const User = require('../../models/User');
const Category = require('../../models/Category');
const Post = require('../../models/Post');
const config = require('../../config');

const { authenticateEndpoint } = require('./authfunctions');

const mongoose = require('mongoose');
const { body, param, validationResult } = require('express-validator');
const express = require('express');

const app = express.Router();
mongoose.connect(config.mongoUrl, {useNewUrlParser: true, useUnifiedTopology: true});

const rateLimit = require("express-rate-limit");

const createLimiter = rateLimit({
    windowMs: 2 * 60 * 1000,
    max: 10,
});

app.post('/category/create', [
    createLimiter,
    body('title').not().isEmpty().trim().isLength({ min: 3, max: 32 }).escape()
], authenticateEndpoint(async (req, res, user) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: 'ERROR_REQUEST_INVALID_DATA', errors: errors.array() });
        return;
    }

    const title = req.body.title;
    const category = await Category.create({
        title: title,
        creator: user._id,
        posts: []
    });
    
    res.status(200).json({
        error: false,
        message: 'SUCCESS_CATEGORY_CREATED',
        category: category.getPublicObject()
    });
}, undefined, config.roleMap.USER));

app.post('/post/create', [
    createLimiter,
    body('category').not().isEmpty().trim().escape().isLength({ min: 24, max: 24 }),
    body('title').not().isEmpty().trim().isLength({ min: 3, max: 32 }).escape(),
    body('body').not().isEmpty().trim().isLength({ min: 3, max: 1000 }).escape(),
], authenticateEndpoint(async (req, res, user) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: 'ERROR_REQUEST_INVALID_DATA', errors: errors.array() });
        return;
    }

    const category = req.body.category;
    const title = req.body.title;
    const content = req.body.body;

    const post = new Post();
    post.title = title;
    post.body = content;
    post.creator = user._id;
    post.category = category;

    const r = await Category.updateOne({
        _id: category
    }, {
        $push: { posts: post }
    });

    if (r.n < 1) {
        res.status(404).json({
            error: true,
            message: 'ERROR_CATEGORY_NOT_FOUND'
        });
        return;
    }

    res.status(200).json({
        error: false,
        message: 'SUCCESS_POST_CREATED',
        post: {
            _id: post._id
        }
    });
}, undefined, config.roleMap.USER));

app.get('/category/:category/info', [
    param('category').not().isEmpty().trim().escape().isLength({ min: 24, max: 24 })
], authenticateEndpoint(async (req, res, user) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: 'ERROR_REQUEST_INVALID_DATA', errors: errors.array() });
        return;
    }

    const categoryId = req.params.category;
    const category = await Category.findById(categoryId).populate('posts.creator', User.getPulicFields());
    
    // TODO: Implement subscribing to a channel and stuff
    const users = await User.find().sort({ _id: -1 }).limit(50).select(User.getPulicFields())

    if (!category) {
        res.status(404).json({
            error: true,
            message: 'ERROR_CATEGORY_NOT_FOUND'
        });
        return;
    }

    res.status(200).json({
        error: false,
        message: 'SUCCESS_CATEGORY_DATA_FETCHED',
        category: category.getPublicObject(),
        userInfo: {
            userListLimit: 50,
            users: users
        }
    });
}));

app.get('/category/list', authenticateEndpoint(async (req, res, user) => {
    let count = parseInt(req.query.count);
    if (!Number.isInteger(count)) {
        count = 10;
    }

    // TODO: This is probably not efficient
    const categories = await Category.find().sort({ _id: -1 }).limit(count).select('-posts -__v').populate('creator', User.getPulicFields());

    res.status(200).json({
        error: false,
        message: 'SUCCESS_CATEGORY_LIST_FETCHED',
        categories
    });
}));

module.exports = app;