// Admin endpoints for managing a bot's authorized-user list:
//   GET    /CollabCentral/:app/admin/users        — list
//   POST   /CollabCentral/:app/admin/users        — add (by email)
//   DELETE /CollabCentral/:app/admin/users/:id    — remove
//
// Admin authority lives in authorized.admins (personIds). Every admin
// route rejects with 403 for non-admin callers — 403 rather than 401 so
// the client can tell an admin-only route apart from a signed-out state
// (which would 401). Admin actions are cross-bot in concept but the
// routes are still :app-scoped because the resource being edited is
// per-bot (authorized users on THAT bot) and it keeps the OAuth session
// model unchanged (admin uses the same session cookie as any other page).
//
// registerAdminRoutes(app, { isAdmin, authorized, webex, saveConfig,
//                            logger })

// requireAdmin returns null on success or an Express-response-sending
// function on failure, so each handler stays a straight-line function.
function makeRequireAdmin(isAdmin) {
    return function requireAdmin(req, res) {
        if (!req.cookies || !req.cookies.id) return res.status(401).send('Unauthorized.');
        if (!isAdmin(req.cookies.id)) return res.status(403).send('Admin only.');
        return null;
    };
}

// Shape of a single row returned by the admin users endpoints. Kept in
// one helper so add / delete / list all produce identical output — the
// client can treat every response as an authoritative "here's the
// current state".
function adminUserRow(entry) {
    var groups = Array.isArray(entry && entry.groups) ? entry.groups : [];
    return {
        id: entry.id,
        displayName: entry.displayName || '',
        email: entry.email || '',
        avatar: entry.avatar || null,
        groupCount: groups.length
    };
}

export function registerAdminRoutes(app, deps) {
    var isAdmin = deps.isAdmin;
    var authorized = deps.authorized;
    var webex = deps.webex;
    var saveConfig = deps.saveConfig;
    var logger = deps.logger || function () {};

    var requireAdmin = makeRequireAdmin(isAdmin);

    function adminUsersList(appName) {
        var bucket = (authorized.bot && authorized.bot[appName]) || {};
        return Object.keys(bucket).map(function (id) { return adminUserRow(bucket[id]); });
    }

    app.get('/CollabCentral/:app/admin/users', function (req, res) {
        if (requireAdmin(req, res)) return;
        logger('apiEndpoint(' + req.params.app + ')', 'GET /admin/users');
        res.status(200).send(adminUsersList(req.params.app));
    });

    app.post('/CollabCentral/:app/admin/users', async function (req, res) {
        if (requireAdmin(req, res)) return;
        var appName = req.params.app;
        var email = req.body && req.body.email && String(req.body.email).trim();
        if (!email) return res.status(400).send('Missing email.');

        var person;
        try {
            person = await webex.findPersonByEmail(email);
        } catch (err) {
            logger('apiEndpoint(' + appName + ')',
                'admin/users lookup failed for "' + email + '": ' + (err && err.message || err));
            return res.status(502).send('Failed to reach Webex directory.');
        }
        if (!person) return res.status(404).send('No Webex user found for that email.');

        if (!authorized.bot[appName]) authorized.bot[appName] = {};
        var bucket = authorized.bot[appName];
        if (!bucket[person.id]) {
            bucket[person.id] = {
                id: person.id,
                displayName: person.displayName,
                email: person.email,
                avatar: person.avatar,
                groups: []
            };
            try {
                saveConfig(authorized, './config/authorized.json');
            } catch (err) {
                logger('apiEndpoint(' + appName + ')',
                    'admin/users save failed: ' + (err && err.message || err));
                return res.status(500).send('Failed to save.');
            }
            logger('apiEndpoint(' + appName + ')',
                'admin/users + "' + person.displayName + '" <' + person.email + '>');
        }
        res.status(200).send({
            user: adminUserRow(bucket[person.id]),
            users: adminUsersList(appName)
        });
    });

    app.delete('/CollabCentral/:app/admin/users/:id', function (req, res) {
        if (requireAdmin(req, res)) return;
        var appName = req.params.app;
        var targetId = req.params.id;
        var bucket = (authorized.bot && authorized.bot[appName]) || {};
        if (!bucket[targetId]) {
            return res.status(200).send({ removed: false, users: adminUsersList(appName) });
        }
        var name = bucket[targetId].displayName || targetId;
        delete bucket[targetId];
        try {
            saveConfig(authorized, './config/authorized.json');
        } catch (err) {
            logger('apiEndpoint(' + appName + ')',
                'admin/users delete save failed: ' + (err && err.message || err));
            return res.status(500).send('Failed to save.');
        }
        logger('apiEndpoint(' + appName + ')', 'admin/users - "' + name + '"');
        res.status(200).send({ removed: true, users: adminUsersList(appName) });
    });
}