displaying translation link

src/app/app.module.ts

@@ -90,6 +90,7 @@ import { TutorialEnhancedComponent } from './components/tutorial-enhanced/tutori
 import { NotificationsTutorialComponent } from './components/tutorial-enhanced/notifications-tutorial/notifications-tutorial.component';
 import { LabelsTutorialComponent } from './components/tutorial-enhanced/labels-tutorial/labels-tutorial.component';
 import { ThankyouTutorialComponent } from './components/tutorial-enhanced/thankyou-tutorial/thankyou-tutorial.component';
+import { StatusTranslateComponent } from './components/stream/status/status-translate/status-translate.component';
 
 const routes: Routes = [
     { path: "", component: StreamsMainDisplayComponent },
@@ -159,7 +160,8 @@ const routes: Routes = [
         TutorialEnhancedComponent,
         NotificationsTutorialComponent,
         LabelsTutorialComponent,
-        ThankyouTutorialComponent
+        ThankyouTutorialComponent,
+        StatusTranslateComponent
     ],
     entryComponents: [
         EmojiPickerComponent

src/app/components/stream/status/status-translate/status-translate.component.html

@@ -0,0 +1,3 @@
+<div class="translation" *ngIf="isTranslationAvailable">
+    <a href class="translation__link">Translate</a>
+</div>

src/app/components/stream/status/status-translate/status-translate.component.scss

@@ -0,0 +1,13 @@
+@import "variables";
+@import "commons";
+
+.translation {
+    margin: 0 10px 0 $avatar-column-space;
+    text-align: center;
+
+    &__link {
+        font-size: 12px;
+        color: #656b8f;
+        padding: 5px;
+    }
+}

src/app/components/stream/status/status-translate/status-translate.component.spec.ts

@@ -0,0 +1,25 @@
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { StatusTranslateComponent } from './status-translate.component';
+
+describe('StatusTranslateComponent', () => {
+  let component: StatusTranslateComponent;
+  let fixture: ComponentFixture<StatusTranslateComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [ StatusTranslateComponent ]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(StatusTranslateComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

src/app/components/stream/status/status-translate/status-translate.component.ts

@@ -0,0 +1,71 @@
+import { Component, Input, OnDestroy, OnInit } from '@angular/core';
+import { Subscription } from 'rxjs';
+
+import { StatusWrapper } from '../../../../models/common.model';
+import { ILanguage } from '../../../../states/settings.state';
+import { LanguageService } from '../../../../services/language.service';
+import { InstancesInfoService } from '../../../../services/instances-info.service';
+
+@Component({
+    selector: 'app-status-translate',
+    templateUrl: './status-translate.component.html',
+    styleUrls: ['./status-translate.component.scss']
+})
+export class StatusTranslateComponent implements OnInit, OnDestroy {
+
+    private languageSub: Subscription;
+    private languagesSub: Subscription;
+
+    selectedLanguage: ILanguage;
+    configuredLanguages: ILanguage[] = [];
+
+    isTranslationAvailable: boolean;
+
+    @Input() status: StatusWrapper;
+
+    constructor(
+        private readonly languageService: LanguageService,
+        private readonly instancesInfoService: InstancesInfoService,
+    ) { }
+
+    ngOnInit() {
+        this.languageSub = this.languageService.selectedLanguageChanged.subscribe(l => {
+            if (l) {
+                this.selectedLanguage = l;
+                this.analyseAvailability();
+            }
+        });
+
+        this.languagesSub = this.languageService.configuredLanguagesChanged.subscribe(l => {
+            if (l) {
+                this.configuredLanguages = l;
+                this.analyseAvailability();
+            }
+        });
+    }
+
+    private analyseAvailability() {
+        this.instancesInfoService.getTranslationAvailability(this.status.provider)
+            .then(canTranslate => {                
+                if (canTranslate
+                    && this.configuredLanguages.length > 0
+                    && this.configuredLanguages.findIndex(x => x.iso639 === this.status.status.language) === -1) {
+
+                        console.warn('can translate');
+                    this.isTranslationAvailable = true;
+                }
+                else {
+                    this.isTranslationAvailable = false;
+                }
+            })
+            .catch(err => {
+                console.error(err);
+                this.isTranslationAvailable = false;
+            });
+    }
+
+    ngOnDestroy(): void {
+        if (this.languageSub) this.languageSub.unsubscribe();
+        if (this.languagesSub) this.languagesSub.unsubscribe();
+    }
+}

src/app/components/stream/status/status.component.html

@@ -102,6 +102,8 @@
                 (accountSelected)="accountSelected($event)" (hashtagSelected)="hashtagSelected($event)"
                 (textSelected)="textSelected()"></app-databinded-text>
 
+            <app-status-translate [status]="displayedStatusWrapper"></app-status-translate>
+
             <app-poll class="status__poll" *ngIf="!isContentWarned && displayedStatus.poll"
                 [poll]="displayedStatus.poll" [statusWrapper]="displayedStatusWrapper"></app-poll>
 

src/app/services/instances-info.service.ts

@@ -11,6 +11,7 @@ import { AccountInfo } from '../states/accounts.state';
 export class InstancesInfoService {
     private defaultMaxChars = 500;
     private cachedMaxInstanceChar: { [id: string]: Promise<number>; } = {};
+    private cachedTranslationAvailability: { [id: string]: Promise<boolean>; } = {};
     private cachedDefaultPrivacy: { [id: string]: Promise<VisibilityEnum>; } = {};
 
     constructor(private mastodonService: MastodonWrapperService) { }
@@ -65,4 +66,30 @@ export class InstancesInfoService {
         }
         return this.cachedDefaultPrivacy[instance];
     }
+
+    getTranslationAvailability(account: AccountInfo): Promise<boolean> {
+        const instance = account.instance;
+        if (!this.cachedTranslationAvailability[instance]) {
+            this.cachedTranslationAvailability[instance] = this.mastodonService.getInstance(instance)
+                .then((instance: Instance) => {
+                    if (+instance.version.split('.')[0] >= 4) {
+                        const instanceV2 = <Instancev2>instance;
+                        if (instanceV2
+                            && instanceV2.configuration
+                            && instanceV2.configuration.translation)
+                            return instanceV2.configuration.translation.enabled;
+                    } else {
+                        const instanceV1 = <Instancev1>instance;
+                        if (instanceV1 && instanceV1.max_toot_chars)
+                            return false;
+                    }
+
+                    return false;
+                })
+                .catch(() => {
+                    return false;
+                });
+        }
+        return this.cachedTranslationAvailability[instance];
+    }
 }