app.js

const express = require("express");
const compression = require("compression");
const nunjucks = require("nunjucks");
const bodyParser = require("body-parser");
const path = require("path");
const appRoutes = require("./app/routes.js");
const dateFilter = require("nunjucks-date-filter");
const markdown = require("nunjucks-markdown");
const marked = require("marked");
const govukMarkdown = require("govuk-markdown");
const Airtable = require("airtable");

const app = express();

const base = new Airtable({ apiKey: process.env.airtableFeedbackKey }).base(
    process.env.airtableFeedbackBase
);

// Set up views and nunjucks environment
var nunjuckEnv = nunjucks.configure(
    [
        "app/views",
        "app/views/layouts",
        "node_modules/govuk-frontend/dist/",
        "node_modules/dfe-frontend/packages/components",
    ], {
        autoescape: true,
        express: app,
        watch: false,
        extension: "html",
        noCache: false,
    }
);

app.use(compression());

// Serve static files
app.use(
    "/govuk",
    express.static(
        path.join(__dirname, "node_modules/govuk-frontend/govuk/assets")
    )
);
app.use(
    "/dfe",
    express.static(path.join(__dirname, "node_modules/dfe-frontend/dist"))
);
app.use("/assets", express.static("app/public"));
app.use("/public", express.static("app/public"));
app.use(express.json());

// Parse URL-encoded bodies (as sent by HTML forms)
app.use(express.urlencoded({ extended: true }));

app.use(
    "/favicon.ico",
    express.static(path.join(__dirname, "public/assets/images/favicon.ico"))
);

nunjuckEnv.addFilter("date", dateFilter);

marked.use(
    govukMarkdown({
        headingsStartWith: "xl",
    })
);

markdown.register(nunjuckEnv, marked.parse);

// Set view engine to Nunjucks with .html extension
app.set("view engine", "html");

// Add a route that serves the app/robots.txt file
app.get("/robots.txt", function(req, res) {
    res.sendFile(path.join(__dirname, "app/robots.txt"));
});

// 301 Redirects

app.get("/design-ops*", (req, res) => {
    res.redirect(301, "/designops");
});

// Define specific subsystems that should be redirected
const archivedRedirects = {
    "rsd-design-system": "https://webarchive.nationalarchives.gov.uk/ukgwa/20241206052023/https://design.education.gov.uk/design-system/rsd-design-system",
    "ncs-design-system": "https://webarchive.nationalarchives.gov.uk/ukgwa/20241206052208/https://design.education.gov.uk/design-system/ncs-design-system",
};

app.get("/design-system/:subsystem*", function(req, res, next) {
    const { subsystem } = req.params;

    if (archivedRedirects[subsystem]) {
        res.redirect(301, archivedRedirects[subsystem]);
    } else {
        next();
    }
});

app.get("/learn/how-many-users", function(req, res, next) {
    res.redirect(
        301,
        "https://accessibility.education.gov.uk/app/how-many-people"
    );
});

app.get("/learn/how-many-users/:count", function(req, res, next) {
    res.redirect(
        301,
        "https://accessibility.education.gov.uk/app/how-many-people/" +
        req.params.count
    );
});

const { buildSearchIndex, search } = require("./middleware/search.js");

buildSearchIndex("http://design.education.gov.uk/sitemap.xml")
    .then(() => console.log("Search index ready"))
    .catch((err) => console.error("Error initialising search:", err));

app.post("/form-response/feedback", (req, res) => {
    const { response } = req.body;

    // Prevent bots submitting empty feedback
    if (!response || response.trim() === "") {
        return res
            .status(400)
            .json({ success: false, message: "No feedback provided" });
    }

    // Prevent long feedback
    if (response.length > 400) {
        return res
            .status(400)
            .json({ success: false, message: "Feedback too long" });
    }

    console.log("Feedback received:", response);

    const service = "Design manual"; // Example service name
    const pageURL = req.headers.referer || "Unknown"; // Capture the referrer URL

    base("Feedback").create(
        [{
            fields: {
                Feedback: response,
                Service: service,
                URL: pageURL,
            },
        }, ],
        function(err, records) {
            if (err) {
                console.error("Airtable Error:", err);
                return res
                    .status(500)
                    .json({ success: false, message: "Could not send feedback" });
            }

            res.json({ success: true, message: "Thank you for your feedback" });
        }
    );
});

// e.g. add a /search route:
app.get("/search", (req, res) => {
    const query = req.query.q || "";
    let data = [];
    if (!query.trim()) {
        return res.render("search/index", { data });
    }
    const results = search(query);
    // Just pass the results to the template
    return res.render("search/index", { data: results, query });
});

// Use application routes
app.use("/", appRoutes);

// Clean URLs
app.get(/\.html?$/i, function(req, res) {
    let urlPath = req.path;
    const parts = urlPath.split(".");
    parts.pop();
    urlPath = parts.join(".");
    res.redirect(urlPath);
});

// Dynamic Route Matching for URLs without extensions
app.get(/^([^.]+)$/, function(req, res, next) {
    matchRoutes(req, res, next);
});

// Render sitemap.xml in XML format
app.get("/sitemap.xml", (_, res) => {
    res.set({ "Content-Type": "application/xml" });
    res.render("sitemap.xml");
});

// Route matching function
function matchRoutes(req, res, next) {
    let path = req.path;

    // Remove the first slash, render won't work with it
    path = path.startsWith("/") ? path.slice(1) : path;

    // If it's blank, render the root index
    if (path === "") {
        path = "index";
    }

    console.log(path);

    renderPath(path, res, next);
}

function renderPath(path, res, next) {
    // Try to render the path
    res.render(path, function(error, html) {
        if (!error) {
            // Success - send the response
            res.set({ "Content-type": "text/html; charset=utf-8" });
            res.end(html);
            return;
        }
        if (!error.message.startsWith("template not found")) {
            // We got an error other than template not found - call next with the error
            next(error);
            return;
        }
        if (!path.endsWith("/index")) {
            // Maybe it's a folder - try to render [path]/index.html
            renderPath(path + "/index", res, next);
            return;
        }
        // We got template not found both times - call next to trigger the 404 page
        next();
    });
}

// Also handle .html files directly
function renderPathWithExtension(path, res, next) {
    // Try to render the path with .html extension
    res.render(path + ".html", function(error, html) {
        if (!error) {
            // Success - send the response
            res.set({ "Content-type": "text/html; charset=utf-8" });
            res.end(html);
            return;
        }
        if (!error.message.startsWith("template not found")) {
            // We got an error other than template not found - call next with the error
            next(error);
            return;
        }
        // Try without .html extension
        renderPath(path, res, next);
    });
}

// Handle 404 errors
app.use(function(req, res, next) {
    res.status(404).render("404.html");
});

// Start the server
const PORT = process.env.PORT || 3066;
app.listen(PORT, () => {
    console.log(`Server is running on http://localhost:${PORT}`);
});