/*
    Hello World - the launcher

    Run this script (for example with the Serverless tool, or from Code
    Studio). It sends hello_world.job.agi to every usable node of the
    cluster, pinning one copy to each node with the "nodes" option, waits
    for the replies and returns them as one JSON document:

        {
            "cluster": "Home Lab",
            "replies": [ {message, node: {...}, health: {...}}, ... ],
            "skipped": [ {node, reason}, ... ]
        }

    Keep hello_world.job.agi in the same folder as this file; the script
    path below is relative to this launcher.
*/

requirelib("cluster");

//How long to wait for each node before giving up on it, in seconds
var WAIT_SECONDS = 60;

function main() {
    if (!cluster.inCluster()) {
        return { error: "This node is not part of a cluster. Create or join one in System Settings > Cluster Settings." };
    }

    var submitted = [];
    var skipped = [];

    //Send one job to each node that can take work right now
    var nodes = cluster.nodes();
    for (var i = 0; i < nodes.length; i++) {
        var n = nodes[i];
        if (n.state !== "ONLINE" && n.state !== "DEGRADED") {
            skipped.push({ node: n.name, reason: "node is " + n.state.toLowerCase() });
            continue;
        }
        try {
            var id = cluster.jobs.submit({
                name: "Hello World on " + n.name,
                script: "hello_world.job.agi",
                nodes: [n.id],      //run on this node and nowhere else
                timeout: WAIT_SECONDS
            });
            submitted.push({ node: n.name, id: id });
        } catch (e) {
            skipped.push({ node: n.name, reason: String(e) });
        }
    }

    //The jobs run in parallel; collect the answers one by one
    var replies = [];
    for (var j = 0; j < submitted.length; j++) {
        var rec;
        try {
            rec = cluster.jobs.wait(submitted[j].id, WAIT_SECONDS);
        } catch (e) {
            //wait() throws when the job is still not finished
            rec = cluster.jobs.status(submitted[j].id);
        }
        if (rec.state.status === "succeeded") {
            replies.push(rec.state.output);
        } else {
            skipped.push({
                node: submitted[j].node,
                reason: "job " + rec.state.status + (rec.state.error ? ": " + rec.state.error : (rec.state.reason ? ": " + rec.state.reason : ""))
            });
        }
    }

    return {
        cluster: cluster.status().cluster.name,
        replies: replies,
        skipped: skipped
    };
}

sendJSONResp(JSON.stringify(main()));