// These globals will be injected into a page that will use them.
/* eslint no-unused-vars: "off" */

// This is quite old and I don't want to waste too much time here. We probably
// should stop using this altogether as the examples should be easy and
// straightforward to understand and this only obscures it.
/* eslint require-jsdoc: "off" */

/* global Alea:false seededRandom:true */

/**
 * Created by Alex on 5/20/2015.
 *
 * @remarks
 * This depends on Alea from https://unpkg.com/alea@1.0.0/alea.js.
 */

/**
 * @param path
 * @param success
 * @param error
 */
function loadJSON(path, success, error) {
    const xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function () {
        if (xhr.readyState === 4) {
            if (xhr.status === 200) {
                success(JSON.parse(xhr.responseText));
            } else {
                error(xhr);
            }
        }
    };
    xhr.open("GET", path, true);
    xhr.send();
}

/**
 * @param nodeCount
 */
function getScaleFreeNetwork(nodeCount) {
    const nodes = [];
    const edges = [];
    const connectionCount = [];
   
    // Add child nodes, change styles…
    // randomly create some nodes and edges
    for (let i = 0; i < nodeCount; i++) {
        nodes.push({
            id: i,
            label: String(i),
        });

        connectionCount[i] = 0;

        // create edges in a scale-free-network way
        if (i == 1) {
            const from = i;
            const to = 0;
            edges.push({
                from: from,
                to: to,
            });
            connectionCount[from]++;
            connectionCount[to]++;
        } else if (i > 1) {
            const conn = edges.length * 2;
            const rand = Math.floor(seededRandom() * conn);
            let cum = 0;
            let j = 0;
            while (j < connectionCount.length && cum < rand) {
                cum += connectionCount[j];
                j++;
            }

            const from = i;
            const to = j;
            edges.push({
                from: from,
                to: to,
            });
            connectionCount[from]++;
            connectionCount[to]++;
        }
    }

    return { nodes: nodes, edges: edges };
}

seededRandom = Alea("SEED");

/**
 * @param nodeCount
 */
function getScaleFreeNetworkSeeded(nodeCount) {
    const nodes = [];
    const edges = [];
    const connectionCount = [];
    let edgesId = 0;

    // randomly create some nodes and edges
    for (let i = 0; i < nodeCount; i++) {
        nodes.push({
            id: i,
            label: String(i),
            title: element(i),
        });

        connectionCount[i] = 0;

        // create edges in a scale-free-network way
        if (i == 1) {
            const from = i;
            const to = 0;
            edges.push({
                id: edgesId++,
                from: from,
                to: to,
            });
            connectionCount[from]++;
            connectionCount[to]++;
        } else if (i > 1) {
            const conn = edges.length * 2;
            const rand = Math.floor(seededRandom() * conn);
            let cum = 0;
            let j = 0;
            while (j < connectionCount.length && cum < rand) {
                cum += connectionCount[j];
                j++;
            }

            const from = i;
            const to = j;
            edges.push({
                id: edgesId++,
                from: from,
                to: to,
            });
            connectionCount[from]++;
            connectionCount[to]++;
        }
    }

    return { nodes: nodes, edges: edges };

}