// Copyright Abridged, Inc. 2021,2024. All Rights Reserved.
// Node module: @collabland/aws
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT

import {
  DescribeEnvironmentResourcesCommand,
  DescribeEnvironmentResourcesCommandInput,
  DescribeInstancesHealthCommand,
  DescribeInstancesHealthCommandInput,
  ElasticBeanstalkClient,
  ElasticBeanstalkClientConfig,
  InstancesHealthAttribute,
} from '@aws-sdk/client-elastic-beanstalk';
import {getFetch, loggers} from '@collabland/common';
import {getDefaultConfig} from '../common/types.js';

const {trace} = loggers('collabland:aws:elastic-beanstalk');

export class ElasticBeanstalkServiceClient {
  readonly client: ElasticBeanstalkClient;

  constructor(options?: ElasticBeanstalkClientConfig) {
    this.client = new ElasticBeanstalkClient({
      ...getDefaultConfig(),
      ...options,
    });
  }

  /**
   * Describe instances health
   * @param environmentName - Elastic Beanstalk environment name
   * @returns
   */
  async describeHealth(environmentName: string) {
    trace('Describing environment health for %s', environmentName);
    const input: DescribeInstancesHealthCommandInput = {
      EnvironmentName: environmentName,
      AttributeNames: [InstancesHealthAttribute.All],
    };
    const cmd = new DescribeInstancesHealthCommand(input);
    const output = await this.client.send(cmd);
    trace('Environment health: %j', output);
    return output;
  }

  /**
   * Describe resources
   * @param environmentName - Elastic Beanstalk environment name
   * @returns
   */
  async describeResources(environmentName: string) {
    trace('Describing environment health for %s', environmentName);
    const input: DescribeEnvironmentResourcesCommandInput = {
      EnvironmentName: environmentName,
    };
    const cmd = new DescribeEnvironmentResourcesCommand(input);
    const output = await this.client.send(cmd);
    trace('Environment resources: %j', output);
    return output;
  }

  /**
   * Get an array of EC2 instance ids
   * @param environmentName - Elastic Beanstalk environment name
   * @returns
   */
  async getEC2InstanceIds(environmentName: string) {
    const instances = (await this.describeHealth(environmentName))
      .InstanceHealthList;
    return (
      instances?.filter(i => i.HealthStatus === 'Ok').map(i => i.InstanceId!) ??
      []
    );
  }

  private metadataToken: string | undefined;
  private expiresAt: number | undefined;

  async getEC2MetadataToken() {
    if (
      this.metadataToken != null &&
      this.expiresAt != null &&
      this.expiresAt > Date.now() + 600 * 1000
    ) {
      return this.metadataToken;
    }
    const fetch = getFetch({timeout: 1000});
    const res = await fetch('http://169.254.169.254/latest/api/token', {
      method: 'put',
      headers: {
        'x-aws-ec2-metadata-token-ttl-seconds': '21600',
      },
    });
    const token = await res.text();
    this.expiresAt = Date.now() + 21600 * 1000;
    this.metadataToken = token;
    return token;
  }

  /**
   * Get the current EC2 instance id for the Elastic Beanstalk application
   * @returns
   */
  // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html
  async getEC2InstanceId() {
    const fetch = getFetch({timeout: 1000});
    const token = await this.getEC2MetadataToken();
    const result = await fetch(
      'http://169.254.169.254/latest/meta-data/instance-id',
      {
        headers: {
          'x-aws-ec2-metadata-token': token,
        },
      },
    );
    const id = await result.text();
    return id;
  }
}