main.swift

import AWSLambdaEvents
import AWSLambdaRuntime
import NIO

import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif

Lambda.run { (context: Lambda.Context, event: APIGateway.Request, callback: @escaping (Result<APIGateway.Response, Error>) -> Void) in
    context.logger.debug("hello, api gateway!")
    
    let botId = "Agent"
    
    guard
        let bodyData = event.body?.data(using: .utf8),
        let json = try? JSONSerialization.jsonObject(with: bodyData, options: []) as? [String: Any],
        json["type"] as? String == "message.new",
        let channelType = json["channel_type"] as? String,
        let channelId = json["channel_id"] as? String,
        let message = json["message"] as? [String: Any],
        let user = message["user"] as? [String: Any],
        let userId = user["id"] as? String,
        userId != botId
    else {
        callback(.success(APIGateway.Response(statusCode: .ok, body: "nope!")))
        return
    }
    
    botReply(channelType: channelType, channelId: channelId, botId: botId) {
        callback(.success(APIGateway.Response(statusCode: .ok)))
    }
}