import * as cdk from 'aws-cdk-lib';
import * as iam from 'aws-cdk-lib/aws-iam';
import { Construct } from 'constructs';

const ACCOUNT_ID = '396287094661';
const REGION = 'us-east-1';
const APPLICATION_NAME = 'shoc-backend';
const ENVIRONMENT_NAME = 'shoc-backend-dev';
const ENVIRONMENT_ID = 'e-hehnrqjjrt';
const ENVIRONMENT_STACK_NAME = `awseb-${ENVIRONMENT_ID}-stack`;
const REPO = 'Sea-Haven-Industries/shoc-backend';

export class DeployDevStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props: cdk.StackProps = {}) {
    super(scope, id, props);

    const manageGithubDeployRole = new cdk.CfnParameter(
      this,
      'ManageGithubDeployRole',
      {
        type: 'String',
        allowedValues: ['true', 'false'],
        description:
          'Set true only before Terraform adoption. After ownership transfer, always reuse false.',
      },
    );
    const manageGithubDeployRoleCondition = new cdk.CfnCondition(
      this,
      'ManageGithubDeployRoleCondition',
      {
        expression: cdk.Fn.conditionEquals(
          manageGithubDeployRole.valueAsString,
          'true',
        ),
      },
    );

    const applicationArn = `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:application/${APPLICATION_NAME}`;
    const environmentArn = `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:environment/${APPLICATION_NAME}/${ENVIRONMENT_NAME}`;
    const oidcProviderArn = `arn:aws:iam::${ACCOUNT_ID}:oidc-provider/token.actions.githubusercontent.com`;

    const deployRole = new iam.Role(this, 'GithubDeployRole', {
      roleName: 'githubdeploy-shoc-backend-dev',
      description:
        'Least-privilege GitHub OIDC deploy role for shoc-backend dev. CDK-owned; application/environment/S3 are owned by Elastic Beanstalk.',
      assumedBy: new iam.FederatedPrincipal(
        oidcProviderArn,
        {
          StringEquals: {
            'token.actions.githubusercontent.com:aud': 'sts.amazonaws.com',
            'token.actions.githubusercontent.com:sub': `repo:${REPO}:environment:dev`,
          },
        },
        'sts:AssumeRoleWithWebIdentity',
      ),
    });

    deployRole.applyRemovalPolicy(cdk.RemovalPolicy.RETAIN);
    const cfnRole = deployRole.node.defaultChild as iam.CfnRole;
    cfnRole.cfnOptions.deletionPolicy = cdk.CfnDeletionPolicy.RETAIN;
    cfnRole.cfnOptions.updateReplacePolicy = cdk.CfnDeletionPolicy.RETAIN;
    cfnRole.cfnOptions.condition = manageGithubDeployRoleCondition;

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: [
          'autoscaling:Describe*',
          'ec2:Describe*',
          'elasticbeanstalk:DescribeEnvironments',
          'elasticbeanstalk:DescribeApplicationVersions',
          'elasticbeanstalk:DescribeEvents',
          'elasticloadbalancing:Describe*',
        ],
        resources: ['*'],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['elasticbeanstalk:CreateApplicationVersion'],
        resources: [
          applicationArn,
          `arn:aws:elasticbeanstalk:${REGION}:${ACCOUNT_ID}:applicationversion/${APPLICATION_NAME}/*`,
        ],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['elasticbeanstalk:UpdateEnvironment'],
        resources: [environmentArn],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: [
          'cloudformation:DescribeStackEvents',
          'cloudformation:DescribeStackResource',
          'cloudformation:GetTemplate',
          'cloudformation:DescribeStackResources',
          'cloudformation:DescribeStacks',
          'cloudformation:ListStackResources',
          'cloudformation:CancelUpdateStack',
          'cloudformation:UpdateStack',
        ],
        resources: [
          `arn:aws:cloudformation:${REGION}:${ACCOUNT_ID}:stack/${ENVIRONMENT_STACK_NAME}/*`,
        ],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: [
          'autoscaling:PutNotificationConfiguration',
          'autoscaling:ResumeProcesses',
          'autoscaling:SuspendProcesses',
        ],
        resources: [
          `arn:aws:autoscaling:${REGION}:${ACCOUNT_ID}:autoScalingGroup:*:autoScalingGroupName/${ENVIRONMENT_STACK_NAME}-*`,
        ],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: ['s3:Delete*', 's3:Get*', 's3:Put*'],
        // AWS Support case 178526484500047 confirmed that UpdateEnvironment
        // reads, writes, versions, ACL-checks, and removes objects in both the
        // account bucket and AWS-owned Elastic Beanstalk service buckets.
        resources: ['arn:aws:s3:::elasticbeanstalk-*/*'],
      }),
    );

    deployRole.addToPolicy(
      new iam.PolicyStatement({
        effect: iam.Effect.ALLOW,
        actions: [
          's3:GetBucket*',
          's3:ListBucket',
          's3:PutBucketOwnershipControls',
          's3:PutBucketPolicy',
          's3:PutBucketPublicAccessBlock',
        ],
        // This is AWS Support's bucket-level UpdateEnvironment set, excluding
        // CreateBucket because the workflow deploys only to an existing
        // application/environment and disables bucket creation.
        resources: ['arn:aws:s3:::elasticbeanstalk-*'],
      }),
    );

    const defaultPolicy = deployRole.node.findChild(
      'DefaultPolicy',
    ) as iam.Policy;
    defaultPolicy.applyRemovalPolicy(cdk.RemovalPolicy.RETAIN);
    const cfnDefaultPolicy = defaultPolicy.node.defaultChild as iam.CfnPolicy;
    cfnDefaultPolicy.cfnOptions.deletionPolicy = cdk.CfnDeletionPolicy.RETAIN;
    cfnDefaultPolicy.cfnOptions.updateReplacePolicy =
      cdk.CfnDeletionPolicy.RETAIN;
    cfnDefaultPolicy.cfnOptions.condition = manageGithubDeployRoleCondition;

    const githubDeployRoleArn = new cdk.CfnOutput(
      this,
      'GithubDeployRoleArn',
      {
        value: deployRole.roleArn,
        description: 'ARN of the GitHub OIDC deploy role for shoc-backend dev.',
        exportName: 'shoc-backend-deploy-dev-role-arn',
      },
    );
    githubDeployRoleArn.condition = manageGithubDeployRoleCondition;
  }
}