##############################################################################
# Copyright (c) 2015 Ericsson AB and others.
#
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Apache License, Version 2.0
# which accompanies this distribution, and is available at
# http://www.apache.org/licenses/LICENSE-2.0
##############################################################################

""" Handler for yardstick command 'task' """

import sys
import os
import yaml
import atexit
import ipaddress
import time
import logging
from yardstick.benchmark.contexts.base import Context
from yardstick.benchmark.runners import base as base_runner
from yardstick.common.task_template import TaskTemplate
from yardstick.common.utils import cliargs

output_file_default = "/tmp/yardstick.out"
test_cases_dir_default = "tests/opnfv/test_cases/"
LOG = logging.getLogger(__name__)


class TaskCommands(object):
    '''Task commands.

       Set of commands to manage benchmark tasks.
    '''

    @cliargs("inputfile", type=str, help="path to task or suite file", nargs=1)
    @cliargs("--task-args", dest="task_args",
             help="Input task args (dict in json). These args are used"
             "to render input task that is jinja2 template.")
    @cliargs("--task-args-file", dest="task_args_file",
             help="Path to the file with input task args (dict in "
             "json/yaml). These args are used to render input"
             "task that is jinja2 template.")
    @cliargs("--keep-deploy", help="keep context deployed in cloud",
             action="store_true")
    @cliargs("--parse-only", help="parse the config file and exit",
             action="store_true")
    @cliargs("--output-file", help="file where output is stored, default %s" %
             output_file_default, default=output_file_default)
    @cliargs("--suite", help="process test suite file instead of a task file",
             action="store_true")
    def do_start(self, args):
        '''Start a benchmark scenario.'''

        atexit.register(atexit_handler)

        total_start_time = time.time()
        parser = TaskParser(args.inputfile[0])

        suite_params = {}
        if args.suite:
            suite_params = parser.parse_suite()
            test_cases_dir = suite_params["test_cases_dir"]
            if test_cases_dir[-1] != os.sep:
                test_cases_dir += os.sep
            task_files = [test_cases_dir + task
                          for task in suite_params["task_fnames"]]
        else:
            task_files = [parser.path]

        task_args = suite_params.get("task_args", [args.task_args])
        task_args_fnames = suite_params.get("task_args_fnames",
                                            [args.task_args_file])

        if args.parse_only:
            sys.exit(0)

        if os.path.isfile(args.output_file):
            os.remove(args.output_file)

        for i in range(0, len(task_files)):
            one_task_start_time = time.time()
            parser.path = task_files[i]
            scenarios, run_in_parallel = parser.parse_task(task_args[i],
                                                           task_args_fnames[i])

            self._run(scenarios, run_in_parallel, args.output_file)

            if args.keep_deploy:
                # keep deployment, forget about stack
                # (hide it for exit handler)
                Context.list = []
            else:
                for context in Context.list:
                    context.undeploy()
                Context.list = []
            one_task_end_time = time.time()
            LOG.info("task %s finished in %d secs", task_files[i],
                     one_task_end_time - one_task_start_time)

        total_end_time = time.time()
        LOG.info("total finished in %d secs",
                 total_end_time - total_start_time)

        print "Done, exiting"

    def _run(self, scenarios, run_in_parallel, output_file):
        '''Deploys context and calls runners'''
        for context in Context.list:
            context.deploy()

        runners = []
        if run_in_parallel:
            for scenario in scenarios:
                runner = run_one_scenario(scenario, output_file)
                runners.append(runner)

            # Wait for runners to finish
            for runner in runners:
                runner_join(runner)
                print "Runner ended, output in", output_file
        else:
            # run serially
            for scenario in scenarios:
                runner = run_one_scenario(scenario, output_file)
                runner_join(runner)
                print "Runner ended, output in", output_file

# TODO: Move stuff below into TaskCommands class !?


class TaskParser(object):
    '''Parser for task config files in yaml format'''
    def __init__(self, path):
        self.path = path

    def parse_suite(self):
        '''parse the suite file and return a list of task config file paths
           and lists of optional parameters if present'''
        print "Parsing suite file:", self.path

        try:
            with open(self.path) as stream:
                cfg = yaml.load(stream)
        except IOError as ioerror:
            sys.exit(ioerror)

        self._check_schema(cfg["schema"], "suite")
        print "Starting suite:", cfg["name"]

        test_cases_dir = cfg.get("test_cases_dir", test_cases_dir_default)
        task_fnames = []
        task_args = []
        task_args_fnames = []

        for task in cfg["test_cases"]:
            task_fnames.append(task["file_name"])
            if "task_args" in task:
                task_args.append(task["task_args"])
            else:
                task_args.append(None)

            if "task_args_file" in task:
                task_args_fnames.append(task["task_args_file"])
            else:
                task_args_fnames.append(None)

        suite_params = {
            "test_cases_dir": test_cases_dir,
            "task_fnames": task_fnames,
            "task_args": task_args,
            "task_args_fnames": task_args_fnames
        }

        return suite_params

    def parse_task(self, task_args=None, task_args_file=None):
        '''parses the task file and return an context and scenario instances'''
        print "Parsing task config:", self.path

        try:
            kw = {}
            if task_args_file:
                with open(task_args_file) as f:
                    kw.update(parse_task_args("task_args_file", f.read()))
            kw.update(parse_task_args("task_args", task_args))
        except TypeError:
            raise TypeError()

        try:
            with open(self.path) as f:
                try:
                    input_task = f.read()
                    rendered_task = TaskTemplate.render(input_task, **kw)
                except Exception as e:
                    print(("Failed to render template:\n%(task)s\n%(err)s\n")
                          % {"task": input_task, "err": e})
                    raise e
                print(("Input task is:\n%s\n") % rendered_task)

                cfg = yaml.load(rendered_task)
        except IOError as ioerror:
            sys.exit(ioerror)

        self._check_schema(cfg["schema"], "task")

        # TODO: support one or many contexts? Many would simpler and precise
        # TODO: support hybrid context type
        if "context" in cfg:
            context_cfgs = [cfg["context"]]
        else:
            context_cfgs = cfg["contexts"]

        for cfg_attrs in context_cfgs:
            context_type = cfg_attrs.get("type", "Heat")
            if "Heat" == context_type and "networks" in cfg_attrs:
                # config external_network based on env var
                for _, attrs in cfg_attrs["networks"].items():
                    attrs["external_network"] = os.environ.get(
                        'EXTERNAL_NETWORK', 'net04_ext')
            context = Context.get(context_type)
            context.init(cfg_attrs)

        run_in_parallel = cfg.get("run_in_parallel", False)

        # TODO we need something better here, a class that represent the file
        return cfg["scenarios"], run_in_parallel

    def _check_schema(self, cfg_schema, schema_type):
        '''Check if config file is using the correct schema type'''

        if cfg_schema != "yardstick:" + schema_type + ":0.1":
            sys.exit("error: file %s has unknown schema %s" % (self.path,
                                                               cfg_schema))


def atexit_handler():
    '''handler for process termination'''
    base_runner.Runner.terminate_all()

    if len(Context.list) > 0:
        print "Undeploying all contexts"
        for context in Context.list:
            context.undeploy()


def is_ip_addr(addr):
    '''check if string addr is an IP address'''
    try:
        ipaddress.ip_address(unicode(addr))
        return True
    except ValueError:
        return False


def _is_same_heat_context(host_attr, target_attr):
    '''check if two servers are in the same heat context
    host_attr: either a name for a server created by yardstick or a dict
    with attribute name mapping when using external heat templates
    target_attr: either a name for a server created by yardstick or a dict
    with attribute name mapping when using external heat templates
    '''
    host = None
    target = None
    for context in Context.list:
        if context.__context_type__ != "Heat":
            continue

        host = context._get_server(host_attr)
        if host is None:
            continue

        target = context._get_server(target_attr)
        if target is None:
            return False

        # Both host and target is not None, then they are in the
        # same heat context.
        return True

    return False


def run_one_scenario(scenario_cfg, output_file):
    '''run one scenario using context'''
    runner_cfg = scenario_cfg["runner"]
    runner_cfg['output_filename'] = output_file

    # TODO support get multi hosts/vms info
    context_cfg = {}
    if "host" in scenario_cfg:
        context_cfg['host'] = Context.get_server(scenario_cfg["host"])

    if "target" in scenario_cfg:
        if is_ip_addr(scenario_cfg["target"]):
            context_cfg['target'] = {}
            context_cfg['target']["ipaddr"] = scenario_cfg["target"]
        else:
            context_cfg['target'] = Context.get_server(scenario_cfg["target"])
            if _is_same_heat_context(scenario_cfg["host"],
                                     scenario_cfg["target"]):
                context_cfg["target"]["ipaddr"] = \
                    context_cfg["target"]["private_ip"]
            else:
                context_cfg["target"]["ipaddr"] = \
                    context_cfg["target"]["ip"]

    if "nodes" in scenario_cfg:
        context_cfg["nodes"] = parse_nodes_with_context(scenario_cfg)
    runner = base_runner.Runner.get(runner_cfg)

    print "Starting runner of type '%s'" % runner_cfg["type"]
    runner.run(scenario_cfg, context_cfg)

    return runner


def parse_nodes_with_context(scenario_cfg):
    '''paras the 'nodes' fields in scenario '''
    nodes = scenario_cfg["nodes"]

    nodes_cfg = {}
    for nodename in nodes:
        nodes_cfg[nodename] = Context.get_server(nodes[nodename])

    return nodes_cfg


def runner_join(runner):
    '''join (wait for) a runner, exit process at runner failure'''
    status = runner.join()
    base_runner.Runner.release(runner)
    if status != 0:
        sys.exit("Runner failed")


def print_invalid_header(source_name, args):
    print(("Invalid %(source)s passed:\n\n %(args)s\n")
          % {"source": source_name, "args": args})


def parse_task_args(src_name, args):
    try:
        kw = args and yaml.safe_load(args)
        kw = {} if kw is None else kw
    except yaml.parser.ParserError as e:
        print_invalid_header(src_name, args)
        print(("%(source)s has to be YAML. Details:\n\n%(err)s\n")
              % {"source": src_name, "err": e})
        raise TypeError()

    if not isinstance(kw, dict):
        print_invalid_header(src_name, args)
        print(("%(src)s had to be dict, actually %(src_type)s\n")
              % {"src": src_name, "src_type": type(kw)})
        raise TypeError()
    return kw