// src/middleware/hbs.js
const path = require("path");
const exphbs = require("express-handlebars");
const Handlebars = require("handlebars");

const { registerHelpers } = require("../utils/hbsHelpers");
const {
  VIEW_ENGINE,
  LAYOUTS_DIR,
  PARTIALS_DIR,
  DEFAULT_LAYOUT,
  EXTENSION,
  RUNTIME_OPTIONS,
} = require("../constants/hbsConstants");
const renderObject = (obj) => {
  if (typeof obj !== "object" || obj === null) {
    return new Handlebars.SafeString(`<span>${String(obj)}</span>`);
  }

  if (Array.isArray(obj)) {
    const items = obj
      .map((item) => `<li>${Handlebars.escapeExpression(String(item))}</li>`)
      .join("");
    return new Handlebars.SafeString(`<ul>${items}</ul>`);
  }

  const entries = Object.entries(obj)
    .map(([key, value]) => {
      const renderedValue = renderObject(value);
      return `<div class="doc-entry"><strong>${Handlebars.escapeExpression(key)}:</strong> ${renderedValue}</div>`;
    })
    .join("");
  return new Handlebars.SafeString(`<div class="doc-object">${entries}</div>`);
};

const hbsMiddleware = (req, res, next) => {
  if (!req.app.get("view engine")) {
    const hbs = exphbs.create({
      layoutsDir: path.join(__dirname, LAYOUTS_DIR),
      partialsDir: path.join(__dirname, PARTIALS_DIR),
      defaultLayout: DEFAULT_LAYOUT,
      helpers: {
        section(name, options) {
          this._sections ??= {};
          this._sections[name] ??= "";
          this._sections[name] += options.fn(this);
          return null;
        },
        json(context) {
          return JSON.stringify(context, null, 2);
        },
        renderObject,
      },
      extname: EXTENSION,
      runtimeOptions: RUNTIME_OPTIONS,
    });

    registerHelpers(hbs);
    req.app.engine(VIEW_ENGINE, hbs.engine);
    req.app.set("view engine", VIEW_ENGINE);
    req.app.set("views", path.join(__dirname, "../views"));
  }

  next();
};

module.exports = hbsMiddleware;