"""
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: MIT-0
"""
import regex as re

from cfnlint.helpers import RESOURCE_SPECS
from cfnlint.rules import CloudFormationLintRule, RuleMatch


class AllowedPattern(CloudFormationLintRule):
    """Check if parameters have a valid value"""

    id = "W2031"
    shortdesc = "Check if parameters have a valid value based on an allowed pattern"
    description = "Check if parameters have a valid value in a pattern. The Parameter's allowed pattern is based on the usages in property (Ref)"
    source_url = "https://github.com/aws-cloudformation/cfn-python-lint/blob/main/docs/cfn-resource-specification.md#allowedpattern"
    tags = ["parameters", "resources", "property", "allowed pattern"]

    def initialize(self, cfn):
        """Initialize the rule"""
        for resource_type_spec in RESOURCE_SPECS.get(cfn.regions[0]).get(
            "ResourceTypes"
        ):
            self.resource_property_types.append(resource_type_spec)
        for property_type_spec in RESOURCE_SPECS.get(cfn.regions[0]).get(
            "PropertyTypes"
        ):
            self.resource_sub_property_types.append(property_type_spec)

    def check_value_ref(self, value, path, **kwargs):
        """Check Ref"""
        matches = []

        cfn = kwargs.get("cfn")
        if "Fn::If" in path:
            self.logger.debug(
                "Not able to guarentee that the default value hasn't been conditioned out"
            )
            return matches
        if path[0] == "Resources" and "Condition" in cfn.template.get(path[0], {}).get(
            path[1]
        ):
            self.logger.debug(
                "Not able to guarentee that the default value "
                "hasn't been conditioned out"
            )
            return matches

        allowed_pattern = kwargs.get("value_specs", {}).get("AllowedPattern", {})
        allowed_pattern_regex = kwargs.get("value_specs", {}).get(
            "AllowedPatternRegex", {}
        )
        allowed_pattern_description = kwargs.get("value_specs", {}).get(
            "AllowedPatternDescription", {}
        )

        if allowed_pattern_regex:
            if value in cfn.template.get("Parameters", {}):
                param = cfn.template.get("Parameters").get(value, {})
                parameter_values = param.get("AllowedValues")
                default_value = param.get("Default")
                parameter_type = param.get("Type")
                if isinstance(parameter_type, str):
                    if (
                        (not parameter_type.startswith("List<"))
                        and (
                            not parameter_type.startswith("AWS::SSM::Parameter::Value<")
                        )
                        and parameter_type not in ["CommaDelimitedList", "List<String>"]
                    ):
                        # Check Allowed Values
                        if parameter_values:
                            for index, allowed_value in enumerate(parameter_values):
                                if not re.match(
                                    allowed_pattern_regex, str(allowed_value)
                                ):
                                    param_path = [
                                        "Parameters",
                                        value,
                                        "AllowedValues",
                                        index,
                                    ]
                                    description = (
                                        allowed_pattern_description
                                        or f"Valid values must match pattern {allowed_pattern}"
                                    )
                                    message = "You must specify a valid allowed value for {0} ({1}). {2}"
                                    matches.append(
                                        RuleMatch(
                                            param_path,
                                            message.format(
                                                value, allowed_value, description
                                            ),
                                        )
                                    )
                        if default_value:
                            # Check Default, only if no allowed Values are specified in the parameter (that's covered by E2015)
                            if not re.match(allowed_pattern_regex, str(default_value)):
                                param_path = ["Parameters", value, "Default"]
                                description = (
                                    allowed_pattern_description
                                    or f"Valid values must match pattern {allowed_pattern}"
                                )
                                message = "You must specify a valid Default value for {0} ({1}). {2}"
                                matches.append(
                                    RuleMatch(
                                        param_path,
                                        message.format(
                                            value, default_value, description
                                        ),
                                    )
                                )

        return matches

    def check(self, cfn, properties, value_specs, property_specs, path):
        """Check itself"""
        matches = []
        for p_value, p_path in properties.items_safe(path[:]):
            for prop in p_value:
                if prop in value_specs:
                    value = value_specs.get(prop).get("Value", {})
                    if value:
                        value_type = value.get("ValueType", "")
                        property_type = (
                            property_specs.get("Properties").get(prop).get("Type")
                        )
                        value_specs = (
                            RESOURCE_SPECS.get(cfn.regions[0])
                            .get("ValueTypes")
                            .get(value_type, {})
                        )
                        if value_specs == "CACHED":
                            value_specs = (
                                RESOURCE_SPECS.get("us-east-1")
                                .get("ValueTypes")
                                .get(value_type, {})
                            )
                        matches.extend(
                            cfn.check_value(
                                p_value,
                                prop,
                                p_path,
                                check_ref=self.check_value_ref,
                                value_specs=value_specs,
                                cfn=cfn,
                                property_type=property_type,
                                property_name=prop,
                            )
                        )

        return matches

    def match_resource_sub_properties(self, properties, property_type, path, cfn):
        """Match for sub properties"""
        matches = []

        specs = (
            RESOURCE_SPECS.get(cfn.regions[0])
            .get("PropertyTypes")
            .get(property_type, {})
            .get("Properties", {})
        )
        property_specs = (
            RESOURCE_SPECS.get(cfn.regions[0]).get("PropertyTypes").get(property_type)
        )
        matches.extend(self.check(cfn, properties, specs, property_specs, path))

        return matches

    def match_resource_properties(self, properties, resource_type, path, cfn):
        """Check CloudFormation Properties"""
        matches = []

        specs = (
            RESOURCE_SPECS.get(cfn.regions[0])
            .get("ResourceTypes")
            .get(resource_type, {})
            .get("Properties", {})
        )
        resource_specs = (
            RESOURCE_SPECS.get(cfn.regions[0]).get("ResourceTypes").get(resource_type)
        )
        matches.extend(self.check(cfn, properties, specs, resource_specs, path))

        return matches
