# Copyright (C) 2015 Canonical Ltd.
#
# Author: Scott Moser <scott.moser@canonical.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
"""Fan: Configure ubuntu fan networking"""

import logging
from textwrap import dedent

from cloudinit import subp, util
from cloudinit.cloud import Cloud
from cloudinit.config import Config
from cloudinit.config.schema import MetaSchema, get_meta_doc
from cloudinit.settings import PER_INSTANCE

MODULE_DESCRIPTION = """\
This module installs, configures and starts the ubuntu fan network system. For
more information about Ubuntu Fan, see:
``https://wiki.ubuntu.com/FanNetworking``.

If cloud-init sees a ``fan`` entry in cloud-config it will:

    - write ``config_path`` with the contents of the ``config`` key
    - install the package ``ubuntu-fan`` if it is not installed
    - ensure the service is started (or restarted if was previously running)

Additionally, the ``ubuntu-fan`` package will be automatically installed
if not present.
"""

distros = ["ubuntu"]
meta: MetaSchema = {
    "id": "cc_fan",
    "name": "Fan",
    "title": "Configure ubuntu fan networking",
    "description": MODULE_DESCRIPTION,
    "distros": distros,
    "frequency": PER_INSTANCE,
    "examples": [
        dedent(
            """\
            fan:
              config: |
                # fan 240
                10.0.0.0/8 eth0/16 dhcp
                10.0.0.0/8 eth1/16 dhcp off
                # fan 241
                241.0.0.0/8 eth0/16 dhcp
              config_path: /etc/network/fan
            """
        )
    ],
    "activate_by_schema_keys": ["fan"],
}

__doc__ = get_meta_doc(meta)

LOG = logging.getLogger(__name__)

BUILTIN_CFG = {
    "config": None,
    "config_path": "/etc/network/fan",
}


def stop_update_start(distro, service, config_file, content):
    try:
        distro.manage_service("stop", service)
        stop_failed = False
    except subp.ProcessExecutionError as e:
        stop_failed = True
        LOG.warning("failed to stop %s: %s", service, e)

    if not content.endswith("\n"):
        content += "\n"
    util.write_file(config_file, content, omode="w")

    try:
        distro.manage_service("start", service)
        if stop_failed:
            LOG.warning("success: %s started", service)
    except subp.ProcessExecutionError as e:
        LOG.warning("failed to start %s: %s", service, e)

    distro.manage_service("enable", service)


def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
    cfgin = cfg.get("fan")
    if not cfgin:
        cfgin = {}
    mycfg = util.mergemanydict([cfgin, BUILTIN_CFG])

    if not mycfg.get("config"):
        LOG.debug("%s: no 'fan' config entry. disabling", name)
        return

    util.write_file(mycfg.get("config_path"), mycfg.get("config"), omode="w")
    distro = cloud.distro
    if not subp.which("fanctl"):
        distro.install_packages(["ubuntu-fan"])

    stop_update_start(
        distro,
        service="ubuntu-fan",
        config_file=mycfg.get("config_path"),
        content=mycfg.get("config"),
    )