/***********************************************************************************************************************************************************************
 * File Name: media.controller.js  (public)
 * Type of Program: Controller
 * Description: Issues stream tokens for publicly accessible S3 assets — no auth required.
 *              Guards:
 *                1. Asset must exist and not be deleted
 *                2. is_public must be true — private assets are always rejected (403)
 *                3. storage_provider must be "s3" — Chibisafe uses its raw CDN URL
 *              Token shape is identical to the client/admin token flows so the
 *              shared stream endpoint (/api/client/media/stream/:token) accepts it.
 *              No user_id is embedded — the token is anonymous.
 *              IP is still bound so a leaked token is useless on another machine.
 *
 * Author: Kenneth Obsequio (@lash0000)
 * Date Created: Jun. 22, 2026
 ***********************************************************************************************************************************************************************/
"use strict";

const jwt = require("jsonwebtoken");

const R          = require("../../utils/response.util");
const mdl_Assets = require("../../models/assets/assets.mdl");

const MEDIA_SECRET  = process.env.MEDIA_JWT_SECRET ?? process.env.JWT_SECRET;
const TOKEN_TTL_SEC = 4 * 60 * 60; // 4 hours — matches client TTL

const SUPPORTED_TYPES = ["video", "audio", "document", "image"];

function resolveIp(req) {
  const forwarded = req.headers["x-forwarded-for"];
  if (forwarded) return forwarded.split(",")[0].trim();
  return req.ip ?? req.socket?.remoteAddress ?? "unknown";
}

// ─── GET /public/media/token?asset_id=X ──────────────────────────────────────

exports.issueToken = async (req, res) => {
  try {
    const asset_id = req.query.asset_id ?? req.body?.asset_id;
    if (!asset_id) return R.error(res, "asset_id is required.", 400);

    const asset = await mdl_Assets.findOne({
      where: { asset_id, deletedAt: null },
      attributes: ["asset_id", "file_type", "storage_provider", "storage_key", "mime_type", "is_public"],
    });

    if (!asset) return R.error(res, "File not found.", 404);

    // Private assets are never served through the public endpoint
    if (!asset.is_public) return R.error(res, "Forbidden.", 403);

    if (!SUPPORTED_TYPES.includes(asset.file_type)) {
      return R.error(res, `File type "${asset.file_type}" is not supported.`, 400);
    }

    if (asset.storage_provider !== "s3") {
      return R.error(res, "Token flow is for S3 files only. Use the raw file_url for other providers.", 400);
    }

    const ip = resolveIp(req);

    const token = jwt.sign(
      {
        asset_id,
        // no user_id — anonymous public token
        storage_key: asset.storage_key,
        file_type:   asset.file_type,
        mime_type:   asset.mime_type,
        ip,
      },
      MEDIA_SECRET,
      { expiresIn: TOKEN_TTL_SEC }
    );

    return R.success(res, "Token issued.", {
      token,
      provider:  "s3",
      file_type: asset.file_type,
    });

  } catch (err) {
    console.error("[PUBLIC][MEDIA][TOKEN]", err);
    return R.error(res, "Could not issue media token.", 500);
  }
};