import { action, comparer, observable, reaction, when } from "mobx";
import { autobind, createStorage } from "../../utils";
import { KubeObjectStore, KubeObjectStoreLoadingParams } from "../../kube-object.store";
import { Namespace, namespacesApi } from "../../api/endpoints/namespaces.api";
import { createPageParam } from "../../navigation";
import { apiManager } from "../../api/api-manager";
import { isAllowedResource } from "../../../common/rbac";
import { clusterStore, getHostedCluster } from "../../../common/cluster-store";

const storage = createStorage<string[]>("context_namespaces", []);

export const namespaceUrlParam = createPageParam<string[]>({
  name: "namespaces",
  isSystem: true,
  multiValues: true,
  get defaultValue() {
    return storage.get(); // initial namespaces coming from URL or local-storage (default)
  }
});

@autobind()
export class NamespaceStore extends KubeObjectStore<Namespace> {
  api = namespacesApi;

  @observable contextNs = observable.array<string>();
  @observable isReady = false;

  whenReady = when(() => this.isReady);

  constructor() {
    super();
    this.init();
  }

  private async init() {
    await clusterStore.whenLoaded;
    if (!getHostedCluster()) return;

    await getHostedCluster().whenReady; // wait for cluster-state from main
    await this.loadAll(); // auto-load allowed namespaces
    this.isReady = true;

    this.setContext(this.initNamespaces);

    return reaction(() => this.contextNs.toJS(), namespaces => {
      storage.set(namespaces); // save to local-storage
      namespaceUrlParam.set(namespaces, { replaceHistory: true }); // update url
    }, {
      fireImmediately: true,
      equals: comparer.identity,
    });
  }

  get allowedNamespaces(): string[] {
    return getHostedCluster().allowedNamespaces;
  }

  // FIXME: page/app reload doesn't restore previously selected namespaces
  get initNamespaces() {
    const allowedNamespaces = new Set(this.allowedNamespaces);
    const lastUsedNamespaces = new Set(storage.get());

    // remove previously saved, but currently disallowed namespaces
    lastUsedNamespaces.forEach(namespace => {
      if (!allowedNamespaces.has(namespace)) {
        lastUsedNamespaces.delete(namespace);
      }
    });

    // return previously saved and currently allowed namespaces
    if (lastUsedNamespaces.size) {
      return Array.from(lastUsedNamespaces);
    }
    // otherwise select "default" or first allowed namespace
    else {
      if (allowedNamespaces.has("default")) {
        return ["default"];
      } else if (allowedNamespaces.size) {
        return [Array.from(allowedNamespaces)[0]];
      }
    }

    return [];
  }

  getContextNamespaces(): string[] {
    let namespaces = this.contextNs.toJS();
    if (!namespaces.length) {
      return [...this.allowedNamespaces]; // show all namespaces when nothing selected
    }
    return namespaces;
  }

  /**
   * @deprecated
   */
  getContextParams() {
    return {
      namespaces: this.getContextNamespaces(),
    };
  }

  subscribe(apis = [this.api]) {
    const { accessibleNamespaces } = getHostedCluster();

    // if user has given static list of namespaces let's not start watches because watch adds stuff that's not wanted
    if (accessibleNamespaces.length > 0) {
      return Function; // no-op
    }

    return super.subscribe(apis);
  }

  async loadAll() {
    return super.loadAll({
      namespaces: this.allowedNamespaces,
    });
  }

  protected async loadItems({ isAdmin, namespaces }: KubeObjectStoreLoadingParams) {
    if (!isAllowedResource("namespaces")) {
      return namespaces.map(this.getDummyNamespace);
    }
    return Promise.all(namespaces.map(name => this.api.get({ name })));
  }

  protected getDummyNamespace(name: string) {
    return new Namespace({
      kind: "Namespace",
      apiVersion: "v1",
      metadata: {
        name,
        uid: "",
        resourceVersion: "",
        selfLink: `/api/v1/namespaces/${name}`
      }
    });
  }

  @action
  setContext(namespaces: string[]) {
    this.contextNs.replace(namespaces);
  }

  hasContext(namespace: string | string[]) {
    const context = Array.isArray(namespace) ? namespace : [namespace];

    return context.every(namespace => this.contextNs.includes(namespace));
  }

  @action
  toggleContext(namespace: string) {
    if (this.hasContext(namespace)) this.contextNs.remove(namespace);
    else this.contextNs.push(namespace);
  }

  @action
  async remove(item: Namespace) {
    await super.remove(item);
    this.contextNs.remove(item.getName());
  }
}

export const namespaceStore = new NamespaceStore();
apiManager.registerStore(namespaceStore);