///
/// Copyright 2015-2026 Micro Focus or one of its affiliates.
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///      http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///

import { Injectable, OnDestroy } from '@angular/core';
import { Subject } from 'rxjs';
import { ConduitSubject } from './conduit-subject';
import { ConduitEvent } from './interfaces/conduit-event';
import { ConduitMetadata } from './interfaces/conduit-metadata';
import { ConduitProperties } from './interfaces/conduit-properties';

@Injectable()
export class ConduitZone implements OnDestroy {
  /** Create a global subject store */
  static subjects: ConduitSubject[] = [];

  /** Expose an event stream of new values */
  static events = new Subject<ConduitEvent>();

  /** Store the zone name */
  private _zoneId: string;

  ngOnDestroy(): void {
    // find all conduit subjects that are part of this zone
    ConduitZone.subjects
      .filter(_subject => _subject.zoneId === this._zoneId)
      .forEach(_subject => this.unregisterConduit(_subject.conduit));
  }

  /** Store reference to the repository and begin watching for and emitting changes */
  registerConduit(conduit: ConduitMetadata): void {
    ConduitZone.subjects.push(new ConduitSubject(conduit, this, this._zoneId));
  }

  /** Destroy a conduit */
  unregisterConduit(conduit: ConduitMetadata): void {
    const subject = this.getConduitSubject(conduit.subject);

    if (subject) {
      // remove the subject from the internal list of conduit subjects
      ConduitZone.subjects = ConduitZone.subjects.filter(_subject => _subject !== subject);

      // perform all unsubscriptions
      subject.destroy();
    }
  }

  /** Provide the zone with an ID */
  setZoneId(zoneId: string): void {
    this._zoneId = zoneId;
  }

  /** Emit a value to all zones for checking */
  emit(event: ConduitEvent): void {
    ConduitZone.events.next(event);
  }

  /** Retrieve a conduit subsject object from the rxjs subject */
  getConduitSubject(subject: Subject<void>): ConduitSubject | null {
    return ConduitZone.subjects.find(_subject => _subject.conduit.subject === subject);
  }

  /** Get all subjects from all zones */
  getSubjects(): ConduitSubject[] {
    return ConduitZone.subjects;
  }

  /** Alter the properties of a conduit dynamically */
  setConduitProperties(subject: Subject<string>, properties: Partial<ConduitProperties>): void {
    // find the conduit with the matching subject
    const conduitSubject = this.getSubjects().find(
      _conduit => _conduit.conduit.subject === subject
    );

    // if a match was found update the properties
    if (conduitSubject) {
      // update each specified property
      for (const prop in properties) {
        conduitSubject.conduit[prop] = properties[prop];
      }
    }
  }

  /** Programmatically create a conduit at runtime */
  createConduit(subject: Subject<void>, properties: ConduitProperties): void {
    // register the conduit with the zone
    this.registerConduit({ ...properties, subject });
  }

  /** Register all conduits in a component */

  registerConduits(component: any): void {
    if (Array.isArray(component._conduits)) {
      component._conduits.forEach((conduit: ConduitMetadata) =>
        this.registerConduit({ ...conduit, subject: component[conduit.propertyKey] })
      );
    }
  }

  /** Register all conduits in a component */

  unregisterConduits(component: any): void {
    if (Array.isArray(component._conduits)) {
      component._conduits.forEach((conduit: ConduitMetadata) => this.unregisterConduit(conduit));
    }
  }

  /** Return the global event stream */
  getEvents(): Subject<ConduitEvent> {
    return ConduitZone.events;
  }
}