#! /usr/bin/env python3

from __future__ import print_function
import argparse
import json
import os
import sys
import vpngen


def eprint(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)


def create_variables(variables, defaults):
    variables_set = defaults.copy()
    for variable in variables:
        if variable == 'name' or variable == 'client':
            continue
        default = variables_set[variable] if variable in variables_set else ''
        print("Enter a value for '%s' [%s]: " % (variable, default), end='', flush=True)
        value = sys.stdin.readline()[:-1]
        if value != '' or variable not in variables_set:
            variables_set[variable] = value
    return variables_set


def main():
    parser = argparse.ArgumentParser(description='Manage OpenVPN VPNs')
    parser.add_argument('--vpn', help='The VPN to use', required=True)
    parser.add_argument('--config', dest='config', default='/etc/vpngen/vpngen.json', help='Configuration file path')

    parser.add_argument('--create', help='Create a VPN', action='store_true')
    parser.add_argument('--remove', help='Remove a VPN', action='store_true')
    parser.add_argument('--create-client', help='Create a client for the VPN', metavar='CLIENT')
    parser.add_argument('--remove-client', help='Remove a client for the VPN', metavar='CLIENT')
    parser.add_argument('--rebuild-client', help='Rebuild a client configuration', metavar='CLIENT')
    parser.add_argument('--rebuild-clients', help='Rebuild clients configurations', action='store_true')

    args = parser.parse_args()

    with open(args.config, "r") as f:
        config = json.load(f)

    vpn_name = config['vpnPrefix'] + args.vpn + config['vpnSuffix']
    if args.create_client is not None:
        client_name = args.create_client
    elif args.remove_client is not None:
        client_name = args.remove_client
    elif args.rebuild_client is not None:
        client_name = args.rebuild_client
    else:
        client_name = None
    if client_name is not None:
        client_name = config['clientPrefix'] + client_name + config['clientSuffix']

    vpng = vpngen.VpnGen(config['defaultConfigPath'], config['ovpnConfigPath'])

    config_path = vpng.get_vpn_variables_path(vpn_name)
    if os.path.exists(config_path):
        with open(config_path, "r") as f:
            data = json.load(f)
        config['defaults'].update(data['variables'])

    if args.create:
        default_variables = config['defaults'].copy()
        variables = create_variables(vpng.get_vpn_vars(), default_variables)
        res = vpng.create_vpn(vpn_name, variables)
        if res == vpngen.VpnGenError.Success:
            print("VPN %s created successfully" % vpn_name)
        else:
            eprint("Failed to create VPN %s: %s" % (vpn_name, res))
            exit(1)
    elif args.remove:
        res = vpng.remove_vpn(vpn_name)
        if res == vpngen.VpnGenError.Success:
            print("VPN %s removed successfully" % vpn_name)
        else:
            eprint("Failed to remove VPN %s: %s" % (vpn_name, res))
            exit(1)
    elif args.create_client:
        default_variables = config['defaults'].copy()
        default_variables.update(vpng.get_server_variables(vpn_name))
        variables = create_variables(vpng.get_client_vars(vpn_name), default_variables)
        if variables is None:
            res = vpngen.VpnGenError.VpnDoesNotExists
        else:
            res = vpng.create_client(vpn_name, client_name, variables)
        if res == vpngen.VpnGenError.Success:
            print("Client %s created successfully on VPN %s" % (client_name, vpn_name))
        else:
            eprint("Failed to create client %s on VPN %s: %s" % (client_name, vpn_name, res))
            exit(1)
    elif args.remove_client:
        res = vpng.remove_client(vpn_name, client_name)
        if res == vpngen.VpnGenError.Success:
            print("Client %s removed successfully on VPN %s" % (client_name, vpn_name))
        else:
            eprint("Failed to remove client %s on VPN %s: %s" % (client_name, vpn_name, res))
            exit(1)
    elif args.rebuild_client:
        default_variables = config['defaults'].copy()
        default_variables.update(vpng.get_server_variables(vpn_name))
        default_variables.update(vpng.get_client_variables(vpn_name, client_name))

        res = vpng.rebuild_client(vpn_name, client_name, default_variables)
        if res == vpngen.VpnGenError.Success:
            print("Client %s configuration rebuilt successfully on VPN %s" % (client_name, vpn_name))
        else:
            eprint("Failed to rebuild client %s configuration on VPN %s: %s" % (client_name, vpn_name, res))
            exit(1)
    elif args.rebuild_clients:
        default_variables = config['defaults'].copy()
        default_variables.update(vpng.get_server_variables(vpn_name))

        for client_name in vpng.get_client_list(vpn_name):
            variables = default_variables.copy()
            variables.update(vpng.get_client_variables(vpn_name, client_name))
            res = vpng.rebuild_client(vpn_name, client_name, variables)
            if res == vpngen.VpnGenError.Success:
                print("Client %s configuration rebuilt successfully on VPN %s" % (client_name, vpn_name))
            else:
                eprint("Failed to rebuild client %s configuration on VPN %s: %s" % (client_name, vpn_name, res))
                exit(1)


main()