const { addBaseUrlToImages, getFullImageUrl } = require("../utils/imageHelper");
const Home = require("../models/home");
const Blog = require("../models/blog");

// Các hàm hỗ trợ
const getHomeDoc = async () => Home.findOne().sort({ updatedAt: -1 });
const getHomeData = async () => (await getHomeDoc())?.toObject() || {};

const getDefaultHomeData = () => ({
  hero: { title: "", subtitle: "", description: "", backgroundImage: "", videoUrl: "", primaryButton: {}, secondaryButton: {} },
  whyChooseUs: { heading: "", subheading: "", description: "", items: [], features: [], ctaButton: {} },
  visaSolutions: { heading: "", subheading: "", items: [] },
  visaCountries: { heading: "", subheading: "", description: "", countries: [], ctaButton: {} },
  testimonials: { heading: "", subheading: "", videoUrl: "", videoThumbnail: "", items: [] },
  videoGallery: { heading: "", videoUrl: "", thumbnail: "" },
  faq: { heading: "", subheading: "", description: "", ctaButton: {}, items: [] },
  achievements: { heading: "", subheading: "", items: [] },
  partners: { visaConsultancy: { items: [] }, brands: { items: [] } },
  blogPreview: { 
    heading: "Latest Insights & Updates", 
    subheading: "Visa Tips & Guides", 
    ctaButton: { label: "View All Articles", href: "/blog" }, 
    items: [],
    selectedBlogIds: [] // Array of manually selected blog IDs
  },
});

// Admin: Xem trang quản lý
exports.index = async (req, res) => {
  try {
    let data = await getHomeData();
    const defaults = getDefaultHomeData();
    
    // Merge dữ liệu mặc định cho tất cả các phần
    const sections = Object.keys(defaults);
    sections.forEach(s => {
      data[s] = data[s] || defaults[s];
    });

    const frontendUrl = process.env.FRONTEND_URL || "http://localhost:3000";
    const backendUrl = process.env.BACKEND_URL || "http://localhost:3001";
    
    // Lấy tất cả blog để chọn trong CMS
    const allBlogs = await Blog.find({ status: "published" }).sort({ createdAt: -1 }).lean();

    return res.render("admin/home/index", {
      layout: "layouts/main",
      title: "Home Management",
      data,
      allBlogs,
      frontendUrl,
      backendUrl,
      getFullImageUrl,
      currentPath: req.path,
      user: req.session.user,
    });
  } catch (err) {
    console.error("Home index error:", err);
    req.flash("error_msg", "Error loading home data");
    return req.session.save(() => res.redirect("/admin/dashboard"));
  }
};

// Admin: Cập nhật dữ liệu (tập trung vào achievements, partners; các phần khác giữ nguyên nếu không có dữ liệu mới)
exports.update = async (req, res) => {
  try {
    const sections = [
      "hero", "whyChooseUs", "visaSolutions", "visaCountries", 
      "testimonials", "videoGallery", "faq", "achievements", 
      "partners", "blogPreview"
    ];

    let doc = await getHomeDoc();
    if (!doc) {
      doc = new Home({});
    }

    let hasChanges = false;
    for (const section of sections) {
      if (req.body[section]) {
        try {
          const payload = JSON.parse(req.body[section]);
          // Gán trực tiếp vào doc, Mongoose sẽ tự check schema
          doc[section] = payload;
          doc.markModified(section);
          hasChanges = true;
        } catch (e) {
          console.error(`Invalid JSON for ${section}:`, e);
        }
      }
    }

    if (!hasChanges) {
      req.flash("info_msg", "No changes were made");
      return req.session.save(() => res.redirect("/admin/home"));
    }

    await doc.save();
    req.flash("success_msg", "Home page configuration has been updated!");
    return req.session.save(() => res.redirect("/admin/home"));
  } catch (err) {
    console.error("Home update error:", err);
    req.flash("error_msg", `Update error: ${err.message}`);
    return req.session.save(() => res.redirect("/admin/home"));
  }
};

// Public API// API lấy danh sách blog cho CMS
exports.apiGetBlogs = async (req, res) => {
  try {
    const blogs = await Blog.find({ status: "published" }).sort({ createdAt: -1 }).select("title slug featuredImage author publishedAt").lean();
    res.json(blogs);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
};
exports.api = async (req, res) => {
  try {
    let data = await getHomeData();
    const baseUrl = process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;

    // === Xử lý Blog Preview động ===
    const blogPreview = data.blogPreview || {};
    let blogs = [];
    
    // Nếu có chọn blog cụ thể
    if (blogPreview.selectedBlogIds && blogPreview.selectedBlogIds.length > 0) {
      blogs = await Blog.find({ 
        _id: { $in: blogPreview.selectedBlogIds },
        status: "published" 
      }).lean();
      
      // Sắp xếp theo thứ tự đã chọn trong selectedBlogIds
      blogs.sort((a, b) => {
        return blogPreview.selectedBlogIds.indexOf(a._id.toString()) - blogPreview.selectedBlogIds.indexOf(b._id.toString());
      });
    } 
    
    // Nếu không chọn hoặc chọn nhưng không đủ, lấy thêm 3 bài mới nhất (hoặc bù vào)
    if (blogs.length === 0) {
      blogs = await Blog.find({ status: "published" })
        .sort({ createdAt: -1 })
        .limit(3)
        .lean();
    }

    // Map dữ liệu blog sang format mà frontend mong đợi
    blogPreview.items = blogs.map(blog => ({
      title: blog.title,
      excerpt: blog.excerpt,
      category: blog.category && blog.category[0] ? blog.category[0] : "Visa",
      date: blog.publishedAt || blog.createdAt,
      author: {
        name: blog.author || "Admin",
        avatar: "" // Frontend đang tự xử lý hoặc dùng logo hệ thống
      },
      comments: blog.commentsCount || 0,
      link: `/blog/${blog.slug}`,
      thumbnail: blog.featuredImage
    }));

    data.blogPreview = blogPreview;
    // ===============================

    const processed = addBaseUrlToImages(data, baseUrl);
    return res.json(processed);
  } catch (err) {
    console.error("Home API error:", err);
    return res.status(500).json({ error: "Error loading home data" });
  }
};