROUTERS = [
    ('10.100.0.100', 'CORE-01'),
    ('10.100.0.200', 'CORE-02'),
    ('10.100.0.1',   'R9K-01'),
    ('10.100.0.2',   'R9K-02'),
    ('10.100.0.3',   'R9K-03'),
    ('10.100.0.4',   'R9K-04'),
    ('10.100.0.5',   'R9K-05'),
    ('10.100.0.6',   'R9K-06'),
    ('10.100.0.7',   'R9K-07'),
]

GRPC_CONFIG_XML = """
<config>
  <grpc xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-man-ems-cfg">
    <port>57400</port>
    <no-tls/>
  </grpc>
</config>
"""


def configure_router(mgmt_ip, label):
    """Apply gRPC configuration via NETCONF edit-config + commit."""
    print(f"\n{'─'*60}")
    print(f"  Configuring {label} ({mgmt_ip})")
    print(f"{'─'*60}")
    print(f"  Applying: gRPC port=57400 no-tls")

    try:
        with manager.connect(
            host=mgmt_ip,
            port=830,
            username='webui',
            password='cisco',
            hostkey_verify=False,
            device_params={'name': 'iosxr'},
            timeout=20,
        ) as m:
            print("  → Applying gRPC configuration...")
            m.edit_config(target='candidate', config=GRPC_CONFIG_XML)

            print("  → Committing...")
            m.commit()
            print(f"  ✓ {label} done.")
            return True

    except Exception as e:
        print(f"  ✗ ERROR on {label}: {e}")
        return False


def verify_router(mgmt_ip, label):
    """Re-read running config to confirm the grpc block is present."""
    try:
        with manager.connect(
            host=mgmt_ip, port=830, username='webui', password='cisco',
            hostkey_verify=False, device_params={'name': 'iosxr'}, timeout=10
        ) as m:
            filt_grpc = """<filter>
              <grpc xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-man-ems-cfg">
                <port/>
                <no-tls/>
              </grpc>
            </filter>"""
            r_grpc = m.get_config(source='running', filter=filt_grpc)

            has_grpc = '<port>57400</port>' in str(r_grpc)
            has_notls = '<no-tls' in str(r_grpc)

            g = '✓' if has_grpc else '✗'
            t = '✓' if has_notls else '✗'
            status = 'OK' if (has_grpc and has_notls) else 'INCOMPLETE'
            print(f"  {label:8s}  grpc-port={g}  no-tls={t}  [{status}]")

    except Exception as e:
        print(f"  {label:8s}  verify error: {e}")


def main():
    print("gNMI gRPC Configuration Script")
    print("================================")
    print(f"Targets: all {len(ROUTERS)} routers")
    print()

    results = []
    for mgmt_ip, label in ROUTERS:
        ok = configure_router(mgmt_ip, label)
        results.append((mgmt_ip, label, ok))

    # Summary
    print(f"\n{'='*60}")
    print("Post-apply verification")
    print('='*60)
    print(f"  {'Router':8s}  {'gRPC Port':9s}  {'No-TLS':6s}  Status")
    for mgmt_ip, label, ok in results:
        if ok:
            verify_router(mgmt_ip, label)
        else:
            print(f"  {label:8s}  skipped (apply failed)")

    failed = [label for _, label, ok in results if not ok]
    print()
    if failed:
        print(f"FAILED: {', '.join(failed)}")
        sys.exit(1)
    else:
        print("All routers configured successfully.")
        print()
        print("gRPC is now listening on port 57400 (no TLS) on all routers.")
        print("Next: start Telegraf with gNMI input plugin to begin collecting telemetry.")


if __name__ == '__main__':
    main()