// ENVIRONMENTS
require('dotenv').config();

// SERVICES
const logger = require("../services/logger.services.js");

// CONSTANTS
const { MINIO_ENDPOINT, MINIO_ACCESS_KEY, MINIO_SECRET_KEY } = process.env;

const Minio = require("minio");

const minioClient = new Minio.Client({
    endPoint: MINIO_ENDPOINT,
    port: 443,
    useSSL: true,
    accessKey: MINIO_ACCESS_KEY,
    secretKey: MINIO_SECRET_KEY,
});

/**
 * Create a new bucket and set default public policy
 */
async function createBucket(bucketName) {
    return new Promise((resolve, reject) => {
        minioClient.makeBucket(bucketName, "", function (err) {
            if (err) return reject(err);
            logger.info(`Bucket "${bucketName}" created successfully`);

            const policy = {
                Version: "2012-10-17",
                Statement: [
                    {
                        Effect: "Allow",
                        Principal: { AWS: "*" },
                        Action: ["s3:GetObject"],
                        Resource: [`arn:aws:s3:::${bucketName}/*`],
                    },
                ],
            };

            minioClient.setBucketPolicy(bucketName, JSON.stringify(policy), (err) => {
                if (err) return reject(err);
                logger.info(`Public policy applied to bucket "${bucketName}"`);
                resolve();
            });
        });
    });
}

/**
 * Delete an existing bucket (must be empty)
 */
async function deleteBucket(bucketName) {
    return new Promise((resolve, reject) => {
        minioClient.removeBucket(bucketName, function (err) {
            if (err) return reject(err);
            logger.info(`Bucket "${bucketName}" deleted successfully`);
            resolve();
        });
    });
}

/**
 * Rename a bucket (create new, copy objects, delete old)
 */
async function renameBucket(oldBucket, newBucket) {
    try {
        await createBucket(newBucket);

        const objects = [];
        const stream = minioClient.listObjects(oldBucket, "", true);

        await new Promise((resolve, reject) => {
            stream.on("data", obj => objects.push(obj));
            stream.on("end", resolve);
            stream.on("error", reject);
        });

        for (const obj of objects) {
            await new Promise((resolve, reject) => {
                minioClient.copyObject(
                    newBucket,
                    obj.name,
                    `/${oldBucket}/${obj.name}`,
                    function (err, etag) {
                        if (err) return reject(err);
                        logger.info(`Copied ${obj.name} to ${newBucket}`);
                        resolve(etag);
                    }
                );
            });
        }

        if (objects.length > 0) {
            await minioClient.removeObjects(
                oldBucket,
                objects.map(o => o.name)
            );
        }

        await deleteBucket(oldBucket);

        logger.info(`Bucket renamed from "${oldBucket}" to "${newBucket}"`);
    } catch (err) {
        throw err;
    }
}

/**
 * Get all buckets
 */
async function getAllBuckets() {
    return new Promise((resolve, reject) => {
        minioClient.listBuckets((err, buckets) => {
            if (err) return reject(err);
            resolve(buckets);
        });
    });
}

/**
 * Set bucket policy (public / private)
 */
async function setBucketPolicy(bucketName, policyType) {
    let policy = "";

    if (policyType === "public") {
        policy = {
            Version: "2012-10-17",
            Statement: [
                {
                    Effect: "Allow",
                    Principal: { AWS: ["*"] },
                    Action: ["s3:GetObject"],
                    Resource: [`arn:aws:s3:::${bucketName}/*`]
                }
            ]
        };
    } else if (policyType === "private") {
        policy = {
            Version: "2012-10-17",
            Statement: []
        };
    } else {
        throw new Error("Invalid policy type, use 'public' or 'private'");
    }

    await minioClient.setBucketPolicy(bucketName, JSON.stringify(policy));
}

module.exports = {
    minioClient,
    createBucket,
    deleteBucket,
    renameBucket,
    getAllBuckets,
    setBucketPolicy
};