# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt

"""Config file for coverage.py"""

import collections
import os
import re
import sys

from coverage.backward import configparser, iitems, string_class
from coverage.misc import contract, CoverageException, isolate_module

os = isolate_module(os)


class HandyConfigParser(configparser.RawConfigParser):
    """Our specialization of ConfigParser."""

    def __init__(self, our_file):
        """Create the HandyConfigParser.

        `our_file` is True if this config file is specifically for coverage,
        False if we are examining another config file (tox.ini, setup.cfg)
        for possible settings.
        """

        configparser.RawConfigParser.__init__(self)
        self.section_prefixes = ["coverage:"]
        if our_file:
            self.section_prefixes.append("")

    def read(self, filenames):
        """Read a file name as UTF-8 configuration data."""
        kwargs = {}
        if sys.version_info >= (3, 2):
            kwargs['encoding'] = "utf-8"
        return configparser.RawConfigParser.read(self, filenames, **kwargs)

    def has_option(self, section, option):
        for section_prefix in self.section_prefixes:
            real_section = section_prefix + section
            has = configparser.RawConfigParser.has_option(self, real_section, option)
            if has:
                return has
        return False

    def has_section(self, section):
        for section_prefix in self.section_prefixes:
            real_section = section_prefix + section
            has = configparser.RawConfigParser.has_section(self, real_section)
            if has:
                return real_section
        return False

    def options(self, section):
        for section_prefix in self.section_prefixes:
            real_section = section_prefix + section
            if configparser.RawConfigParser.has_section(self, real_section):
                return configparser.RawConfigParser.options(self, real_section)
        raise configparser.NoSectionError

    def get_section(self, section):
        """Get the contents of a section, as a dictionary."""
        d = {}
        for opt in self.options(section):
            d[opt] = self.get(section, opt)
        return d

    def get(self, section, option, *args, **kwargs):        # pylint: disable=arguments-differ
        """Get a value, replacing environment variables also.

        The arguments are the same as `RawConfigParser.get`, but in the found
        value, ``$WORD`` or ``${WORD}`` are replaced by the value of the
        environment variable ``WORD``.

        Returns the finished value.

        """
        for section_prefix in self.section_prefixes:
            real_section = section_prefix + section
            if configparser.RawConfigParser.has_option(self, real_section, option):
                break
        else:
            raise configparser.NoOptionError

        v = configparser.RawConfigParser.get(self, real_section, option, *args, **kwargs)
        def dollar_replace(m):
            """Called for each $replacement."""
            # Only one of the groups will have matched, just get its text.
            word = next(w for w in m.groups() if w is not None)     # pragma: part covered
            if word == "$":
                return "$"
            else:
                return os.environ.get(word, '')

        dollar_pattern = r"""(?x)   # Use extended regex syntax
            \$(?:                   # A dollar sign, then
            (?P<v1>\w+) |           #   a plain word,
            {(?P<v2>\w+)} |         #   or a {-wrapped word,
            (?P<char>[$])           #   or a dollar sign.
            )
            """
        v = re.sub(dollar_pattern, dollar_replace, v)
        return v

    def getlist(self, section, option):
        """Read a list of strings.

        The value of `section` and `option` is treated as a comma- and newline-
        separated list of strings.  Each value is stripped of whitespace.

        Returns the list of strings.

        """
        value_list = self.get(section, option)
        values = []
        for value_line in value_list.split('\n'):
            for value in value_line.split(','):
                value = value.strip()
                if value:
                    values.append(value)
        return values

    def getregexlist(self, section, option):
        """Read a list of full-line regexes.

        The value of `section` and `option` is treated as a newline-separated
        list of regexes.  Each value is stripped of whitespace.

        Returns the list of strings.

        """
        line_list = self.get(section, option)
        value_list = []
        for value in line_list.splitlines():
            value = value.strip()
            try:
                re.compile(value)
            except re.error as e:
                raise CoverageException(
                    "Invalid [%s].%s value %r: %s" % (section, option, value, e)
                )
            if value:
                value_list.append(value)
        return value_list


# The default line exclusion regexes.
DEFAULT_EXCLUDE = [
    r'#\s*(pragma|PRAGMA)[:\s]?\s*(no|NO)\s*(cover|COVER)',
]

# The default partial branch regexes, to be modified by the user.
DEFAULT_PARTIAL = [
    r'#\s*(pragma|PRAGMA)[:\s]?\s*(no|NO)\s*(branch|BRANCH)',
]

# The default partial branch regexes, based on Python semantics.
# These are any Python branching constructs that can't actually execute all
# their branches.
DEFAULT_PARTIAL_ALWAYS = [
    'while (True|1|False|0):',
    'if (True|1|False|0):',
]


class CoverageConfig(object):
    """Coverage.py configuration.

    The attributes of this class are the various settings that control the
    operation of coverage.py.

    """
    def __init__(self):
        """Initialize the configuration attributes to their defaults."""
        # Metadata about the config.
        self.attempted_config_files = []
        self.config_files = []

        # Defaults for [run] and [report]
        self._include = None
        self._omit = None

        # Defaults for [run]
        self.branch = False
        self.concurrency = None
        self.cover_pylib = False
        self.data_file = ".coverage"
        self.debug = []
        self.disable_warnings = []
        self.note = None
        self.parallel = False
        self.plugins = []
        self.source = None
        self.run_include = None
        self.run_omit = None
        self.timid = False

        # Defaults for [report]
        self.exclude_list = DEFAULT_EXCLUDE[:]
        self.fail_under = 0.0
        self.ignore_errors = False
        self.report_include = None
        self.report_omit = None
        self.partial_always_list = DEFAULT_PARTIAL_ALWAYS[:]
        self.partial_list = DEFAULT_PARTIAL[:]
        self.precision = 0
        self.show_missing = False
        self.skip_covered = False

        # Defaults for [html]
        self.extra_css = None
        self.html_dir = "htmlcov"
        self.html_title = "Coverage report"

        # Defaults for [xml]
        self.xml_output = "coverage.xml"
        self.xml_package_depth = 99

        # Defaults for [paths]
        self.paths = {}

        # Options for plugins
        self.plugin_options = {}

    MUST_BE_LIST = [
        "debug", "concurrency", "plugins",
        "report_omit", "report_include",
        "run_omit", "run_include",
    ]

    def from_args(self, **kwargs):
        """Read config values from `kwargs`."""
        for k, v in iitems(kwargs):
            if v is not None:
                if k in self.MUST_BE_LIST and isinstance(v, string_class):
                    v = [v]
                setattr(self, k, v)

    @contract(filename=str)
    def from_file(self, filename, our_file):
        """Read configuration from a .rc file.

        `filename` is a file name to read.

        `our_file` is True if this config file is specifically for coverage,
        False if we are examining another config file (tox.ini, setup.cfg)
        for possible settings.

        Returns True or False, whether the file could be read, and it had some
        coverage.py settings in it.

        """
        self.attempted_config_files.append(filename)

        cp = HandyConfigParser(our_file)
        try:
            files_read = cp.read(filename)
        except configparser.Error as err:
            raise CoverageException("Couldn't read config file %s: %s" % (filename, err))
        if not files_read:
            return False

        self.config_files.extend(files_read)

        any_set = False
        try:
            for option_spec in self.CONFIG_FILE_OPTIONS:
                was_set = self._set_attr_from_config_option(cp, *option_spec)
                if was_set:
                    any_set = True
        except ValueError as err:
            raise CoverageException("Couldn't read config file %s: %s" % (filename, err))

        # Check that there are no unrecognized options.
        all_options = collections.defaultdict(set)
        for option_spec in self.CONFIG_FILE_OPTIONS:
            section, option = option_spec[1].split(":")
            all_options[section].add(option)

        for section, options in iitems(all_options):
            real_section = cp.has_section(section)
            if real_section:
                for unknown in set(cp.options(section)) - options:
                    raise CoverageException(
                        "Unrecognized option '[%s] %s=' in config file %s" % (
                            real_section, unknown, filename
                        )
                    )

        # [paths] is special
        if cp.has_section('paths'):
            for option in cp.options('paths'):
                self.paths[option] = cp.getlist('paths', option)
                any_set = True

        # plugins can have options
        for plugin in self.plugins:
            if cp.has_section(plugin):
                self.plugin_options[plugin] = cp.get_section(plugin)
                any_set = True

        # Was this file used as a config file? If it's specifically our file,
        # then it was used.  If we're piggybacking on someone else's file,
        # then it was only used if we found some settings in it.
        if our_file:
            return True
        else:
            return any_set

    CONFIG_FILE_OPTIONS = [
        # These are *args for _set_attr_from_config_option:
        #   (attr, where, type_="")
        #
        #   attr is the attribute to set on the CoverageConfig object.
        #   where is the section:name to read from the configuration file.
        #   type_ is the optional type to apply, by using .getTYPE to read the
        #       configuration value from the file.

        # [run]
        ('branch', 'run:branch', 'boolean'),
        ('concurrency', 'run:concurrency', 'list'),
        ('cover_pylib', 'run:cover_pylib', 'boolean'),
        ('data_file', 'run:data_file'),
        ('debug', 'run:debug', 'list'),
        ('disable_warnings', 'run:disable_warnings', 'list'),
        ('note', 'run:note'),
        ('parallel', 'run:parallel', 'boolean'),
        ('plugins', 'run:plugins', 'list'),
        ('run_include', 'run:include', 'list'),
        ('run_omit', 'run:omit', 'list'),
        ('source', 'run:source', 'list'),
        ('timid', 'run:timid', 'boolean'),

        # [report]
        ('exclude_list', 'report:exclude_lines', 'regexlist'),
        ('fail_under', 'report:fail_under', 'float'),
        ('ignore_errors', 'report:ignore_errors', 'boolean'),
        ('partial_always_list', 'report:partial_branches_always', 'regexlist'),
        ('partial_list', 'report:partial_branches', 'regexlist'),
        ('precision', 'report:precision', 'int'),
        ('report_include', 'report:include', 'list'),
        ('report_omit', 'report:omit', 'list'),
        ('show_missing', 'report:show_missing', 'boolean'),
        ('skip_covered', 'report:skip_covered', 'boolean'),
        ('sort', 'report:sort'),

        # [html]
        ('extra_css', 'html:extra_css'),
        ('html_dir', 'html:directory'),
        ('html_title', 'html:title'),

        # [xml]
        ('xml_output', 'xml:output'),
        ('xml_package_depth', 'xml:package_depth', 'int'),
    ]

    def _set_attr_from_config_option(self, cp, attr, where, type_=''):
        """Set an attribute on self if it exists in the ConfigParser.

        Returns True if the attribute was set.

        """
        section, option = where.split(":")
        if cp.has_option(section, option):
            method = getattr(cp, 'get' + type_)
            setattr(self, attr, method(section, option))
            return True
        return False

    def get_plugin_options(self, plugin):
        """Get a dictionary of options for the plugin named `plugin`."""
        return self.plugin_options.get(plugin, {})

    def set_option(self, option_name, value):
        """Set an option in the configuration.

        `option_name` is a colon-separated string indicating the section and
        option name.  For example, the ``branch`` option in the ``[run]``
        section of the config file would be indicated with `"run:branch"`.

        `value` is the new value for the option.

        """

        # Check all the hard-coded options.
        for option_spec in self.CONFIG_FILE_OPTIONS:
            attr, where = option_spec[:2]
            if where == option_name:
                setattr(self, attr, value)
                return

        # See if it's a plugin option.
        plugin_name, _, key = option_name.partition(":")
        if key and plugin_name in self.plugins:
            self.plugin_options.setdefault(plugin_name, {})[key] = value
            return

        # If we get here, we didn't find the option.
        raise CoverageException("No such option: %r" % option_name)

    def get_option(self, option_name):
        """Get an option from the configuration.

        `option_name` is a colon-separated string indicating the section and
        option name.  For example, the ``branch`` option in the ``[run]``
        section of the config file would be indicated with `"run:branch"`.

        Returns the value of the option.

        """
        # Check all the hard-coded options.
        for option_spec in self.CONFIG_FILE_OPTIONS:
            attr, where = option_spec[:2]
            if where == option_name:
                return getattr(self, attr)

        # See if it's a plugin option.
        plugin_name, _, key = option_name.partition(":")
        if key and plugin_name in self.plugins:
            return self.plugin_options.get(plugin_name, {}).get(key)

        # If we get here, we didn't find the option.
        raise CoverageException("No such option: %r" % option_name)


def read_coverage_config(config_file, **kwargs):
    """Read the coverage.py configuration.

    Arguments:
        config_file: a boolean or string, see the `Coverage` class for the
            tricky details.
        all others: keyword arguments from the `Coverage` class, used for
            setting values in the configuration.

    Returns:
        config_file, config:
            config_file is the value to use for config_file in other
            invocations of coverage.

            config is a CoverageConfig object read from the appropriate
            configuration file.

    """
    # Build the configuration from a number of sources:
    # 1) defaults:
    config = CoverageConfig()

    # 2) from a file:
    if config_file:
        # Some API users were specifying ".coveragerc" to mean the same as
        # True, so make it so.
        if config_file == ".coveragerc":
            config_file = True
        specified_file = (config_file is not True)
        if not specified_file:
            config_file = ".coveragerc"

        for fname, our_file in [(config_file, True),
                                ("setup.cfg", False),
                                ("tox.ini", False)]:
            config_read = config.from_file(fname, our_file=our_file)
            is_config_file = fname == config_file

            if not config_read and is_config_file and specified_file:
                raise CoverageException("Couldn't read '%s' as a config file" % fname)

            if config_read:
                break

    # 3) from environment variables:
    env_data_file = os.environ.get('COVERAGE_FILE')
    if env_data_file:
        config.data_file = env_data_file
    debugs = os.environ.get('COVERAGE_DEBUG')
    if debugs:
        config.debug.extend(d.strip() for d in debugs.split(","))

    # 4) from constructor arguments:
    config.from_args(**kwargs)

    # Once all the config has been collected, there's a little post-processing
    # to do.
    config.data_file = os.path.expanduser(config.data_file)
    config.html_dir = os.path.expanduser(config.html_dir)
    config.xml_output = os.path.expanduser(config.xml_output)

    return config_file, config
