Make find as a clean architecture

src/content/usecases/FindUseCase.ts

@@ -0,0 +1,81 @@
+import FindPresenter, { FindPresenterImpl } from '../presenters/FindPresenter';
+import FindRepository, { FindRepositoryImpl }
+  from '../repositories/FindRepository';
+import FindClient, { FindClientImpl } from '../client/FindClient';
+import ConsoleClient, { ConsoleClientImpl } from '../client/ConsoleClient';
+
+export default class FindUseCase {
+  private presenter: FindPresenter;
+
+  private repository: FindRepository;
+
+  private client: FindClient;
+
+  private consoleClient: ConsoleClient;
+
+  constructor({
+    presenter = new FindPresenterImpl() as FindPresenter,
+    repository = new FindRepositoryImpl(),
+    client = new FindClientImpl(),
+    consoleClient = new ConsoleClientImpl(),
+  } = {}) {
+    this.presenter = presenter;
+    this.repository = repository;
+    this.client = client;
+    this.consoleClient = consoleClient;
+  }
+
+  async startFind(keyword: string | null): Promise<void> {
+    this.presenter.clearSelection();
+    if (keyword) {
+      this.saveKeyword(keyword);
+    } else {
+      let lastKeyword = await this.getKeyword();
+      if (!lastKeyword) {
+        return this.showNoLastKeywordError();
+      }
+      this.saveKeyword(lastKeyword);
+    }
+    return this.findNext();
+  }
+
+  findNext(): Promise<void> {
+    return this.findNextPrev(false);
+  }
+
+  findPrev(): Promise<void> {
+    return this.findNextPrev(true);
+  }
+
+  private async findNextPrev(
+    backwards: boolean,
+  ): Promise<void> {
+    let keyword = await this.getKeyword();
+    if (!keyword) {
+      return this.showNoLastKeywordError();
+    }
+    let found = this.presenter.find(keyword, backwards);
+    if (found) {
+      this.consoleClient.info('Pattern found: ' + keyword);
+    } else {
+      this.consoleClient.error('Pattern not found: ' + keyword);
+    }
+  }
+
+  private async getKeyword(): Promise<string | null> {
+    let keyword = this.repository.getLastKeyword();
+    if (!keyword) {
+      keyword = await this.client.getGlobalLastKeyword();
+    }
+    return keyword;
+  }
+
+  private async saveKeyword(keyword: string): Promise<void> {
+    this.repository.setLastKeyword(keyword);
+    await this.client.setGlobalLastKeyword(keyword);
+  }
+
+  private async showNoLastKeywordError(): Promise<void> {
+    await this.consoleClient.error('No previous search keywords');
+  }
+}