"""
Module holds all stuff regarding Grinder tool usage

Copyright 2015 BlazeMeter Inc.

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 os
import re
import subprocess
import time

from bzt.engine import ScenarioExecutor, Scenario, FileLister, HavingInstallableTools
from bzt.modules.aggregator import ConsolidatingAggregator, ResultsReader
from bzt.modules.console import WidgetProvider, ExecutorWidget
from bzt.six import iteritems
from bzt import TaurusConfigError, ToolError
from bzt.utils import shell_exec, MirrorsManager, dehumanize_time, get_full_path, PythonGenerator
from bzt.utils import unzip, RequiredTool, JavaVM, shutdown_process, TclLibrary


class GrinderExecutor(ScenarioExecutor, WidgetProvider, FileLister, HavingInstallableTools):
    """
    Grinder executor module
    """
    # OLD_DOWNLOAD_LINK = "http://switch.dl.sourceforge.net/project/grinder/The%20Grinder%203/{version}" \
    # "/grinder-{version}-binary.zip"
    DOWNLOAD_LINK = "http://sourceforge.net/projects/grinder/files/The%20Grinder%203/{version}" \
                    "/grinder-{version}-binary.zip/download"
    VERSION = "3.11"
    MIRRORS_SOURCE = "http://sourceforge.net/settings/mirror_choices?projectname=grinder&filename=The%20Grinder" \
                     "%203/{version}/grinder-{version}-binary.zip&dialog=true".format(version=VERSION)

    def __init__(self):
        super(GrinderExecutor, self).__init__()
        self.script = None
        self.exec_id = "grinder-bzt-%s" % id(self)
        self.properties_file = None
        self.kpi_file = None
        self.cmd_line = None
        self.process = None
        self.end_time = None
        self.retcode = None
        self.stdout_file = None
        self.stderr_file = None

    def __write_base_props(self, fds):
        """
        write base properties and base properties file contents to fds
        :param fds: fds
        :return:
        """
        base_props_file = self.settings.get("properties-file", None)
        if base_props_file:
            fds.write("# Base Properies File Start: %s\n" % base_props_file)
            with open(base_props_file) as bpf:
                fds.write(bpf.read())
            fds.write("# Base Properies File End: %s\n\n" % base_props_file)

        # base props
        base_props = self.settings.get("properties")
        if base_props:
            fds.write("# Base Properies Start\n")
            for key, val in iteritems(base_props):
                fds.write("%s=%s\n" % (key, val))
            fds.write("# Base Properies End\n\n")

    def __write_scenario_props(self, fds, scenario):
        """
        Write scenario props and scenario file props to fds
        :param fds:
        :param scenario: dict
        :return:
        """
        script_props_file = scenario.get("properties-file", None)
        if script_props_file:
            fds.write("# Script Properies File Start: %s\n" % script_props_file)
            with open(script_props_file) as spf:
                fds.write(spf.read())
            fds.write("# Script Properies File End: %s\n\n" % script_props_file)

        # scenario props
        local_props = scenario.get("properties")
        if local_props:
            fds.write("# Scenario Properies Start\n")
            for key, val in iteritems(local_props):
                fds.write("%s=%s\n" % (key, val))
            fds.write("# Scenario Properies End\n\n")

    def __write_bzt_props(self, fds):
        """
        Write bzt properties to fds
        :param fds:
        :return:
        """
        fds.write("# BZT Properies Start\n")
        fds.write("grinder.hostID=%s\n" % self.exec_id)
        fds.write("grinder.script=%s\n" % self.script.replace(os.path.sep, "/"))
        dirname = self.engine.artifacts_dir
        fds.write("grinder.logDirectory=%s\n" % dirname.replace(os.path.sep, "/"))

        load = self.get_load()
        if load.concurrency:
            if load.ramp_up:
                interval = int(1000 * load.ramp_up / load.concurrency)
                fds.write("grinder.processIncrementInterval=%s\n" % interval)
                fds.write("grinder.processIncrement=1\n")
            fds.write("grinder.processes=%s\n" % int(load.concurrency))
            fds.write("grinder.runs=%s\n" % load.iterations)
            if load.duration:
                fds.write("grinder.duration=%s\n" % int(load.duration * 1000))
        fds.write("# BZT Properies End\n")

    def prepare(self):
        self.install_required_tools()

        scenario = self.get_scenario()

        self.script = self.get_script_path()
        if self.script:
            self.engine.existing_artifact(self.script)
        elif "requests" in scenario:
            self.script = self.__scenario_from_requests()
        else:
            msg = "There must be a script file or requests for its generation "
            msg += "to run Grinder tool (%s)" % self.execution.get('scenario')
            raise TaurusConfigError(msg)

        self.properties_file = self.engine.create_artifact("grinder", ".properties")

        with open(self.properties_file, 'w') as fds:
            self.__write_base_props(fds)
            self.__write_scenario_props(fds, scenario)
            self.__write_bzt_props(fds)

        self.kpi_file = os.path.join(self.engine.artifacts_dir, self.exec_id + "-kpi.log")

        self.reader = DataLogReader(self.kpi_file, self.log)
        if isinstance(self.engine.aggregator, ConsolidatingAggregator):
            self.engine.aggregator.add_underling(self.reader)

        # add logback configurations used by worker processes (logback-worker.xml)
        classpath = os.path.join(get_full_path(__file__, step_up=2), 'resources')

        path = self.settings.get("path", None)
        if path:
            classpath += os.path.pathsep + path

        self.cmd_line = ["java", "-classpath", classpath]
        self.cmd_line += ["net.grinder.Grinder", self.properties_file]

    def startup(self):
        """
        Should start the tool as fast as possible.
        """
        self.start_time = time.time()
        out = self.engine.create_artifact("grinder-stdout", ".log")
        err = self.engine.create_artifact("grinder-stderr", ".log")
        self.stdout_file = open(out, "w")
        self.stderr_file = open(err, "w")

        env = {"T_GRINDER_PREFIX": self.exec_id}
        self.process = self.execute(self.cmd_line, cwd=self.engine.artifacts_dir,
                                    stdout=self.stdout_file,
                                    stderr=self.stderr_file,
                                    env=env)

    def check(self):
        """
        Checks if tool is still running. Also checks if resulting logs contains
        any data and throws exception otherwise.

        :return: bool
        :raise TaurusToolError:
        """
        self.retcode = self.process.poll()
        if self.retcode is not None:
            if self.retcode != 0:
                raise ToolError("Gatling tool exited with non-zero code: %s" % self.retcode)

            return True
        return False

    def shutdown(self):
        """
        If tool is still running - let's stop it.
        """
        shutdown_process(self.process, self.log)

        if self.stdout_file:
            self.stdout_file.close()
        if self.stderr_file:
            self.stderr_file.close()

        if self.start_time:
            self.end_time = time.time()
            self.log.debug("Grinder worked for %s seconds", self.end_time - self.start_time)

    def post_process(self):
        """
        Collect data file artifact
        """
        if self.kpi_file:
            self.engine.existing_artifact(self.kpi_file)

    def __scenario_from_requests(self):
        """
        Generate grinder scenario from requests
        :return: script
        """
        script = self.engine.create_artifact("grinder_requests", ".py")
        builder = GrinderScriptBuilder(self.get_scenario(), self.log)
        builder.build_source_code()
        builder.save(script)
        return script

    def install_required_tools(self):
        grinder_path = self.settings.get("path", "~/.bzt/grinder-taurus/lib/grinder.jar")
        grinder_path = os.path.abspath(os.path.expanduser(grinder_path))
        self.settings["path"] = grinder_path
        required_tools = [TclLibrary(self.log),
                          JavaVM("", "", self.log),
                          Grinder(grinder_path, self.log, GrinderExecutor.VERSION)]

        for tool in required_tools:
            if not tool.check_if_installed():
                tool.install()

    def get_widget(self):
        if not self.widget:
            if self.script is not None:
                label = "Grinder: %s" % os.path.basename(self.script)
            else:
                label = None
            self.widget = ExecutorWidget(self, label)
            if self.get_load().ramp_up:
                self.widget.duration += self.get_load().ramp_up
        return self.widget

    def resource_files(self):
        resource_files = []
        script_file_path = self.get_scenario().get(Scenario.SCRIPT, None)
        if script_file_path:
            resource_files.append(script_file_path)

        prop_file = self.get_scenario().get("properties-file", None)
        if prop_file:
            resource_files.append(prop_file)

        return resource_files


class DataLogReader(ResultsReader):
    """ Class to read KPI from data log """

    def __init__(self, filename, parent_logger):
        super(DataLogReader, self).__init__()
        self.log = parent_logger.getChild(self.__class__.__name__)
        self.filename = filename
        self.fds = None
        self.idx = {}
        self.partial_buffer = ""
        self.delimiter = ","
        self.offset = 0
        self.start_time = 0
        self.end_time = 0
        self.concurrency = 0

    def _read(self, last_pass=False):
        """
        Generator method that returns next portion of data

        :param last_pass:
        """
        while not self.fds and not self.__open_fds():
            self.log.debug("No data to start reading yet")
            yield None

        self.log.debug("Reading grinder results...")
        self.fds.seek(self.offset)  # without this we have a stuck reads on Mac
        if last_pass:
            lines = self.fds.readlines()  # unlimited
        else:
            lines = self.fds.readlines(1024 * 1024)  # 1MB limit to read
        self.offset = self.fds.tell()

        for lnum, line in enumerate(lines):
            data_fields = self.__split(line)
            if not data_fields:
                self.log.debug("Skipping line: %s", line)
                continue

            t_stamp = int(data_fields[self.idx["Start time (ms since Epoch)"]]) / 1000.0
            r_time = int(data_fields[self.idx["Test time"]]) / 1000.0
            latency = int(data_fields[self.idx["Time to first byte"]]) / 1000.0
            r_code = data_fields[self.idx["HTTP response code"]].strip()
            con_time = int(data_fields[self.idx["Time to resolve host"]]) / 1000.0
            con_time += int(data_fields[self.idx["Time to establish connection"]]) / 1000.0
            bytes_count = int(data_fields[self.idx["HTTP response length"]].strip())

            label, error_msg = self.__parse_prev_line(lines, lnum)
            source_id = ''

            yield int(t_stamp), label, self.concurrency, r_time, con_time, \
                    latency, r_code, error_msg, source_id, bytes_count

    def __split(self, line):
        if not line.endswith("\n"):
            self.partial_buffer += line
            return None

        line = "%s%s" % (self.partial_buffer, line)
        self.partial_buffer = ""

        if not line.startswith('data'):
            line_parts = line.split(' ')
            if len(line_parts) > 1:
                if line_parts[1] == 'starting,':
                    self.concurrency += 1
                if line_parts[1] == 'shut':
                    self.concurrency -= 1
            return None

        line = line.strip()
        line = line[len('data'):]
        data_fields = line.split(self.delimiter)
        if not data_fields[1].strip().isdigit():
            return None

        if len(data_fields) < max(self.idx.values()):
            return None

        return data_fields

    def __parse_prev_line(self, lines, lnum):
        label = ''
        error_msg = None
        if lnum > 0:
            line = lines[lnum - 1].strip()
            if line.endswith('bytes'):
                line = line.split(self.delimiter)[0]
                log_parts = line.split(' ')
                if len(log_parts) > 4:
                    log_parts.pop(0)  # worker_id
                    label = log_parts.pop(0)
                    log_parts.pop(0)  # skip arrow
                    status = log_parts.pop(0)
                    if status != '200':
                        error_msg = ' '.join(log_parts)

        return label, error_msg

    def __open_fds(self):
        """
        opens grinder kpi-file
        """
        if not os.path.isfile(self.filename):
            self.log.debug("File not appeared yet: %s", self.filename)
            return False

        if not os.path.getsize(self.filename):
            self.log.debug("File is empty: %s", self.filename)
            return False

        self.fds = open(self.filename)
        line = ''
        while not line.startswith('data'):
            line = self.fds.readline()
            if line == '':  # end of file
                self.fds.close()
                self.fds = None
                return False

        self.offset = self.fds.tell()
        line = line[len('data '):]

        header_list = line.strip().split(self.delimiter)
        for _ix, field in enumerate(header_list):
            self.idx[field.strip()] = _ix
        return True

    def __del__(self):
        if self.fds:
            self.fds.close()


class Grinder(RequiredTool):
    def __init__(self, tool_path, parent_logger, version):
        super(Grinder, self).__init__("Grinder", tool_path)
        self.log = parent_logger.getChild(self.__class__.__name__)
        self.version = version
        self.mirror_manager = GrinderMirrorsManager(self.log, self.version)

    def check_if_installed(self):
        self.log.debug("Trying grinder: %s", self.tool_path)
        grinder_launch_command = ["java", "-classpath", self.tool_path, "net.grinder.Grinder"]
        grinder_subprocess = shell_exec(grinder_launch_command, stderr=subprocess.STDOUT)
        output = grinder_subprocess.communicate()
        self.log.debug("%s output: %s", self.tool_name, output)
        if grinder_subprocess.returncode == 0:
            self.already_installed = True
            return True
        else:
            return False

    def install(self):
        dest = get_full_path(self.tool_path, step_up=2)
        self.log.info("Will install %s into %s", self.tool_name, dest)
        grinder_dist = self._download()
        self.log.info("Unzipping %s", grinder_dist)
        unzip(grinder_dist, dest, 'grinder-' + self.version)
        os.remove(grinder_dist)
        self.log.info("Installed grinder successfully")
        if not self.check_if_installed():
            raise ToolError("Unable to run %s after installation!" % self.tool_name)


class GrinderMirrorsManager(MirrorsManager):
    def __init__(self, parent_logger, grinder_version):
        self.grinder_version = grinder_version
        super(GrinderMirrorsManager, self).__init__(GrinderExecutor.MIRRORS_SOURCE, parent_logger)

    def _parse_mirrors(self):
        links = []
        if self.page_source is not None:
            self.log.debug('Parsing mirrors...')
            base_link = "http://sourceforge.net/projects/grinder/files/The%20Grinder%203/{version}/grinder-{version}" \
                        "-binary.zip/download?use_mirror={mirror}"
            li_search_pattern = re.compile(r'<li id=".*?">')
            li_elements = li_search_pattern.findall(self.page_source)
            if li_elements:
                links = [base_link.format(version=self.grinder_version, mirror=link.strip('<li id="').strip('">')) for
                         link in li_elements]
        default_link = GrinderExecutor.DOWNLOAD_LINK.format(version=self.grinder_version)
        if default_link not in links:
            links.append(default_link)
        self.log.debug('Total mirrors: %d', len(links))
        return links


class GrinderScriptBuilder(PythonGenerator):
    IMPORTS = """
from net.grinder.script import Test
from net.grinder.script.Grinder import grinder
from net.grinder.plugin.http import HTTPRequest, HTTPPluginControl, HTTPUtilities
from HTTPClient import NVPair
"""

    def build_source_code(self):
        self.log.debug("Generating Python script for Grinder")
        self.root.append(self.gen_comment("This script was generated by Taurus", indent=0))
        self.root.append(self.add_imports())

        self.root.append(self.gen_new_line(indent=0))

        default_address = self.scenario.get("default-address", None)
        url_arg = "url=%r" % default_address if default_address else ""
        self.root.append(self.gen_statement('request = HTTPRequest(%s)' % url_arg, indent=0))
        self.root.append(self.gen_statement('test = Test(1, "BZT Requests")', indent=0))
        self.root.append(self.gen_statement('test.record(request)', indent=0))

        self.root.append(self.gen_new_line(indent=0))

        self.root.append(self.gen_statement("defaults = HTTPPluginControl.getConnectionDefaults()", indent=0))
        self.root.append(self.gen_statement("utilities = HTTPPluginControl.getHTTPUtilities()", indent=0))

        headers = self.scenario.get_headers()
        if not self.scenario.get("keepalive", True):
            headers['Connection'] = 'close'

        if headers:
            self.root.append(self.gen_statement("defaults.setDefaultHeaders([", indent=0))
            for header, value in iteritems(headers):
                self.root.append(self.gen_statement("NVPair(%r, %r)," % (header, value), indent=4))
            self.root.append(self.gen_statement("])", indent=0))

        global_timeout = dehumanize_time(self.scenario.get("timeout", None))
        if global_timeout:
            self.root.append(self.gen_statement("defaults.setTimeout(%s)" % int(global_timeout * 1000), indent=0))

        cookie_flag = int(self.scenario.get("store-cookie", True))
        self.root.append(self.gen_statement("defaults.setUseCookies(%s)" % cookie_flag, indent=0))

        self.root.append(self.gen_new_line(indent=0))

        self.root.append(self.gen_runner_class())

    @staticmethod
    def __list_to_nvpair_list(items):
        return "[" + ",".join("NVPair(%r, %r)" % (header, value) for header, value in items) + "]"

    def gen_runner_class(self):
        runner_classdef = self.gen_class_definition("TestRunner", ["object"], indent=0)
        main_method = self.gen_method_definition("__call__", ["self"], indent=4)

        for req in self.scenario.get_requests():
            method = req.method.upper()
            url = req.url
            local_headers = req.headers

            params = "[]"
            headers = self.__list_to_nvpair_list(iteritems(local_headers))

            main_method.append(self.gen_statement("request.%s(%r, %s, %s)" % (method, url, params, headers), indent=8))

            think_time = dehumanize_time(req.priority_option('think-time'))
            if think_time:
                main_method.append(self.gen_statement("grinder.sleep(%s)" % int(think_time * 1000), indent=8))

        runner_classdef.append(main_method)

        return runner_classdef
