#!/usr/bin/env python
#
# Copyright (c) 2015, Arista Networks, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#  - Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#  - Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
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#  - Neither the name of Arista Networks nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ARISTA NETWORKS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
# IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# pylint: disable=C0209

import io
import os

from six import raise_from

TEMP_CONFIG = "/tmp/tmp-add-config"


def main(attributes):
    """Appends config section to startup-config.

    This action is dual-supervisor compatible.

    Attributes:
        url: path to source config/template
        substitution_mode: loose|strict (default: loose)
        variables: list of value substitutions

    Special_attributes:
        NODE: API object - see documentation for details

    Example:
        ::

          -
            action: add_config
            attributes:
              url: files/templates/ma1.template
              variables:
                ipaddress: allocate('mgmt_subnet')
            name: "configure ma1"
            onstart: "Starting to configure ma1"
            onsuccess: "SUCCESS: ma1 configure"
            onfailure: "FAIL: IM provisioning@example.com for help"

    """

    node = attributes.get("NODE")
    url = attributes.get("url")

    if not url:
        raise RuntimeError("Missing attribute('url')")

    substitution_mode = attributes.get("substitution_mode", "loose")
    if substitution_mode not in ["loose", "strict"]:
        raise RuntimeError("Invalid option specified for substitution_mode attribute")

    try:
        node.retrieve_url(url, TEMP_CONFIG)
    except Exception as exc:
        raise_from(RuntimeError("Unable to retrieve config from URL"), exc)

    with io.open(TEMP_CONFIG, encoding="utf8") as fd:
        contents = fd.read()

    variables = attributes.get("variables")
    if not variables:
        variables = {}

    if not isinstance(variables, dict):
        node.log_msg("Variables: {}".format(variables))
        raise RuntimeError("Unable to perform variable substitution - invalid variables")

    contents = node.substitute(contents, variables, substitution_mode == "strict")
    node.append_startup_config_lines(contents.split("\n"))

    # Only remove this in case everything else succeeded
    # for debugging purposes
    os.remove(TEMP_CONFIG)
