import { CommonModule, Location } from "@angular/common";
import { Component, EventEmitter, inject, Input, OnChanges, OnDestroy, Output } from "@angular/core";
import { FormBuilder, FormControl, FormGroup, ReactiveFormsModule, Validators } from "@angular/forms";
import { MatDialogModule } from "@angular/material/dialog";
import { MatIconModule } from "@angular/material/icon";
import { MatInputModule } from "@angular/material/input";
import { MatProgressSpinnerModule } from "@angular/material/progress-spinner";
import { MatSelectModule } from "@angular/material/select";
import { MatTabsModule } from "@angular/material/tabs";
import { MatTooltipModule } from "@angular/material/tooltip";
import { map, Observable, of, Subscription } from "rxjs";
import { Category } from "../../core/rest-services/category/model/category";
import { Publication } from "../../core/rest-services/publications/model/publication";
import { CategoryService } from "../../core/service/category.service";
import { SubmitButtonComponent } from "../submit-button/submit-button.component";
import { PictureSelectionDialog } from "./picture-selection-dialog/picture-selection-dialog.component";
import { PublicationEditionService } from "./publication-edition.service";

@Component({
    selector: 'app-publication-edition',
    standalone: true,
    templateUrl: './publication-edition.component.html',
    styleUrl: './publication-edition.component.scss',
    imports: [
        CommonModule,
        MatDialogModule,
        MatIconModule,
        MatInputModule,
        MatProgressSpinnerModule,
        MatSelectModule,
        MatTabsModule,
        MatTooltipModule,
        PictureSelectionDialog,
        ReactiveFormsModule,
        SubmitButtonComponent
    ],
    providers: [PublicationEditionService]
})
export class PublicationEditionComponent implements OnChanges, OnDestroy {
    @Input()
    publication!: Publication;
    @Input()
    title!: string;
    @Input()
    isSaving$: Observable<boolean> = of(false);
    @Output()
    publicationSave = new EventEmitter<Publication>();

    publicationInEdition!: Publication;
    private readonly categoryService = inject(CategoryService);
    private readonly formBuilder = inject(FormBuilder);
    private readonly location = inject(Location);
    private readonly publicationEditionService = inject(PublicationEditionService);
    private subscriptions: Subscription[] = [];

    publicationEditionForm: FormGroup = this.formBuilder.group({
        title: new FormControl<string | undefined>('', [Validators.required]),
        description: new FormControl<string | undefined>('', [Validators.required]),
        text: new FormControl<string | undefined>('', [Validators.required]),
        illustrationId: new FormControl<string | undefined>('', [Validators.required]),
        categoryId: new FormControl<string | undefined>('', [Validators.required])
    });

    get isLoading$(): Observable<boolean> {
        return this.publicationEditionService.isLoading$;
    }

    get isPreviewing$(): Observable<boolean> {
        return this.publicationEditionService.isPreviewing$;
    }

    get categories$(): Observable<Category[]> {
        return this.categoryService.categories$
            .pipe(
                map(categories =>
                    categories.filter(category => category.subCategories.length == 0)
                    .sort(this.byNameAscComparator())
                )
            );
    }

    private byNameAscComparator(): (categoryA: Category, categoryB: Category) => number {
        return (categoryA, categoryB) => this.compareStrings(categoryA.name, categoryB.name);
    }

    private compareStrings(stringA: string, stringB: string): number {
        if (stringA < stringB) {
            return -1;
        }
        if (stringA > stringB) {
            return 1;
        }
        return 0;
    }
    
    ngOnChanges(): void {
        this.ngOnDestroy();

        this.publicationInEdition = this.publication;
        this.publicationEditionService.init(this.publicationInEdition);

        ['title', 'description', 'text'].forEach(fieldName => {
            const fieldSubscription = this.publicationEditionForm.controls[fieldName].valueChanges
                .pipe(
                    map(value => value?.length ? value as string : '')
                )
                .subscribe(fieldValue => {
                    switch (fieldName) {
                        case 'title':
                            this.publicationEditionService.editTitle(fieldValue);
                            break;
                        case 'description':
                            this.publicationEditionService.editDescription(fieldValue);
                            break;
                        case 'text':
                            this.publicationEditionService.editText(fieldValue);
                            break;
                        default:
                            break;
                    }
                });
            this.subscriptions.push(fieldSubscription);
        });

        const categoryIdChangeSubscription = this.publicationEditionForm.controls['categoryId'].valueChanges
            .subscribe(newCategoryId => {
                this.publicationEditionService.editCategoryId(newCategoryId);
            });
        this.subscriptions.push(categoryIdChangeSubscription);

        const publicationSubscription = this.publicationEditionService.state$.subscribe(state => {
            console.log(state.publication.parsedText.substring(0, 15));
            this.publicationInEdition = state.publication;
            this.publicationEditionForm.controls['title'].setValue(this.publicationInEdition.title, { emitEvent: false });
            this.publicationEditionForm.controls['description'].setValue(this.publicationInEdition.description, { emitEvent: false });
            this.publicationEditionForm.controls['text'].setValue(this.publicationInEdition.text, { emitEvent: false });
            this.publicationEditionForm.controls['illustrationId'].setValue(this.publicationInEdition.illustrationId, { emitEvent: false });
            this.publicationEditionForm.controls['categoryId'].setValue(this.publicationInEdition.categoryId, { emitEvent: false });
        });
        this.subscriptions.push(publicationSubscription);
    }

    ngOnDestroy(): void {
        this.subscriptions.forEach(subscription => subscription?.unsubscribe());
    }

    goPreviousLocation(): void {
        this.location.back();
    }

    insertTitle(titleNumber: number): void {
        this.publicationEditionService.insertTitle(titleNumber);
    }

    selectAPicture(): void {
        this.publicationEditionService.selectAPicture();
    }

    insertLink(): void {
        this.publicationEditionService.insertLink();
    }

    displayCodeBlockDialog(): void {
        this.publicationEditionService.displayCodeBlockDialog();
    }

    save(): void {
        this.publicationSave.emit(this.publicationInEdition);
    }

    displayPictureSectionDialog(): void {
        this.publicationEditionService.displayPictureSectionDialog();
    }

    updateCursorPosition(event: KeyboardEvent | MouseEvent): void {
        if (event.target) {
            const textarea = event.target as HTMLTextAreaElement;

            const positionStart = textarea.selectionStart;
            const positionEnd = textarea.selectionEnd;

            this.publicationEditionService.editCursorPosition(positionStart, positionEnd);
        }
    }

    onTabChange(tabSelectedIndex: number): void {
        if (tabSelectedIndex === 1) {
            this.publicationEditionService.loadPreview();
        }
    }
}