# -*- coding: utf-8 -*-
# Copyright (c) 2016  Red Hat, Inc.
#
# 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.
#
# Written by Petr Šabata <contyk@redhat.com>
#            Luboš Kocman <lkocman@redhat.com>

"""Generic component build functions."""

# TODO: Query the PDC to find what modules satisfy the build dependencies and
#       their tag names.
# TODO: Ensure the RPM %dist tag is set according to the policy.

import six
from abc import ABCMeta, abstractmethod
import logging
import os

from mock import Mock
from kobo.shortcuts import run
import koji
import tempfile
import glob
import datetime
import time
import random
import string
import kobo.rpmlib
import xmlrpclib
import shutil
import subprocess
import threading

import munch
from OpenSSL.SSL import SysCallError

from module_build_service import conf, log, db
from module_build_service.models import ModuleBuild
from module_build_service import pdc
import module_build_service.scm
import module_build_service.utils
import module_build_service.scheduler
import module_build_service.scheduler.consumer

from requests.exceptions import ConnectionError
from base import GenericBuilder, _execute_cmd, build_from_scm
from KojiModuleBuilder import KojiModuleBuilder

logging.basicConfig(level=logging.DEBUG)


class MockModuleBuilder(GenericBuilder):
    """
    See http://blog.samalik.com/copr-in-the-modularity-world/
    especially section "Building a stack"
    """

    backend = "mock"
    # Global build_id/task_id we increment when new build is executed.
    _build_id_lock = threading.Lock()
    _build_id = 1
    _config_lock = threading.Lock()

    MOCK_CONFIG_TEMPLATE = """
config_opts['root'] = '$root'
config_opts['target_arch'] = '$arch'
config_opts['legal_host_arches'] = ('$arch',)
config_opts['chroot_setup_cmd'] = 'install $group'
config_opts['dist'] = ''
config_opts['extra_chroot_dirs'] = [ '/run/lock', ]
config_opts['releasever'] = ''
config_opts['package_manager'] = 'dnf'
config_opts['nosync'] = True

config_opts['yum.conf'] = \"\"\"
$yum_conf
\"\"\"
"""

    MOCK_YUM_CONF_TEMPLATE = """
[main]
keepcache=1
debuglevel=2
reposdir=/dev/null
logfile=/var/log/yum.log
retries=20
obsoletes=1
gpgcheck=0
assumeyes=1
syslog_ident=mock
syslog_device=
install_weak_deps=0
metadata_expire=3600
mdpolicy=group:primary

# repos

"""

    @module_build_service.utils.validate_koji_tag('tag_name')
    def __init__(self, owner, module, config, tag_name, components):
        self.module_str = module
        self.tag_name = tag_name
        self.config = config
        self.groups = []
        self.arch = "x86_64" # TODO: We may need to change that in the future
        self.yum_conf = MockModuleBuilder.MOCK_YUM_CONF_TEMPLATE

        # Create main directory for this tag
        self.tag_dir = os.path.join(self.config.mock_resultsdir, tag_name)
        if not os.path.exists(self.tag_dir):
            os.makedirs(self.tag_dir)

        # Create "results" sub-directory for this tag to store build results
        # and local repository.
        self.resultsdir = os.path.join(self.tag_dir, "results")
        if not os.path.exists(self.resultsdir):
            os.makedirs(self.resultsdir)

        # Create "config" sub-directory.
        self.configdir = os.path.join(self.tag_dir, "config")
        if not os.path.exists(self.configdir):
            os.makedirs(self.configdir)

        # Generate path to mock config and add local repository there.
        self._add_repo("localrepo", "file://" + self.resultsdir, "metadata_expire=1\n")

        # Remove old files from the previous build of this tag but only
        # before the first build is done, otherwise we would remove files
        # which we already build in this module build.
        if MockModuleBuilder._build_id == 1:
            # Remove all RPMs from the results directory, but keep old logs.
            for name in os.listdir(self.resultsdir):
                if name.endswith(".rpm"):
                    os.remove(os.path.join(self.resultsdir, name))

            # Remove the old RPM repository from the results directory.
            if os.path.exists(os.path.join(self.resultsdir, "repodata/repomd.xml")):
                os.remove(os.path.join(self.resultsdir, "repodata/repomd.xml"))

            # Remove old config files from config directory.
            for name in os.listdir(self.configdir):
                os.remove(os.path.join(self.configdir, name))

        log.info("MockModuleBuilder initialized, tag_name=%s, tag_dir=%s" %
                 (tag_name, self.tag_dir))

    @property
    def module_build_tag(self):
        # Workaround koji specific code in modules.py
        return {"name": self.tag_name}

    def _createrepo(self):
        """
        Creates the repository using "createrepo_c" command in the resultsdir.
        """
        log.debug("Creating repository in %s" % self.resultsdir)
        path = self.resultsdir
        if os.path.exists(path + '/repodata/repomd.xml'):
            comm = ['/usr/bin/createrepo_c', '--update', path]
        else:
            comm = ['/usr/bin/createrepo_c', path]
        cmd = subprocess.Popen(
            comm, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        out, err = cmd.communicate()
        return out, err

    def _add_repo(self, name, baseurl, extra = ""):
        """
        Adds repository to Mock config file. Call _write_mock_config() to
        actually write the config file to filesystem.
        """
        self.yum_conf += "[%s]\n" % name
        self.yum_conf += "name=%s\n" % name
        self.yum_conf += "baseurl=%s\n" % baseurl
        self.yum_conf += extra
        self.yum_conf += "enabled=1\n"

    def _load_mock_config(self):
        """
        Loads the variables which are generated only during the first
        initialization of mock config. This should be called before
        every _write_mock_config otherwise we overwrite Mock
        repositories or groups ...
        """

        # We do not want to load old file from previous builds here, so if
        # this is the first build in this module, skip the load completely.
        if MockModuleBuilder._build_id == 1:
            return

        with MockModuleBuilder._config_lock:
            infile = os.path.join(self.configdir, "mock.cfg")
            with open(infile, 'r') as f:
                # This looks scary, but it is the way how mock itself loads the
                # config file ...
                config_opts = {}
                code = compile(f.read(), infile, 'exec')
                # pylint: disable=exec-used
                exec(code)

                self.groups = config_opts["chroot_setup_cmd"].split(" ")[1:]
                self.yum_conf = config_opts['yum.conf']

    def _write_mock_config(self):
        """
        Writes Mock config file to local file.
        """

        with MockModuleBuilder._config_lock:
            config = str(MockModuleBuilder.MOCK_CONFIG_TEMPLATE)
            config = config.replace("$root", "%s-%s" % (self.tag_name,
                                                        str(threading.current_thread().name)))
            config = config.replace("$arch", self.arch)
            config = config.replace("$group", " ".join(self.groups))
            config = config.replace("$yum_conf", self.yum_conf)

            # We write the most recent config to "mock.cfg", so thread-related
            # configs can be later (re-)generated from it using _load_mock_config.
            outfile = os.path.join(self.configdir, "mock.cfg")
            with open(outfile, 'w') as f:
                f.write(config)

            # Write the config to thread-related configuration file.
            outfile = os.path.join(self.configdir, "mock-%s.cfg" %
                                   str(threading.current_thread().name))
            with open(outfile, 'w') as f:
                f.write(config)

    def buildroot_connect(self, groups):
        self._load_mock_config()
        self.groups = list(set().union(groups["build"], self.groups))
        log.debug("Mock builder groups: %s" % self.groups)
        self._write_mock_config()

    def buildroot_prep(self):
        pass

    def buildroot_resume(self):
        pass

    def buildroot_ready(self, artifacts=None):
        return True

    def buildroot_add_dependency(self, dependencies):
        pass

    def buildroot_add_artifacts(self, artifacts, install=False):
        self._createrepo()

        # TODO: This is just hack to install module-build-macros into the
        # buildroot. We should really install the RPMs belonging to the
        # right source RPM into the buildroot here, but we do not track
        # what RPMs are output of particular SRPM build yet.
        for artifact in artifacts:
            if artifact and artifact.startswith("module-build-macros"):
                self._load_mock_config()
                self.groups.append("module-build-macros")
                self._write_mock_config()

        self._send_repo_done()

    def _send_repo_done(self):
        msg = module_build_service.messaging.KojiRepoChange(
            msg_id='a faked internal message',
            repo_tag=self.tag_name + "-build",
        )
        module_build_service.scheduler.consumer.work_queue_put(msg)

    def tag_artifacts(self, artifacts):
        pass

    def buildroot_add_repos(self, dependencies):
        # TODO: We support only dependencies from Koji here. This should be
        # extended to Copr in the future.
        self._load_mock_config()
        for tag in dependencies:
            baseurl = KojiModuleBuilder.repo_from_tag(self.config, tag, self.arch)
            self._add_repo(tag, baseurl)
        self._write_mock_config()

    def _send_build_change(self, state, source, build_id):
        nvr = kobo.rpmlib.parse_nvr(source)

        # build_id=1 and task_id=1 are OK here, because we are building just
        # one RPM at the time.
        msg = module_build_service.messaging.KojiBuildChange(
            msg_id='a faked internal message',
            build_id=build_id,
            task_id=build_id,
            build_name=nvr["name"],
            build_new_state=state,
            build_release=nvr["release"],
            build_version=nvr["version"]
        )
        module_build_service.scheduler.consumer.work_queue_put(msg)

    def _save_log(self, resultsdir, log_name, artifact_name):
        old_log = os.path.join(resultsdir, log_name)
        new_log = os.path.join(resultsdir, artifact_name + "-" + log_name)
        if os.path.exists(old_log):
            os.rename(old_log, new_log)

    def build_srpm(self, artifact_name, source, build_id):
        """
        Builds the artifact from the SRPM.
        """
        state = koji.BUILD_STATES['BUILDING']

        # Use the mock config associated with this thread.
        mock_config = os.path.join(self.configdir,
                                   "mock-%s.cfg" % str(threading.current_thread().name))

        # Clear resultsdir associated with this thread or in case it does not
        # exist, create it.
        resultsdir = os.path.join(self.resultsdir,
                                  str(threading.current_thread().name))
        if os.path.exists(resultsdir):
            for name in os.listdir(resultsdir):
                os.remove(os.path.join(resultsdir, name))
        else:
            os.makedirs(resultsdir)

        # Open the logs to which we will forward mock stdout/stderr.
        mock_stdout_log = open(os.path.join(self.resultsdir,
                                            artifact_name + "-mock-stdout.log"), "w")
        mock_stderr_log = open(os.path.join(self.resultsdir,
                                            artifact_name + "-mock-stderr.log"), "w")

        try:
            # Initialize mock.
            _execute_cmd(["mock", "-v", "-r", mock_config, "--init"],
                         stdout=mock_stdout_log, stderr=mock_stderr_log)

            # Start the build and store results to resultsdir
            _execute_cmd(["mock", "-v", "-r", mock_config,
                          "--no-clean", "--rebuild", source,
                          "--resultdir=%s" % resultsdir],
                         stdout=mock_stdout_log, stderr=mock_stderr_log)

            # Emit messages simulating complete build. These messages
            # are put in the scheduler's work queue and are handled
            # by MBS after the build_srpm() method returns and scope gets
            # back to scheduler.main.main() method.
            state = koji.BUILD_STATES['COMPLETE']
            self._send_build_change(state, source, build_id)

            with open(os.path.join(resultsdir, "status.log"), 'w') as f:
                f.write("complete\n")
        except Exception as e:
            log.error("Error while building artifact %s: %s" % (artifact_name,
                                                                str(e)))

            # Emit messages simulating complete build. These messages
            # are put in the scheduler's work queue and are handled
            # by MBS after the build_srpm() method returns and scope gets
            # back to scheduler.main.main() method.
            state = koji.BUILD_STATES['FAILED']
            self._send_build_change(state, source,
                                    build_id)
            with open(os.path.join(resultsdir, "status.log"), 'w') as f:
                f.write("failed\n")

        mock_stdout_log.close()
        mock_stderr_log.close()

        self._save_log(resultsdir, "state.log", artifact_name)
        self._save_log(resultsdir, "root.log", artifact_name)
        self._save_log(resultsdir, "build.log", artifact_name)
        self._save_log(resultsdir, "status.log", artifact_name)

        # Copy files from thread-related resultsdire to the main resultsdir.
        for name in os.listdir(resultsdir):
            shutil.copyfile(os.path.join(resultsdir, name), os.path.join(self.resultsdir, name))

        # We return BUILDING state here even when we know it is already
        # completed or failed, because otherwise utils.start_build_batch
        # would think this component is already built and also tagged, but
        # we have just built it - tagging will happen as result of build
        # change message we are sending above using _send_build_change.
        # It is just to make this backend compatible with other backends,
        # which return COMPLETE here only in case the resulting build is
        # already in repository ready to be used. This is not a case for Mock
        # backend in the time we return here.
        reason = "Building %s in Mock" % (artifact_name)
        return build_id, koji.BUILD_STATES['BUILDING'], reason, None

    def build(self, artifact_name, source):
        log.info("Starting building artifact %s: %s" % (artifact_name, source))

        # Load global mock config for this module build from mock.cfg and
        # generate the thread-specific mock config by writing it to fs again.
        self._load_mock_config()
        self._write_mock_config()

        # Get the build-id in thread-safe manner.
        build_id = None
        with MockModuleBuilder._build_id_lock:
            MockModuleBuilder._build_id += 1
            build_id = int(MockModuleBuilder._build_id)

        # Git sources are treated specially.
        if source.startswith("git://"):
            # Open the srpm-stdout and srpm-stderr logs and build from SCM.
            srpm_stdout_fn = os.path.join(self.resultsdir,
                                          artifact_name + "-srpm-stdout.log")
            srpm_stderr_fn = os.path.join(self.resultsdir,
                                          artifact_name + "-srpm-stderr.log")
            with open(srpm_stdout_fn, "w") as srpm_stdout_log, open(srpm_stderr_fn, "w") as srpm_stderr_log:
                return build_from_scm(artifact_name, source,
                                      self.config, self.build_srpm, data=build_id,
                                      stdout=srpm_stdout_log, stderr=srpm_stderr_log)
        else:
            return self.build_srpm(artifact_name, source, build_id)

    @staticmethod
    def get_disttag_srpm(disttag):
        # @FIXME
        return KojiModuleBuilder.get_disttag_srpm(disttag)

    def cancel_build(self, task_id):
        pass

    def list_tasks_for_components(self, component_builds=None, state='active'):
        pass