# Copyright 2021 Max Planck Institute for Software Systems, and
# National University of Singapore
#
# 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 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 os
import asyncio
from collections import defaultdict
import simbricks.exectools as exectools
import simbricks.proxy
import shlex
import time
import itertools
import json
import traceback

class Experiment(object):
    name = None
    timeout = None
    checkpoint = False
    no_simbricks = False

    def __init__(self, name):
        self.name = name
        self.hosts = []
        self.nics = []
        self.networks = []
        self.metadata = {}

    def add_host(self, sim):
        for h in self.hosts:
            if h.name == sim.name:
                raise Exception('Duplicate host name')
        self.hosts.append(sim)

    def add_nic(self, sim):
        for n in self.nics:
            if n.name == sim.name:
                raise Exception('Duplicate nic name')
        self.nics.append(sim)

    def add_network(self, sim):
        for n in self.networks:
            if n.name == sim.name:
                raise Exception('Duplicate net name')
        self.networks.append(sim)

    def all_simulators(self):
        """ All simulators used in experiment. """
        return itertools.chain(self.hosts, self.nics, self.networks)

    def resreq_mem(self):
        mem = 0
        for s in self.all_simulators():
            mem += s.resreq_mem()
        return mem

    def resreq_cores(self):
        cores = 0
        for s in self.all_simulators():
            cores += s.resreq_cores()
        return cores

class DistributedExperiment(Experiment):
    num_hosts = 1
    host_mapping = None
    proxies_listen = None
    proxies_connect = None

    def __init__(self, name, num_hosts):
        self.num_hosts = num_hosts
        self.host_mapping = {}
        self.proxies_listen = []
        self.proxies_connect = []
        super().__init__(name)

    def add_proxy(self, proxy):
        if proxy.listen:
            self.proxies_listen.append(proxy)
        else:
            self.proxies_connect.append(proxy)

    def all_simulators(self):
        return itertools.chain(super().all_simulators(),
                self.proxies_listen, self.proxies_connect)

    def assign_sim_host(self, sim, host):
        """ Assign host ID (< self.num_hosts) for a simulator. """
        assert(host >= 0 and host < self.num_hosts)
        self.host_mapping[sim] = host


    def all_sims_assigned(self):
        """ Check if all simulators are assigned to a host. """
        for s in self.all_simulators():
            if s not in self.host_mapping:
                return False
        return True


class ExperimentBaseRunner(object):
    def __init__(self, exp, env, verbose):
        self.exp = exp
        self.env = env
        self.verbose = verbose
        self.out = ExpOutput(exp)
        self.running = []
        self.sockets = []
        self.wait_hosts = []

    def sim_executor(self, sim):
        raise NotImplementedError("Please implement this method")

    async def before_nics(self):
        pass

    async def before_nets(self):
        pass

    async def before_hosts(self):
        pass

    async def before_wait(self):
        pass

    async def before_cleanup(self):
        pass

    async def after_cleanup(self):
        pass


    async def prepare(self):
        # generate config tars
        copies = []
        for host in self.exp.hosts:
            path = self.env.cfgtar_path(host)
            if self.verbose:
                print('preparing config tar:', path)
            host.node_config.make_tar(path)
            copies.append(self.sim_executor(host).send_file(path, self.verbose))
        await asyncio.wait(copies)

        # prepare all simulators in parallel
        sims = []
        for sim in self.exp.hosts + self.exp.nics + self.exp.networks:
            prep_cmds = [pc for pc in sim.prep_cmds(self.env)]
            exec = self.sim_executor(sim)
            sims.append(exec.run_cmdlist('prepare_' + self.exp.name, prep_cmds,
                verbose=self.verbose))
        await asyncio.wait(sims)

    async def run_nics(self):
        """ Start all NIC simulators. """
        if self.verbose:
            print('%s: starting NICS' % self.exp.name)
        starts = []
        for nic in self.exp.nics:
            if self.verbose:
                print('start NIC:', nic.run_cmd(self.env))
            exec = self.sim_executor(nic)
            sc = exec.create_component(nic.full_name(),
                    shlex.split(nic.run_cmd(self.env)), verbose=self.verbose,
                    canfail=True)
            starts.append(sc.start())
            self.running.append((nic, sc))

            self.sockets.append((exec, self.env.nic_pci_path(nic)))
            self.sockets.append((exec, self.env.nic_eth_path(nic)))
            self.sockets.append((exec, self.env.nic_shm_path(nic)))
        await asyncio.wait(starts)

        # Wait till all NIC sockets exist
        if self.verbose:
            print('%s: waiting for sockets' % self.exp.name)
        byexec = defaultdict(lambda: [])
        for (exec, s) in self.sockets:
            byexec[exec].append(s)
        for (exec, ss) in byexec.items():
            await exec.await_files(ss, verbose=self.verbose)

        # just a bit of a safety delay
        await asyncio.sleep(0.5)

    async def run_nets(self):
        """ Start all network simulators (typically one). """
        if self.verbose:
            print('%s: starting networks' % self.exp.name)
        starts = []
        for net in self.exp.networks:
            if self.verbose:
                print('start Net:', net.run_cmd(self.env))

            exec = self.sim_executor(net)
            sc = exec.create_component(net.full_name(),
                    shlex.split(net.run_cmd(self.env)), verbose=self.verbose,
                    canfail=True)
            starts.append(sc.start())
            self.running.append((net, sc))
        await asyncio.wait(starts)

    async def run_hosts(self):
        """ Start all host simulators. """
        if self.verbose:
            print('%s: starting hosts' % self.exp.name)
        starts = []
        for host in self.exp.hosts:
            if self.verbose:
                print('start Host:', host.run_cmd(self.env))

            exec = self.sim_executor(host)
            sc = exec.create_component(host.full_name(),
                    shlex.split(host.run_cmd(self.env)), verbose=self.verbose,
                    canfail=True)
            starts.append(sc.start())
            self.running.append((host,sc))

            if host.wait:
                self.wait_hosts.append(sc)

            if host.sleep > 0:
                await asyncio.sleep(host.sleep)
        await asyncio.wait(starts)

    async def wait_for_hosts(self):
        """ Wait for hosts to terminate (the ones marked to wait on). """
        if self.verbose:
            print('%s: waiting for hosts to terminate' % self.exp.name)
        for sc in self.wait_hosts:
            await sc.wait()

    async def run(self):
        try:
            self.out.set_start()

            await self.before_nics()
            await self.run_nics()

            await self.before_nets()
            await self.run_nets()

            await self.before_hosts()
            await self.run_hosts()

            await self.before_wait()
            await self.wait_for_hosts()
        except:
            self.out.set_failed()
            traceback.print_exc()

        finally:
            self.out.set_end()

            # shut things back down
            if self.verbose:
                print('%s: cleaning up' % self.exp.name)

            await self.before_cleanup()

            # "interrupt, terminate, kill" all processes
            scs = []
            for _,sc in self.running:
                scs.append(sc.int_term_kill())
            await asyncio.wait(scs)

            # wait for all processes to terminate
            for _,sc in self.running:
                await sc.wait()

            # remove all sockets
            for (exec,sock) in self.sockets:
                await exec.rmtree(sock)

            # add all simulator components to the output
            for sim,sc in self.running:
                self.out.add_sim(sim, sc)

            await self.after_cleanup()
        return self.out


class ExperimentSimpleRunner(ExperimentBaseRunner):
    """ Simple experiment runner with just one executor. """
    def __init__(self, exec, *args, **kwargs):
        self.exec = exec
        super().__init__(*args, **kwargs)

    def sim_executor(self, sim):
        return self.exec


class ExperimentDistributedRunner(ExperimentBaseRunner):
    """ Simple experiment runner with just one executor. """
    def __init__(self, execs, *args, **kwargs):
        self.execs = execs
        super().__init__(*args, **kwargs)
        assert self.exp.num_hosts <= len(execs)

    def sim_executor(self, sim):
        h_id = self.exp.host_mapping[sim]
        return self.execs[h_id]

    async def prepare(self):
        # make sure all simulators are assigned to an executor
        assert(self.exp.all_sims_assigned())

        # set IP addresses for proxies based on assigned executors
        for p in itertools.chain(
                self.exp.proxies_listen, self.exp.proxies_connect):
            exec = self.sim_executor(p)
            p.ip = exec.ip

        await super().prepare()

    def add_proxy_sockets(self, exec, proxy):
        # add shared memory region for proxy
        self.sockets.append((exec, self.env.proxy_shm_path(proxy)))

        # add each listening unix socket
        for (nic, local) in proxy.nics:
            add = False
            if (isinstance(proxy, simbricks.proxy.NetProxyConnecter) and local) \
                or (isinstance(proxy, simbricks.proxy.NetProxyListener) \
                    and not local):
                self.sockets.append((exec, self.env.nic_eth_path(nic)))

    async def run_proxies_listeners(self):
        """ Start all listening proxies. """
        if self.verbose:
            print('%s: starting listening proxies' % self.exp.name)
        for proxy in self.exp.proxies_listen:
            if self.verbose:
                print('start listening proxy:', proxy.run_cmd(self.env))

            exec = self.sim_executor(proxy)
            sc = exec.create_component(proxy.full_name(),
                    shlex.split(proxy.run_cmd(self.env)), verbose=self.verbose,
                    canfail=True)
            await sc.start()

            self.running.append((proxy, sc))
            self.add_proxy_sockets(exec, proxy)
        await asyncio.sleep(10)

    async def run_proxies_connecters(self):
        """ Start all connecting proxies. """
        if self.verbose:
            print('%s: starting connecting proxies' % self.exp.name)
        for proxy in self.exp.proxies_connect:
            if self.verbose:
                print('start connecting proxy:', proxy.run_cmd(self.env))

            exec = self.sim_executor(proxy)
            sc = exec.create_component(proxy.full_name(),
                    shlex.split(proxy.run_cmd(self.env)), verbose=self.verbose,
                    canfail=True)
            await sc.start()

            self.running.append((proxy, sc))
            self.add_proxy_sockets(exec, proxy)
        await asyncio.sleep(10)

    async def wait_proxy_sockets(self):
        """ Make sure all sockets exist. """
        paths = {}
        for proxy in itertools.chain(
                    self.exp.proxies_connect, self.exp.proxies_listen):
            for (nic, local) in proxy.nics:
                if local:
                    continue
                exec = self.sim_executor(proxy)
                if exec not in paths:
                    paths[exec] = []
                paths[exec].append(self.env.nic_eth_path(nic))

        for (exec, paths) in paths.items():
            await exec.await_files(paths, verbose=self.verbose)

    async def before_nets(self):
        await self.run_proxies_listeners()
        await self.run_proxies_connecters()
        await self.wait_proxy_sockets()
        await super().before_nets()


class ExpEnv(object):
    def __init__(self, repo_path, workdir, cpdir):
        self.repodir = os.path.abspath(repo_path)
        self.workdir = os.path.abspath(workdir)
        self.cpdir = os.path.abspath(cpdir)
        self.qemu_img_path = self.repodir + '/sims/external/qemu/build/qemu-img'
        self.qemu_path = self.repodir + '/sims/external/qemu/build/x86_64-softmmu/qemu-system-x86_64'
        self.qemu_kernel_path = self.repodir + '/images/bzImage'
        self.gem5_path = self.repodir + '/sims/external/gem5/build/X86/gem5.fast'
        self.gem5_py_path = self.repodir + '/sims/external/gem5/configs/simbricks/simbricks.py'
        self.gem5_kernel_path = self.repodir + '/images/vmlinux'

    def hdcopy_path(self, sim):
        return '%s/hdcopy.%s' % (self.workdir, sim.name)

    def hd_path(self, hd_name):
        return '%s/images/output-%s/%s' % (self.repodir, hd_name, hd_name)

    def hd_raw_path(self, hd_name):
        return '%s/images/output-%s/%s.raw' % (self.repodir, hd_name, hd_name)

    def cfgtar_path(self, sim):
        return '%s/cfg.%s.tar' % (self.workdir, sim.name)

    def nic_pci_path(self, sim):
        return '%s/nic.pci.%s' % (self.workdir, sim.name)

    def nic_eth_path(self, sim):
        return '%s/nic.eth.%s' % (self.workdir, sim.name)

    def nic_shm_path(self, sim):
        return '%s/nic.shm.%s' % (self.workdir, sim.name)

    def proxy_shm_path(self, sim):
        return '%s/proxy.shm.%s' % (self.workdir, sim.name)

    def gem5_outdir(self, sim):
        return '%s/gem5-out.%s' % (self.workdir, sim.name)

    def gem5_cpdir(self, sim):
        return '%s/gem5-cp.%s' % (self.cpdir, sim.name)

class ExpOutput(object):
    def __init__(self, exp):
        self.exp_name = exp.name
        self.metadata = exp.metadata
        self.start_time = None
        self.end_time = None
        self.sims = {}
        self.success = True

    def set_start(self):
        self.start_time = time.time()

    def set_end(self):
        self.end_time = time.time()

    def set_failed(self):
        self.success = False

    def add_sim(self, sim, comp):
        obj = {
            'class': sim.__class__.__name__,
            'cmd': comp.cmd_parts,
            'stdout': comp.stdout,
            'stderr': comp.stderr,
        }
        self.sims[sim.full_name()] = obj

    def dumps(self):
        return json.dumps(self.__dict__)
