# Reticulum License
#
# Copyright (c) 2016-2025 Mark Qvist
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# - The Software shall not be used in any kind of system which includes amongst
#   its functions the ability to purposefully do harm to human beings.
#
# - The Software shall not be used, directly or indirectly, in the creation of
#   an artificial intelligence, machine learning or language model training
#   dataset, including but not limited to any use that contributes to the
#   training or development of such a model or algorithm.
#
# - The above copyright notice and this permission notice shall be included in
#   all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import RNS
import time
import threading
from collections import deque
from RNS.vendor.configobj import ConfigObj

class Interface:
    IN  = False
    OUT = False
    FWD = False
    RPT = False
    name = None

    # Interface mode definitions
    MODE_FULL           = 0x01
    MODE_POINT_TO_POINT = 0x02
    MODE_ACCESS_POINT   = 0x03
    MODE_ROAMING        = 0x04
    MODE_BOUNDARY       = 0x05
    MODE_GATEWAY        = 0x06
    MODE_INTERNAL       = 0x07

    # Which interface modes a Transport Node should
    # actively discover paths for.
    DISCOVER_PATHS_FOR    = [MODE_ACCESS_POINT, MODE_GATEWAY, MODE_ROAMING, MODE_INTERNAL]
    BOUNDARY_SEARCH_MODES = [MODE_BOUNDARY, MODE_GATEWAY]

    # How many samples to use for announce
    # frequency calculations
    IA_FREQ_SAMPLES     = 48
    OA_FREQ_SAMPLES     = 48
    IP_FREQ_SAMPLES     = 48
    OP_FREQ_SAMPLES     = 48

    AR_MINFREQ_HZ       = 0.1
    PR_MINFREQ_HZ       = 0.1
    AR_FREQ_DECAY       = 1/AR_MINFREQ_HZ
    PR_FREQ_DECAY       = 1/PR_MINFREQ_HZ

    # Maximum amount of ingress limited announces
    # to hold at any given time.
    MAX_HELD_ANNOUNCES  = 256

    # Control parameters
    DEFAULT_GRAVITY          = 0
    IC_NEW_TIME              = 2*60*60
    IC_BURST_FREQ_NEW        = 3
    IC_BURST_FREQ            = 10
    IC_PR_BURST_FREQ_NEW     = 3
    IC_PR_BURST_FREQ         = 8
    IC_BURST_HOLD            = 15
    IC_BURST_PENALTY         = 15
    IC_HELD_RELEASE_INTERVAL = 5
    IC_DEQUE_MIN_SAMPLE      = 2
    IC_BURST_MIN_SAMPLES     = 6
    EC_PR_FREQ               = 5
    EGRESS_CONTROL           = False

    # Default announce rate targets
    DEFAULT_AR_TARGET        = 3600
    DEFAULT_AR_PENALTY       = 0
    DEFAULT_AR_GRACE         = 5

    AUTOCONFIGURE_MTU = False
    FIXED_MTU         = False

    def __init__(self):
        self.rxb      = 0
        self.txb      = 0
        self.gravity  = 0
        self.created  = time.time()
        self.detached = False
        self.online   = False
        self.bitrate  = 62500
        self.HW_MTU   = None
        self.__hash   = None

        self.supports_discovery       = False
        self.discoverable             = False
        self.last_discovery_announce  = 0
        self.bootstrap_only           = False
        self.recursive_prs            = False
        self.announces_from_internal  = True
        self.announces_to_internal    = None
        self.parent_interface         = None
        self.spawned_interfaces       = None
        self.tunnel_id                = None
        self.ingress_control          = True
        self.phy_keepalive            = False
        
        self.ic_burst_active          = False
        self.ic_burst_activated       = 0
        self.ic_pr_burst_active       = False
        self.ic_pr_burst_activated    = 0
        self.ic_held_release          = 0
        self.ic_max_held_announces    = RNS.Reticulum.get_instance()._default_ic_max_held_announces()
        self.ic_burst_hold            = RNS.Reticulum.get_instance()._default_ic_burst_hold()
        self.ic_burst_freq_new        = RNS.Reticulum.get_instance()._default_ic_burst_freq_new()
        self.ic_burst_freq            = RNS.Reticulum.get_instance()._default_ic_burst_freq()
        self.ic_pr_burst_freq_new     = RNS.Reticulum.get_instance()._default_ic_pr_burst_freq_new()
        self.ic_pr_burst_freq         = RNS.Reticulum.get_instance()._default_ic_pr_burst_freq()
        self.ic_new_time              = RNS.Reticulum.get_instance()._default_ic_new_time()
        self.ic_burst_penalty         = RNS.Reticulum.get_instance()._default_ic_burst_penalty()
        self.ic_held_release_interval = RNS.Reticulum.get_instance()._default_ic_held_release_interval()
        self.ec_pr_freq               = RNS.Reticulum.get_instance()._default_ec_pr_freq()
        self.egress_control           = RNS.Reticulum.get_instance()._default_egress_control()
        self.held_announces           = {}

        self.ia_freq_deque = deque(maxlen=Interface.IA_FREQ_SAMPLES)
        self.oa_freq_deque = deque(maxlen=Interface.OA_FREQ_SAMPLES)
        self.ip_freq_deque = deque(maxlen=Interface.IA_FREQ_SAMPLES)
        self.op_freq_deque = deque(maxlen=Interface.OA_FREQ_SAMPLES)

    def get_hash(self):
        if not self.__hash: self.__hash = RNS.Identity.full_hash(str(self).encode("utf-8"))
        return self.__hash

    # This is a generic function for determining when an interface
    # should activate ingress limiting. Since this can vary for
    # different interface types, this function should be overwritten
    # in case a particular interface requires a different approach.
    def should_ingress_limit(self):
        if self.ingress_control:
            freq_threshold = self.ic_burst_freq_new if self.age() < self.ic_new_time else self.ic_burst_freq
            ia_freq = self.incoming_announce_frequency()

            if self.ic_burst_active:
                if ia_freq < freq_threshold and time.time() > self.ic_burst_activated+self.ic_burst_hold:
                    if len(self.ia_freq_deque) >= self.IC_DEQUE_MIN_SAMPLE: self.ic_burst_active = False

                return True

            else:
                if ia_freq > freq_threshold:
                    self.ic_burst_active = True
                    self.ic_burst_activated = time.time()
                    self.ic_held_release = time.time() + self.ic_burst_penalty
                    return True

                else: return False

        else: return False

    def should_ingress_limit_pr(self):
        if self.ingress_control:
            freq_threshold = self.ic_pr_burst_freq_new if self.age() < self.ic_new_time else self.ic_pr_burst_freq
            ip_freq = self.incoming_pr_frequency()

            if self.ic_pr_burst_active:
                if ip_freq < freq_threshold and time.time() > self.ic_pr_burst_activated+self.ic_burst_hold:
                    self.ic_pr_burst_active = False

                return True

            else:
                if ip_freq > freq_threshold:
                    self.ic_pr_burst_active = True
                    self.ic_pr_burst_activated = time.time()
                    return True

                else: return False

        else: return False

    def should_egress_limit_pr(self):
        if self.egress_control:
            freq_threshold = self.ec_pr_freq
            op_freq = self.outgoing_pr_frequency()

            if op_freq > freq_threshold:
                if len(self.op_freq_deque) >= self.IC_BURST_MIN_SAMPLES: return True
            
        return False

    def optimise_mtu(self):
        if self.AUTOCONFIGURE_MTU:
            if self.bitrate   >= 1_000_000_000:  self.HW_MTU = 524288
            elif self.bitrate > 750_000_000:     self.HW_MTU = 262144
            elif self.bitrate > 400_000_000:     self.HW_MTU = 131072
            elif self.bitrate > 200_000_000:     self.HW_MTU = 65536
            elif self.bitrate > 100_000_000:     self.HW_MTU = 32768
            elif self.bitrate > 10_000_000:      self.HW_MTU = 16384
            elif self.bitrate > 5_000_000:       self.HW_MTU = 8192
            elif self.bitrate > 2_000_000:       self.HW_MTU = 4096
            elif self.bitrate > 1_000_000:       self.HW_MTU = 2048
            elif self.bitrate > 62_500:          self.HW_MTU = 1024
            else:                                self.HW_MTU = None

        RNS.log(f"{self} hardware MTU set to {self.HW_MTU}", RNS.LOG_PATHING)

    def age(self):
        return time.time()-self.created

    def hold_announce(self, announce_packet):
        if announce_packet.hops >= RNS.Transport.PATHFINDER_M-1:
            return
        elif announce_packet.destination_hash in self.held_announces:
            self.held_announces[announce_packet.destination_hash] = announce_packet
        elif not len(self.held_announces) >= self.ic_max_held_announces:
            self.held_announces[announce_packet.destination_hash] = announce_packet

    def process_held_announces(self):
        try:
            if len(self.held_announces) > 0 and time.time() > self.ic_held_release:
                freq_threshold = self.ic_burst_freq_new if self.age() < self.ic_new_time else self.ic_burst_freq
                ia_freq = self.incoming_announce_frequency()
                if ia_freq < freq_threshold:
                    selected_announce_packet = None
                    min_hops = RNS.Transport.PATHFINDER_M
                    for destination_hash in self.held_announces:
                        announce_packet = self.held_announces[destination_hash]
                        if announce_packet.hops < min_hops:
                            min_hops = announce_packet.hops
                            selected_announce_packet = announce_packet

                    if selected_announce_packet != None:
                        RNS.log("Releasing held announce packet "+str(selected_announce_packet)+" from "+str(self), RNS.LOG_EXTREME)
                        self.ic_held_release = time.time() + self.ic_held_release_interval
                        self.held_announces.pop(selected_announce_packet.destination_hash)
                        def release(): RNS.Transport.inbound(selected_announce_packet.raw, selected_announce_packet.receiving_interface)
                        threading.Thread(target=release, daemon=True).start()
        
        except Exception as e:
            RNS.log("An error occurred while processing held announces for "+str(self), RNS.LOG_ERROR)
            RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)

    def received_announce(self, from_spawned=False):
        self.ia_freq_deque.append(time.time())
        if hasattr(self, "parent_interface") and self.parent_interface != None:
            self.parent_interface.received_announce(from_spawned=True)

    def sent_announce(self, from_spawned=False):
        self.oa_freq_deque.append(time.time())
        if hasattr(self, "parent_interface") and self.parent_interface != None:
            self.parent_interface.sent_announce(from_spawned=True)

    def received_path_request(self, from_spawned=False):
        self.ip_freq_deque.append(time.time())
        if hasattr(self, "parent_interface") and self.parent_interface != None:
            self.parent_interface.received_path_request(from_spawned=True)

    def sent_path_request(self, from_spawned=False):
        self.op_freq_deque.append(time.time())
        if hasattr(self, "parent_interface") and self.parent_interface != None:
            self.parent_interface.sent_path_request(from_spawned=True)

    def incoming_announce_frequency(self):
        n = len(self.ia_freq_deque)
        if not n > self.IC_DEQUE_MIN_SAMPLE: return 0
        else:
            oldest = self.ia_freq_deque[0]
            span = time.time() - oldest
            if span > self.AR_FREQ_DECAY: self.ia_freq_deque.popleft()
            if span <= 0: return 0
            hz = n / span
            return hz

    def outgoing_announce_frequency(self):
        n = len(self.oa_freq_deque)
        if not len(self.oa_freq_deque) > 1: return 0
        else:
            oldest = self.oa_freq_deque[0]
            span   = time.time() - oldest
            if span > self.AR_FREQ_DECAY: self.oa_freq_deque.popleft()
            if span <= 0: return 0
            hz = n / span
            return hz

    def incoming_pr_frequency(self):
        n = len(self.ip_freq_deque)
        if not n > self.IC_DEQUE_MIN_SAMPLE: return 0
        else:
            oldest = self.ip_freq_deque[0]
            span = time.time() - oldest
            if span > self.PR_FREQ_DECAY: self.ip_freq_deque.popleft()
            if span <= 0: return 0
            hz = n / span
            return hz

    def outgoing_pr_frequency(self):
        n = len(self.op_freq_deque)
        if not len(self.op_freq_deque) > 1: return 0
        else:
            oldest = self.op_freq_deque[0]
            span   = time.time() - oldest
            if span > self.PR_FREQ_DECAY: self.op_freq_deque.popleft()
            if span <= 0: return 0
            hz = n / span
            return hz

    def process_announce_queue(self):
        if not hasattr(self, "announce_cap"):
            self.announce_cap = RNS.Reticulum.ANNOUNCE_CAP

        if hasattr(self, "announce_queue"):
            try:
                now = time.time()
                stale = []
                for a in self.announce_queue:
                    if now > a["time"]+RNS.Reticulum.QUEUED_ANNOUNCE_LIFE:
                        stale.append(a)

                for s in stale:
                    if s in self.announce_queue:
                        self.announce_queue.remove(s)

                if len(self.announce_queue) > 0:
                    min_hops = min(entry["hops"] for entry in self.announce_queue)
                    entries = list(filter(lambda e: e["hops"] == min_hops, self.announce_queue))
                    entries.sort(key=lambda e: e["time"])
                    selected = entries[0]

                    now       = time.time()
                    tx_time   = (len(selected["raw"])*8) / self.bitrate
                    wait_time = (tx_time / self.announce_cap)
                    self.announce_allowed_at = now + wait_time

                    self.process_outgoing(selected["raw"])
                    self.sent_announce()

                    if selected in self.announce_queue:
                        self.announce_queue.remove(selected)

                    if len(self.announce_queue) > 0:
                        timer = threading.Timer(wait_time, self.process_announce_queue)
                        timer.start()

            except Exception as e:
                self.announce_queue = []
                RNS.log("Error while processing announce queue on "+str(self)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
                RNS.log("The announce queue for this interface has been cleared.", RNS.LOG_ERROR)

    def final_init(self):
        pass

    def detach(self):
        pass

    @staticmethod
    def get_config_obj(config_in):
        if type(config_in) == ConfigObj: return config_in
        else:
            try: return ConfigObj(config_in)
            except Exception as e:
                RNS.log(f"Could not parse supplied configuration data. The contained exception was: {e}", RNS.LOG_ERROR)
                raise SystemError("Invalid configuration data supplied")