// controllers/client/advertisements.controller.js

const Advertisement = require("../../models/advertisements/advertisements.mdl");
const mdl_Assets = require("../../models/assets/assets.mdl");
const mediaToken = require("../../services/mediaToken.service");
const R = require('../../utils/response.util');
const { PLACEMENT_MAP } = require("../../models/advertisements/advertisements.placements");

const { Op } = require('sequelize');

const AD_IMAGE_INCLUDE = {
  model:     mdl_Assets,
  as:        "image",
  attributes: ["asset_id", "display_name", "file_url", "thumbnail_url", "storage_provider", "storage_key", "file_type", "mime_type"],
  required:  false,
};

const AD_CLIENT_EXCLUDE = ["createdBy", "updatedBy", "deletedBy", "deletedAt", "image_asset_id"];

// ─── Media proxying ─────────────────────────────────────────────────────────
// Mirrors controllers/admin/advertisements.controller.js's attachImageStreamToken.
// Kept duplicated rather than shared to avoid a cross-boundary import between
// admin and client controllers (same rationale as deriveStatus above). Private
// (S3-backed) images never expose a raw file_url — the frontend resolves the
// stream_token through GET /api/client/media/stream/:token instead.
async function attachImageStreamToken(image, req) {
  if (!image || image.storage_provider !== "s3" || !mediaToken.SUPPORTED_TYPES.includes(image.file_type)) {
    return image;
  }
  const ip = mediaToken.resolveIp(req);
  const { token } = await mediaToken.issueForAsset(image, req.user?.user_id, ip);
  image.stream_token = token;
  image.file_url = null;
  image.thumbnail_url = null;
  delete image.storage_key;
  return image;
}

// ─── Status derivation ─────────────────────────────────────────────────────
// Mirrors admin controller's deriveStatus — single source of truth for what
// "live right now" means. Kept duplicated rather than shared to avoid a
// cross-boundary import between admin and client controllers.
function deriveStatus(advertisement) {
  if (advertisement.deletedAt) return "archived";
  if (!advertisement.is_active) return "draft";

  const now   = new Date();
  const start = advertisement.start_date ? new Date(advertisement.start_date) : null;
  const end   = advertisement.end_date   ? new Date(advertisement.end_date)   : null;

  if (end && end < now) return "expired";
  if (start && start > now) return "scheduled";
  return "active";
}

// ─── Live window helper ─────────────────────────────────────────────────────
// "Live" means is_active = true AND within start_date/end_date window —
// computed the same way as deriveStatus, but expressed as a SQL WHERE clause
// here since we want the DB to do the filtering/ordering, not JS.
function liveWhere(extra) {
  const now = new Date();
  return {
    ...extra,
    is_active: true,
    deletedAt: null,
    [Op.and]: [
      { [Op.or]: [{ start_date: null }, { start_date: { [Op.lte]: now } }] },
      { [Op.or]: [{ end_date: null },   { end_date:   { [Op.gte]: now } }] },
    ],
  };
}

// ─── GET ACTIVE ───────────────────────────────────────────────────────────────
//
// Resolves the single highest-priority live advertisement for a given placement.
//
// GET /api/client/advertisements/active?placement=dashboard.hero
//
exports.getActiveAdvertisement = async (req, res) => {
  try {
    const { placement } = req.query;

    if (!placement) return R.error(res, "placement is required.", 400);
    if (!PLACEMENT_MAP[placement]) return R.error(res, "Invalid placement.", 400);

    const advertisement = await Advertisement.findOne({
      where: liveWhere({ placement }),
      order: [["order", "ASC"], ["createdAt", "DESC"]],
      include: [AD_IMAGE_INCLUDE],
      attributes: { exclude: AD_CLIENT_EXCLUDE },
    });

    if (!advertisement) return R.success(res, "No active advertisement for this placement.", { data: null });

    const json = advertisement.toJSON();
    json.status = deriveStatus(json); // will always be "active" given the WHERE clause, but kept for shape consistency

    if (json.image) await attachImageStreamToken(json.image, req);

    return R.success(res, "Active advertisement retrieved.", { data: json });
  } catch (err) {
    console.error("[CLIENT][ADVERTISEMENT][GET ACTIVE]", err);
    return R.error(res, "Could not retrieve advertisement.", 500);
  }
};

// ─── GET ACTIVE (batch) ─────────────────────────────────────────────────────
//
// Resolves the highest-priority live advertisement for each of several
// placements in a single round-trip — pages that need multiple simultaneous
// slots (e.g. dashboard.hero + dashboard.popup) use this instead of N calls
// to /active.
//
// GET /api/client/advertisements/active-batch?placements=dashboard.hero,dashboard.popup
//
exports.getActiveAdvertisements = async (req, res) => {
  try {
    const raw = req.query.placements;
    const placements = (Array.isArray(raw) ? raw : String(raw ?? "").split(","))
      .map((p) => p.trim())
      .filter(Boolean);

    if (!placements.length) return R.error(res, "placements is required.", 400);

    const invalid = placements.filter((p) => !PLACEMENT_MAP[p]);
    if (invalid.length) return R.error(res, `Invalid placement(s): ${invalid.join(", ")}`, 400);

    const advertisements = await Advertisement.findAll({
      where: liveWhere({ placement: { [Op.in]: placements } }),
      order: [["order", "ASC"], ["createdAt", "DESC"]],
      include: [AD_IMAGE_INCLUDE],
      attributes: { exclude: AD_CLIENT_EXCLUDE },
    });

    // Keep only the highest-priority row per placement (order ASC, createdAt DESC already applied).
    const data = Object.fromEntries(placements.map((p) => [p, null]));
    for (const ad of advertisements) {
      const json = ad.toJSON();
      if (data[json.placement] !== null) continue; // already have the winner for this placement
      json.status = deriveStatus(json);
      if (json.image) await attachImageStreamToken(json.image, req);
      data[json.placement] = json;
    }

    return R.success(res, "Active advertisements retrieved.", { data });
  } catch (err) {
    console.error("[CLIENT][ADVERTISEMENT][GET ACTIVE BATCH]", err);
    return R.error(res, "Could not retrieve advertisements.", 500);
  }
};

// ─── TRACK CLICK ──────────────────────────────────────────────────────────────
//
// POST /api/client/advertisements/:advertisementId/click
// Fire-and-forget increment. Never blocks or surfaces errors to the user —
// a failed click tracking call should never disrupt navigation to the CTA link.
//
exports.trackClick = async (req, res) => {
  try {
    const { advertisementId } = req.params;
    if (!advertisementId || advertisementId === "undefined") return R.error(res, "Invalid advertisement ID.", 400);

    const advertisement = await Advertisement.findOne({ where: { advertisement_id: advertisementId, deletedAt: null } });
    if (!advertisement) return R.success(res, "Advertisement not found, skipped.", { data: null });

    await advertisement.increment("click_count");

    return R.success(res, "Click tracked.", { data: { click_count: advertisement.click_count + 1 } });
  } catch (err) {
    console.error("[CLIENT][ADVERTISEMENT][TRACK CLICK]", err);
    // Still respond 200-ish/success shape — click tracking failures shouldn't surface to the user.
    return R.success(res, "Click tracking failed silently.", { data: null });
  }
};