Typed variables pt1: Use discriminated union for variable model (#52981)

* wip

* make diff easier to read

* Update template_srv getVariables to return new TypedVariableModel

* update VariableType to use the type from TypedVariableModel

* tidy things up

packages/grafana-data/src/types/templateVars.ts

@@ -1,7 +1,159 @@
-export type VariableType = 'query' | 'adhoc' | 'constant' | 'datasource' | 'interval' | 'textbox' | 'custom' | 'system';
+import { LoadingState } from './data';
+import { DataSourceRef } from './query';
 
+export type VariableType = TypedVariableModel['type'];
+
+/** @deprecated Use TypedVariableModel instead */
 export interface VariableModel {
   type: VariableType;
   name: string;
   label?: string;
 }
+
+export type TypedVariableModel =
+  | QueryVariableModel
+  | AdHocVariableModel
+  | ConstantVariableModel
+  | DataSourceVariableModel
+  | IntervalVariableModel
+  | TextBoxVariableModel
+  | CustomVariableModel
+  | UserVariableModel
+  | OrgVariableModel
+  | DashboardVariableModel;
+
+export enum VariableRefresh {
+  never, // removed from the UI
+  onDashboardLoad,
+  onTimeRangeChanged,
+}
+
+export enum VariableSort {
+  disabled,
+  alphabeticalAsc,
+  alphabeticalDesc,
+  numericalAsc,
+  numericalDesc,
+  alphabeticalCaseInsensitiveAsc,
+  alphabeticalCaseInsensitiveDesc,
+}
+
+export enum VariableHide {
+  dontHide,
+  hideLabel,
+  hideVariable,
+}
+
+export interface AdHocVariableFilter {
+  key: string;
+  operator: string;
+  value: string;
+  condition: string;
+}
+
+export interface AdHocVariableModel extends BaseVariableModel {
+  type: 'adhoc';
+  datasource: DataSourceRef | null;
+  filters: AdHocVariableFilter[];
+}
+
+export interface VariableOption {
+  selected: boolean;
+  text: string | string[];
+  value: string | string[];
+  isNone?: boolean;
+}
+
+export interface IntervalVariableModel extends VariableWithOptions {
+  type: 'interval';
+  auto: boolean;
+  auto_min: string;
+  auto_count: number;
+  refresh: VariableRefresh;
+}
+
+export interface CustomVariableModel extends VariableWithMultiSupport {
+  type: 'custom';
+}
+
+export interface DataSourceVariableModel extends VariableWithMultiSupport {
+  type: 'datasource';
+  regex: string;
+  refresh: VariableRefresh;
+}
+
+export interface QueryVariableModel extends VariableWithMultiSupport {
+  type: 'query';
+  datasource: DataSourceRef | null;
+  definition: string;
+  sort: VariableSort;
+  queryValue?: string;
+  query: any;
+  regex: string;
+  refresh: VariableRefresh;
+}
+
+export interface TextBoxVariableModel extends VariableWithOptions {
+  type: 'textbox';
+  originalQuery: string | null;
+}
+
+export interface ConstantVariableModel extends VariableWithOptions {
+  type: 'constant';
+}
+
+export interface VariableWithMultiSupport extends VariableWithOptions {
+  multi: boolean;
+  includeAll: boolean;
+  allValue?: string | null;
+}
+
+export interface VariableWithOptions extends BaseVariableModel {
+  current: VariableOption;
+  options: VariableOption[];
+  query: string;
+}
+
+export interface DashboardProps {
+  name: string;
+  uid: string;
+  toString: () => string;
+}
+
+export interface DashboardVariableModel extends SystemVariable<DashboardProps> {}
+
+export interface OrgProps {
+  name: string;
+  id: number;
+  toString: () => string;
+}
+
+export interface OrgVariableModel extends SystemVariable<OrgProps> {}
+
+export interface UserProps {
+  login: string;
+  id: number;
+  email?: string;
+  toString: () => string;
+}
+
+export interface UserVariableModel extends SystemVariable<UserProps> {}
+
+export interface SystemVariable<TProps extends { toString: () => string }> extends BaseVariableModel {
+  type: 'system';
+  current: { value: TProps };
+}
+
+export interface BaseVariableModel extends VariableModel {
+  name: string;
+  label?: string;
+  id: string;
+  rootStateKey: string | null;
+  global: boolean;
+  hide: VariableHide;
+  skipUrlSync: boolean;
+  index: number;
+  state: LoadingState;
+  error: any | null;
+  description: string | null;
+}

packages/grafana-runtime/src/services/templateSrv.ts

@@ -1,4 +1,4 @@
-import { VariableModel, ScopedVars, TimeRange } from '@grafana/data';
+import { ScopedVars, TimeRange, TypedVariableModel } from '@grafana/data';
 
 /**
  * Via the TemplateSrv consumers get access to all the available template variables
@@ -11,7 +11,7 @@ export interface TemplateSrv {
   /**
    * List the dashboard variables
    */
-  getVariables(): VariableModel[];
+  getVariables(): TypedVariableModel[];
 
   /**
    * Replace the values within the target string.  See also {@link InterpolateFunction}