/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/utils/s3Upload.util.js

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

const { getSignedUrl } = require("@aws-sdk/s3-request-presigner");
const s3 = require("../config/s3.config");
const { v4: uuidv4 } = require("uuid");
const path = require("path");
const redis = require("../config/redisClient");
const { log } = require("./consoleLog.utill");

// Upload + return key (BEST PRACTICE)
const uploadToS3 = async (file, usedFor) => {
  try {
    const fileExtension = path.extname(file.originalname);
    const fileName = `${uuidv4()}${fileExtension}`;
    let key = `uploads/${fileName}`;

    if (usedFor === "asset") {
      key = `assets/${fileName}`;
    } 

    log("Uploading file to S3 with key:", key);

    const params = {
      Bucket: process.env.AWS_S3_BUCKET_NAME,
      Key: key,
      Body: file.buffer,
      ContentType: file.mimetype,
    };

    await s3.send(new PutObjectCommand(params));

    // Return KEY (not URL)
    return key;
  } catch (error) {
    log("S3 Upload Error:", error);
    throw new Error("File upload failed");
  }
};

// Generate signed URL with Redis caching
const getSignedFileUrl = async (key) => {
  try {
    const cacheKey = `s3:url:${key}`;

    // 1. Check cache
    const cachedUrl = await redis.get(cacheKey);

    if (cachedUrl) {
      log("⚡ Cache HIT - returning signed URL from Redis");
      return cachedUrl;
    }

    log("🐢 Cache MISS - generating new signed URL");

    // 2. Generate signed URL
    const command = new GetObjectCommand({
      Bucket: process.env.AWS_S3_BUCKET_NAME,
      Key: key,
    });

    const signedUrl = await getSignedUrl(s3, command, {
      expiresIn: 3600, // 1 hour
    });

    // 3. Store in Redis (TTL: 55 minutes)
    await redis.set(cacheKey, signedUrl, "EX", 3300);

    return signedUrl;
  } catch (error) {
    log("Signed URL Error:", error);
    throw new Error("Failed to generate file URL");
  }
};

module.exports = {
  uploadToS3,
  getSignedFileUrl,
};