const s3 = require("@aws-sdk/client-s3");
const { S3Client, PutObjectCommand, GetObjectCommand } = s3;

const s3Client = new S3Client({
    region: process.env.AWS_REGION,
    endpoint: process.env.S3_ENDPOINT,
    credentials: {
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
    },
    forcePathStyle: process.env.S3_FORCE_PATH_STYLE === 'true',
});

module.exports = {};

module.exports.uploadFile = async (key, body) => {
    return new Promise(async (resolve, reject) => {
        const command = new PutObjectCommand({
            Bucket: process.env.S3_BUCKET,
            Key: key,
            Body: body,
        });
        try {
            await s3Client.send(command);
            resolve();
        } catch (err) {
            reject(err);
        }
    });
};

module.exports.downloadFile = async (key) => {
    return new Promise(async (resolve, reject) => {
        const command = new GetObjectCommand({
            Bucket: process.env.S3_BUCKET,
            Key: key,
        });
        try {
            const response = await s3Client.send(command);
            const stream = response.Body;
            const chunks = [];
            try {
                for await (const chunk of stream) {
                    chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
                }
                resolve(Buffer.concat(chunks));
            } catch (streamErr) {
                reject(streamErr);
            }
        } catch (err) {
            reject(err);
        }
    });
};

// Function to see if file/folder exists
module.exports.fileExists = async (key) => {
    return new Promise(async (resolve, reject) => {
        try {
            const command = new GetObjectCommand({
                Bucket: process.env.S3_BUCKET,
                Key: key,
            });
            await s3Client.send(command);
            resolve(true);
        } catch (err) {
            resolve(false);
        }
    });
};

// List files in a folder
module.exports.listFiles = async (prefix) => {
    const { ListObjectsV2Command } = require("@aws-sdk/client-s3");
    return new Promise(async (resolve, reject) => {
        const command = new ListObjectsV2Command({
            Bucket: process.env.S3_BUCKET,
            Prefix: prefix,
        });
        try {
            const response = await s3Client.send(command);
            const files = response.Contents ? response.Contents.map(item => item.Key) : [];
            resolve(files);
        } catch (err) {
            reject(err);
        }
    });
};