#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import gc
import logging
import os
import sys

import synapse
import synapse.config.logger
from synapse import events
from synapse.api.urls import CONTENT_REPO_PREFIX, FEDERATION_PREFIX, \
    LEGACY_MEDIA_PREFIX, MEDIA_PREFIX, SERVER_KEY_PREFIX, SERVER_KEY_V2_PREFIX, \
    STATIC_PREFIX, WEB_CLIENT_PREFIX
from synapse.app import _base
from synapse.app._base import quit_with_error, listen_ssl, listen_tcp
from synapse.config._base import ConfigError
from synapse.config.homeserver import HomeServerConfig
from synapse.crypto import context_factory
from synapse.federation.transport.server import TransportLayerServer
from synapse.module_api import ModuleApi
from synapse.http.additional_resource import AdditionalResource
from synapse.http.server import RootRedirect
from synapse.http.site import SynapseSite
from synapse.metrics import register_memory_metrics
from synapse.metrics.resource import METRICS_PREFIX, MetricsResource
from synapse.python_dependencies import CONDITIONAL_REQUIREMENTS, \
    check_requirements
from synapse.replication.http import ReplicationRestResource, REPLICATION_PREFIX
from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
from synapse.rest import ClientRestResource
from synapse.rest.key.v1.server_key_resource import LocalKey
from synapse.rest.key.v2 import KeyApiV2Resource
from synapse.rest.media.v0.content_repository import ContentRepoResource
from synapse.server import HomeServer
from synapse.storage import are_all_users_on_domain
from synapse.storage.engines import IncorrectDatabaseSetup, create_engine
from synapse.storage.prepare_database import UpgradeDatabaseException, prepare_database
from synapse.util.caches import CACHE_SIZE_FACTOR
from synapse.util.httpresourcetree import create_resource_tree
from synapse.util.logcontext import LoggingContext
from synapse.util.manhole import manhole
from synapse.util.module_loader import load_module
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
from twisted.application import service
from twisted.internet import defer, reactor
from twisted.web.resource import EncodingResourceWrapper, NoResource
from twisted.web.server import GzipEncoderFactory
from twisted.web.static import File

logger = logging.getLogger("synapse.app.homeserver")


def gz_wrap(r):
    return EncodingResourceWrapper(r, [GzipEncoderFactory()])


def build_resource_for_web_client(hs):
    webclient_path = hs.get_config().web_client_location
    if not webclient_path:
        try:
            import syweb
        except ImportError:
            quit_with_error(
                "Could not find a webclient.\n\n"
                "Please either install the matrix-angular-sdk or configure\n"
                "the location of the source to serve via the configuration\n"
                "option `web_client_location`\n\n"
                "To install the `matrix-angular-sdk` via pip, run:\n\n"
                "    pip install '%(dep)s'\n"
                "\n"
                "You can also disable hosting of the webclient via the\n"
                "configuration option `web_client`\n"
                % {"dep": CONDITIONAL_REQUIREMENTS["web_client"].keys()[0]}
            )
        syweb_path = os.path.dirname(syweb.__file__)
        webclient_path = os.path.join(syweb_path, "webclient")
    # GZip is disabled here due to
    # https://twistedmatrix.com/trac/ticket/7678
    # (It can stay enabled for the API resources: they call
    # write() with the whole body and then finish() straight
    # after and so do not trigger the bug.
    # GzipFile was removed in commit 184ba09
    # return GzipFile(webclient_path)  # TODO configurable?
    return File(webclient_path)  # TODO configurable?


class SynapseHomeServer(HomeServer):
    def _listener_http(self, config, listener_config):
        port = listener_config["port"]
        bind_addresses = listener_config["bind_addresses"]
        tls = listener_config.get("tls", False)
        site_tag = listener_config.get("tag", port)

        if tls and config.no_tls:
            return

        resources = {}
        for res in listener_config["resources"]:
            for name in res["names"]:
                resources.update(self._configure_named_resource(
                    name, res.get("compress", False),
                ))

        additional_resources = listener_config.get("additional_resources", {})
        logger.debug("Configuring additional resources: %r",
                     additional_resources)
        module_api = ModuleApi(self, self.get_auth_handler())
        for path, resmodule in additional_resources.items():
            handler_cls, config = load_module(resmodule)
            handler = handler_cls(config, module_api)
            resources[path] = AdditionalResource(self, handler.handle_request)

        if WEB_CLIENT_PREFIX in resources:
            root_resource = RootRedirect(WEB_CLIENT_PREFIX)
        else:
            root_resource = NoResource()

        root_resource = create_resource_tree(resources, root_resource)

        if tls:
            listen_ssl(
                bind_addresses,
                port,
                SynapseSite(
                    "synapse.access.https.%s" % (site_tag,),
                    site_tag,
                    listener_config,
                    root_resource,
                ),
                self.tls_server_context_factory,
            )

        else:
            listen_tcp(
                bind_addresses,
                port,
                SynapseSite(
                    "synapse.access.http.%s" % (site_tag,),
                    site_tag,
                    listener_config,
                    root_resource,
                )
            )
        logger.info("Synapse now listening on port %d", port)

    def _configure_named_resource(self, name, compress=False):
        """Build a resource map for a named resource

        Args:
            name (str): named resource: one of "client", "federation", etc
            compress (bool): whether to enable gzip compression for this
                resource

        Returns:
            dict[str, Resource]: map from path to HTTP resource
        """
        resources = {}
        if name == "client":
            client_resource = ClientRestResource(self)
            if compress:
                client_resource = gz_wrap(client_resource)

            resources.update({
                "/_matrix/client/api/v1": client_resource,
                "/_matrix/client/r0": client_resource,
                "/_matrix/client/unstable": client_resource,
                "/_matrix/client/v2_alpha": client_resource,
                "/_matrix/client/versions": client_resource,
            })

        if name == "federation":
            resources.update({
                FEDERATION_PREFIX: TransportLayerServer(self),
            })

        if name in ["static", "client"]:
            resources.update({
                STATIC_PREFIX: File(
                    os.path.join(os.path.dirname(synapse.__file__), "static")
                ),
            })

        if name in ["media", "federation", "client"]:
            if self.get_config().enable_media_repo:
                media_repo = self.get_media_repository_resource()
                resources.update({
                    MEDIA_PREFIX: media_repo,
                    LEGACY_MEDIA_PREFIX: media_repo,
                    CONTENT_REPO_PREFIX: ContentRepoResource(
                        self, self.config.uploads_path
                    ),
                })
            elif name == "media":
                raise ConfigError(
                    "'media' resource conflicts with enable_media_repo=False",
                )

        if name in ["keys", "federation"]:
            resources.update({
                SERVER_KEY_PREFIX: LocalKey(self),
                SERVER_KEY_V2_PREFIX: KeyApiV2Resource(self),
            })

        if name == "webclient":
            resources[WEB_CLIENT_PREFIX] = build_resource_for_web_client(self)

        if name == "metrics" and self.get_config().enable_metrics:
            resources[METRICS_PREFIX] = MetricsResource(self)

        if name == "replication":
            resources[REPLICATION_PREFIX] = ReplicationRestResource(self)

        return resources

    def start_listening(self):
        config = self.get_config()

        for listener in config.listeners:
            if listener["type"] == "http":
                self._listener_http(config, listener)
            elif listener["type"] == "manhole":
                listen_tcp(
                    listener["bind_addresses"],
                    listener["port"],
                    manhole(
                        username="matrix",
                        password="rabbithole",
                        globals={"hs": self},
                    )
                )
            elif listener["type"] == "replication":
                bind_addresses = listener["bind_addresses"]
                for address in bind_addresses:
                    factory = ReplicationStreamProtocolFactory(self)
                    server_listener = reactor.listenTCP(
                        listener["port"], factory, interface=address
                    )
                    reactor.addSystemEventTrigger(
                        "before", "shutdown", server_listener.stopListening,
                    )
            else:
                logger.warn("Unrecognized listener type: %s", listener["type"])

    def run_startup_checks(self, db_conn, database_engine):
        all_users_native = are_all_users_on_domain(
            db_conn.cursor(), database_engine, self.hostname
        )
        if not all_users_native:
            quit_with_error(
                "Found users in database not native to %s!\n"
                "You cannot changed a synapse server_name after it's been configured"
                % (self.hostname,)
            )

        try:
            database_engine.check_database(db_conn.cursor())
        except IncorrectDatabaseSetup as e:
            quit_with_error(e.message)


def setup(config_options):
    """
    Args:
        config_options_options: The options passed to Synapse. Usually
            `sys.argv[1:]`.

    Returns:
        HomeServer
    """
    try:
        config = HomeServerConfig.load_or_generate_config(
            "Synapse Homeserver",
            config_options,
        )
    except ConfigError as e:
        sys.stderr.write("\n" + e.message + "\n")
        sys.exit(1)

    if not config:
        # If a config isn't returned, and an exception isn't raised, we're just
        # generating config files and shouldn't try to continue.
        sys.exit(0)

    synapse.config.logger.setup_logging(config, use_worker_options=False)

    # check any extra requirements we have now we have a config
    check_requirements(config)

    version_string = "Synapse/" + get_version_string(synapse)

    logger.info("Server hostname: %s", config.server_name)
    logger.info("Server version: %s", version_string)

    events.USE_FROZEN_DICTS = config.use_frozen_dicts

    tls_server_context_factory = context_factory.ServerContextFactory(config)

    database_engine = create_engine(config.database_config)
    config.database_config["args"]["cp_openfun"] = database_engine.on_new_connection

    hs = SynapseHomeServer(
        config.server_name,
        db_config=config.database_config,
        tls_server_context_factory=tls_server_context_factory,
        config=config,
        version_string=version_string,
        database_engine=database_engine,
    )

    logger.info("Preparing database: %s...", config.database_config['name'])

    try:
        db_conn = hs.get_db_conn(run_new_connection=False)
        prepare_database(db_conn, database_engine, config=config)
        database_engine.on_new_connection(db_conn)

        hs.run_startup_checks(db_conn, database_engine)

        db_conn.commit()
    except UpgradeDatabaseException:
        sys.stderr.write(
            "\nFailed to upgrade database.\n"
            "Have you checked for version specific instructions in"
            " UPGRADES.rst?\n"
        )
        sys.exit(1)

    logger.info("Database prepared in %s.", config.database_config['name'])

    hs.setup()
    hs.start_listening()

    def start():
        hs.get_pusherpool().start()
        hs.get_state_handler().start_caching()
        hs.get_datastore().start_profiling()
        hs.get_datastore().start_doing_background_updates()
        hs.get_federation_client().start_get_pdu_cache()

        register_memory_metrics(hs)

    reactor.callWhenRunning(start)

    return hs


class SynapseService(service.Service):
    """A twisted Service class that will start synapse. Used to run synapse
    via twistd and a .tac.
    """
    def __init__(self, config):
        self.config = config

    def startService(self):
        hs = setup(self.config)
        change_resource_limit(hs.config.soft_file_limit)
        if hs.config.gc_thresholds:
            gc.set_threshold(*hs.config.gc_thresholds)

    def stopService(self):
        return self._port.stopListening()


def run(hs):
    PROFILE_SYNAPSE = False
    if PROFILE_SYNAPSE:
        def profile(func):
            from cProfile import Profile
            from threading import current_thread

            def profiled(*args, **kargs):
                profile = Profile()
                profile.enable()
                func(*args, **kargs)
                profile.disable()
                ident = current_thread().ident
                profile.dump_stats("/tmp/%s.%s.%i.pstat" % (
                    hs.hostname, func.__name__, ident
                ))

            return profiled

        from twisted.python.threadpool import ThreadPool
        ThreadPool._worker = profile(ThreadPool._worker)
        reactor.run = profile(reactor.run)

    clock = hs.get_clock()
    start_time = clock.time()

    stats = {}

    # Contains the list of processes we will be monitoring
    # currently either 0 or 1
    stats_process = []

    @defer.inlineCallbacks
    def phone_stats_home():
        logger.info("Gathering stats for reporting")
        now = int(hs.get_clock().time())
        uptime = int(now - start_time)
        if uptime < 0:
            uptime = 0

        stats["homeserver"] = hs.config.server_name
        stats["timestamp"] = now
        stats["uptime_seconds"] = uptime
        stats["total_users"] = yield hs.get_datastore().count_all_users()

        total_nonbridged_users = yield hs.get_datastore().count_nonbridged_users()
        stats["total_nonbridged_users"] = total_nonbridged_users

        room_count = yield hs.get_datastore().get_room_count()
        stats["total_room_count"] = room_count

        stats["daily_active_users"] = yield hs.get_datastore().count_daily_users()
        stats["daily_active_rooms"] = yield hs.get_datastore().count_daily_active_rooms()
        stats["daily_messages"] = yield hs.get_datastore().count_daily_messages()

        r30_results = yield hs.get_datastore().count_r30_users()
        for name, count in r30_results.iteritems():
            stats["r30_users_" + name] = count

        daily_sent_messages = yield hs.get_datastore().count_daily_sent_messages()
        stats["daily_sent_messages"] = daily_sent_messages
        stats["cache_factor"] = CACHE_SIZE_FACTOR
        stats["event_cache_size"] = hs.config.event_cache_size

        if len(stats_process) > 0:
            stats["memory_rss"] = 0
            stats["cpu_average"] = 0
            for process in stats_process:
                stats["memory_rss"] += process.memory_info().rss
                stats["cpu_average"] += int(process.cpu_percent(interval=None))

        logger.info("Reporting stats to matrix.org: %s" % (stats,))
        try:
            yield hs.get_simple_http_client().put_json(
                "https://matrix.org/report-usage-stats/push",
                stats
            )
        except Exception as e:
            logger.warn("Error reporting stats: %s", e)

    def performance_stats_init():
        try:
            import psutil
            process = psutil.Process()
            # Ensure we can fetch both, and make the initial request for cpu_percent
            # so the next request will use this as the initial point.
            process.memory_info().rss
            process.cpu_percent(interval=None)
            logger.info("report_stats can use psutil")
            stats_process.append(process)
        except (ImportError, AttributeError):
            logger.warn(
                "report_stats enabled but psutil is not installed or incorrect version."
                " Disabling reporting of memory/cpu stats."
                " Ensuring psutil is available will help matrix.org track performance"
                " changes across releases."
            )

    if hs.config.report_stats:
        logger.info("Scheduling stats reporting for 3 hour intervals")
        clock.looping_call(phone_stats_home, 3 * 60 * 60 * 1000)

        # We need to defer this init for the cases that we daemonize
        # otherwise the process ID we get is that of the non-daemon process
        clock.call_later(0, performance_stats_init)

        # We wait 5 minutes to send the first set of stats as the server can
        # be quite busy the first few minutes
        clock.call_later(5 * 60, phone_stats_home)

    if hs.config.daemonize and hs.config.print_pidfile:
        print (hs.config.pid_file)

    _base.start_reactor(
        "synapse-homeserver",
        hs.config.soft_file_limit,
        hs.config.gc_thresholds,
        hs.config.pid_file,
        hs.config.daemonize,
        hs.config.cpu_affinity,
        logger,
    )


def main():
    with LoggingContext("main"):
        # check base requirements
        check_requirements()
        hs = setup(sys.argv[1:])
        run(hs)


if __name__ == '__main__':
    main()
