"""
Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: MIT-0
"""
import sys
import argparse
import logging
import glob
import json
import os
import copy
import six
import jsonschema
import cfnlint.decode.cfn_yaml
from cfnlint.version import __version__
from cfnlint.helpers import REGIONS
try:  # pragma: no cover
    from pathlib import Path
except ImportError:  # pragma: no cover
    from pathlib2 import Path

LOGGER = logging.getLogger('cfnlint')


def configure_logging(debug_logging, info_logging):
    """Setup Logging"""
    ch = logging.StreamHandler()
    ch.setLevel(logging.DEBUG)

    if debug_logging:
        LOGGER.setLevel(logging.DEBUG)
    elif info_logging:
        LOGGER.setLevel(logging.INFO)
    else:
        LOGGER.setLevel(logging.NOTSET)
    log_formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    ch.setFormatter(log_formatter)

    # make sure all other log handlers are removed before adding it back
    for handler in LOGGER.handlers:
        LOGGER.removeHandler(handler)
    LOGGER.addHandler(ch)


class ConfigFileArgs(object):
    """
        Config File arguments.
        Parses .cfnlintrc in the Home and Project folder.
    """
    file_args = {}

    def __init__(self, schema=None):
        # self.file_args = self.get_config_file_defaults()
        self.__user_config_file = None
        self.__project_config_file = None
        self.file_args = {}
        self.default_schema_file = Path(__file__).parent.joinpath(
            'data/CfnLintCli/config/schema.json')
        with self.default_schema_file.open() as f:
            self.default_schema = json.load(f)
        self.schema = self.default_schema if not schema else schema
        self.load()

    def _find_config(self):
        """Looks up for user and project level config
        Returns
        -------
        Tuple
            (Path, Path)
            Tuple with both configs and whether they were found
        Example
        -------
            > user_config, project_config = self._find_config()
        """
        config_file_name = '.cfnlintrc'
        if six.PY34:
            self.__user_config_file = Path(os.path.expanduser('~')).joinpath(config_file_name)
        else:
            self.__user_config_file = Path.home().joinpath(config_file_name)
        self.__project_config_file = Path.cwd().joinpath(config_file_name)

        user_config_path = ''
        project_config_path = ''

        if self._has_file(self.__user_config_file):
            LOGGER.debug('Found User CFNLINTRC')
            user_config_path = self.__user_config_file

        if self._has_file(self.__project_config_file):
            LOGGER.debug('Found Project level CFNLINTRC')
            project_config_path = self.__project_config_file

        return user_config_path, project_config_path

    def _has_file(self, filename):
        """Confirm whether file exists
        Parameters
        ----------
        filename : str
            Path to a file
        Returns
        -------
        Boolean
        """

        return Path(filename).is_file()

    def load(self):
        """Load configuration file and expose as a dictionary
        Returns
        -------
        Dict
            CFLINTRC configuration
        """

        LOGGER.debug('Looking for CFLINTRC before attempting to load')
        user_config, project_config = self._find_config()

        user_config = self._read_config(user_config)
        LOGGER.debug('Validating User CFNLINTRC')
        self.validate_config(user_config, self.schema)

        project_config = self._read_config(project_config)
        LOGGER.debug('Validating Project CFNLINTRC')
        self.validate_config(project_config, self.schema)

        LOGGER.debug('User configuration loaded as')
        LOGGER.debug('%s', user_config)
        LOGGER.debug('Project configuration loaded as')
        LOGGER.debug('%s', project_config)

        LOGGER.debug('Merging configurations...')
        self.file_args = self.merge_config(user_config, project_config)

    def validate_config(self, config, schema):
        """Validate configuration against schema
        Parameters
        ----------
        config : dict
            CFNLINTRC configuration
        schema : dict
            JSONSchema to validate against
        Raises
        -------
        jsonschema.exceptions.ValidationError
            Returned when cfnlintrc doesn't match schema provided
        """
        LOGGER.debug('Validating CFNLINTRC config with given JSONSchema')
        LOGGER.debug('Schema used: %s', schema)
        LOGGER.debug('Config used: %s', config)

        jsonschema.validate(config, schema)
        LOGGER.debug('CFNLINTRC looks valid!')

    def merge_config(self, user_config, project_config):
        """Merge project and user configuration into a single dictionary
        Creates a new configuration with both configuration merged
        it favours project level over user configuration if keys are duplicated
        NOTE
        ----
            It takes any number of nested dicts
            It overrides lists found in user_config with project_config
        Parameters
        ----------
        user_config : Dict
            User configuration (~/.cfnlintrc) found at user's home directory
        project_config : Dict
            Project configuration (.cfnlintrc) found at current directory
        Returns
        -------
        Dict
            Merged configuration
        """
        # Recursively override User config with Project config
        for key in user_config:
            if key in project_config:
                # If both keys are the same, let's check whether they have nested keys
                if isinstance(user_config[key], dict) and isinstance(project_config[key], dict):
                    self.merge_config(user_config[key], project_config[key])
                else:
                    user_config[key] = project_config[key]
                    LOGGER.debug(
                        'Overriding User\'s key %s with Project\'s specific value %s.', key, project_config[key])

        # Project may have unique config we need to copy over too
        # so that we can have user+project config available as one
        for key in project_config:
            if key not in user_config:
                user_config[key] = project_config[key]

        return user_config

    def _read_config(self, config):
        """Parse given YAML configuration
        Returns
        -------
        Dict
            Parsed YAML configuration as dictionary
        """
        config = Path(config)
        config_template = None

        if self._has_file(config):
            LOGGER.debug('Parsing CFNLINTRC')
            config_template = cfnlint.decode.cfn_yaml.load(str(config))

        if not config_template:
            config_template = {}

        return config_template


def comma_separated_arg(string):
    """ Split a comma separated string """
    return string.split(',')


def _ensure_value(namespace, name, value):
    if getattr(namespace, name, None) is None:
        setattr(namespace, name, value)
    return getattr(namespace, name)


class RuleConfigurationAction(argparse.Action):
    """ Override the default Action """

    def __init__(self, option_strings, dest, nargs=None, const=None, default=None,
                 type=None, choices=None, required=False, help=None, metavar=None):  # pylint: disable=W0622
        super(RuleConfigurationAction, self).__init__(
            option_strings=option_strings,
            dest=dest,
            nargs=nargs,
            const=const,
            default=default,
            type=type,
            choices=choices,
            required=required,
            help=help,
            metavar=metavar)

    def _parse_rule_configuration(self, string):
        """ Parse the config rule structure """
        configs = comma_separated_arg(string)
        results = {}
        for config in configs:
            rule_id = config.split(':')[0]
            config_name = config.split(':')[1].split('=')[0]
            config_value = config.split(':')[1].split('=')[1]
            if rule_id not in results:
                results[rule_id] = {}
            results[rule_id][config_name] = config_value

        return results

    def __call__(self, parser, namespace, values, option_string=None):
        items = copy.copy(_ensure_value(namespace, self.dest, {}))
        try:
            for value in values:
                new_value = self._parse_rule_configuration(value)
                for v_k, v_vs in new_value.items():
                    if v_k in items:
                        for s_k, s_v in v_vs.items():
                            items[v_k][s_k] = s_v
                    else:
                        items[v_k] = v_vs
            setattr(namespace, self.dest, items)
        except Exception:  # pylint: disable=W0703
            parser.print_help()
            parser.exit()


class CliArgs(object):
    """ Base Args class"""
    cli_args = {}

    def __init__(self, cli_args):
        self.parser = self.create_parser()
        self.cli_args, _ = self.parser.parse_known_args(cli_args)

    def create_parser(self):
        """Do first round of parsing parameters to set options"""
        class ArgumentParser(argparse.ArgumentParser):
            """ Override Argument Parser so we can control the exit code"""

            def error(self, message):
                self.print_help(sys.stderr)
                self.exit(32, '%s: error: %s\n' % (self.prog, message))

        class ExtendAction(argparse.Action):
            """Support argument types that are lists and can be specified multiple times."""

            def __call__(self, parser, namespace, values, option_string=None):
                items = getattr(namespace, self.dest)
                items = [] if items is None else items
                for value in values:
                    if isinstance(value, list):
                        items.extend(value)
                    else:
                        items.append(value)
                setattr(namespace, self.dest, items)

        usage = (
            '\nBasic: cfn-lint test.yaml\n'
            'Ignore a rule: cfn-lint -I E3012 -- test.yaml\n'
            'Configure a rule: cfn-lint -x E3012:strict=false -t test.yaml\n'
            'Lint all yaml files in a folder: cfn-lint dir/**/*.yaml'
        )

        parser = ArgumentParser(
            description='CloudFormation Linter',
            usage=usage)
        parser.register('action', 'extend', ExtendAction)

        standard = parser.add_argument_group('Standard')
        advanced = parser.add_argument_group('Advanced / Debugging')

        # Alllow the template to be passes as an optional or a positional argument
        standard.add_argument(
            'templates', metavar='TEMPLATE', nargs='*', help='The CloudFormation template to be linted')
        standard.add_argument(
            '-t', '--template', metavar='TEMPLATE', dest='template_alt',
            help='The CloudFormation template to be linted', nargs='+', default=[], action='extend')
        standard.add_argument(
            '-b', '--ignore-bad-template', help='Ignore failures with Bad template',
            action='store_true'
        )
        standard.add_argument(
            '--ignore-templates', dest='ignore_templates',
            help='Ignore templates', nargs='+', default=[], action='extend'
        )
        advanced.add_argument(
            '-D', '--debug', help='Enable debug logging', action='store_true'
        )
        advanced.add_argument(
            '-I', '--info', help='Enable information logging', action='store_true'
        )
        standard.add_argument(
            '-f', '--format', help='Output Format', choices=['quiet', 'parseable', 'json']
        )

        standard.add_argument(
            '-l', '--list-rules', dest='listrules', default=False,
            action='store_true', help='list all the rules'
        )
        standard.add_argument(
            '-r', '--regions', dest='regions', nargs='+', default=[],
            type=comma_separated_arg, action='extend',
            help='list the regions to validate against.'
        )
        advanced.add_argument(
            '-a', '--append-rules', dest='append_rules', nargs='+', default=[],
            type=comma_separated_arg, action='extend',
            help='specify one or more rules directories using '
                 'one or more --append-rules arguments. '
        )
        standard.add_argument(
            '-i', '--ignore-checks', dest='ignore_checks', nargs='+', default=[],
            type=comma_separated_arg, action='extend',
            help='only check rules whose id do not match these values'
        )
        standard.add_argument(
            '-c', '--include-checks', dest='include_checks', nargs='+', default=[],
            type=comma_separated_arg, action='extend',
            help='include rules whose id match these values'
        )
        standard.add_argument(
            '-m', '--mandatory-checks', dest='mandatory_checks', nargs='+', default=[],
            type=comma_separated_arg, action='extend',
            help='always check rules whose id match these values, regardless of template exclusions'
        )
        standard.add_argument(
            '-e', '--include-experimental', help='Include experimental rules', action='store_true'
        )

        standard.add_argument(
            '-x', '--configure-rule', dest='configure_rules', nargs='+', default={},
            action=RuleConfigurationAction,
            help='Provide configuration for a rule. Format RuleId:key=value. Example: E3012:strict=false'
        )

        advanced.add_argument(
            '-o', '--override-spec', dest='override_spec',
            help='A CloudFormation Spec override file that allows customization'
        )

        standard.add_argument(
            '-v', '--version', help='Version of cfn-lint', action='version',
            version='%(prog)s {version}'.format(version=__version__)
        )
        advanced.add_argument(
            '-u', '--update-specs', help='Update the CloudFormation Specs',
            action='store_true'
        )
        advanced.add_argument(
            '--update-documentation', help=argparse.SUPPRESS,
            action='store_true'
        )
        advanced.add_argument(
            '--update-iam-policies', help=argparse.SUPPRESS,
            action='store_true'
        )

        return parser


class TemplateArgs(object):
    """ Per Template Args """

    def __init__(self, template_args):
        self.set_template_args(template_args)

    def get_template_args(self):
        """ Get Template Args"""
        return self._template_args

    def set_template_args(self, template):
        """ Set Template Args"""
        defaults = {}
        if isinstance(template, dict):
            configs = template.get('Metadata', {}).get('cfn-lint', {}).get('config', {})

            if isinstance(configs, dict):
                for config_name, config_value in configs.items():
                    if config_name == 'ignore_checks':
                        if isinstance(config_value, list):
                            defaults['ignore_checks'] = config_value
                    if config_name == 'regions':
                        if isinstance(config_value, list):
                            defaults['regions'] = config_value
                    if config_name == 'append_rules':
                        if isinstance(config_value, list):
                            defaults['append_rules'] = config_value
                    if config_name == 'override_spec':
                        if isinstance(config_value, (six.string_types)):
                            defaults['override_spec'] = config_value
                    if config_name == 'ignore_bad_template':
                        if isinstance(config_value, bool):
                            defaults['ignore_bad_template'] = config_value
                    if config_name == 'include_checks':
                        if isinstance(config_value, list):
                            defaults['include_checks'] = config_value
                    if config_name == 'configure_rules':
                        if isinstance(config_value, dict):
                            defaults['configure_rules'] = config_value

        self._template_args = defaults

    template_args = property(get_template_args, set_template_args)


class ConfigMixIn(TemplateArgs, CliArgs, ConfigFileArgs, object):
    """ Mixin for the Configs """

    def __init__(self, cli_args):
        CliArgs.__init__(self, cli_args)
        # configure debug as soon as we can
        configure_logging(self.cli_args.debug, self.cli_args.info)
        ConfigFileArgs.__init__(self)
        TemplateArgs.__init__(self, {})

    def _get_argument_value(self, arg_name, is_template, is_config_file):
        """ Get Argument value """
        cli_value = getattr(self.cli_args, arg_name)
        template_value = self.template_args.get(arg_name)
        file_value = self.file_args.get(arg_name)
        if cli_value:
            return cli_value
        if template_value and is_template:
            return template_value
        if file_value and is_config_file:
            return file_value
        return cli_value

    @property
    def ignore_checks(self):
        """ ignore_checks """
        return self._get_argument_value('ignore_checks', True, True)

    @property
    def include_checks(self):
        """ include_checks """
        return self._get_argument_value('include_checks', True, True)

    @property
    def mandatory_checks(self):
        """ mandatory_checks """
        return self._get_argument_value('mandatory_checks', False, True)

    @property
    def include_experimental(self):
        """ include_experimental """
        return self._get_argument_value('include_experimental', True, True)

    @property
    def regions(self):
        """ regions """
        results = self._get_argument_value('regions', True, True)
        if not results:
            return ['us-east-1']
        if 'ALL_REGIONS' in results:
            return REGIONS
        return results

    @property
    def ignore_bad_template(self):
        """ ignore_bad_template """
        return self._get_argument_value('ignore_bad_template', True, True)

    @property
    def debug(self):
        """ debug """
        return self._get_argument_value('debug', False, False)

    @property
    def format(self):
        """ format """
        return self._get_argument_value('format', False, True)

    @property
    def templates(self):
        """ templates """
        templates_args = self._get_argument_value('templates', False, True)
        template_alt_args = self._get_argument_value('template_alt', False, False)
        if template_alt_args:
            filenames = template_alt_args
        elif templates_args:
            filenames = templates_args
        else:
            return None

        # if only one is specified convert it to array
        if isinstance(filenames, six.string_types):
            filenames = [filenames]

        # handle different shells and Config files
        # some shells don't expand * and configparser won't expand wildcards
        all_filenames = []
        ignore_templates = self._ignore_templates()
        for filename in filenames:
            if sys.version_info >= (3, 5):
                # pylint: disable=E1123
                add_filenames = glob.glob(filename, recursive=True)
            else:
                add_filenames = glob.glob(filename)
            # only way to know of the glob failed is to test it
            # then add the filename as requested
            if not add_filenames:
                if filename not in ignore_templates:
                    all_filenames.append(filename)
            else:
                for add_filename in add_filenames:
                    if add_filename not in ignore_templates:
                        all_filenames.append(add_filename)

        return sorted(all_filenames)

    def _ignore_templates(self):
        """ templates """
        ignore_template_args = self._get_argument_value('ignore_templates', False, True)
        if ignore_template_args:
            filenames = ignore_template_args
        else:
            return []

        # if only one is specified convert it to array
        if isinstance(filenames, six.string_types):
            filenames = [filenames]

        # handle different shells and Config files
        # some shells don't expand * and configparser won't expand wildcards
        all_filenames = []
        for filename in filenames:
            if sys.version_info >= (3, 5):
                # pylint: disable=E1123
                add_filenames = glob.glob(filename, recursive=True)
            else:
                add_filenames = glob.glob(filename)
            # only way to know of the glob failed is to test it
            # then add the filename as requested
            if not add_filenames:
                all_filenames.append(filename)
            else:
                all_filenames.extend(add_filenames)

        return all_filenames

    @property
    def append_rules(self):
        """ append_rules """
        return self._get_argument_value('append_rules', False, True)

    @property
    def override_spec(self):
        """ override_spec """
        return self._get_argument_value('override_spec', False, True)

    @property
    def update_specs(self):
        """ update_specs """
        return self._get_argument_value('update_specs', False, False)

    @property
    def update_documentation(self):
        """ update_specs """
        return self._get_argument_value('update_documentation', False, False)

    @property
    def update_iam_policies(self):
        """ update_iam_policies """
        return self._get_argument_value('update_iam_policies', False, False)

    @property
    def listrules(self):
        """ listrules """
        return self._get_argument_value('listrules', False, False)

    @property
    def configure_rules(self):
        """ Configure rules """
        return self._get_argument_value('configure_rules', True, True)
