"""Module to hold the logger instances themselves."""

import logging
import re
import shutil
import subprocess
import sys

from buildscripts.resmokelib import config
from buildscripts.resmokelib import errors
from buildscripts.resmokelib.core import redirect as redirect_lib
from buildscripts.resmokelib.logging import buildlogger
from buildscripts.resmokelib.logging import formatters
from buildscripts.resmokelib.logging.handlers import ExceptionExtractionHandler, ExceptionExtractor, Truncate

_DEFAULT_FORMAT = "[%(name)s] %(message)s"

BUILDLOGGER_SERVER = None

# Executor logger logs information from the testing infrastructure.
EXECUTOR_LOGGER_NAME = "executor"

# Fixture logger captures the log output of server fixtures.
FIXTURE_LOGGER_NAME = "fixture"

# Test logger logs output from actual client-side tests.
TESTS_LOGGER_NAME = "tests"

ROOT_EXECUTOR_LOGGER = None
ROOT_FIXTURE_LOGGER = None
ROOT_TESTS_LOGGER = None

# Maps job nums to build IDs.
_BUILD_ID_REGISTRY: dict = {}

# Maps job nums to fixture loggers.
_FIXTURE_LOGGER_REGISTRY: dict = {}


def _build_logger_server():
    """Create and return a new BuildloggerServer.

    This occurs if "buildlogger" is configured as one of the handler class in the configuration,
    return None otherwise.
    """
    for logger_name in (FIXTURE_LOGGER_NAME, TESTS_LOGGER_NAME):
        logger_info = config.LOGGING_CONFIG[logger_name]
        for handler_info in logger_info["handlers"]:
            if handler_info["class"] == "buildlogger":
                return buildlogger.BuildloggerServer()
    return None


def _setup_redirects():
    redirect_cmds = []
    redirects = []
    if config.MRLOG:
        redirect_cmds.append(config.MRLOG)

    if config.USER_FRIENDLY_OUTPUT:
        if not config.MRLOG and shutil.which("mrlog"):
            redirect_cmds.append("mrlog")

        redirect_cmds.append(["tee", config.USER_FRIENDLY_OUTPUT])
        redirect_cmds.append([
            "grep", "-Ea",
            r"Summary of|Running.*\.\.\.|invariant|fassert|BACKTRACE|Invalid access|Workload\(s\) started|Workload\(s\)|WiredTiger error|AddressSanitizer|threads with tids|failed to load|Completed cmd|Completed stepdown"
        ])

    for idx, redirect in enumerate(redirect_cmds):
        # The first redirect reads from stdout. Otherwise read from the previous redirect.
        stdin = sys.stdout if idx == 0 else redirects[idx - 1].get_stdout()
        # The last redirect writes back to real stdout file descriptor.
        stdout = sys.__stdout__ if idx + 1 == len(redirect_cmds) else subprocess.PIPE
        redirects.append(redirect_lib.Pipe(redirect, stdin, stdout))


def configure_loggers():
    """Configure the loggers and setup redirects."""
    _setup_redirects()

    buildlogger.BUILDLOGGER_FALLBACK = logging.Logger("buildlogger")
    # The 'buildlogger' prefix is not added to the fallback logger since the prefix of the original
    # logger will be there as part of the logged message.
    buildlogger.BUILDLOGGER_FALLBACK.addHandler(
        _fallback_buildlogger_handler(include_logger_name=False))

    global BUILDLOGGER_SERVER  # pylint: disable=global-statement
    BUILDLOGGER_SERVER = _build_logger_server()

    global ROOT_TESTS_LOGGER  # pylint: disable=global-statement
    ROOT_TESTS_LOGGER = new_root_logger(TESTS_LOGGER_NAME)
    global ROOT_FIXTURE_LOGGER  # pylint: disable=global-statement
    ROOT_FIXTURE_LOGGER = new_root_logger(FIXTURE_LOGGER_NAME)
    global ROOT_EXECUTOR_LOGGER  # pylint: disable=global-statement
    ROOT_EXECUTOR_LOGGER = new_root_logger(EXECUTOR_LOGGER_NAME)


def new_root_logger(name):
    """
    Create and configure a new root logger.

    :param name: The name of the new root logger.
    """
    if name not in config.LOGGING_CONFIG:
        raise ValueError("Logging configuration should contain the %s component" % name)

    logger = logging.getLogger(name)
    logger.setLevel(logging.DEBUG)
    logger_info = config.LOGGING_CONFIG[name]
    formatter = _get_formatter(logger_info)

    for handler_info in logger_info.get("handlers", []):
        _add_handler(logger, handler_info, formatter)

    return logger


def new_resmoke_logger():
    """Create a child logger of the executor logger with the name "resmoke"."""
    logger = logging.Logger("resmoke")
    logger.parent = ROOT_EXECUTOR_LOGGER
    return logger


def new_job_logger(test_kind, job_num) -> logging.Logger:
    """Create a new logger for a given job thread."""
    name = "executor:%s:job%d" % (test_kind, job_num)
    logger = logging.Logger(name)
    logger.parent = ROOT_EXECUTOR_LOGGER

    def _prepare_build_id(job_num):
        """Prepare the build ID for a given job num."""
        if BUILDLOGGER_SERVER:
            # If we're configured to log messages to the buildlogger server, then request a new
            # build_id for this job.
            build_id = BUILDLOGGER_SERVER.new_build_id("job%d" % job_num)
            if not build_id:
                buildlogger.set_log_output_incomplete()
                raise errors.LoggerRuntimeConfigError(
                    "Encountered an error configuring buildlogger for job #{:d}: Failed to get a"
                    " new build_id".format(job_num))

            url = BUILDLOGGER_SERVER.get_build_log_url(build_id)
            ROOT_EXECUTOR_LOGGER.info("Writing output of job #%d to %s.", job_num, url)
        else:
            build_id = None

        _BUILD_ID_REGISTRY[job_num] = build_id

    _prepare_build_id(job_num)

    return logger


# Fixture loggers


class FixtureLogger(logging.Logger):
    """Custom fixture logger."""

    def __init__(self, name, full_name, external_sut_hostname=None):
        """Initialize fixture logger."""
        self.full_name = full_name
        self.external_sut_hostname = external_sut_hostname
        super().__init__(name)


def new_fixture_logger(fixture_class, job_num):
    """Create a logger for a particular fixture class."""
    full_name = "%s:job%d" % (fixture_class, job_num)
    external_sut_hostname = full_name.replace(":", "_").lower()
    logger = FixtureLogger(_shorten(full_name), full_name, external_sut_hostname)
    logger.parent = ROOT_FIXTURE_LOGGER
    _add_build_logger_handler(logger, job_num)

    _FIXTURE_LOGGER_REGISTRY[job_num] = logger
    return logger


def new_fixture_node_logger(fixture_class, job_num, node_name):
    """Create a logger for a particular element in a multi-process fixture."""
    full_name = "%s:job%d:%s" % (fixture_class, job_num, node_name)
    external_sut_hostname = node_name.replace(":", "_")
    logger = FixtureLogger(_shorten(full_name), full_name, external_sut_hostname)
    logger.parent = _FIXTURE_LOGGER_REGISTRY[job_num]
    return logger


# Test loggers


def new_testqueue_logger(test_kind):
    """Create a new test queue logger that associates the test kind to tests."""
    logger = logging.Logger(name=test_kind)
    logger.parent = ROOT_TESTS_LOGGER
    return logger


def configure_exception_capture(test_logger):
    """Configure the test logger to extract exceptions and return the exception extractors."""
    js_exception = ExceptionExtractor(
        start_regex=r"^uncaught exception:",
        end_regex=r"^exiting with code",
        truncate=Truncate.LAST,
    )
    py_exception = ExceptionExtractor(
        start_regex=r"^Traceback",
        end_regex=r"^\S*:",
        truncate=Truncate.FIRST,
    )

    # py_exception extracts Python exception messages from the stdout of a Python subprocess.
    # Both it and js_exception are registered as logging.Handlers to avoid specializing which
    # programming language exceptions to expect from certain kinds of tests. Python exceptions
    # from resmoke hooks and fixtures are handled separately through TestReport.addError().
    test_logger.addHandler(ExceptionExtractionHandler(js_exception))
    test_logger.addHandler(ExceptionExtractionHandler(py_exception))

    return [js_exception, py_exception]


def new_test_logger(test_shortname, test_basename, command, parent, job_num, test_id, job_logger):
    """Create a new test logger that will be a child of the given parent."""
    name = "%s:%s" % (parent.name, test_shortname)
    logger = logging.Logger(name)
    logger.parent = parent

    def _get_test_endpoint(job_num, test_basename, command, meta_logger):
        """Get a new test endpoint for the buildlogger server."""
        test_id = None
        url = None
        build_id = _BUILD_ID_REGISTRY[job_num]
        if build_id:
            # If we're configured to log messages to the buildlogger server, then request a new
            # test_id for this test.
            test_id = BUILDLOGGER_SERVER.new_test_id(build_id, test_basename, command)
            if not test_id:
                buildlogger.set_log_output_incomplete()
                raise errors.LoggerRuntimeConfigError(
                    "Encountered an error configuring buildlogger for test {}: Failed to get a new"
                    " test_id".format(test_basename))

            url = BUILDLOGGER_SERVER.get_test_log_url(build_id, test_id)
            meta_logger.info("Writing output of %s to %s.", test_basename, url)

        return (test_id, url)

    (test_id, url) = _get_test_endpoint(job_num, test_basename, command, job_logger)
    _add_build_logger_handler(logger, job_num, test_id)
    return (logger, url)


def new_test_thread_logger(parent, test_kind, thread_id):
    """Create a new test thread logger that will be the child of the given parent."""
    name = "%s:%s" % (test_kind, thread_id)
    logger = logging.Logger(name)
    logger.parent = parent
    return logger


def new_hook_logger(hook_class, job_num):
    """Create a new hook logger from a given fixture logger."""
    name = "{}:job{:d}".format(hook_class, job_num)
    logger = logging.Logger(name)
    logger.parent = _FIXTURE_LOGGER_REGISTRY[job_num]
    return logger


# Util methods


def _add_handler(logger, handler_info, formatter):
    """Add non-buildlogger handlers to a logger based on configuration."""
    handler_class = handler_info["class"]
    if handler_class == "logging.FileHandler":
        handler = logging.FileHandler(filename=handler_info["filename"], mode=handler_info.get(
            "mode", "w"))
    elif handler_class == "logging.NullHandler":
        handler = logging.NullHandler()
    elif handler_class == "logging.StreamHandler":
        handler = logging.StreamHandler(sys.stdout)
    elif handler_class == "buildlogger":
        return  # Buildlogger handlers are applied when creating specific child loggers
    else:
        raise ValueError("Unknown handler class '%s'" % handler_class)
    handler.setFormatter(formatter)
    logger.addHandler(handler)


def _add_build_logger_handler(logger, job_num, test_id=None):
    """Add a new buildlogger handler to a logger."""
    build_id = _BUILD_ID_REGISTRY[job_num]
    logger_info = config.LOGGING_CONFIG[TESTS_LOGGER_NAME]
    handler_info = _get_buildlogger_handler_info(logger_info)
    if handler_info is not None:
        if test_id is not None:
            handler = BUILDLOGGER_SERVER.get_test_handler(build_id, test_id, handler_info)
        else:
            handler = BUILDLOGGER_SERVER.get_global_handler(build_id, handler_info)
        handler.setFormatter(_get_formatter(logger_info))
        logger.addHandler(handler)


def _get_buildlogger_handler_info(logger_info):
    """Return the buildlogger handler information if it exists, and None otherwise."""
    for handler_info in logger_info["handlers"]:
        handler_info = handler_info.copy()
        if handler_info.pop("class") == "buildlogger":
            return handler_info
    return None


def _fallback_buildlogger_handler(include_logger_name=True):
    """Return a handler that writes to stderr."""
    if include_logger_name:
        log_format = "[fallback] [%(name)s] %(message)s"
    else:
        log_format = "[fallback] %(message)s"
    formatter = formatters.TimestampFormatter(fmt=log_format)

    handler = logging.StreamHandler(sys.stderr)
    handler.setFormatter(formatter)

    return handler


def _get_formatter(logger_info):
    """Return formatter."""
    if "format" in logger_info:
        log_format = logger_info["format"]
    else:
        log_format = _DEFAULT_FORMAT
    return formatters.TimestampFormatter(fmt=log_format)


def _shorten(logger_name):
    """Modify logger name."""
    # TODO: this function is only called for the fixture and fixture node loggers.
    #  If additional abbreviation is desired, we will need to call _shorten() in the appropriate places.

    removes = config.SHORTEN_LOGGER_NAME_CONFIG.get("remove", [])
    for remove in removes:
        logger_name = logger_name.replace(remove, "")

    replaces = config.SHORTEN_LOGGER_NAME_CONFIG.get("replace", {})
    for key, value in replaces.items():
        logger_name = logger_name.replace(key, value)

    # remove leading and trailing colons and underscores
    logger_name = re.sub(r"(^[:_]+|[:_]+$)", "", logger_name)

    return logger_name