const Schema = require('validate');
const isIp = require('is-ip');
const NodeS7 = require('nodes7');
const slowConnect = 5000;
function hop(obj, key) {
    return Object.prototype.hasOwnProperty.call(obj, key);
}
function pos_integer(n) {
    return parseInt(n) == n && n >= 0;
}
function is_ip(s) {
    return isIp.version(s) !== undefined;
}
const plc_schema = new Schema({
    ip: {
        type: String,
        required: true,
        use: { is_ip }
    },
    port: {
        type: Number,
        required: true,
        use: { pos_integer }
    },
    rack: {
        type: Number,
        required: true,
        use: { pos_integer }
    },
    slot: {
        type: Number,
        required: true,
        use: { pos_integer }
    }
});
const write_msg = new Schema({
    plc: plc_schema,
    payload: {
        variable: {
            type: String,
            required: true
        },
        value: {
            required: true
        }
    }
});
const read_payload = new Schema({
    variable: {
        type: String,
        required: true
    },
});
const read_msg = new Schema({
    plc: plc_schema,
    payload: read_payload
});
let s7nodes = {};
let s7promises = {};
let s7_read_write_queue = {}; // lista di {msg, resolve, reject}
let s7write_lock = {}; // si può scrivere
function s7node_from_plc(plc) {
    if (hop(s7nodes, plc.ip)) {
        // c'è già un oggetto connessione
        let s7obj = s7nodes[plc.ip];
        if (s7obj.isoConnectionState == 4) {
            // è connesso
            return new Promise((resolve, reject) => {
                resolve(s7obj)
            });
        } else {
            // non è connesso: rifare
            delete s7nodes[plc.ip];
            return s7node_from_plc(plc);
        }
    } else if (hop(s7promises, plc.ip)) {
        // sta già provando a connettersi ma bisogna aspettare la promise
        let prom = s7promises[plc.ip];
        return prom.then(() => {
            return s7nodes[plc.ip];
        }, () => {
            return s7node_from_plc(plc)
        });
    } else {
        let conn_opt = {
            host: plc.ip,
            port: plc.port,
            rack: plc.rack,
            slot: plc.slot,
            timeout: plc.timeout || 10000,
        };
        let nuovo = new NodeS7({
            silent: !plc.debug,
            debug: plc.debug || false,
        });
        let prom = new Promise(
            (resolve, reject) => {
                setTimeout(() => {
                    nuovo.initiateConnection(
                        conn_opt,
                        (arg1) => {
                            delete s7promises[plc.ip];
                            if (arg1 !== undefined) {
                                reject(arg1)
                            } else {
                                s7nodes[plc.ip] = nuovo;
                                resolve(nuovo)
                            }
                        })
                }, slowConnect);
            });
        s7promises[plc.ip] = prom;
        return prom;
    }
};
function s7_write(plc, obj, variable, value) {
    if (!hop(s7_read_write_queue, plc.ip)) {
        s7_read_write_queue[plc.ip] = [];
    }
    let queue_prom = {};
    let out = new Promise((resolve, reject) => {
        queue_prom.resolve = resolve;
        queue_prom.reject = reject;
    });
    s7_read_write_queue[plc.ip].push({ action: "write", variable, value, reject: queue_prom.reject, resolve: queue_prom.resolve });
    s7_read_write_loop(plc.ip, obj);
    return out;
}
function s7_read(plc, obj, variable) {
    if (!hop(s7_read_write_queue, plc.ip)) {
        s7_read_write_queue[plc.ip] = [];
    }
    let queue_prom = {};
    let out = new Promise((resolve, reject) => {
        queue_prom.resolve = resolve;
        queue_prom.reject = reject;
    });
    s7_read_write_queue[plc.ip].push({ action: "read", variable, reject: queue_prom.reject, resolve: queue_prom.resolve });
    s7_read_write_loop(plc.ip, obj);
    return out;
}
function s7_read_write_loop(ip, obj) {
    let q = s7_read_write_queue[ip];
    if (!hop(s7write_lock, ip)) {
        s7write_lock[ip] = false;
    }
    if (!s7write_lock[ip] && q.length > 0) {
        s7write_lock[ip] = true;
        let item = q.shift();
        if (item.action == "write") {
            let timeout_id = null;
            let callback = (e) => {
                if (e) {
                    // questa scrittura è fallita
                    item.reject(e);
                } else {
                    // questa scrittura è riuscita
                    item.resolve();
                }
                try {
                    clearTimeout(timeout_id);
                } catch (e) { }
                s7write_lock[ip] = false;
                s7_read_write_loop(ip, obj);
            };
            timeout_id = setTimeout(() => callback('timeout error'), 60000);
            obj.writeItems(item.variable, item.value, callback)
        } else if (item.action == "read") {
            obj.removeItems(undefined); // questo elimina tutte
            obj.addItems(item.variable);
            let timeout_id = null;
            let callback = (anyBadQualities, dataObject) => {
                if (anyBadQualities) {
                    console.error("Can't read variables (" + ip + "): bad qualities", anyBadQualities)
                    item.reject(anyBadQualities);
                } else {
                    // console.log("letti", dataObject);
                    item.resolve(dataObject[item.variable]);
                }
                try {
                    clearTimeout(timeout_id);
                } catch (e) { }
                s7write_lock[ip] = false;
                s7_read_write_loop(ip, obj);
            };
            timeout_id = setTimeout(() => callback('timeout error', null), 60000);
            obj.readAllItems(callback)
        }
    } else {
        // è già lockato o vuoto
    }
}
module.exports = function (RED) {
    function S7BriqWrite(config) {
        RED.nodes.createNode(this, config);
        var node = this;
        node.on('input', function (msg) {
            /*try {
                write_msg.assert(msg);
            } catch (e) {
                let errors = write_msg.validate(msg);
                node.error("Msg non valido: " + errors.map(x => x.path + ": " + x.message).join("\n"));
                return;
            }*/
            s7node_from_plc(msg.plc).then(s7conn => {
                return s7_write(msg.plc, s7conn, msg.payload.variable, msg.payload.value);
            }).then(() => {
                msg.result = "ok";
                node.send(msg);
                return true;
            }).catch(err => {
                msg.result = "err";
                msg.payload.err = "(" + msg.plc.ip + ") Impossibile scrivere il valore: " + err;
                node.send(msg);
            });
        });
    }
    RED.nodes.registerType("s7briqwrite", S7BriqWrite);

    function S7BriqRead(config) {
        RED.nodes.createNode(this, config);
        var node = this;
        node.on('input', function (msg) {
            // console.log("input", msg);
            /*try {
                read_msg.assert(msg);
            } catch (e) {
                let errors = read_msg.validate(msg);
                node.error("Msg " + JSON.stringify(msg) + " non valido: " + errors.map(x => x.path + ": " + x.message).join("\n"));
                return;
            }*/
            s7node_from_plc(msg.plc).then(s7conn => {
                return s7_read(msg.plc, s7conn, msg.payload.variable);
            }).then((out) => {
                msg.result = "ok";
                msg.payload.value = out;
                node.send(msg);
                return true;
            }).catch(err => {
                msg.result = "err";
                msg.payload.err = "(" + msg.plc.ip + ") Impossibile leggere il valore: " + err;
                node.send(msg);
            });
        });
    }
    RED.nodes.registerType("s7briqread", S7BriqRead);
}