/**
 * Copyright (c) 2020-present, Goldman Sachs
 *
 * 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 {
  type GeneratorFn,
  ActionState,
  LogEvent,
  assertErrorThrown,
  guaranteeNonNullable,
  isNonNullable,
} from '@finos/legend-shared';
import { action, computed, flow, makeObservable, observable } from 'mobx';
import { LEGEND_STUDIO_APP_EVENT } from '../__lib__/LegendStudioEvent.js';
import {
  type Showcase,
  type ShowcaseMetadata,
  ShowcaseRegistryServerClient,
  type ShowcaseTextSearchMatch,
  type ShowcaseTextSearchResult,
} from '@finos/legend-server-showcase';
import type { LegendStudioApplicationStore } from './LegendStudioBaseStore.js';
import {
  ApplicationExtensionState,
  DEFAULT_TYPEAHEAD_SEARCH_MINIMUM_SEARCH_LENGTH,
  type GenericLegendApplicationStore,
} from '@finos/legend-application';
import type { TreeData, TreeNodeData } from '@finos/legend-art';
import { DIRECTORY_PATH_DELIMITER } from '@finos/legend-graph';
import { SHOWCASE_MANAGER_VIRTUAL_ASSISTANT_TAB_KEY } from '../components/extensions/Core_LegendStudioApplicationPlugin.js';
import { LegendStudioTelemetryHelper } from '../__lib__/LegendStudioTelemetryHelper.js';

export enum SHOWCASE_MANAGER_VIEW {
  EXPLORER = 'EXPLORER',
  SEARCH = 'SEARCH',
}

export enum SHOWCASE_MANAGER_SEARCH_CATEGORY {
  SHOWCASE = 'SHOWCASE',
  CODE = 'CODE',
}

export class ShowcasesExplorerTreeNodeData implements TreeNodeData {
  isOpen?: boolean | undefined;
  id: string;
  label: string;
  parentId?: string | undefined;
  childrenIds: string[] = [];
  metadata?: ShowcaseMetadata | undefined;

  constructor(
    id: string,
    label: string,
    parentId: string | undefined,
    metadata?: ShowcaseMetadata | undefined,
  ) {
    this.id = id;
    this.label = label;
    this.parentId = parentId;
    this.metadata = metadata;
  }
}

const buildShowcasesExplorerTreeNode = (
  showcase: ShowcaseMetadata,
  path: string,
  parentId: string | undefined,
  nodes: Map<string, ShowcasesExplorerTreeNodeData>,
  rootIds: string[],
): ShowcasesExplorerTreeNodeData => {
  let node: ShowcasesExplorerTreeNodeData;
  const idx = path.indexOf(DIRECTORY_PATH_DELIMITER);
  if (idx === -1) {
    // showcase node
    node = new ShowcasesExplorerTreeNodeData(
      `${parentId ? `${parentId}${DIRECTORY_PATH_DELIMITER}` : ''}${path}`,
      showcase.title,
      parentId,
      showcase,
    );
  } else {
    // directory node
    const directoryName = path.substring(0, idx);
    const directoryNodeId = `${
      parentId ? `${parentId}${DIRECTORY_PATH_DELIMITER}` : ''
    }${directoryName}`;
    node =
      nodes.get(directoryNodeId) ??
      new ShowcasesExplorerTreeNodeData(
        directoryNodeId,
        directoryName,
        undefined,
        undefined,
      );
  }
  nodes.set(node.id, node);
  if (!parentId && !rootIds.includes(node.id)) {
    rootIds.push(node.id);
  }
  if (parentId) {
    const parentNode = nodes.get(parentId);
    if (parentNode) {
      if (!parentNode.childrenIds.includes(node.id)) {
        parentNode.childrenIds.push(node.id);
      }
    }
  }
  if (idx !== -1) {
    buildShowcasesExplorerTreeNode(
      showcase,
      path.substring(idx + 1),
      node.id,
      nodes,
      rootIds,
    );
  }
  return node;
};

const buildShowcasesExplorerTreeData = (
  showcases: ShowcaseMetadata[],
): TreeData<ShowcasesExplorerTreeNodeData> => {
  const rootIds: string[] = [];
  const nodes = new Map<string, ShowcasesExplorerTreeNodeData>();
  showcases.forEach((showcase) =>
    buildShowcasesExplorerTreeNode(
      showcase,
      showcase.path,
      undefined,
      nodes,
      rootIds,
    ),
  );
  return { rootIds, nodes };
};

export type ShowcaseTextSearchMatchResult = {
  match: ShowcaseTextSearchMatch;
  showcase: ShowcaseMetadata;
};

export class ShowcaseManagerState extends ApplicationExtensionState {
  private static readonly IDENTIFIER = 'showcase-manager';

  readonly applicationStore: LegendStudioApplicationStore;
  readonly initState = ActionState.create();
  readonly fetchShowcaseState = ActionState.create();
  readonly textSearchState = ActionState.create();

  private readonly showcaseServerClient?: ShowcaseRegistryServerClient;

  allShowcases: ShowcaseMetadata[] | undefined;
  currentShowcase?: Showcase | undefined;
  showcaseLineToScroll?: number | undefined;

  currentView = SHOWCASE_MANAGER_VIEW.EXPLORER;
  explorerTreeData?: TreeData<ShowcasesExplorerTreeNodeData> | undefined;

  searchText = '';
  showcaseSearchResults?: ShowcaseMetadata[] | undefined;
  textSearchResults?: ShowcaseTextSearchMatchResult[] | undefined;
  currentSearchCaterogy = SHOWCASE_MANAGER_SEARCH_CATEGORY.SHOWCASE;

  constructor(applicationStore: LegendStudioApplicationStore) {
    super();

    makeObservable(this, {
      allShowcases: observable,
      currentShowcase: observable,
      currentView: observable,
      explorerTreeData: observable.ref,
      searchText: observable,
      textSearchResults: observable.ref,
      showcaseSearchResults: observable.ref,
      currentSearchCaterogy: observable,
      showcaseLineToScroll: observable,
      nonDevShowcases: computed,
      logOpenManager: action,
      setCurrentView: action,
      closeShowcase: action,
      setExplorerTreeData: action,
      setSearchText: action,
      resetSearch: action,
      setCurrentSearchCategory: action,
      search: flow,
      initialize: flow,
      openShowcase: flow,
    });

    this.applicationStore = applicationStore;

    if (this.applicationStore.config.showcaseServerUrl) {
      this.showcaseServerClient = new ShowcaseRegistryServerClient({
        baseUrl: this.applicationStore.config.showcaseServerUrl,
      });
    }
  }

  override get INTERNAL__identifierKey(): string {
    return ShowcaseManagerState.IDENTIFIER;
  }

  get nonDevShowcases(): ShowcaseMetadata[] {
    return this.allShowcases?.filter((showcase) => !showcase.development) ?? [];
  }

  static retrieveNullableState(
    applicationStore: GenericLegendApplicationStore,
  ): ShowcaseManagerState | undefined {
    return applicationStore.extensionStates.find((extensionState) => {
      if (
        /**
         * In development mode, when we make changes in certain areas like utils or base states, the following `instanceof`
         * check will fail as if there were multiple copies of the classes with the same name, this could be caused by either
         * React `fast-refresh` or `webpack HMR`; we didn't have time to really do a thorough debug here, as such,
         * we will just do a simple key check to match the right state to bypass the problem for development mode.
         */
        // eslint-disable-next-line no-process-env
        process.env.NODE_ENV === 'development'
      ) {
        return (
          extensionState.INTERNAL__identifierKey ===
          ShowcaseManagerState.IDENTIFIER
        );
      }
      return extensionState instanceof ShowcaseManagerState;
    }) as ShowcaseManagerState;
  }

  static retrieveState(
    applicationStore: GenericLegendApplicationStore,
  ): ShowcaseManagerState {
    return guaranteeNonNullable(
      ShowcaseManagerState.retrieveNullableState(applicationStore),
      `Can't find showcase manager state: make sure it is added as an editor extension state`,
    );
  }

  get isEnabled(): boolean {
    return Boolean(this.showcaseServerClient);
  }

  private get client(): ShowcaseRegistryServerClient {
    return guaranteeNonNullable(
      this.showcaseServerClient,
      `Showcase registry server client is not configured`,
    );
  }

  setCurrentView(val: SHOWCASE_MANAGER_VIEW): void {
    this.currentView = val;
  }

  *openShowcase(
    metadata: ShowcaseMetadata,
    showcaseLineToScroll?: number | undefined,
  ): GeneratorFn<void> {
    this.fetchShowcaseState.inProgress();

    try {
      const showcase = (yield this.client.getShowcase(
        metadata.path,
      )) as Showcase;
      this.currentShowcase = showcase;
      LegendStudioTelemetryHelper.logEvent_ShowcaseManagerShowcaseProjectLaunch(
        this.applicationStore.telemetryService,
        {
          showcasePath: showcase.path,
        },
      );
      this.showcaseLineToScroll = showcaseLineToScroll;
      this.fetchShowcaseState.pass();
    } catch (error) {
      assertErrorThrown(error);
      this.applicationStore.logService.error(
        LogEvent.create(LEGEND_STUDIO_APP_EVENT.SHOWCASE_MANAGER_FAILURE),
        error,
      );
      this.fetchShowcaseState.fail();
    }
  }

  logOpenManager(): void {
    if (this.allShowcases) {
      const report = {
        showcasesTotalCount: this.allShowcases.length,
        showcasesDevelopmentCount: this.nonDevShowcases.length,
      };
      LegendStudioTelemetryHelper.logEvent_ShowcaseManagerLaunch(
        this.applicationStore.telemetryService,
        report,
      );
    }
  }

  closeShowcase(): void {
    this.currentShowcase = undefined;
    this.showcaseLineToScroll = undefined;
  }

  setExplorerTreeData(val: TreeData<ShowcasesExplorerTreeNodeData>): void {
    this.explorerTreeData = val;
  }

  setSearchText(val: string): void {
    this.searchText = val;
  }

  resetSearch(): void {
    this.searchText = '';
    this.textSearchResults = undefined;
    this.showcaseSearchResults = undefined;
  }

  setCurrentSearchCategory(val: SHOWCASE_MANAGER_SEARCH_CATEGORY): void {
    this.currentSearchCaterogy = val;
  }

  *initialize(): GeneratorFn<void> {
    if (!this.isEnabled || this.initState.isInProgress) {
      return;
    }
    this.initState.inProgress();

    try {
      this.allShowcases =
        (yield this.client.getShowcases()) as ShowcaseMetadata[];
      this.explorerTreeData = buildShowcasesExplorerTreeData(
        this.nonDevShowcases,
      );
      // expand all the root nodes by default
      this.explorerTreeData.rootIds.forEach((rootId) => {
        const rootNode = this.explorerTreeData?.nodes.get(rootId);
        if (rootNode) {
          rootNode.isOpen = true;
        }
      });
      this.setExplorerTreeData({ ...this.explorerTreeData });
      this.initState.pass();
    } catch (error) {
      assertErrorThrown(error);
      this.applicationStore.logService.error(
        LogEvent.create(LEGEND_STUDIO_APP_EVENT.SHOWCASE_MANAGER_FAILURE),
        error,
      );
      this.initState.fail();
    }
  }

  *search(): GeneratorFn<void> {
    if (
      this.textSearchState.isInProgress ||
      this.searchText.length <= DEFAULT_TYPEAHEAD_SEARCH_MINIMUM_SEARCH_LENGTH
    ) {
      return;
    }
    this.textSearchState.inProgress();

    try {
      const result = (yield this.client.search(
        this.searchText,
      )) as ShowcaseTextSearchResult;
      this.textSearchResults = result.textMatches
        .map((match) => {
          const matchingShowcase = this.nonDevShowcases.find(
            (showcase) => showcase.path === match.path,
          );
          if (matchingShowcase) {
            return {
              showcase: matchingShowcase,
              match,
            };
          }
          return undefined;
        })
        .filter(isNonNullable);
      this.showcaseSearchResults = result.showcases
        .map((showcasePath) =>
          this.nonDevShowcases.find(
            (showcase) => showcase.path === showcasePath,
          ),
        )
        .filter(isNonNullable);
    } catch (error) {
      assertErrorThrown(error);
      this.applicationStore.logService.error(
        LogEvent.create(LEGEND_STUDIO_APP_EVENT.SHOWCASE_MANAGER_FAILURE),
        error,
      );
    } finally {
      this.textSearchState.complete();
    }
  }
}

export const openShowcaseManager = (
  applicationStore: LegendStudioApplicationStore,
): void => {
  const showcaseManagerState =
    ShowcaseManagerState.retrieveNullableState(applicationStore);
  if (showcaseManagerState?.isEnabled) {
    applicationStore.assistantService.setIsHidden(false);
    applicationStore.assistantService.setIsOpen(true);
    applicationStore.assistantService.setIsPanelMaximized(true);
    applicationStore.assistantService.setSelectedTab(
      SHOWCASE_MANAGER_VIRTUAL_ASSISTANT_TAB_KEY,
    );
    showcaseManagerState.logOpenManager();
  }
};