import {
  aws_codebuild,
  aws_codepipeline,
  aws_codepipeline_actions,
  aws_ec2,
  aws_ecr,
  aws_ecs,
  aws_ssm,
} from 'aws-cdk-lib';
import { Construct } from 'constructs';
import { Namer } from 'multi-convention-namer';
// import { ServicePrincipals } from 'cdk-constants';

export interface CouplerPipelineProps {
  /**
   * The AWS account hosting the ECR.
   */
  readonly account: string;
  /**
   * A string containing a python re which will be used to identify the tag to put
   * in the `imagedefinitions.json` file that will be handed off to the EcsDeployAction.
   * Typically you want SemVer tags. But...
   *
   * @default '^v\\d+\\.\\d+\\.\\d+'
   */
  readonly immutableTagPattern?: string;
  /**
   * The AWS region hosting the ECR.
   */
  readonly region: string;
  /**
   * When referencing the ECS Cluster, we can optionally provide the list of
   * securityGroups it is in. We haven't seen a need for this yet.
   *
   * @default []
   */
  readonly securityGroups?: aws_ec2.ISecurityGroup[];
  /**
   * Which docker tag should we watch for pushes?
   * This will be used by the EcrSourceAction to filter.
   * Until we get a proper resolution to https://github.com/aws/aws-cdk/issues/20594
   *
   * @default 'latest'
   */
  readonly triggerTag?: string;
  /**
   * The VPC in which the ECS Cluster resides.
   */
  readonly vpc: aws_ec2.IVpc;
  /**
   * The Repository which to connect it to. If omitted it will make certain
   * assumptions about the repo.
   * @default - service specific repository pulled from ssm params
   */
  readonly repository?: aws_ecr.IRepository;
}

export class CouplerPipeline extends Construct {
  constructor(scope: Construct, id: Namer, props: CouplerPipelineProps) {
    super(scope, id.addSuffix(['coupler']).pascal);

    const immutableTagPattern = props.immutableTagPattern ?? '^v\\d+\\.\\d+\\.\\d+';

    const imageInput = new aws_codepipeline.Artifact('Image');
    const updateInput = new aws_codepipeline.Artifact('ImageDefinitions');

    const repository =
      props.repository ??
      aws_ecr.Repository.fromRepositoryAttributes(this, 'Repository', {
        repositoryArn: aws_ssm.StringParameter.valueForStringParameter(
          this,
          `/${id.pascal}/${id.addSuffix(['repository']).pascal}/${id.pascal}/repositoryArn`,
        ),
        repositoryName: id.kebab,
      });

    const cluster = aws_ecs.Cluster.fromClusterAttributes(this, 'Cluster', {
      clusterName: id.kebab,
      securityGroups: props.securityGroups ?? [],
      vpc: props.vpc,
    });

    const service = aws_ecs.FargateService.fromFargateServiceAttributes(this, 'Service', {
      cluster,
      serviceName: id.pascal,
    });

    new aws_codepipeline.Pipeline(this, id.pascal, {
      pipelineName: id.pascal,
      stages: [
        {
          stageName: 'Received',
          actions: [
            new aws_codepipeline_actions.EcrSourceAction({
              actionName: 'Image',
              imageTag: props.triggerTag ?? 'latest',
              repository,
              output: imageInput,
            }),
          ],
        },
        {
          stageName: 'GenerateImageDefinitions',
          actions: [
            new aws_codepipeline_actions.CodeBuildAction({
              environmentVariables: {
                ECR_REPO_URI: { value: `${props.account}.dkr.ecr.${props.region}.amazonaws.com/${id.kebab}` },
              },
              input: imageInput,
              outputs: [updateInput],
              actionName: 'GenerateImageDefinitions',
              project: new aws_codebuild.Project(this, 'GenerateImageDefinitions', {
                buildSpec: aws_codebuild.BuildSpec.fromObject({
                  version: '0.2',
                  phases: {
                    build: {
                      commands: [
                        'cat imageDetail.json',
                        //https://stackoverflow.com/a/57015190
                        `TAG=$(cat imageDetail.json | python -c "import re, sys, json; p=re.compile('${immutableTagPattern}'); tags=json.load(sys.stdin)['ImageTags']; print([s for s in tags if p.match(s)][0])")`,
                        'echo "${ECR_REPO_URI}:${TAG}"',
                        `printf '[{\"name\":\"${id.kebab}\",\"imageUri\":\"%s\"}]' $ECR_REPO_URI:$TAG > imagedefinitions.json`,
                        'pwd; ls -al; cat imagedefinitions.json',
                      ],
                    },
                  },
                  artifacts: { files: ['imagedefinitions.json'] },
                }),
              }),
            }),
          ],
        },
        {
          stageName: 'UpdateFargate',
          actions: [
            new aws_codepipeline_actions.EcsDeployAction({
              actionName: 'Deploy',
              input: updateInput,
              service,
            }),
          ],
        },
      ],
    });
  }
}