import glob
import logging
import shutil
import os
import re
from collections import namedtuple
import lief

import pytest
import yaml

from contrib.namespaces import LinuxNamespace

Scenario = namedtuple("Scenario", ["path", "qmin", "config"])


def config_sanity_check(config_dict, config_name):
    """Checks if parsed configuration is valid"""
    mandatory_keys = {'name', 'binary', 'templates', 'configs', 'additional'}
    for cfg in config_dict['programs']:
        missing_keys = mandatory_keys - set(cfg.keys())
        assert not missing_keys, f'Mandatory fields in configuration are missing: {missing_keys}'

        # sanity check templates vs. configs
        assert len(cfg['templates']) == len(cfg['configs']), \
            (
                'Number of jinja2 template files is not equal '
                'to number of config files to be generated for '
                f'program "{cfg["name"]}" ({config_name}), i.e. len(templates) != len(configs)'
            )

        for additional in cfg["additional"]:
            assert isinstance(additional, str), \
                (
                    "All additional arguments in yaml should be strings. "
                    f"({cfg['name']}, {config_name})"
                )


def get_qmin_config(path):
    """Reads configuration from the *.rpl file and determines query-minimization setting."""
    with open(path, encoding='utf-8') as f:
        for line in f:
            if re.search(r"^CONFIG_END", line) or re.search(r"^SCENARIO_BEGIN", line):
                return None
            if re.search(r"^\s*query-minimization:\s*(on|yes)", line):
                return True
            if re.search(r"^\s*query-minimization:\s*(off|no)", line):
                return False
    return None


def check_jemalloc_link(config_dict):
    # pylint: disable=no-member
    for program in config_dict['programs']:
        binary = lief.parse(shutil.which(program['binary']))
        assert binary is not None
        for lib in binary.libraries:
            if re.search(r"libjemalloc\.so.*", lib) is not None:
                logging.error("The binary '%s' is dynamically linked to "
                              "libjemalloc, which is incompatible with faketime. "
                              "Use --force-run to ignore this check", program['name'])
                pytest.skip("libjemalloc")


def scenarios(paths, configs, force_run):
    """Returns list of *.rpl files from given path and packs them with their minimization setting"""

    assert len(paths) == len(configs), \
        "Number of --config has to be equal to number of --scenarios arguments."

    scenario_list = []

    for path, config in zip(paths, configs):
        with open(config, encoding='utf-8') as f:
            config_dict = yaml.load(f, yaml.SafeLoader)
        config_sanity_check(config_dict, config)

        if not force_run:
            check_jemalloc_link(config_dict)

        if os.path.isfile(path):
            filelist = [path]  # path to single file, accept it
        else:
            filelist = sorted(glob.glob(os.path.join(path, "*.rpl")))

        if not filelist:
            raise ValueError(f'no *.rpl files found in path "{path}"')

        for file in filelist:
            scenario_list.append(Scenario(file, get_qmin_config(file), config_dict))

    return scenario_list


def rpls(paths):
    for path in paths:
        if os.path.isfile(path):
            filelist = [path]  # path to single file, accept it
        else:
            filelist = sorted(glob.glob(os.path.join(path, "*.rpl")))

        return filelist


def pytest_addoption(parser):
    parser.addoption("--config", action="append", help="path to Deckard configuration .yaml file")
    parser.addoption("--scenarios", action="append", help="directory with .rpl files")
    parser.addoption("--retries", action="store", help=("number of retries per"
                                                        "test when Deckard is under load"))
    parser.addoption("--force-run", action="store_true", default=False,
                     help="disable libjemalloc link check")


def pytest_generate_tests(metafunc):
    """This is pytest weirdness to parametrize the test over all the *.rpl files.
    See https://docs.pytest.org/en/latest/parametrize.html#basic-pytest-generate-tests-example
    for more info."""

    if 'scenario' in metafunc.fixturenames:
        if metafunc.config.option.config is None:
            configs = []
        else:
            configs = metafunc.config.option.config

        if metafunc.config.option.scenarios is None:
            paths = ["sets/resolver"] * len(configs)
        else:
            paths = metafunc.config.option.scenarios

        metafunc.parametrize("scenario",
                             scenarios(paths, configs, metafunc.config.getoption("--force-run")),
                             ids=str)

    if 'rpl_path' in metafunc.fixturenames:
        paths = metafunc.config.option.scenarios
        metafunc.parametrize("rpl_path", rpls(paths), ids=str)
    if 'max_retries' in metafunc.fixturenames:
        max_retries = metafunc.config.option.retries
        if max_retries is None:
            max_retries = 3
        metafunc.parametrize("max_retries", [max_retries], ids=lambda id: "max-retries-"+str(id))


def pytest_collection_modifyitems(items):
    """We automatically mark test that need faking monotonic time and run them separately."""
    for item in items:
        if "monotonic" in item.nodeid:
            item.add_marker(pytest.mark.monotonic)


def pytest_runtest_setup(item):  # pylint: disable=unused-argument
    LinuxNamespace("user").__enter__()  # pylint: disable=unnecessary-dunder-call