import os
import asyncio
import aiohttp
import logging
import math
import binascii
import typing
import socket
from hashlib import sha256
from types import SimpleNamespace

from aioupnp import __version__ as aioupnp_version
from aioupnp.upnp import UPnP
from aioupnp.fault import UPnPError

import lbrynet.schema
from lbrynet.conf import HEADERS_FILE_SHA256_CHECKSUM
from lbrynet.dht.node import Node
from lbrynet.dht.peer import KademliaPeer
from lbrynet.dht.blob_announcer import BlobAnnouncer
from lbrynet.blob.blob_manager import BlobFileManager
from lbrynet.blob_exchange.server import BlobServer
from lbrynet.stream.stream_manager import StreamManager
from lbrynet.extras.daemon.Component import Component
from lbrynet.extras.daemon.exchange_rate_manager import ExchangeRateManager
from lbrynet.extras.daemon.storage import SQLiteStorage
from lbrynet.extras.wallet import LbryWalletManager
from lbrynet.extras.wallet import Network


log = logging.getLogger(__name__)

# settings must be initialized before this file is imported

DATABASE_COMPONENT = "database"
BLOB_COMPONENT = "blob_manager"
HEADERS_COMPONENT = "blockchain_headers"
WALLET_COMPONENT = "wallet"
DHT_COMPONENT = "dht"
HASH_ANNOUNCER_COMPONENT = "hash_announcer"
STREAM_MANAGER_COMPONENT = "stream_manager"
PEER_PROTOCOL_SERVER_COMPONENT = "peer_protocol_server"
UPNP_COMPONENT = "upnp"
EXCHANGE_RATE_MANAGER_COMPONENT = "exchange_rate_manager"


async def gather_dict(tasks: dict):
    async def wait_value(key, value):
        return key, await value
    return dict(await asyncio.gather(*(
        wait_value(*kv) for kv in tasks.items()
    )))


async def get_external_ip():  # used if upnp is disabled or non-functioning
    try:
        async with aiohttp.ClientSession() as session:
            async with session.get("https://api.lbry.io/ip") as resp:
                response = await resp.json()
                if response['success']:
                    return response['data']['ip']
    except Exception as e:
        pass


async def resolve_host(loop: asyncio.BaseEventLoop, url: str):
    info = await loop.getaddrinfo(
        url, 'https',
        proto=socket.IPPROTO_TCP,
    )
    return info[0][4][0]


class DatabaseComponent(Component):
    component_name = DATABASE_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.storage = None

    @property
    def component(self):
        return self.storage

    @staticmethod
    def get_current_db_revision():
        return 9

    @property
    def revision_filename(self):
        return self.component_manager.daemon.db_revision_file_path

    def _write_db_revision_file(self, version_num):
        with open(self.revision_filename, mode='w') as db_revision:
            db_revision.write(str(version_num))

    async def start(self):
        # check directories exist, create them if they don't
        log.info("Loading databases")

        if not os.path.exists(self.revision_filename):
            log.warning("db_revision file not found. Creating it")
            self._write_db_revision_file(self.get_current_db_revision())

        # check the db migration and run any needed migrations
        with open(self.revision_filename, "r") as revision_read_handle:
            old_revision = int(revision_read_handle.read().strip())

        if old_revision > self.get_current_db_revision():
            raise Exception('This version of lbrynet is not compatible with the database\n'
                            'Your database is revision %i, expected %i' %
                            (old_revision, self.get_current_db_revision()))
        if old_revision < self.get_current_db_revision():
            from lbrynet.extras.daemon.migrator import dbmigrator
            log.info("Upgrading your databases (revision %i to %i)", old_revision, self.get_current_db_revision())
            await asyncio.get_event_loop().run_in_executor(
                None, dbmigrator.migrate_db, self.conf.data_dir, old_revision, self.get_current_db_revision()
            )
            self._write_db_revision_file(self.get_current_db_revision())
            log.info("Finished upgrading the databases.")

        self.storage = SQLiteStorage(
            self.conf, os.path.join(self.conf.data_dir, "lbrynet.sqlite")
        )
        await self.storage.open()

    async def stop(self):
        await self.storage.close()
        self.storage = None


HEADERS_URL = "https://headers.lbry.io/blockchain_headers_latest"
HEADER_SIZE = 112


class HeadersComponent(Component):
    component_name = HEADERS_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.headers_dir = os.path.join(self.conf.wallet_dir, 'lbc_mainnet')
        self.headers_file = os.path.join(self.headers_dir, 'headers')
        self.old_file = os.path.join(self.conf.wallet_dir, 'blockchain_headers')
        self._downloading_headers = None
        self._headers_progress_percent = 0

    @property
    def component(self):
        return self

    async def get_status(self):
        return {} if not self._downloading_headers else {
            'downloading_headers': self._downloading_headers,
            'download_progress': self._headers_progress_percent
        }

    async def fetch_headers_from_s3(self):
        def collector(d, h_file):
            h_file.write(d)
            local_size = float(h_file.tell())
            final_size = float(final_size_after_download)
            self._headers_progress_percent = math.ceil(local_size / final_size * 100)

        local_header_size = self.local_header_file_size()
        resume_header = {"Range": f"bytes={local_header_size}-"}
        async with aiohttp.request('get', HEADERS_URL, headers=resume_header) as response:
            got_406 = response.status == 406  # our file is bigger
            final_size_after_download = response.content_length + local_header_size
            if got_406:
                log.warning("s3 is more out of date than we are")
            # should have something to download and a final length divisible by the header size
            elif final_size_after_download and not final_size_after_download % HEADER_SIZE:
                s3_height = (final_size_after_download / HEADER_SIZE) - 1
                local_height = self.local_header_file_height()
                if s3_height > local_height:
                    data = await response.read()

                    if local_header_size:
                        log.info("Resuming download of %i bytes from s3", response.content_length)
                        with open(self.headers_file, "a+b") as headers_file:
                            collector(data, headers_file)
                    else:
                        with open(self.headers_file, "wb") as headers_file:
                            collector(data, headers_file)
                    log.info("fetched headers from s3 (s3 height: %i), now verifying integrity after download.",
                             s3_height)
                    self._check_header_file_integrity()
                else:
                    log.warning("s3 is more out of date than we are")
            else:
                log.error("invalid size for headers from s3")

    def local_header_file_height(self):
        return max((self.local_header_file_size() / HEADER_SIZE) - 1, 0)

    def local_header_file_size(self):
        if os.path.isfile(self.headers_file):
            return os.stat(self.headers_file).st_size
        return 0

    async def get_remote_height(self):
        ledger = SimpleNamespace()
        ledger.config = {
            'default_servers': self.conf.lbryum_servers,
            'data_path': self.conf.wallet_dir
        }
        net = Network(ledger)
        first_connection = net.on_connected.first
        asyncio.ensure_future(net.start())
        await first_connection
        remote_height = await net.get_server_height()
        await net.stop()
        return remote_height

    async def should_download_headers_from_s3(self):
        if self.conf.blockchain_name != "lbrycrd_main":
            return False
        self._check_header_file_integrity()
        s3_headers_depth = self.conf.s3_headers_depth
        if not s3_headers_depth:
            return False
        local_height = self.local_header_file_height()
        remote_height = await self.get_remote_height()
        log.info("remote height: %i, local height: %i", remote_height, local_height)
        if remote_height > (local_height + s3_headers_depth):
            return True
        return False

    def _check_header_file_integrity(self):
        # TODO: temporary workaround for usability. move to txlbryum and check headers instead of file integrity
        if self.conf.blockchain_name != "lbrycrd_main":
            return
        hashsum = sha256()
        checksum_height, checksum = HEADERS_FILE_SHA256_CHECKSUM
        checksum_length_in_bytes = checksum_height * HEADER_SIZE
        if self.local_header_file_size() < checksum_length_in_bytes:
            return
        with open(self.headers_file, "rb") as headers_file:
            hashsum.update(headers_file.read(checksum_length_in_bytes))
        current_checksum = hashsum.hexdigest()
        if current_checksum != checksum:
            msg = f"Expected checksum {checksum}, got {current_checksum}"
            log.warning("Wallet file corrupted, checksum mismatch. " + msg)
            log.warning("Deleting header file so it can be downloaded again.")
            os.unlink(self.headers_file)
        elif (self.local_header_file_size() % HEADER_SIZE) != 0:
            log.warning("Header file is good up to checkpoint height, but incomplete. Truncating to checkpoint.")
            with open(self.headers_file, "rb+") as headers_file:
                headers_file.truncate(checksum_length_in_bytes)

    async def start(self):
        if not os.path.exists(self.headers_dir):
            os.mkdir(self.headers_dir)
        if os.path.exists(self.old_file):
            log.warning("Moving old headers from %s to %s.", self.old_file, self.headers_file)
            os.rename(self.old_file, self.headers_file)
        self._downloading_headers = await self.should_download_headers_from_s3()
        if self._downloading_headers:
            try:
                await self.fetch_headers_from_s3()
            except Exception as err:
                log.error("failed to fetch headers from s3: %s", err)
            finally:
                self._downloading_headers = False

    async def stop(self):
        pass


class WalletComponent(Component):
    component_name = WALLET_COMPONENT
    depends_on = [DATABASE_COMPONENT, HEADERS_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.wallet_manager = None

    @property
    def component(self):
        return self.wallet_manager

    async def get_status(self):
        if self.wallet_manager and self.running:
            local_height = self.wallet_manager.network.get_local_height()
            remote_height = self.wallet_manager.network.get_server_height()
            best_hash = self.wallet_manager.get_best_blockhash()
            return {
                'blocks': max(local_height, 0),
                'blocks_behind': max(remote_height - local_height, 0),
                'best_blockhash': best_hash,
                'is_encrypted': self.wallet_manager.wallet.use_encryption,
                'is_locked': not self.wallet_manager.is_wallet_unlocked,
            }

    async def start(self):
        log.info("Starting torba wallet")
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        lbrynet.schema.BLOCKCHAIN_NAME = self.conf.blockchain_name
        self.wallet_manager = await LbryWalletManager.from_lbrynet_config(self.conf, storage)
        self.wallet_manager.old_db = storage
        await self.wallet_manager.start()

    async def stop(self):
        await self.wallet_manager.stop()
        self.wallet_manager = None


class BlobComponent(Component):
    component_name = BLOB_COMPONENT
    depends_on = [DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.blob_manager: BlobFileManager = None

    @property
    def component(self) -> typing.Optional[BlobFileManager]:
        return self.blob_manager

    async def start(self):
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        data_store = None
        if DHT_COMPONENT not in self.component_manager.skip_components:
            dht_node: Node = self.component_manager.get_component(DHT_COMPONENT)
            if dht_node:
                data_store = dht_node.protocol.data_store
        self.blob_manager = BlobFileManager(asyncio.get_event_loop(), os.path.join(self.conf.data_dir, "blobfiles"),
                                            storage, data_store)
        return await self.blob_manager.setup()

    async def stop(self):
        while self.blob_manager and self.blob_manager.blobs:
            _, blob = self.blob_manager.blobs.popitem()
            await blob.close()

    async def get_status(self):
        count = 0
        if self.blob_manager:
            count = len(self.blob_manager.completed_blob_hashes)
        return {'finished_blobs': count}


class DHTComponent(Component):
    component_name = DHT_COMPONENT
    depends_on = [UPNP_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.dht_node: Node = None
        self.upnp_component = None
        self.external_udp_port = None
        self.external_peer_port = None

    @property
    def component(self) -> typing.Optional[Node]:
        return self.dht_node

    async def get_status(self):
        return {
            'node_id': binascii.hexlify(self.component_manager.daemon.node_id),
            'peers_in_routing_table': 0 if not self.dht_node else len(self.dht_node.protocol.routing_table.get_peers())
        }

    async def start(self):
        log.info("start the dht")
        self.upnp_component = self.component_manager.get_component(UPNP_COMPONENT)
        self.external_peer_port = self.upnp_component.upnp_redirects.get("TCP", self.conf.peer_port)
        self.external_udp_port = self.upnp_component.upnp_redirects.get("UDP", self.conf.dht_node_port)
        node_id = self.component_manager.daemon.node_id
        external_ip = self.upnp_component.external_ip
        if not external_ip:
            log.warning("UPnP component failed to get external ip")
            external_ip = await get_external_ip()
            if not external_ip:
                log.warning("failed to get external ip")

        self.dht_node = Node(
            asyncio.get_event_loop(),
            self.component_manager.peer_manager,
            node_id=node_id,
            internal_udp_port=self.conf.dht_node_port,
            udp_port=self.external_udp_port,
            external_ip=external_ip,
            peer_port=self.external_peer_port
        )
        self.dht_node.start(
            interface='0.0.0.0', known_node_urls=self.conf.known_dht_nodes
        )
        log.info("Started the dht")

    async def stop(self):
        self.dht_node.stop()


class HashAnnouncerComponent(Component):
    component_name = HASH_ANNOUNCER_COMPONENT
    depends_on = [DHT_COMPONENT, DATABASE_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.hash_announcer: BlobAnnouncer = None

    @property
    def component(self) -> typing.Optional[BlobAnnouncer]:
        return self.hash_announcer

    async def start(self):
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        dht_node = self.component_manager.get_component(DHT_COMPONENT)
        self.hash_announcer = BlobAnnouncer(asyncio.get_event_loop(), dht_node, storage)
        self.hash_announcer.start(self.conf.concurrent_announcers)
        log.info("Started blob announcer")

    async def stop(self):
        self.hash_announcer.stop()
        log.info("Stopped blob announcer")

    async def get_status(self):
        return {
            'announce_queue_size': 0 if not self.hash_announcer else len(self.hash_announcer.announce_queue)
        }


class StreamManagerComponent(Component):
    component_name = STREAM_MANAGER_COMPONENT
    depends_on = [BLOB_COMPONENT, DATABASE_COMPONENT, WALLET_COMPONENT, DHT_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.stream_manager: StreamManager = None

    @property
    def component(self) -> typing.Optional[StreamManager]:
        return self.stream_manager

    async def get_status(self):
        if not self.stream_manager:
            return
        return {
            'managed_files': len(self.stream_manager.streams)
        }

    async def start(self):
        blob_manager = self.component_manager.get_component(BLOB_COMPONENT)
        storage = self.component_manager.get_component(DATABASE_COMPONENT)
        wallet = self.component_manager.get_component(WALLET_COMPONENT)
        node = self.component_manager.get_component(DHT_COMPONENT)

        log.info('Starting the file manager')
        loop = asyncio.get_event_loop()
        self.stream_manager = StreamManager(
            loop, blob_manager, wallet, storage, node, self.conf.blob_download_timeout,
            self.conf.peer_connect_timeout, [
                KademliaPeer(loop, address=(await resolve_host(loop, url)), tcp_port=port + 1)
                for url, port in self.conf.reflector_servers
            ]
        )
        await self.stream_manager.start()
        log.info('Done setting up file manager')

    async def stop(self):
        await self.stream_manager.stop()


class PeerProtocolServerComponent(Component):
    component_name = PEER_PROTOCOL_SERVER_COMPONENT
    depends_on = [UPNP_COMPONENT, BLOB_COMPONENT, WALLET_COMPONENT]

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self.blob_server: BlobServer = None

    @property
    def component(self) -> typing.Optional[BlobServer]:
        return self.blob_server

    async def start(self):
        log.info("start blob server")
        upnp = self.component_manager.get_component(UPNP_COMPONENT)
        blob_manager: BlobFileManager = self.component_manager.get_component(BLOB_COMPONENT)
        wallet: LbryWalletManager = self.component_manager.get_component(WALLET_COMPONENT)
        peer_port = upnp.upnp_redirects.get("TCP", self.conf.settings["peer_port"])
        address = await wallet.get_unused_address()
        self.blob_server = BlobServer(asyncio.get_event_loop(), blob_manager, address)
        self.blob_server.start_server(peer_port, interface='0.0.0.0')
        await self.blob_server.started_listening.wait()

    async def stop(self):
        if self.blob_server:
            self.blob_server.stop_server()


class UPnPComponent(Component):
    component_name = UPNP_COMPONENT

    def __init__(self, component_manager):
        super().__init__(component_manager)
        self._int_peer_port = self.conf.peer_port
        self._int_dht_node_port = self.conf.dht_node_port
        self.use_upnp = self.conf.use_upnp
        self.upnp = None
        self.upnp_redirects = {}
        self.external_ip = None
        self._maintain_redirects_task = None

    @property
    def component(self) -> 'UPnPComponent':
        return self

    async def _repeatedly_maintain_redirects(self, now=True):
        while True:
            if now:
                await self._maintain_redirects()
            await asyncio.sleep(360)

    async def _maintain_redirects(self):
        # setup the gateway if necessary
        if not self.upnp:
            try:
                self.upnp = await UPnP.discover()
                log.info("found upnp gateway: %s", self.upnp.gateway.manufacturer_string)
            except Exception as err:
                log.warning("upnp discovery failed: %s", err)
                self.upnp = None

        # update the external ip
        external_ip = None
        if self.upnp:
            try:
                external_ip = await self.upnp.get_external_ip()
                if external_ip != "0.0.0.0" and not self.external_ip:
                    log.info("got external ip from UPnP: %s", external_ip)
            except (asyncio.TimeoutError, UPnPError):
                pass

        if external_ip == "0.0.0.0" or not external_ip:
            log.warning("unable to get external ip from UPnP, checking lbry.io fallback")
            external_ip = await get_external_ip()
        if self.external_ip and self.external_ip != external_ip:
            log.info("external ip changed from %s to %s", self.external_ip, external_ip)
        self.external_ip = external_ip
        assert self.external_ip is not None   # TODO: handle going/starting offline

        if not self.upnp_redirects and self.upnp:  # setup missing redirects
            try:
                log.info("add UPnP port mappings")
                d = {}
                if PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components:
                    d["TCP"] = self.upnp.get_next_mapping(self._int_peer_port, "TCP", "LBRY peer port")
                if DHT_COMPONENT not in self.component_manager.skip_components:
                    d["UDP"] = self.upnp.get_next_mapping(self._int_dht_node_port, "UDP", "LBRY DHT port")
                upnp_redirects = await gather_dict(d)
                log.info("set up redirects: %s", upnp_redirects)
                self.upnp_redirects.update(upnp_redirects)
            except (asyncio.TimeoutError, UPnPError):
                self.upnp = None
                return self._maintain_redirects()
        elif self.upnp:  # check existing redirects are still active
            found = set()
            mappings = await self.upnp.get_redirects()
            for mapping in mappings:
                proto = mapping['NewProtocol']
                if proto in self.upnp_redirects and mapping['NewExternalPort'] == self.upnp_redirects[proto]:
                    if mapping['NewInternalClient'] == self.upnp.lan_address:
                        found.add(proto)
            if 'UDP' not in found and DHT_COMPONENT not in self.component_manager.skip_components:
                try:
                    udp_port = await self.upnp.get_next_mapping(self._int_dht_node_port, "UDP", "LBRY DHT port")
                    self.upnp_redirects['UDP'] = udp_port
                    log.info("refreshed upnp redirect for dht port: %i", udp_port)
                except (asyncio.TimeoutError, UPnPError):
                    del self.upnp_redirects['UDP']
            if 'TCP' not in found and PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components:
                try:
                    tcp_port = await self.upnp.get_next_mapping(self._int_peer_port, "TCP", "LBRY peer port")
                    self.upnp_redirects['TCP'] = tcp_port
                    log.info("refreshed upnp redirect for peer port: %i", tcp_port)
                except (asyncio.TimeoutError, UPnPError):
                    del self.upnp_redirects['TCP']
            if ('TCP' in self.upnp_redirects
                and PEER_PROTOCOL_SERVER_COMPONENT not in self.component_manager.skip_components) and (
                    'UDP' in self.upnp_redirects and DHT_COMPONENT not in self.component_manager.skip_components):
                if self.upnp_redirects:
                    log.debug("upnp redirects are still active")

    async def start(self):
        log.info("detecting external ip")
        if not self.use_upnp:
            self.external_ip = await get_external_ip()
            return
        success = False
        await self._maintain_redirects()
        if self.upnp:
            if not self.upnp_redirects and not all([x in self.component_manager.skip_components for x in
                                                    (DHT_COMPONENT, PEER_PROTOCOL_SERVER_COMPONENT)]):
                log.error("failed to setup upnp, debugging infomation: %s", self.upnp.zipped_debugging_info)
            else:
                success = True
                if self.upnp_redirects:
                    log.debug("set up upnp port redirects for gateway: %s", self.upnp.gateway.manufacturer_string)
        else:
            log.error("failed to setup upnp")
        if self.component_manager.analytics_manager:
            self.component_manager.analytics_manager.send_upnp_setup_success_fail(success, await self.get_status())
        self._maintain_redirects_task = asyncio.create_task(self._repeatedly_maintain_redirects(now=False))

    async def stop(self):
        if self.upnp_redirects:
            await asyncio.wait([
                self.upnp.delete_port_mapping(port, protocol) for protocol, port in self.upnp_redirects.items()
            ])
        if self._maintain_redirects_task and not self._maintain_redirects_task.done():
            self._maintain_redirects_task.cancel()

    async def get_status(self):
        return {
            'aioupnp_version': aioupnp_version,
            'redirects': self.upnp_redirects,
            'gateway': 'No gateway found' if not self.upnp else self.upnp.gateway.manufacturer_string,
            'dht_redirect_set': 'UDP' in self.upnp_redirects,
            'peer_redirect_set': 'TCP' in self.upnp_redirects,
            'external_ip': self.external_ip
        }


class ExchangeRateManagerComponent(Component):
    component_name = EXCHANGE_RATE_MANAGER_COMPONENT

    def __init__(self, component_manager):
        Component.__init__(self, component_manager)
        self.exchange_rate_manager = ExchangeRateManager()

    @property
    def component(self) -> ExchangeRateManager:
        return self.exchange_rate_manager

    async def start(self):
        self.exchange_rate_manager.start()

    async def stop(self):
        self.exchange_rate_manager.stop()