const express = require('express');
const bodyParser = require('body-parser');
const MTree = require('./m-tree/mtree');
const dimensions = 2;

// Generator used to generate random points for the MTree
const Generator = require('./data/generator');

// Express app
const app = express();
app.use(bodyParser.json());

// Euclidean distance function used as the distance metric for the MTree
function euclideanDistance(a, b) {
    return Math.sqrt(a.reduce((acc, val, i) => acc + (val - b[i]) ** 2, 0));
}

// Create an MTree with the given dimensions and capacity, using the Euclidean distance
const mtree = new MTree(dimensions, 10, euclideanDistance);

// Generate 1000 random points
const generator = new Generator(dimensions);
const points = generator.generateMany(10000);

// Insert all points into the MTree
points.forEach(point => mtree.insert(point));

// Serve the index.html file
app.get('/', (req, res) => {
    res.sendFile(__dirname + '/index.html');
});

// Return the MTree
app.get('/tree', (req, res) => {
    res.send(JSON.parse(JSON.stringify(mtree, (key, value) => {
        if (key === 'parent' || key === 'mtree') return value && value.id;
        return value;
    })));
});

// Insert a point into the MTree
app.post('/insert', (req, res) => {
    const point = req.body.point;
    if (!point || !Array.isArray(point)) {
        return res.status(400).send('Invalid point');
    }
    mtree.insert(point);
    res.send('Point inserted');
});

// Perform a range query on the MTree
app.get('/rangeQuery', (req, res) => {
    const { queryPoint, radius } = req.query;
    if (!queryPoint || !radius || JSON.parse(queryPoint).length !== dimensions) {
        return res.status(400).send('Invalid query parameters');
    }
    console.time('mtreeRangeQuery');
    const result = mtree.rangeQuery(JSON.parse(queryPoint), parseFloat(radius));
    console.timeEnd('mtreeRangeQuery');
    console.log(result);

    console.time('sequentialSearch');
    const sequentialResult = points.filter(point => euclideanDistance(point, JSON.parse(queryPoint)) <= parseFloat(radius));
    console.timeEnd('sequentialSearch');
    //console.log(sequentialResult.map(point => "point:" + point +" distance: " + euclideanDistance(point, JSON.parse(queryPoint))));
    console.log(sequentialResult);

    /*const furthestPoint = points.reduce((furthest, point) => {
        const distance = euclideanDistance(point, mtree.root.entries[0].point);
        return distance > euclideanDistance(furthest, mtree.root.entries[0].point) ? point : furthest;
    }, points[0]);
    console.log(`distance between first routing entry centroid and furthest point: ${euclideanDistance(furthestPoint, mtree.root.entries[0].point)}`);
    console.log(`radius of first routing entry: ${furthestPoint, mtree.root.entries[0].radius}`);*/

    res.send(result);
});

// Perform a k-NN query on the MTree
app.get('/kNNQuery', (req, res) => {
    const { queryPoint, k } = req.query;
    if (!queryPoint || !k) {
        return res.status(400).send('Invalid query parameters');
    }
    const parsedQueryPoint = JSON.parse(queryPoint);
    const kInt = parseInt(k, 10);

    console.time('mtreeSearch');
    const result = mtree.kNNQuery(parsedQueryPoint, kInt);
    console.timeEnd('mtreeSearch');

    console.time('sequentialSearch');
    const sequentialResult = points.sort((a, b) => euclideanDistance(a, parsedQueryPoint) - euclideanDistance(b, parsedQueryPoint)).slice(0, kInt);
    console.timeEnd('sequentialSearch');

    console.log(sequentialResult);

    res.send(result);
});

// Start the server
app.listen(3000, () => {
    console.log('MTree API is running on port 3000');
});

// Recreate the MTree with the given dimensions
app.post('/recreate', (req, res) => {
    const { dimensions } = req.body;
    if (!dimensions || typeof dimensions !== 'number') {
        return res.status(400).send('Invalid dimensions');
    }
    mtree = new MTree(dimensions, 10);
    points = generator.generateMany(100);
    points.forEach(point => mtree.insert(point));
    res.send('MTree recreated');
});