"""
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: MIT-0
"""
from cfnlint.helpers import bool_compare
from cfnlint.rules import CloudFormationLintRule, RuleMatch


class NoEcho(CloudFormationLintRule):
    id = "W4002"
    shortdesc = "Check for NoEcho References"
    description = "Check if there is a NoEcho enabled parameter referenced within a resources Metadata section"
    source_url = "https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/parameters-section-structure.html#parameters-section-structure-properties"
    tags = ["resources", "NoEcho"]

    def _get_no_echo_params(self, cfn):
        """Get no Echo Params"""
        no_echo_params = []
        for parameter_name, parameter_value in cfn.get_parameters().items():
            if isinstance(parameter_value, dict):
                noecho = parameter_value.get("NoEcho", default=False)
                if bool_compare(noecho, True):
                    no_echo_params.append(parameter_name)
        return no_echo_params

    def _check_ref(self, cfn, no_echo_params):
        """Check Refs"""
        matches = []
        refs = cfn.search_deep_keys("Ref")
        for ref in refs:
            if ref[-1] in no_echo_params:
                if len(ref) > 3:
                    if ref[0] == "Resources" and ref[2] == "Metadata":
                        matches.append(
                            RuleMatch(
                                ref,
                                'As the resource "metadata" section contains '
                                + 'reference to a "NoEcho" parameter '
                                + str(ref[-1])
                                + ", CloudFormation will display the parameter value in "
                                + "plaintext",
                            )
                        )

        return matches

    def _check_sub(self, cfn, no_echo_params):
        """Check Subs"""
        matches = []
        subs = cfn.search_deep_keys("Fn::Sub")
        for sub in subs:
            if isinstance(sub[-1], str):
                params = cfn.get_sub_parameters(sub[-1])
                for param in params:
                    if param in no_echo_params:
                        if len(sub) > 2:
                            if sub[0] == "Resources" and sub[2] == "Metadata":
                                matches.append(
                                    RuleMatch(
                                        sub[:-1],
                                        'As the resource "metadata" section contains '
                                        + 'reference to a "NoEcho" parameter '
                                        + str(param)
                                        + ", CloudFormation will display the parameter value in "
                                        + "plaintext",
                                    )
                                )

        return matches

    def match(self, cfn):
        matches = []
        no_echo_params = self._get_no_echo_params(cfn)
        if not no_echo_params:
            return matches
        matches.extend(self._check_ref(cfn, no_echo_params))
        matches.extend(self._check_sub(cfn, no_echo_params))

        return matches
