#!/usr/bin/python
# -*- coding: utf-8 -*-
#    
# Copyright (C) 2013, Arista Networks <netdevops@aristanetworks.com>
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
DOCUMENTATION = '''
---
module: arista_l2interface
author: Peter Sprygada
short_description: Manage layer 2 interfaces
requirements:
    - Arista EOS 4.10
    - Netdev extension for EOS
description:
    - Manage layer 2 interface resources on Arista EOS network devices
options:
    interface_id:
        description:
            - the full name of the interface
        required: true
    state:
        description:
            - describe the desired state of the interface related to the config
        required: false
        default: 'present'
        choices: [ 'present', 'absent' ]
    logging:
        description:
            - enables or disables the syslog facility for this module
        required: false
        default: false
        choices: [ 'true', 'false', 'yes', 'no' ]
    vlan_tagging:
        description:
            - specifies whether or not vlan tagging should be enabled for 
              this interface
        required: false
        default: true
        choices: [ 'enable', 'disable' ]
    tagged_vlans: 
        description:
            - specifies the list of vlans that should be allowed to transit
              this interface
        required: false
    untagged_vlan:
        description:
            - specifies the vlan that untagged traffic should be placed in for
              transit across a vlan tagged link
        required: false
        default: 'default'
notes:
    - Requires EOS 4.10 or later 
    - The Netdev extension for EOS must be installed and active in the 
      available extensions (show extensions from the EOS CLI)
    - See http://eos.aristanetworks.com for details
'''
EXAMPLES = '''
Example playbook entries using the arista_l2interface module to manage resource 
state. Note that interface names must be the full interface name not shortcut
names (ie Ethernet, not Et1)

    tasks:
    - name: create switchport ethernet1 access port 
      action: arista_l2interface interface_id=Ethernet1 logging=true

    - name: create switchport ethernet2 trunk port
      action: arista_l2interface interface_id=Ethernet2 vlan_tagging=enable logging=true

    - name: add vlans to red and blue switchport ethernet2
      action: arista_l2interface interface_id=Ethernet2 tagged_vlans=red,blue logging=true

    - name: set untagged vlan for Ethernet1
      action: arista_l2interface interface_id=Ethernet1 untagged_vlan=red logging=true

    - name: convert access to trunk
      action: arista_l2interface interface_id=Ethernet1 vlan_tagging=enable tagged_vlans=red,blue logging=true

    - name: convert trunk to access
      action: arista_l2interface interface_id=Ethernet2 vlan_tagging=disable untagged_vlan=blue logging=true

    - name: delete switchport ethernet1
      action: arista_l2interface interface_id=Ethernet1 state=absent logging=true
'''
import syslog
import json

class AristaL2Interface(object):
    """ This is the base class  managing layer 2 interfaces (switchport) 
        resources in Arista EOS network devices.  This class provides an 
        implementation for creating, updating and deleting layer 2 interfaces.
        
        Note: The netdev extension for EOS must be installed in order of this
        module to work properly.
        
        The following commands are implemented in this module:
            * netdev l2interface list
            * netdev l2interface show
            * netdev l2interface edit
            * netdev l2interface delete

    """
    
    attributes= ['vlan_tagging', 'tagged_vlans', 'untagged_vlan']
    
    def __init__(self, module):
        self.module         = module
        self.interface_id   = module.params['interface_id']
        self.state          = module.params['state']
        self.vlan_tagging   = module.params['vlan_tagging']
        self.tagged_vlans   = module.params['tagged_vlans']
        self.untagged_vlan  = module.params['untagged_vlan']
        self.logging        = module.params['logging']

    @property
    def changed(self):
        """ The changed property provides a boolean response if the currently
            loaded resouces has changed from the resource running in EOS.
            
            Returns True if the object is not in sync 
            Returns False if the object is in sync.
        """
        return len(self.updates()) > 0

    def log(self, entry):
        """ This method is responsible for sending log messages to the local
            syslog.
        """
        if self.logging:
            syslog.openlog('ansible-%s' % os.path.basename(__file__))
            syslog.syslog(syslog.LOG_NOTICE, entry)

    def run_command(self, cmd):
        """ Calls the Ansible module run_command method. This method will 
            directly return the results of the run_command method
        """        
        self.log("Command: %s" % cmd)
        return self.module.run_command(cmd.split())


    def get(self):
        """ This method will return a dictionary with the attributes of the
            layer 2 interface resource specified in interface_id.  The layer
            2 interface resource has the following stucture:
            
              {
                "interface_id": <interface_id>,
                "vlan_tagging": [enable* | disable],
                "tagged_vlans": <array of vlan names>,
                "untagged_vlan": <vlan name>
              }
            
            If the layer 2 interface specified by interface_id does not
            exist in the system, this method will return None.
        """
        cmd = "netdev l2interface show %s" % self.interface_id
        (rc, out, err) = self.run_command(cmd)
        obj = json.loads(out)
        if obj.get('status') != 200: 
            return None
        return obj['result']

    def create(self):
        """ Creates a layer 2 interface resource in the current running 
            configuration.  If the layer 2 interface already exists, the 
            function will return successfully.
            
            This function implements the following commands:
                * netdev l2interface create {interface_id} [attributes]
            
            Returns the layer 2 interface resource if the create method was 
            successful
            Returns an error message if there as a problem creating the layer
            2 interface
        """
        attribs = []
        for attrib in self.attributes:
            if getattr(self, attrib):
                attribs.append("--%s" % attrib)
                attribs.append(getattr(self, attrib))

            cmd = "netdev l2interface create %s " % self.interface_id
            cmd += " ".join(attribs)

            (rc, out, err) = self.run_command(cmd)
            resp = json.loads(out)
            if resp.get('status') != 201:
                rc = int(resp['status'])
                err = resp['message']
                out = None
            else:
                out = resp['result']
        return (rc, out, err)

    def update(self):
        """ Updates an existing VLAN resource in the current running 
            configuration.   If the VLAN resource does not exist, this method
            will return an error.
            
            This method implements the following commands:
                * netdev l2interface edit {interface_id} [attributes]
            
            Returns an updated layer 2 interafce resoure if the update method 
            was successful
        """
        attribs = list()        
        for attrib in self.updates():
            attribs.append("--%s" % attrib)
            attribs.append(getattr(self, attrib))

            cmd = "netdev l2interface edit %s " % self.interface_id
            cmd += " ".join(attribs)

            (rc, out, err) = self.run_command(cmd)
            resp = json.loads(out)
            if resp.get('status') != 200:
                rc = int(resp['status'])
                err = resp['message']
                out = None
            else:
                out = resp['result']
            return (rc, out, err)
  
        return (0, None, "No attributes have been modified")

    def delete(self):
        """ Deletes an existing layer 2 interface resource from the current 
            running configuration.  A nonexistent layer 2 interface will 
            return successful for this operation.
            
            This method implements the following commands:
                * netdev l2interface delete {interface_id}
            
            Returns nothing if the delete was successful
            Returns error message if there was a problem deleting the resource 
        """
        cmd = "netdev l2interface delete %s" % self.interface_id
        (rc, out, err) = self.run_command(cmd)
        resp = json.loads(out)
        if resp.get('status') != 200: 
            rc = resp['status']
            err = resp['message']
            out = None
        return (rc, out, err)

    def updates(self):
        """ This method will check the current layer 2 interface resource in 
            the running configuration and return a list of attributes that are
            not in sync with the current resource.
        """
        obj = self.get()
        update = lambda a, z: a != z

        updates = list()
        for attrib in self.attributes:
            value = getattr(self, attrib)
            if update(obj[attrib], value) and value is not None:
                updates.append(attrib)
        self.log("Updates: %s" % updates)
        return updates

    def exists(self):
        """ Returns True if the current layer 2 interface resource exists and 
            returns False if it does not.   This method only checks for the 
            existence of the interface as specified in interface_id.
        """
        (rc, out, err) = self.run_command("netdev l2interface list")
        collection = json.loads(out)
        return self.interface_id in collection.get('result')
        

def main():
    module = AnsibleModule(
        argument_spec = dict(
            interface_id=dict(default=None, type='str'),
            state=dict(default='present', choices=['present', 'absent'], type='str'),
            vlan_tagging=dict(default=None, choices=['enable', 'disable']),
            tagged_vlans=dict(default=None, type='str'),
            untagged_vlan=dict(default=None, type='str'),
            logging=dict(default=False, type='bool')
        ),
        supports_check_mode = True
    )
    
    obj = AristaL2Interface(module)
    
    rc = None
    result = dict()

    if obj.state == 'absent':
        if obj.exists():
            if module.check_mode: 
                module.exit_json(changed=True)
            (rc, out, err) = obj.delete()
            if rc !=0: 
                module.fail_json(msg=err, rc=rc)                

    elif obj.state == 'present':
        if not obj.exists():
            if module.check_mode: 
                module.exit_json(changed=True)
            (rc, out, err) = obj.create()
            result['results'] = out
        else:
            if obj.changed:
                if module.check_mode: 
                    module.exit_json(changed=obj.changed)
                (rc, out, err) = obj.update()
                result['results'] = out

        if rc is not None and rc != 0:
            module.fail_json(msg=err, rc=rc)

    if rc is None:
        result['changed'] = False
    else:
        result['changed'] = True

    module.exit_json(**result)


# include magic from lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()
