import { S3 } from '@aws-sdk/client-s3';
import { ParsedMail, simpleParser } from 'mailparser';
// from https://docs.aws.amazon.com/ses/latest/dg/receiving-email-action-lambda-event.html
export interface EventRecord {
    eventSource: string;
    eventVersion: string;
    ses: Ses;
}

export interface Ses {
    mail: Mail;
    receipt: Receipt;
}

export interface Mail {
    timestamp: string;
    source: string;
    messageId: string;
    destination: string[];
    headersTruncated: boolean;
    headers: Header[];
    commonHeaders: CommonHeaders;
}

export interface Header {
    name: string;
    value: string;
}

export interface CommonHeaders {
    returnPath: string;
    from: string[];
    date: string;
    to: string[];
    messageId: string;
    subject: string;
}

export interface Receipt {
    timestamp: string;
    processingTimeMillis: number;
    recipients: string[];
    spamVerdict: Verdict;
    virusVerdict: Verdict;
    spfVerdict: Verdict;
    dkimVerdict: Verdict;
    dmarcVerdict: Verdict;
    action: Action;
}

export interface Verdict {
    status: string;
}

export interface Action {
    type: string;
    functionArn: string;
    invocationType: string;
}

export interface SESEventRecordsToLambda {
    Records: EventRecord[];
}

const emailBucket = process.env.EMAIL_BUCKET;
const emailBucketArn = process.env.EMAIL_BUCKET_ARN;
const s3 = new S3();

export const handler = async (event: SESEventRecordsToLambda) => {
    for (const record of event.Records) {
        
        const id = record.ses.mail.messageId;
        const key = `RootMail/${id}`;
        const response = await s3.getObject({ Bucket: emailBucket as string, Key: key });
        
        const msg: ParsedMail = await simpleParser(response.Body as unknown as Buffer);
        
        let title = msg.subject;
        console.log(`Title: ${title} from emailBucketArn: ${emailBucketArn}`);
    }

    // test custom permission to list s3 buckets
    const buckets = await s3.listBuckets({});
    if (!buckets.Buckets) {
        console.log('No buckets found');
        return;
    }
    console.log('Buckets:');
    for (const bucket of buckets.Buckets || []) {
        console.log(bucket.Name);
    }
};