#!/usr/bin/env python
"""sonic-cfggen

A tool to read SONiC config data from one or more of the following sources:
minigraph file, config DB, json file(s), yaml files(s), command line input,
and write the data into DB, print as json, or render a jinja2 config template.

Examples:
    Render template with minigraph:        
        sonic-cfggen -m -t /usr/share/template/bgpd.conf.j2
    Dump config DB content into json file: 
        sonic-cfggen -d --print-data > db_dump.json
    Load content of json file into config DB:
        sonic-cfggen -j db_dump.json --write-to-db
See usage string for detail description for arguments.
"""

import sys
import os.path
import argparse
import yaml
import jinja2
import netaddr
import json
from minigraph import minigraph_encoder
from minigraph import parse_xml
from minigraph import parse_device_desc_xml
from sonic_platform import get_machine_info
from sonic_platform import get_platform_info
from swsssdk import ConfigDBConnector

def is_ipv4(value):
    if not value:
        return False
    if isinstance(value, netaddr.IPAddress):
        addr = value
    else:
        try:
            addr = netaddr.IPAddress(str(value))
        except:
            return False
    return addr.version == 4

def is_ipv6(value):
    if not value:
        return False
    if isinstance(value, netaddr.IPAddress):
        addr = value
    else:
        try:
            addr = netaddr.IPAddress(str(value))
        except:
            return False
    return addr.version == 6

def unique_name(l):
    name_list = []
    new_list = []
    for item in l:
        if item['name'] not in name_list:
            name_list.append(item['name'])
            new_list.append(item)
    return new_list


class FormatConverter:
    """Convert config DB based schema to legacy minigraph based schema for backward capability.
We will move to DB schema and remove this class when the config templates are modified.

TODO(taoyl): Current version of config db only supports BGP admin states.
    All other configuration are still loaded from minigraph. Plan to remove 
    minigraph and move everything into config db in a later commit.
    """
    @staticmethod
    def db_to_output(db_data):
        return db_data

    @staticmethod
    def output_to_db(output_data):
        db_data = {}
        for table_name in output_data:
            if table_name == 'BGP_NEIGHBOR' or table_name == 'BGP_PEER_RANGE' or table_name == 'DEVICE_METADATA':
                db_data[table_name] = output_data[table_name]
        return db_data

def deep_update(dst, src):
    for key, value in src.iteritems():
        if isinstance(value, dict):
             node = dst.setdefault(key, {})
             deep_update(node, value)
        else:
             dst[key] = value
    return dst


def main():
    parser=argparse.ArgumentParser(description="Render configuration file from minigraph data and jinja2 template.")
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-m", "--minigraph", help="minigraph xml file", nargs='?', const='/etc/sonic/minigraph.xml')
    group.add_argument("-M", "--device-description", help="device description xml file")
    parser.add_argument("-p", "--port-config", help="port config file, used with -m")
    parser.add_argument("-y", "--yaml", help="yaml file that contains additional variables", action='append', default=[])
    parser.add_argument("-j", "--json", help="json file that contains additional variables", action='append', default=[])
    parser.add_argument("-a", "--additional-data", help="addition data, in json string")
    parser.add_argument("-d", "--from-db", help="read config from configdb", action='store_true')
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-t", "--template", help="render the data with the template file")
    group.add_argument("-v", "--var", help="print the value of a variable, support jinja2 expression")
    group.add_argument("--var-json", help="print the value of a variable, in json format")
    group.add_argument("--write-to-db", help="write config into configdb", action='store_true')
    group.add_argument("--print-data", help="print all data", action='store_true')
    args = parser.parse_args()

    data = {}
    machine_info = get_machine_info()
    if machine_info != None:
        deep_update(data, machine_info)
        platform_info = get_platform_info(machine_info)
        if platform_info != None:
            data['platform'] = platform_info

    if args.minigraph != None:
        minigraph = args.minigraph
        if data.has_key('platform'):
            if args.port_config != None:
                deep_update(data, parse_xml(minigraph, data['platform'], args.port_config))
            else:
                deep_update(data, parse_xml(minigraph, data['platform']))
        else:
            if args.port_config != None:
                deep_update(data, parse_xml(minigraph, port_config_file=args.port_config))
            else:
                deep_update(data, parse_xml(minigraph))

    if args.device_description != None:
        deep_update(data, parse_device_desc_xml(args.device_description))

    for yaml_file in args.yaml:
        with open(yaml_file, 'r') as stream:
            additional_data = yaml.load(stream)      
            deep_update(data, additional_data)

    for json_file in args.json:
        with open(json_file, 'r') as stream:
            deep_update(data, json.load(stream))

    if args.additional_data != None:
        deep_update(data, json.loads(args.additional_data))
  
    if args.from_db:
        configdb = ConfigDBConnector()
        configdb.connect()
        deep_update(data, FormatConverter.db_to_output(configdb.get_config()))

    if args.template != None:
        template_file = os.path.abspath(args.template)
        env = jinja2.Environment(loader=jinja2.FileSystemLoader('/'), trim_blocks=True)
        env.filters['ipv4'] = is_ipv4
        env.filters['ipv6'] = is_ipv6
        env.filters['unique_name'] = unique_name
        template = env.get_template(template_file)
        print template.render(data)
    
    if args.var != None:
        template = jinja2.Template('{{' + args.var + '}}')
        print template.render(data)

    if args.var_json != None:
        print json.dumps(data[args.var_json], indent=4, cls=minigraph_encoder)

    if args.write_to_db:
        configdb = ConfigDBConnector()
        configdb.connect(False)
        configdb.set_config(FormatConverter.output_to_db(data))

    if args.print_data:
        print json.dumps(data, indent=4, cls=minigraph_encoder)


if __name__ == "__main__":
    main()