# -*- coding: utf-8 -*-

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

from __future__ import absolute_import
from __future__ import print_function
from __future__ import division
import collections
import configparser
import os
import operator

from clcommon.clcagefs import in_cagefs

from .clselect import ClSelect
from .clselectexcept import ClSelectExcept
from .clselectprint import clprint
from . import utils

# dependencies modulse dict. Example { 'ext_name': 'ext1' } - ext1 depends from ext_name
depend_modules_dict = dict()


class ClExtSelect(ClSelect):
    CONFLICTS_PATH = (
        '/etc/cl.selector.conf.d/php.extensions.conflicts'
        if in_cagefs()
        else '/etc/cl.selector/php.extensions.conflicts'
    )
    SYSTEM_ALT_PATH = '/opt/alt'

    def __init__(self, item='php'):
        ClSelect.__init__(self, item)
        self._conflicts = []
        # Sets in _get_enabled_extensions method
        #  True  - extension list was read from native php built-ins
        #  False - extension list was read from /etc/cl.selector/defaults.cfg
        self._use_default_exts_from_native_php = False

    def _is_disabled_extention(self, ext_name):
        return ext_name in self._hidden_extensions

    def enable_extensions(self, version, ext_list):
        """
        Adds extensions to default list of extensions for a version
        """
        alternatives = self.get_all_alternatives_data()
        self._check_alternative(version, alternatives)
        defaults_contents = self._process_ini_file(
            self.DEFAULTS_PATH,
            (self._item, version),
            self._add_extensions,
            ext_list, action = 'enable_extentions')
        self._write_to_file(
            '\n'.join(defaults_contents), ClExtSelect.DEFAULTS_PATH)

    def replace_extensions(self, version, ext_list):
        """
        Replaces extensions to default list of extensions for a version.
        Writes/updates /etc/cl.selector/defaults.cfg file
        :param version: alt-php version to process
        :param ext_list: list extensions to set as defaults for the version
        """
        alternatives = self.get_all_alternatives_data()
        self._check_alternative(version, alternatives)
        defaults_contents = self._process_ini_file(
            self.DEFAULTS_PATH,
            (self._item, version),
            self._replace_extensions,
            ext_list)
        self._write_to_file(
            '\n'.join(defaults_contents), self.DEFAULTS_PATH)

    def disable_extensions(self, version, ext_list):
        """
        Removes extensions from default list of extensions for a version
        :param version: alt-php version to process
        :param ext_list: comma separated extensions list to delete
        """
        alternatives = self.get_all_alternatives_data()
        self._check_alternative(version, alternatives)
        defaults_contents = self._process_ini_file(
            self.DEFAULTS_PATH,
            (self._item, version),
            self._del_extensions,
            ext_list, action = 'disable_extentions')
        self._write_to_file('\n'.join(defaults_contents), self.DEFAULTS_PATH)

    def list_extensions(self, version):
        """
        Returns list of extensions marking built-ins and enabled ones
        Also replaces mysqli->nd_mysqli in defaults.cfg for new installations according to LVEMAN-1399
        :param version: php version
        :return Tuple: (extension_name, extension_state)
            extension_state:
                None        -- built-in extension
                False/True  -- disabled/enabled extension
        """
        ext_mysqli_name = 'mysqli'
        ext_nd_mysqli_name = 'nd_mysqli'
        ext_list_to_write = list()
        is_need_to_write_defaults = False
        alternatives = self.get_all_alternatives_data()
        self._check_alternative(version, alternatives)
        # Get extensions list from /etc/cl.selector/defaults.cfg for supplied verson or
        # list of built-in extesions for native if version does not present in defaults.cfg
        enabled_extensions = self._get_enabled_extensions(version)
        # Get extension list for version
        as_built_in = self._get_builtins(version)
        try:
            # Get extensions list for version - list of files
            # /opt/alt/phpXX/etc/php.d.all/*.ini without .ini extension
            # Without dependencies analysis
            as_extensions = self._load_extensions_list(version)
        except ClSelectExcept.UnableToGetExtensions:
            as_extensions = []
        # ['bz2', 'calendar'] -> ('bz2', None), ('calendar', None)
        all_extensions = list(map((lambda i: (i, None)), as_built_in))
        for ext in as_extensions:
            status = False
            if (ext in enabled_extensions) and (ext not in as_built_in):
                status = True
            ext_set = set([(ext, True), (ext, False), (ext, None)])
            if not set(all_extensions).intersection(ext_set):
                # add ext and its status to result list
                # LVEMAN-1399:
                # If defaults modules was taken from native php built-ins
                # replace mysqli to nd_mysqli (if it exist) and set status True to it
                if ext == ext_mysqli_name and self._use_default_exts_from_native_php\
                        and ext_nd_mysqli_name in as_extensions:
                    all_extensions.append((ext_mysqli_name, False))
                    all_extensions.append((ext_nd_mysqli_name, True))
                    # After module replacement we need to write new list as defaults
                    is_need_to_write_defaults = True
                    # add nd_mysqli to list for write
                    ext_list_to_write.append(ext_nd_mysqli_name)
                else:
                    all_extensions.append((ext, status))
                    if status:
                        # if module enabled, add it to list for write
                        ext_list_to_write.append(ext)
        # all_extensions example: [('bz2', None), ('calendar', None), (u'zip', True), (u'zmq', False)]
        # If module replacement occures, write list to defaults.cfg
        if is_need_to_write_defaults:
            self.replace_extensions(version, ext_list_to_write)
        return tuple(sorted(all_extensions, key=operator.itemgetter(0)))

    def _get_enabled_extensions(self, version):
        """
        Returns list of enabled extensions for a version
        """
        try:
            # reads extensions list from /etc/cl.selector/defaults.cfg
            data = self._dh.get(
                "%s%s" % (self._item, version), 'modules')
            self._use_default_exts_from_native_php = False
            return list(map((lambda i: i.strip()), data.split(',')))
        except (configparser.NoSectionError, configparser.NoOptionError):
            self._use_default_exts_from_native_php = True
            return self._get_builtins('native')

    def _add_extensions(self, section_info, section, data, trace=True):
        """
        Adds 'modules' option to section or extends it
        @param section_info: tuple (item and version)
        @param section: list
        @param data: list
        @return: list
        """
        section_header = self._make_section_header(section_info)
        if len(section) == 0 or section_header != section[0]:
            return section
        midx = None
        modules = []
        alt_path = self._compose_alt_path(section_info[1])
        for idx in range(len(section)):
            if section[idx].startswith('modules'):
                midx = idx
                break
        if midx:
            modules_string = section[midx][section[midx].find('=')+1:].strip()
            modules.extend(
                list(map((lambda i: i.strip()), modules_string.split(','))))
        modules.extend(data)
        modules = self._check_for_conflicts(modules)
        resolved_modules = self._include_dependencies(modules, alt_path)
        modules_string = 'modules = %s' % (','.join(sorted(resolved_modules)))
        if midx:
            section[midx] = modules_string
        else:
            section.append(modules_string)
        return self._smooth_data(section)

    def _replace_extensions(self, section_info, section, data, trace=True):
        """
        Adds 'modules' option to section or extends it
        @param section_info: tuple (item and version).
            Example: ('php', '5.2')
        @param section: list. Modules from /etc/cl.selecto/defaults.cfg for supplied php version
            Example: ['[php5.2]',
                      'modules = bcmath,dom,gd,imap,json,mcrypt,mysql,mysqli,phar,posix,sockets,uuid,wddx,xmlreader,zip',
                      '', '']
        @param data: list: Modules list to set from command line
        @:param trace: ????, Currently not using, always True
        @return: list
        """
        global depend_modules_dict
        section_header = self._make_section_header(section_info)
        if len(section) == 0 or section_header != section[0]:
            return section
        midx = None
        alt_path = self._compose_alt_path(section_info[1])
        for idx in range(len(section)):
            if section[idx].startswith('modules'):
                midx = idx
                break
        modules = data[:]
        if trace:
            resolved_modules = set()
            modules = self._check_for_conflicts(modules)
            for mod in modules:
                include_dep = self._include_dependencies([mod], alt_path)
                if len(include_dep) != 1:
                    # Dependencies found, add them to depend_modules_dict
                    # Add deps to dict
                    depend_modules_dict.update({dep_module: mod for dep_module in include_dep if dep_module != mod})
                resolved_modules.update(include_dep)
            modules_string = 'modules = %s' % (','.join(sorted(resolved_modules)))
        else:
            modules_string = 'modules = %s' % (','.join(sorted(data)))
        if midx:
            section[midx] = modules_string
        else:
            section.append(modules_string)
        # Cleanup dependency list - remove from dependencies all modules, present in command line
        modules = depend_modules_dict.copy()
        for dep_module in modules.keys():
            if dep_module in data:
                del depend_modules_dict[dep_module]
        return self._smooth_data(section)

    def _del_extensions(self, section_info, section, data, trace=True):
        """
        Deletes items in data list from section list
        @param section_info: tuple (item and version)
        @param section: list
        @param data: list of extension names to delete
        @return: list
        """
        section_header = self._make_section_header(section_info)
        if len(section) == 0 or section_header != section[0]:
            return section
        midx = None
        alt_path = self._compose_alt_path(section_info[1])
        for idx in range(len(section)):
            if section[idx].startswith('modules'):
                midx = idx
                break
        if not midx:
            return section
        modules_string = section[midx][section[midx].find('=')+1:].strip()
        modules = set(map((lambda i: i.strip()), modules_string.split(',')))
        resolved_modules = modules.copy()
        for item in set(data):
            if item not in modules:
                continue
            rest_of_modules = modules.difference([item])
            if self._is_dependency(item, rest_of_modules, alt_path):
                continue
            resolved_modules.discard(item)
        resolved_modules = self._include_dependencies(resolved_modules, alt_path)
        modules_string = 'modules = %s' % (','.join(sorted(resolved_modules)))
        section[midx] = modules_string
        return self._smooth_data(section)

    def _is_dependency(cls, ext, modules, alt_path):
        """
        Checks if module in modules dependent on ext and returns true or false
        @param ext: Module to check
        @param modules: set of names of installed modules
        @param alt_path: Path to alt-php ini dir: /opt/alt/phpXX/etc/php.d.all
        @return: bool. True if ext present in dependencies of any module in modules list
        """
        global depend_modules_dict
        for mod in modules:
            dependencies = cls._get_dependencies(mod, alt_path)
            if ext in dependencies:
                depend_modules_dict[ext] = mod
                return True
        return False
    _is_dependency = classmethod(_is_dependency)

    def _compose_alt_path(self, version):
        """
        Composes and returns path for alternatives
        """
        return os.path.join(
            self.SYSTEM_ALT_PATH,
            "%s%s" % (self._item, version.replace('.', '')),
            "etc",
            "%s.d.all" % (self._item,))

    def _include_dependencies(cls, ext_list, alt_path, data=None):
        """
        Includes dependencies into extensions list and update data dict
        if present
        @param ext_list: list
        @param alt_path: string
        @param data: dict
        @return: list
        """
        in_section = False
        result_ext_list = []
        handled = set()
        q = collections.deque(ext_list)

        while q:
            ext = q.popleft()
            if ext in handled:
                continue

            handled.add(ext)

            ext_path = os.path.join(alt_path, f'{ext}.ini')
            try:
                f = open(ext_path)
                file_contents = []
                pending_contents = []

                for line in f:
                    if line.startswith('extension') or line.startswith('zend_extension'):
                        ext_name = cls._single_out_extension(ext, line)
                        if ext_name != ext and ext_name not in handled:
                            q.appendleft(ext_name)
                            continue

                        file_contents.append(f';---{ext}---')
                        in_section = True
                        file_contents.extend(pending_contents)
                        pending_contents = []

                    if not (line.startswith(';') or line.startswith('\n')):
                        if in_section:
                            file_contents.append(line.rstrip())
                        else:
                            pending_contents.append(line.rstrip())
                f.close()

                if data is not None and ext not in data:
                    data[ext] = file_contents

                # Adding to the beggining of the result list due to LVEMAN-504
                result_ext_list.insert(0, ext)
            except (OSError, IOError):
                continue

        return result_ext_list
    _include_dependencies = classmethod(_include_dependencies)

    def _get_dependencies(cls, ext, alt_path):
        """
        Checks if an extension has dependencies and if so returns them
        Otherwise returns None
        @param ext: string
        @return: set
        """
        dependencies = set()
        ext_path = os.path.join(alt_path, "%s.ini" % (ext,))
        try:
            f = open(ext_path)
            for line in f:
                if line.startswith('extension'):
                    ext_name = cls._single_out_extension(ext, line)
                    if ext_name != ext:
                        dependencies.add(ext_name)
            return dependencies
        except (OSError, IOError):
            return dependencies
    _get_dependencies = classmethod(_get_dependencies)

    def _single_out_extension(ext, line):
        """
        Singles out and returns extension from line
        """
        quirks = {'ixed': 'sourceguardian'}
        if '/' in line:
            ext_name = line[line.rfind('/')+1:].strip()
        else:
            ext_name = line[line.find('=')+1:].strip(' "')
        if '.' in ext_name:
            ext_name = ext_name[:ext_name.find('.')]
        if '-' in ext_name:
            ext_name = ext_name[:ext_name.rfind('-')]
        if ext_name in quirks:
            ext_name = quirks[ext_name]
        elif ext in ext_name:
            ext_name = ext
        elif ('_' in ext and ''.join(map((lambda i: i.capitalize()),
                ext.split('_'))) == ext_name):
            ext_name = ext
        return ext_name
    _single_out_extension = staticmethod(_single_out_extension)

    def _check_for_conflicts(self, ext_list):
        """
        Removes from extensions list conflicting ones
        """
        if not self._conflicts:
            self._load_conflicting_extensions()
        clean_set = set()
        for ext in ext_list:
            if self._is_not_conflicting(ext, clean_set) and \
                    not self._is_disabled_extention(ext):
                clean_set.add(ext)
            #else:
                #clprint.print_diag(
                #    'text',
                #    {'status': 'WARN',
                #     'message': '%s skipped as conflicting (%s)' % (ext, str(clean_set))})
        return clean_set

    def _is_not_conflicting(self, ext, clean_set):
        """
        Checks extension against conflicting sets
        """
        for conflict in self._conflicts:
            if ext in conflict:
                if len(clean_set.copy().intersection(conflict)) != 0:
                    return False
        return True

    def _load_conflicting_extensions(self):
        """
        Loads conflicting extensions from file and saves'em as list of sets
        """
        conflicts = utils.read_file_as_string(self.CONFLICTS_PATH)
        for line in conflicts.splitlines():
            if ',' not in line:
                continue
            conflict_set = set(map((lambda i: i.strip()), line.split(',')))
            if len(conflict_set) < 2:
                continue
            self._conflicts.append(conflict_set)

    def _load_extensions_list(self, version):
        """
        Loads alternative extensions list for a version
        @param version: string
        """
        alt_path = self._compose_alt_path(version)
        try:
            alt_extensions = []
            for filename in os.listdir(alt_path):
                if not filename.endswith('.ini'):
                    continue
                extension = filename[:filename.find('.ini')]
                if extension in self._hidden_extensions:
                    continue
                alt_extensions.append(extension)
            return sorted(alt_extensions)
        except OSError:
            raise ClSelectExcept.UnableToGetExtensions(version)

    @staticmethod
    def _print_dependencies_info(dependens_info):
        """
        Prints info
        @param ext: string
        @param data: list
        """
        for (i, ext) in dependens_info:
            clprint.print_diag(
                'text',
                {'status': 'WARN',
                 'message': '%s enabled as dependency (%s)'
                 % (i, ext)})

    @staticmethod
    def get_dependencies_list(ext, data, ext_list):
        """
        Get array of dependenses [(ext, depending ext)]
        @param ext: string
        @param data: list
        """
        if not data:
            return []
        diff = set(data).difference([ext])
        return [(i, ext) for i in diff if i not in ext_list]

    @staticmethod
    def get_conflicts_info(init_list, processed_set):
        return list(set(init_list).difference(processed_set))

    @staticmethod
    def _print_conflicts_info(diff):
        """
        Prepares data for printing conflicts if any
        @param init_list: list
        @param processed_set: set
        """
        if diff:
            for i in diff:
                clprint.print_diag(
                    'text',
                    {'status': 'WARN',
                     'message': '%s skipped as conflicting' % (i,)})