import {
    S3Client,
    ListObjectsV2Command,
    GetObjectCommand,
    PutObjectCommand,
    DeleteObjectCommand
  } from '@aws-sdk/client-s3';
  
  const S3: S3Client = new S3Client({});
  const bucketName: string = process.env.BUCKET  ?? "widget-default-bucket";
  
  export const handler = async function(event: any, context: any): Promise<any> {
    try {
      const method: string = event.httpMethod;
      const widgetName: string = event.path.startsWith('/') ? event.path.substring(1) : event.path;
  
      if (method === "GET") {
        if (event.path === "/") {
          const data = await S3.send(new ListObjectsV2Command({ Bucket: bucketName }));
          const body = {widgets: data?.Contents?.map(function(e: any) { return e.Key })};
          return {
            statusCode: 200,
            headers: {},
            body: JSON.stringify(body)
          };
        }
  
        if (widgetName) {
          const data = await S3.send(new GetObjectCommand({ Bucket: bucketName, Key: widgetName}));
          const body = data?.Body?.toString(); //'utf-8');
  
          return {
            statusCode: 200,
            headers: {},
            body: JSON.stringify(body)
          };
        }
      }
  
      if (method === "POST") {
        if (!widgetName) {
          return {
            statusCode: 400,
            headers: {},
            body: "Widget name missing"
          };
        }
  
        const now: Date = new Date();
        const data: string = widgetName + " created: " + now;
  
        const base64data: Buffer = Buffer.from(data, 'binary');
  
        await S3.send(new PutObjectCommand({
          Bucket: bucketName,
          Key: widgetName,
          Body: base64data,
          ContentType: 'application/json'
        }));
  
        return {
          statusCode: 200,
          headers: {},
          body: data
        };
      }
  
      if (method === "DELETE") {
        if (!widgetName) {
          return {
            statusCode: 400,
            headers: {},
            body: "Widget name missing"
          };
        }
  
        await S3.send(new DeleteObjectCommand({
          Bucket: bucketName, Key: widgetName
        }));
  
        return {
          statusCode: 200,
          headers: {},
          body: "Successfully deleted widget " + widgetName
        };
      }
  
      return {
        statusCode: 400,
        headers: {},
        body: "We only accept GET, POST, and DELETE, not " + method
      };

    } catch(error) {
      var body = error.stack || JSON.stringify(error, null, 2);
      return {
        statusCode: 400,
        headers: {},
        body: body
      }
    }
}