/**
 * @module node-opcua-client-private
 */
// tslint:disable:no-empty
import { EventEmitter } from "node:events";
import { assert } from "node-opcua-assert";
import { coerceTimestampsToReturn, type DataValue, TimestampsToReturn } from "node-opcua-data-value";
import { checkDebugFlag, make_debugLog, make_warningLog } from "node-opcua-debug";
import { NodeId, resolveNodeId } from "node-opcua-nodeid";
import { MonitoringMode, type MonitoringParametersOptions } from "node-opcua-service-subscription";
import type { Callback, ErrorCallback, StatusCode } from "node-opcua-status-code";
import type { MonitoredItemModifyResult, ReadValueIdOptions } from "node-opcua-types";
import type { ClientMonitoredItemBase } from "../client_monitored_item_base";
import { ClientMonitoredItemGroup } from "../client_monitored_item_group";
import { type ClientMonitoredItemBaseEx, ClientMonitoredItemToolbox } from "../client_monitored_item_toolbox";
import type { ClientSubscription } from "../client_subscription";
import { ClientMonitoredItemImpl } from "./client_monitored_item_impl";
import type { ClientSubscriptionImpl } from "./client_subscription_impl";


const warningLog = make_warningLog(__filename);

/**
 * ClientMonitoredItemGroup
 * event:
 *    "initialized"
 *    "err"
 *    "changed"
 *
 *  note: this.monitoringMode = subscription_service.MonitoringMode.Reporting;
 */
export class ClientMonitoredItemGroupImpl extends EventEmitter implements ClientMonitoredItemGroup {
    public readonly monitoredItems: ClientMonitoredItemBaseEx[];
    private readonly subscription: ClientSubscription;
    private timestampsToReturn: TimestampsToReturn;
    private readonly monitoringMode: MonitoringMode;

    constructor(
        subscription: ClientSubscription,
        itemsToMonitor: ReadValueIdOptions[],
        monitoringParameters: MonitoringParametersOptions,
        timestampsToReturn: TimestampsToReturn,
        monitoringMode: MonitoringMode = MonitoringMode.Reporting
    ) {
        super();
        assert(Array.isArray(itemsToMonitor));
        // Try to resolve the nodeId and fail fast if we can't.
        itemsToMonitor.forEach((itemToMonitor: ReadValueIdOptions) => {
            itemToMonitor.nodeId = resolveNodeId(itemToMonitor.nodeId || NodeId.nullNodeId);
        });

        timestampsToReturn = coerceTimestampsToReturn(timestampsToReturn);

        assert(subscription.constructor.name === "ClientSubscriptionImpl");

        this.subscription = subscription;
        this.timestampsToReturn = timestampsToReturn;
        this.monitoringMode = monitoringMode;

        this.monitoredItems = itemsToMonitor.map(
            (itemToMonitor) =>
                new ClientMonitoredItemImpl(
                    subscription,
                    itemToMonitor,
                    monitoringParameters,
                    TimestampsToReturn.Both,
                    this.monitoringMode
                )
        );
    }

    public toString(): string {
        let ret = "ClientMonitoredItemGroup : \n";
        ret +=
            "itemsToMonitor:       = [\n " +
            this.monitoredItems
                .slice(0, 10)
                .map((monitoredItem: ClientMonitoredItemBase) =>
                    //  monitoredItem.itemToMonitor.toString() +
                    monitoredItem.toString()
                )
                .join("\n") +
            "\n];\n";
        ret += `timestampsToReturn:   ${TimestampsToReturn[this.timestampsToReturn]}\n`;
        ret += `monitoringMode        ${MonitoringMode[this.monitoringMode]}`;
        return ret;
    }

    /**
     * remove the MonitoredItem from its subscription
     */
    public async terminate(): Promise<void>;
    public terminate(done: ErrorCallback): void;
    public terminate(...args: any[]): any {
        const done = args[0] as ErrorCallback;
        assert(!done || typeof done === "function");
        const subscription = this.subscription as ClientSubscriptionImpl;
        subscription._delete_monitored_items(this.monitoredItems, (err?: Error) => {
            subscription._removeGroup(this);

            if (done) {
                done(err);
            }
        });
    }

    // tslint:disable:unified-signatures
    /**

     */
    public async modify(parameters: MonitoringParametersOptions): Promise<MonitoredItemModifyResult>;
    public async modify(parameters: MonitoringParametersOptions, timestampsToReturn: TimestampsToReturn): Promise<MonitoredItemModifyResult>;
    public modify(parameters: MonitoringParametersOptions, callback: Callback<MonitoredItemModifyResult>): void;
    public modify(
        parameters: MonitoringParametersOptions,
        timestampsToReturn: TimestampsToReturn | null,
        callback: Callback<MonitoredItemModifyResult>
    ): void;
    public modify(...args: any[]): any {
        if (args.length === 2) {
            return this.modify(args[0], null, args[1]);
        }
        const parameters = args[0] as MonitoringParametersOptions;
        const timestampsToReturn = args[1] as TimestampsToReturn;
        const callback = args[2] as ErrorCallback;
        this.timestampsToReturn = timestampsToReturn || this.timestampsToReturn;
        ClientMonitoredItemToolbox._toolbox_modify(
            this.subscription,
            this.monitoredItems,
            parameters,
            this.timestampsToReturn,
            (err: Error | null) => {
                callback(err ? err : undefined);
            }
        );
    }

    public async setMonitoringMode(monitoringMode: MonitoringMode): Promise<StatusCode>;
    public setMonitoringMode(monitoringMode: MonitoringMode, callback: Callback<StatusCode>): void;
    public setMonitoringMode(...args: any[]): any {
        const monitoringMode = args[0] as MonitoringMode;
        const callback = args[1] as Callback<StatusCode>;
        ClientMonitoredItemToolbox._toolbox_setMonitoringMode(
            this.subscription,
            this.monitoredItems,
            monitoringMode,
            (err: Error | null, statusCode?: StatusCode[]) => {
                // todo fix me
                callback(err, statusCode![0]);
            }
        );
    }

    /**
     * @internal

     * Creates the monitor item (monitoring mode = Reporting)
     * @private
     */
    public _monitor(done: ErrorCallback): void {
        assert(done === undefined || typeof done === "function");
        assert(this.subscription, "expecting a valid subscription");
        this.monitoredItems.forEach((monitoredItem: ClientMonitoredItemBase, index: number) => {
            monitoredItem.on("changed", (dataValue: DataValue) => {
                /**
                 * Notify the observers that a group MonitoredItem value has changed on the server side.
                 * @event changed
                 * @param monitoredItem
                 * @param value
                 * @param index
                 */
                try {
                    this.emit("changed", monitoredItem, dataValue, index);
                } catch (err) {
                    warningLog(
                        `[NODE-OPCUA-W20] the monitoredItem.on('changed') handler has raised an exception.
error message : ${(<Error>err).message}
Please investigate the code of the event handler function to fix the error.`
                    );
                }
            });
        });

        ClientMonitoredItemToolbox._toolbox_monitor(
            this.subscription,
            this.timestampsToReturn,
            this.monitoredItems,
            (err?: Error) => {
                if (err) {
                    this._terminate_and_emit(err);
                } else {
                    this.emit("initialized");
                    // set the event handler
                    const priv_subscription = this.subscription as ClientSubscriptionImpl;
                    priv_subscription._add_monitored_items_group(this);
                }
                if (done) {
                    done(err);
                }
            }
        );
    }
    public _terminate_and_emit(err?: Error): void {
        assert(!(this as any)._terminated);
        (this as any)._terminated = true;
        if (err) {
            this.emit("err", err.message);
        }
        this.emit("terminated", err);
    }
}

// tslint:disable:no-var-requires
// tslint:disable:max-line-length
import { withCallback } from "thenify-ex";

const opts = { multiArgs: false };

ClientMonitoredItemGroupImpl.prototype.terminate = withCallback(ClientMonitoredItemGroupImpl.prototype.terminate);
ClientMonitoredItemGroupImpl.prototype.setMonitoringMode = withCallback(ClientMonitoredItemGroupImpl.prototype.setMonitoringMode);
ClientMonitoredItemGroupImpl.prototype.modify = withCallback(ClientMonitoredItemGroupImpl.prototype.modify);

ClientMonitoredItemGroup.create = (
    subscription: ClientSubscription,
    itemsToMonitor: ReadValueIdOptions[],
    monitoringParameters: MonitoringParametersOptions,
    timestampsToReturn: TimestampsToReturn
) => {
    const monitoredItemGroup = new ClientMonitoredItemGroupImpl(
        subscription,
        itemsToMonitor,
        monitoringParameters,
        timestampsToReturn
    );
    const priv_subscription = subscription as ClientSubscriptionImpl;
    priv_subscription._wait_for_subscription_to_be_ready((err?: Error) => {
        if (err) {
            return;
        }
        monitoredItemGroup._monitor((_err1?: Error) => {
            /** */
        });
    });
    return monitoredItemGroup;
};