const User = require("../../models/User");
const Channel = require("../../models/Channel");
const Post = require("../../models/Post");
const Message = require("../../models/Message");
const config = require("../../config");
const { authenticateEndpoint } = require("./../../common/auth/authfunctions");

const mongoose = require("mongoose");
const { body, param, validationResult } = require("express-validator");
const express = require("express");
const rateLimit = require("express-rate-limit");

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

mongoose.connect(config.mongoUrl, {useNewUrlParser: true, useUnifiedTopology: true});

app.post("/channel/create", [
    createLimiter,
    body("title").not().isEmpty().trim().isLength({ min: 3, max: 32 }).escape()
], authenticateEndpoint(async (req, res, user) => {
    if (!config.policies.allowChannelCreation) return res.status(403).json({ error: true, message: "ERROR_FORBIDDEN_BY_POLICY" });

    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 channel = await Channel.create({
        title: title,
        creator: user._id,
        posts: []
    });
    
    res.status(200).json({
        error: false,
        message: "SUCCESS_CHANNEL_CREATED",
        channel: channel.getPublicObject()
    });
}, undefined, config.roleMap.USER));

app.post("/post/create", [
    createLimiter,
    body("channel").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) => {
    if (!config.policies.allowPostCreation) return res.status(403).json({ error: true, message: "ERROR_FORBIDDEN_BY_POLICY" });

    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: "ERROR_REQUEST_INVALID_DATA", errors: errors.array() });
        return;
    }

    const channel = req.body.channel;
    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.channel = channel;

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

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

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

app.get("/channel/:channel/messages", [
    param("channel").not().isEmpty().trim().escape().isLength({ min: 24, max: 24 })
], authenticateEndpoint(async (req, res) => {
    if (!config.policies.allowSavingMessages) {
        // TODO: hack
        res.status(200).json({
            error: false,
            message: "SUCCESS_CHANNEL_MESSAGES_FETCHED",
            channelMessages: []
        });
        return;
    }

    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: "ERROR_REQUEST_INVALID_DATA", errors: errors.array() });
        return;
    }

    let idSearch = {};
    if (req.query.before) {
        idSearch = { _id: { $lt: req.query.before } };
    }

    const messages = await Message.find({ channel: req.params.channel, ...idSearch })
        .sort({ _id: -1 })
        .limit(50)
        .select("-__v -channel")
        .populate("author", "_id username");

    res.status(200).json({
        error: false,
        message: "SUCCESS_CHANNEL_MESSAGES_FETCHED",
        channelMessages: messages
    });
}, undefined, config.roleMap.USER));

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

    const channel = await Channel.findById(req.params.channel).populate("posts.creator", User.getPulicFields());
    
    const users = await User.find().sort({ _id: -1 }).limit(50).select(User.getPulicFields());

    if (!channel) {
        res.status(404).json({
            error: true,
            message: "ERROR_CHANNEL_NOT_FOUND"
        });
        return;
    }

    res.status(200).json({
        error: false,
        message: "SUCCESS_CHANNEL_DATA_FETCHED",
        channel: channel.getPublicObject(),
        userInfo: {
            userListLimit: 50,
            users: users
        }
    });
}, undefined, config.roleMap.USER));

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

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

    res.status(200).json({
        error: false,
        message: "SUCCESS_CHANNEL_LIST_FETCHED",
        channels
    });
}, undefined, config.roleMap.USER));

module.exports = app;