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


class CodepipelineStages(CloudFormationLintRule):
    """Check if CodePipeline Stages are set up properly."""

    id = "E2540"
    shortdesc = "CodePipeline Stages"
    description = "See if CodePipeline stages are set correctly"
    source_url = "https://docs.aws.amazon.com/codepipeline/latest/userguide/reference-pipeline-structure.html#pipeline-requirements"
    tags = ["properties", "codepipeline"]

    def _format_error_message(self, message, scenario):
        """Format error message with scenario text"""
        if scenario:
            scenario_text = " When " + " and ".join(
                [f'condition "{k}" is {v}' for (k, v) in scenario.items()]
            )
            return message + scenario_text

        return message

    def check_stage_count(self, stages, path, scenario):
        """Check that there is minimum 2 stages."""
        matches = []

        if len(stages) < 2:
            message = f"CodePipeline has {len(stages)} stages. There must be at least two stages."
            matches.append(
                RuleMatch(path, self._format_error_message(message, scenario))
            )

        return matches

    def check_first_stage(self, stages, path, scenario):
        """Validate the first stage of a pipeline has source actions."""
        matches = []

        if len(stages) < 1:  # pylint: disable=C1801
            self.logger.debug(
                "Stages was empty. Should have been caught by generic linting."
            )
            return matches

        # pylint: disable=R1718
        first_stage = set(
            [a.get("ActionTypeId").get("Category") for a in stages[0]["Actions"]]
        )
        if first_stage and "Source" not in first_stage:
            message = (
                "The first stage of a pipeline must contain at least one source action."
            )
            matches.append(
                RuleMatch(
                    path + [0, "Name"], self._format_error_message(message, scenario)
                )
            )

        if len(first_stage) != 1:
            message = "The first stage of a pipeline must contain only source actions."
            matches.append(
                RuleMatch(
                    path + [0, "Name"], self._format_error_message(message, scenario)
                )
            )

        return matches

    def check_source_actions(self, stages, path, scenario):
        """Validate the all of the stages."""
        matches = []
        categories = set()

        if len(stages) < 1:  # pylint: disable=C1801
            self.logger.debug(
                "Stages was empty. Should have been caught by generic linting."
            )
            return matches

        for sidx, stage in enumerate(stages):
            for aidx, action in enumerate(stage.get("Actions", [])):
                action_type_id = action.get("ActionTypeId")
                categories.add(action_type_id.get("Category"))
                if sidx > 0 and action_type_id.get("Category") == "Source":
                    message = (
                        "Only the first stage of a pipeline may contain source actions."
                    )
                    matches.append(
                        RuleMatch(
                            path + [sidx, "Actions", aidx],
                            self._format_error_message(message, scenario),
                        )
                    )

        if not categories - set(["Source"]):
            message = "At least one stage in pipeline must contain an action that is not a source action."
            matches.append(
                RuleMatch(path, self._format_error_message(message, scenario))
            )

        return matches

    def check_names_unique(self, value, path, scenario):
        """Check that stage names are unique."""
        matches = []
        stage_names = set()
        for sidx, stage in enumerate(value):
            stage_name = stage.get("Name")
            if isinstance(stage_name, str):
                if stage_name in stage_names:
                    message = f"All stage names within a pipeline must be unique. ({stage_name})"
                    matches.append(
                        RuleMatch(
                            path + [sidx, "Name"],
                            self._format_error_message(message, scenario),
                        )
                    )
                stage_names.add(stage_name)
            else:
                self.logger.debug("Found non string for stage name: %s", stage_name)
        return matches

    def match(self, cfn):
        """Check CodePipeline stages"""
        matches = []

        resources = cfn.get_resource_properties(["AWS::CodePipeline::Pipeline"])
        for resource in resources:
            path = resource["Path"] + ["Stages"]
            properties = resource["Value"]

            s_stages = cfn.get_object_without_nested_conditions(
                properties.get("Stages"), path
            )
            for s_stage in s_stages:
                s_stage_obj = s_stage.get("Object")
                s_scenario = s_stage.get("Scenario")
                if not isinstance(s_stage_obj, list):
                    self.logger.debug(
                        "Stages not list. Should have been caught by generic linting."
                    )
                    continue

                try:
                    matches.extend(
                        self.check_stage_count(s_stage_obj, path, s_scenario)
                    )
                    matches.extend(
                        self.check_first_stage(s_stage_obj, path, s_scenario)
                    )
                    matches.extend(
                        self.check_source_actions(s_stage_obj, path, s_scenario)
                    )
                    matches.extend(
                        self.check_names_unique(s_stage_obj, path, s_scenario)
                    )
                except AttributeError as err:
                    self.logger.debug(
                        "Got AttributeError. Should have been caught by generic linting. "
                        "Ignoring the error here: %s",
                        str(err),
                    )

        return matches
