import { S3Client, PutObjectCommand } from "@aws-sdk/client-s3";
import { getSignedUrl } from "@aws-sdk/s3-request-presigner";
import { readMultipartFormData } from 'h3';

export default defineEventHandler(async (event) => {
    // Create S3 client with config
    const client = new S3Client({
        region: process.env.NUXT_AWS_REGION,
        credentials: {
            accessKeyId: process.env.NUXT_AWS_ACCESS_KEY_ID,
            secretAccessKey: process.env.NUXT_AWS_SECRET_ACCESS_KEY
        }
    });

    try {
        const parts = await readMultipartFormData(event, { maxSize: 1024 * 1024 }); // 1MB limit since we're only handling metadata

        if (!parts) {
            return {
                status: 400,
                message: "Bad request. No parts found."
            }
        }

        // Extract form data
        const fileNamePart = parts.find(p => p.name === "fileName");
        const fileTypePart = parts.find(p => p.name === "fileType");

        if (!fileNamePart || !fileTypePart) {
            return {
                status: 400,
                message: "Missing required fields { fileName, fileType }"
            }
        }

        const fileName = fileNamePart.data.toString();
        const fileType = fileTypePart.data.toString();

        // Generate a unique key using timestamp and filename
        const uploadKey = `uploads/${Date.now()}-${fileName}`;

        const command = new PutObjectCommand({
            Bucket: process.env.NUXT_AWS_BUCKET,
            Key: uploadKey,
            ContentType: fileType,
        });

        // Generate signed URL
        const signedUrl = await getSignedUrl(client, command, { expiresIn: 60 });

        return {
            status: 200,
            message: `Signed URL generated for file: ${fileName}`,
            signedUrl
        };

    } catch (error) {
        console.error('Error processing request:', error);
        return {
            status: 500,
            message: "Failed to generate signed URL",
            error: error.message
        }
    }
})