import argparse
import difflib
import getpass
import logging

from pprint import pprint

import colorlog
import requests
import termcolor
import yaml

from jinja2 import Template

from core import connect_to_switch, sftp_read_file, sftp_write_file

logger = logging.getLogger()

def syntax_from_range(value, vlan_syntax=False):
    if value == []:
        return None
    value = set(value)
    prec = None
    syntax = ""
    in_range = False
    for i in value:
        if prec is None or prec != i - 1:
            if syntax == "":
                syntax = str(i)
            elif in_range:
                if vlan_syntax:
                    syntax += "-{} {}".format(prec,i)
                else:
                    syntax += "-{},{}".format(prec,i)
                in_range = False
            else:
                if vlan_syntax:
                    syntax += " {}".format(i)
                else:
                    syntax += ",{}".format(i)
                in_range = False
        elif i == max(value):
            syntax += "-{}".format(i)
        else:
            in_range = True
        prec = i
    if vlan_syntax:
        syntax += " "
    return syntax

def range_from_syntax(value, vlan_syntax=False):
    if value is None:
        return []
    ret_range = list()
    if vlan_syntax:
        value = str(value).split(" ")
    else:
        value = str(value).split(",")
    for v in value:
        v = v.split("-")
        if len(v) == 2:
            v = list(range(int(v[0]), int(v[1])+1))
        elif len(v) == 1:
            v = [int(v[0])]
        else:
            raise RuntimeError("You fucked")
        ret_range += v
    return ret_range

def gen_vlan(vlan_number, switch_config, dhcp_snooping_vlans):
    vlan_config = yaml.load(open("configs/vlans/{}.yml".format(vlan_number), "r"), yaml.Loader)
    vlan = {
        "name": vlan_config.get("name"),
        "tagged": list(),
        "untagged": list(),
    }
    if vlan_config.get("dhcp_snooping", True):
        dhcp_snooping_vlans.append(int(vlan_number))
    if vlan_config.get("has_ip"):
        vlan["ip"] = dict()
        v4 = switch_config.get("ipv4-addr")
        v4_sub = switch_config.get("ipv4-subnet")
        if v4 is not None and v4_sub is not None:
            logger.debug("Adding {} {} to vlan {}".format(v4, v4_sub, vlan_number))
            vlan["ip"]["addr"] = v4
            vlan["ip"]["subnet"] = v4_sub
        v6 = switch_config.get("ipv6-addr")
        v6_sub = switch_config.get("ipv6-subnet")
        if v6 is not None and v6_sub is not None:
            logger.debug("Adding {}/{} to vlan {}".format(v6, v6_sub, vlan_number))
            vlan["ip"]["addr6"] = v6
            vlan["ip"]["subnet6"] = v6_sub
        if vlan["ip"] == {}:
            logger.critical("Missing IPs or subnets configurations for vlan {}".format(vlan_number))
            raise RuntimeError()
    return vlan, dhcp_snooping_vlans

def gen_interfaces(switch_config):
    dhcp_snooping_vlans = list()
    mac_based_ports = list()
    ra_guard_ports = list()
    ifaces_done = list()
    interfaces = list()
    vlans = dict()
    has_ip = False
    for iface, if_config in switch_config.get("interfaces").items():
       if_profile = yaml.load(open("configs/profiles/{}.yml".format(if_config.get("profile"))), yaml.Loader)
       iface = range_from_syntax(iface)
       for iface_number in iface:
           if not if_profile.get("ignore_port", False):
               interface = {
                   "number": iface_number,
      	       }
               generic = if_profile.get("generic_name", None)
               if generic is None:
                   interface["name"] = if_config["name"]
               else:
                   interface["name"] = "TODO {} {}".format(generic, iface_number)
                   interface["mac_based"] = if_profile.get("mac_based", False)
                   if interface["mac_based"]:
                       mac_based_ports.append(iface_number)
                   if if_profile.get("ra_guard", True):
                       ra_guard_ports.append(iface_number)
                   interface["addr_limit"] = if_profile.get("addr_limit", 5)
                   interface["logoff"] = if_profile.get("logoff", 3600)
               interfaces.append(interface)
           ifaces_done.append(iface_number)
           for vlan in range_from_syntax(if_profile.get("vlans").get("untagged")):
               if vlans.get(vlan) is None:
                   vlans[vlan], dhcp_snooping_vlans = gen_vlan(vlan, switch_config, dhcp_snooping_vlans)
               vlans[vlan]["untagged"].append(iface_number)
           for vlan in range_from_syntax(if_profile.get("vlans").get("tagged")):
               if vlans.get(vlan) is None:
                   vlans[vlan], dhcp_snooping_vlans = gen_vlan(vlan, switch_config, dhcp_snooping_vlans)
               vlans[vlan]["tagged"].append(iface_number)
    ifaces_done = set(ifaces_done)
    # on reformatte les interfaces des vlans
    for vlan, v_conf in vlans.items():
        vlans[vlan]["tagged"] = syntax_from_range(v_conf["tagged"])
        vlans[vlan]["untagged"] = syntax_from_range(v_conf["untagged"])

    if max(ifaces_done) != switch_config.get("nb_ports") or len(ifaces_done) != switch_config.get("nb_ports"):
        raise RuntimeError("Interfaces fucked")
    interfaces.sort(key=lambda x: x["number"])
    return interfaces, vlans, mac_based_ports, ra_guard_ports, dhcp_snooping_vlans

def get_header(old_config):
    header = "\n".join(old_config.split("\n")[:2])
    return header

def conf_from_dict(config_dict):
    with open("configs/config.j2", "r") as template_file:
        template = Template(template_file.read())
        configuration = template.render(config_dict)
    return configuration

def gen_conf(master_config, switch_config, header):
    interfaces, vlans, mac_based_ports, ra_guard_ports, dhcp_snooping_vlans = gen_interfaces(switch_config)
    config_dict = {
        "header": header,
        "hostname": switch_config.get("hostname"),
        "dhcp_servers": master_config.get("dhcp_servers"),
        "dhcpv6_servers": master_config.get("dhcpv6_servers"),
        "snmp_user": master_config.get("snmp_user"),
        "interfaces": interfaces,
        "vlans": vlans,
        "sntp": master_config.get("sntp_servers"),
        "ipv4_managers": master_config.get("managers_v4", {}),
        "ipv6_managers": master_config.get("managers_v6", {}),
        "dns": master_config.get("dns"),
        "location": switch_config["location"],
        "radius_servers": master_config.get("radius_servers"),
        "mac_based_ports": syntax_from_range(mac_based_ports),
        "ra_guard_ports": syntax_from_range(ra_guard_ports),
        "unauth_redirect": master_config.get("unauth_redirect"),
        "dhcp_snooping_vlans": syntax_from_range(dhcp_snooping_vlans, vlan_syntax=True),
    }
    return conf_from_dict(config_dict)

def gen_conf_re2o(re2o_config, header):
    print(re2o_config.keys())
    raise RuntimeError()
    config_dict = {
       "header": header
    }
    return conf_from_dict(config_dict)

def connect_as_self(base_url, username=None):
    """Get a re2o token for the current unix user """
    if username is None:
        username = getpass.getuser()
    r = requests.post(
            base_url + "token-auth",
            data={
                "username": username,
                "password": getpass.getpass("Login to {} as {} with password :".format(base_url, username))
            }
    )
    if r.status_code != 200:
        logger.critical("Wrong login/password")
        exit(1)
    token = r.json().get("token")
    return token

def get_switch_from_results(results, switch_name):
    for s in results:
        if s.get("short_name"):
            return s
    return None

def get_switch_from_re2o(re2o_instance, switch_name, re2o_user):
    base_url = "{}/api/".format(re2o_instance)
    token = connect_as_self(base_url, re2o_user)
    headers = {"Authorization": "Token " + token}
    r = requests.get(base_url + "switchs/ports-config", headers=headers)
    sw_config = get_switch_from_results(r.json()["results"], switch_name)
    while r.json().get("next") and s is None:
        r = requests.get(r.json().get("next"), headers=headers)
        sw_config = get_switch_from_results(r.json()["results"], switch_name)
    return sw_config

if __name__ == "__main__":
    format_string = "%(asctime)s - %(levelname)s - %(message)s"
    stdout_handler = logging.StreamHandler()
    stdout_formatter = colorlog.ColoredFormatter("%(log_color)s{}".format(format_string))
    stdout_handler.setFormatter(stdout_formatter)
    logger.addHandler(stdout_handler)
    logger.setLevel(logging.DEBUG)

    parser = argparse.ArgumentParser(description="Script de déploiement de la configuration des switchs")
    parser.add_argument("-d", "--dry-run", action="store_true", help="Génère la nouvelle configuration et affiche le diff \
        sans tenter de l'appliquer")
    parser.add_argument("-w", "--whole", action="store_true", help="Affiche la configuration en entier au lieu du diff")
    parser.add_argument("switch_name", type=str, help="Génère le template de ce switch")
    parser.add_argument("-H", "--host", type=str, required=False, help="Host sur lequel de déployer la configuration au lieu de l'adresse dans le template")
    parser.add_argument("-r", "--re2o", type=str, required=False, help="Si renseigné, la configuration sera récupérée depuis l'instance de re2o indiquée au lieu d'utiliser les fichiers yaml")
    parser.add_argument("--re2o-user", type=str, required=False, help="Permet de choisir l'user pour se connecter à l'api re2o, par défaut on prend l'user unix courant")
    parser.add_argument("-4", "--force-ipv4", action="store_true", help="Force le provisionning en ipv4")

    args = parser.parse_args()

    if args.re2o:
       logger.debug("Loading master config")
       master_config = yaml.load(open("configs/master.yml", "r"), yaml.Loader)
       logger.debug("Loading config from re2o")
       re2o_config = get_switch_from_re2o(args.re2o, args.switch_name, args.re2o_user)
    else:
       logger.debug("Loading master config")
       master_config = yaml.load(open("configs/master.yml", "r"), yaml.Loader)
       logger.debug("Loading config for {}".format(args.switch_name))
       switch_config = yaml.load(open("configs/switches/{}.yml".format(args.switch_name), "r"), yaml.Loader)

    if args.host:
        switch_address = args.host
    elif args.re2o:
        if args.force_ipv4:
            switch_address = re2o_config.get("ipv4")
        else:
            switch_address = re2o_config.get("ipv6") or re2o_config.get("ipv4")
    else:
        if args.force_ipv4:
            switch_address = switch_config.get("ipv4-addr")
        else:
            switch_address = switch_config.get("ipv6-addr") or switch_config.get("ipv4-addr")

    if switch_address is None:
        switch_address = "{}.switches.crans.org".format(args.switch_name) #TODO: crans

    logger.info("Connecting to {} with address {}".format(args.switch_name, switch_address))
    session = connect_to_switch(switch_address, user="root", key=master_config.get("ssh_private_key")) #TODO: spécifier chemin clef
    old_config = sftp_read_file(session, "cfg/running-config").decode("utf-8")
    header = get_header(old_config)

    # génération de la conf
    logging.info("Generating configuration for {}".format(args.switch_name))
    if args.re2o:
        configuration = gen_conf_re2o(re2o_config, header)
    else:
        configuration = gen_conf(master_config, switch_config, header)

    # génération du diff
    for line in difflib.unified_diff(old_config.split("\n"), configuration.split("\n"), fromfile='origin', tofile='new', lineterm=""):
        if line.startswith("-"):
            termcolor.cprint(line, "red")
        elif line.startswith("+"):
            termcolor.cprint(line, "green")
        elif line.startswith("@"):
            termcolor.cprint(line, "yellow")
        else:
            print(line)
    if args.dry_run or input("Voulez-vous déployer la configuration sur le switch ? y/[n]").lower() not in ["o","y"]:
        logger.info("Aborting deployement")
        exit(0)
    with open("/tmp/conf_tmp", "w") as conf_tmp:
        conf_tmp.write(configuration)
    del session
    logging.info("Uploading configuration for {}".format(args.switch_name))
    session = connect_to_switch(switch_address, user="crans", key=master_config.get("ssh_private_key"))
    sftp_write_file(session, "/tmp/conf_tmp", "cfg/startup-config")
    logging.info("Deployement done for {}".format(args.switch_name))