import express from 'express';
import * as msgCtrl from '../controllers/messageController.js';
import { authenticate } from '../middleware/auth.js';

const router = express.Router();

// Apply auth to all message routes
router.use(authenticate);

const TEXT_MIN = 1;
const TEXT_MAX = 1000;
const ROOM_ID_MAX = 100;
const DEFAULT_LIMIT = 50;
const MAX_LIMIT = 200;

function isValidText(text) {
    if (typeof text !== 'string') {
        return false;
    }
    if (text.length < TEXT_MIN || text.length > TEXT_MAX) {
        return false;
    }
    return true;
}

function isValidRoomId(roomId) {
    if (roomId === undefined || roomId === null) {
        return true;
    }
    if (typeof roomId !== 'string') {
        return false;
    }
    return roomId.length <= ROOM_ID_MAX;
}

function isValidAuthorId(authorId) {
    if (typeof authorId !== 'string') {
        return false;
    }
    if (authorId.length < 1) {
        return false;
    }
    return true;
}

// Search messages (must be before /:id)
router.get('/search', async function(req, res) {
    const q = req.query.q;
    if (typeof q !== 'string' || q.length < 1) {
        return res.status(400).json({ error: 'invalid_query' });
    }
    const results = await msgCtrl.searchMessages({ q: q, fields: ['text'], filters: {} });
    res.json(results);
});

// List messages with pagination
router.get('/', async function(req, res) {
    let limit = parseInt(req.query.limit, 10);
    let offset = parseInt(req.query.offset, 10);

    if (isNaN(limit) || limit < 1) {
        limit = DEFAULT_LIMIT;
    }
    if (limit > MAX_LIMIT) {
        limit = MAX_LIMIT;
    }
    if (isNaN(offset) || offset < 0) {
        offset = 0;
    }

    const filters = {};
    if (req.query.authorId) {
        filters.authorId = req.query.authorId;
    }

    const messages = await msgCtrl.listMessages({ limit: limit, offset: offset, filters: filters });
    res.json(messages);
});

// Get message by id
router.get('/:id', async function(req, res) {
    const message = await msgCtrl.getMessageById(req.params.id);
    if (!message) {
        return res.status(404).json({ error: 'not_found' });
    }
    res.json(message);
});

// Create message
router.post('/', async function(req, res) {
    const authorId = req.body.authorId;
    const text = req.body.text;
    const roomId = req.body.roomId;

    if (!isValidAuthorId(authorId)) {
        return res.status(400).json({ error: 'invalid_author_id' });
    }
    if (!isValidText(text)) {
        return res.status(400).json({ error: 'invalid_text' });
    }
    if (!isValidRoomId(roomId)) {
        return res.status(400).json({ error: 'invalid_room_id' });
    }

    const result = await msgCtrl.createMessage({ authorId: authorId, text: text, roomId: roomId });
    if (result.error === 'author_not_found') {
        return res.status(400).json({ error: 'author_not_found' });
    }

    res.status(201).json(result);
});

// Update message
router.put('/:id', async function(req, res) {
    const text = req.body.text;
    const roomId = req.body.roomId;

    if (text !== undefined && !isValidText(text)) {
        return res.status(400).json({ error: 'invalid_text' });
    }
    if (!isValidRoomId(roomId)) {
        return res.status(400).json({ error: 'invalid_room_id' });
    }

    const updates = {};
    if (text !== undefined) {
        updates.text = text;
    }
    if (roomId !== undefined) {
        updates.roomId = roomId;
    }

    const message = await msgCtrl.updateMessage(req.params.id, updates);
    if (!message) {
        return res.status(404).json({ error: 'not_found' });
    }
    res.json(message);
});

// Delete message
router.delete('/:id', async function(req, res) {
    const ok = await msgCtrl.deleteMessage(req.params.id);
    if (!ok) {
        return res.status(404).json({ error: 'not_found' });
    }
    res.status(204).send();
});

export default router;