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

export class ConversationLogConstruct extends Construct {
  public readonly table: dynamodb.Table;

  constructor(scope: Construct, id: string) {
    super(scope, id);

    this.table = new dynamodb.Table(this, 'Table', {
      tableName: 'seahaven-conversations',
      // PK: Slack user ID (e.g. U0123456789)
      partitionKey: { name: 'userId', type: dynamodb.AttributeType.STRING },
      // SK: ISO-8601 timestamp — enables range queries for session lookup
      sortKey: { name: 'timestamp', type: dynamodb.AttributeType.STRING },
      billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
      removalPolicy: cdk.RemovalPolicy.RETAIN,
      pointInTimeRecoverySpecification: { pointInTimeRecoveryEnabled: true },
      // TTL attribute — records are automatically expired after 90 days
      timeToLiveAttribute: 'ttl',
    });

    // GSI for looking up all turns in a given Bedrock session (for context retrieval)
    this.table.addGlobalSecondaryIndex({
      indexName: 'sessionId-index',
      partitionKey: { name: 'sessionId', type: dynamodb.AttributeType.STRING },
      sortKey: { name: 'timestamp', type: dynamodb.AttributeType.STRING },
    });
  }
}