"""
Edit ini files

:maintainer: <akilesh1597@gmail.com>
:maturity: new
:depends: re
:platform: all

(for example /etc/sysctl.conf)
"""

import logging
import os
import re

import salt.utils.data
import salt.utils.files
import salt.utils.json
import salt.utils.stringutils
from salt.exceptions import CommandExecutionError
from salt.utils.odict import OrderedDict

log = logging.getLogger(__name__)

__virtualname__ = "ini"


def __virtual__():
    """
    Rename to ini
    """
    return __virtualname__


INI_REGX = re.compile(r"^\s*\[(.+?)\]\s*$", flags=re.M)
COM_REGX = re.compile(r"^\s*(#|;)\s*(.*)")
INDENTED_REGX = re.compile(r"(\s+)(.*)")


def set_option(file_name, sections=None, separator="=", encoding=None):
    """
    Edit an ini file, replacing one or more sections. Returns a dictionary
    containing the changes made.

    Args:

        file_name (str):
            The full path to the ini file.

        sections (dict):
            A dictionary representing the sections to be edited in the ini file.
            The keys are the section names and the values are a dictionary
            containing the options. If the ini file does not contain sections
            the keys and values represent the options. The default is ``None``.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        dict: A dictionary representing the changes made to the ini file

    API Example:

    .. code-block:: python

        import salt.client
        with salt.client.get_local_client() as sc:
            sc.cmd(
                'target', 'ini.set_option', ['path_to_ini_file', '{"section_to_change": {"key": "value"}}']
            )

    CLI Example:

    .. code-block:: bash

        salt '*' ini.set_option /path/to/ini '{section_foo: {key: value}}'

    """

    sections = sections or {}
    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    changes = inifile.update(sections)
    inifile.flush()
    return changes


def get_option(file_name, section, option, separator="=", encoding=None):
    """
    Get value of a key from a section in an ini file. Returns ``None`` if
    no matching key was found.

    Args:

        file_name (str):
            The full path to the ini file.

        section (str):
            A string value representing the section of the ini that the option
            is in. If the option is not in a section, leave this empty.

        option (str):
            A string value representing the option to search for.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        str: The value as defined in the ini file, or ``None`` if empty or not
            found

    API Example:

    .. code-block:: python

        import salt.client
        with salt.client.get_local_client() as sc:
            sc.cmd('target', 'ini.get_option', [path_to_ini_file, section_name, option])

    CLI Example:

    .. code-block:: bash

        salt '*' ini.get_option /path/to/ini section_name option_name

    """

    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    if section:
        try:
            return inifile.get(section, {}).get(option, None)
        except AttributeError:
            return None
    else:
        return inifile.get(option, None)


def remove_option(file_name, section, option, separator="=", encoding=None):
    """
    Remove a key/value pair from a section in an ini file. Returns the value of
    the removed key, or ``None`` if nothing was removed.

    Args:

        file_name (str):
            The full path to the ini file.

        section (str):
            A string value representing the section of the ini that the option
            is in. If the option is not in a section, leave this empty.

        option (str):
            A string value representing the option to search for.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        str: A string value representing the option that was removed or ``None``
            if nothing was removed

    API Example:

    .. code-block:: python

        import salt
        sc = salt.client.get_local_client()
        sc.cmd('target', 'ini.remove_option', [path_to_ini_file, section_name, option])

    CLI Example:

    .. code-block:: bash

        salt '*' ini.remove_option /path/to/ini section_name option_name

    """

    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    if isinstance(inifile.get(section), (dict, OrderedDict)):
        value = inifile.get(section, {}).pop(option, None)
    else:
        value = inifile.pop(option, None)
    inifile.flush()
    return value


def get_section(file_name, section, separator="=", encoding=None):
    """
    Retrieve a section from an ini file. Returns the section as a dictionary. If
    the section is not found, an empty dictionary is returned.

    Args:

        file_name (str):
            The full path to the ini file.

        section (str):
            A string value representing name of the section to search for.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        dict: A dictionary containing the names and values of all items in the
            section of the ini file. If the section is not found, an empty
            dictionary is returned

    API Example:

    .. code-block:: python

        import salt.client
        with salt.client.get_local_client() as sc:
            sc.cmd('target', 'ini.get_section', [path_to_ini_file, section_name])

    CLI Example:

    .. code-block:: bash

        salt '*' ini.get_section /path/to/ini section_name

    """

    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    ret = {}
    for key, value in inifile.get(section, {}).items():
        if key[0] != "#":
            ret.update({key: value})
    return ret


def remove_section(file_name, section, separator="=", encoding=None):
    """
    Remove a section in an ini file. Returns the removed section as a
    dictionary, or ``None`` if nothing is removed.

    Args:

        file_name (str):
            The full path to the ini file.

        section (str):
            A string value representing the name of the section search for.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        dict: A dictionary containing the names and values of all items in the
            section that was removed or ``None`` if nothing was removed

    API Example:

    .. code-block:: python

        import salt.client
        with  salt.client.get_local_client() as sc:
            sc.cmd('target', 'ini.remove_section', [path_to_ini_file, section_name])

    CLI Example:

    .. code-block:: bash

        salt '*' ini.remove_section /path/to/ini section_name

    """

    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    if section in inifile:
        section = inifile.pop(section)
        inifile.flush()
        ret = {}
        for key, value in section.items():
            if key[0] != "#":
                ret.update({key: value})
        return ret


def get_ini(file_name, separator="=", encoding=None):
    """
    Retrieve the whole structure from an ini file and return it as a dictionary.

    Args:

        file_name (str):
            The full path to the ini file.

        separator (str):
            The character used to separate keys and values. Standard ini files
            use the "=" character. The default is ``=``.

            .. versionadded:: 2016.11.0

        encoding (str):
            A string value representing encoding of the target ini file. If
            ``None`` is passed, it uses the system default which is likely
            ``utf-8``. Default is ``None``

            .. versionadded:: 3006.6

    Returns:
        dict: A dictionary containing the sections along with the values and
            names contained in each section

    API Example:

    .. code-block:: python

        import salt.client
        with salt.client.get_local_client() as sc:
            sc.cmd('target', 'ini.get_ini', [path_to_ini_file])

    CLI Example:

    .. code-block:: bash

        salt '*' ini.get_ini /path/to/ini

    """

    def ini_odict2dict(odict):
        """
        Transform OrderedDict to regular dict recursively
        :param odict: OrderedDict
        :return: regular dict
        """

        ret = {}
        for key, val in odict.items():
            if key[0] != "#":
                if isinstance(val, (dict, OrderedDict)):
                    ret.update({key: ini_odict2dict(val)})
                else:
                    ret.update({key: val})
        return ret

    inifile = _Ini.get_ini_file(file_name, separator=separator, encoding=encoding)
    return ini_odict2dict(inifile)


class _Section(OrderedDict):
    def __init__(self, name, inicontents="", separator="=", commenter="#"):
        super().__init__(self)
        self.name = name
        self.inicontents = inicontents
        self.sep = separator
        self.com = commenter

        opt_regx_prefix = r"(\s*)(.+?)\s*"
        opt_regx_suffix = r"\s*(.*)\s*"
        self.opt_regx_str = r"{}(\{}){}".format(
            opt_regx_prefix, self.sep, opt_regx_suffix
        )
        self.opt_regx = re.compile(self.opt_regx_str)

    def refresh(self, inicontents=None):
        comment_count = 1
        unknown_count = 1
        curr_indent = ""
        inicontents = inicontents or self.inicontents
        inicontents = inicontents.strip(os.linesep)

        if not inicontents:
            return
        for opt in self:
            self.pop(opt)
        for opt_str in inicontents.split(os.linesep):
            # Match comments
            com_match = COM_REGX.match(opt_str)
            if com_match:
                name = f"#comment{comment_count}"
                self.com = com_match.group(1)
                comment_count += 1
                self.update({name: opt_str})
                continue
            # Add indented lines to the value of the previous entry.
            indented_match = INDENTED_REGX.match(opt_str)
            if indented_match:
                indent = indented_match.group(1).replace("\t", "    ")
                if indent > curr_indent:
                    options = list(self)
                    if options:
                        prev_opt = options[-1]
                        value = self.get(prev_opt)
                        self.update({prev_opt: os.linesep.join((value, opt_str))})
                    continue
            # Match normal key+value lines.
            opt_match = self.opt_regx.match(opt_str)
            if opt_match:
                curr_indent, name, self.sep, value = opt_match.groups()
                curr_indent = curr_indent.replace("\t", "    ")
                self.update({name: value})
                continue
            # Anything remaining is a mystery.
            name = f"#unknown{unknown_count}"
            self.update({name: opt_str})
            unknown_count += 1

    def _uncomment_if_commented(self, opt_key):
        # should be called only if opt_key is not already present
        # will uncomment the key if commented and create a place holder
        # for the key where the correct value can be update later
        # used to preserve the ordering of comments and commented options
        # and to make sure options without sectons go above any section
        options_backup = OrderedDict()
        comment_index = None
        for key, value in self.items():
            if comment_index is not None:
                options_backup.update({key: value})
                continue
            if "#comment" not in key:
                continue
            opt_match = self.opt_regx.match(value.lstrip("#"))
            if opt_match and opt_match.group(2) == opt_key:
                comment_index = key
        for key in options_backup:
            self.pop(key)
        self.pop(comment_index, None)
        super().update({opt_key: None})
        for key, value in options_backup.items():
            super().update({key: value})

    def update(self, update_dict):
        changes = {}
        for key, value in update_dict.items():
            # Ensure the value is either a _Section or a string
            if isinstance(value, (dict, OrderedDict)):
                sect = _Section(
                    name=key, inicontents="", separator=self.sep, commenter=self.com
                )
                sect.update(value)
                value = sect
                value_plain = value.as_dict()
            else:
                value = str(value)
                value_plain = value

            if key not in self:
                changes.update({key: {"before": None, "after": value_plain}})
                # If it's not a section, it may already exist as a
                # commented-out key/value pair
                if not isinstance(value, _Section):
                    self._uncomment_if_commented(key)

                super().update({key: value})
            else:
                curr_value = self.get(key, None)
                if isinstance(curr_value, _Section):
                    sub_changes = curr_value.update(value)
                    if sub_changes:
                        changes.update({key: sub_changes})
                else:
                    if curr_value != value:
                        changes.update(
                            {key: {"before": curr_value, "after": value_plain}}
                        )
                        super().update({key: value})
        return changes

    def gen_ini(self):
        yield "{0}[{1}]{0}".format(os.linesep, self.name)
        sections_dict = OrderedDict()
        for name, value in self.items():
            # Handle Comment Lines
            if COM_REGX.match(name):
                yield f"{value}{os.linesep}"
            # Handle Sections
            elif isinstance(value, _Section):
                sections_dict.update({name: value})
            # Key / Value pairs
            # Adds spaces between the separator
            else:
                yield "{}{}{}{}".format(
                    name,
                    f" {self.sep} " if self.sep != " " else self.sep,
                    value,
                    os.linesep,
                )
        for name, value in sections_dict.items():
            yield from value.gen_ini()

    def as_ini(self):
        return "".join(self.gen_ini())

    def as_dict(self):
        return dict(self)

    def dump(self):
        print(str(self))

    def __repr__(self, _repr_running=None):
        _repr_running = _repr_running or {}
        try:
            super_repr = super().__repr__(_repr_running)
        except TypeError:
            super_repr = super().__repr__()
        return os.linesep.join((super_repr, salt.utils.json.dumps(self, indent=4)))

    def __str__(self):
        return salt.utils.json.dumps(self, indent=4)

    def __eq__(self, item):
        return isinstance(item, self.__class__) and self.name == item.name

    def __ne__(self, item):
        return not (isinstance(item, self.__class__) and self.name == item.name)


class _Ini(_Section):
    def __init__(
        self, name, inicontents="", separator="=", commenter="#", encoding=None
    ):
        super().__init__(
            self, inicontents=inicontents, separator=separator, commenter=commenter
        )
        self.name = name
        if encoding is None:
            encoding = __salt_system_encoding__
        self.encoding = encoding

    def refresh(self, inicontents=None):
        if inicontents is None:
            if not os.path.exists(self.name):
                log.trace("File %s does not exist and will be created", self.name)
                return
            try:
                # We need to set decode on open and not try to do it later with
                # stringutils
                with salt.utils.files.fopen(
                    self.name, "r", encoding=self.encoding
                ) as rfh:
                    inicontents = rfh.read()
                    inicontents = os.linesep.join(inicontents.splitlines())
            except OSError as exc:
                if __opts__["test"] is False:
                    raise CommandExecutionError(
                        f"Unable to open file '{self.name}'. Exception: {exc}"
                    )
        if not inicontents:
            return
        # Remove anything left behind from a previous run.
        self.clear()

        inicontents = INI_REGX.split(inicontents)
        inicontents.reverse()
        # Pop anything defined outside of a section (ie. at the top of
        # the ini file).
        super().refresh(inicontents.pop())
        for section_name, sect_ini in self._gen_tuples(inicontents):
            try:
                sect_obj = _Section(section_name, sect_ini, separator=self.sep)
                sect_obj.refresh()
                self.update({sect_obj.name: sect_obj})
            except StopIteration:
                pass

    def flush(self):
        try:
            # We need to encode in the fopen command instead of using
            # data.encode in the writelines command. Using data.encode will
            # cause a BoM to be placed on every line of the file
            with salt.utils.files.fopen(
                self.name, "w", encoding=self.encoding
            ) as outfile:
                ini_gen = self.gen_ini()
                next(ini_gen)
                ini_gen_list = list(ini_gen)
                # Avoid writing an initial line separator.
                if ini_gen_list:
                    ini_gen_list[0] = ini_gen_list[0].lstrip(os.linesep)
                outfile.writelines(ini_gen_list)
        except OSError as exc:
            raise CommandExecutionError(
                f"Unable to write file '{self.name}'. Exception: {exc}"
            )

    @staticmethod
    def get_ini_file(file_name, separator="=", encoding=None):
        inifile = _Ini(file_name, separator=separator, encoding=encoding)
        inifile.refresh()
        return inifile

    @staticmethod
    def _gen_tuples(list_object):
        while True:
            try:
                key = list_object.pop()
                value = list_object.pop()
            except IndexError:
                return
            else:
                yield key, value
