import { Injectable } from '@angular/core';
import { BehaviorSubject, Observable } from 'rxjs';

import { MessageSeverity } from '../enums/message-severity.enum';
import { Answer } from '../enums/answer.enum';
import { Choice } from '../models/choice.model';
import { Poll } from '../models/poll.model';
import { User } from '../models/user.model';
import { ApiService } from './api.service';
import { ToastService } from './toast.service';

@Injectable({
	providedIn: 'root',
})
export class PollService {
	private _poll: BehaviorSubject<Poll | undefined> = new BehaviorSubject<Poll | undefined>(undefined);
	public readonly poll: Observable<Poll | undefined> = this._poll.asObservable();

	constructor(private apiService: ApiService, private toastService: ToastService) {}

	public updateCurrentPoll(poll: Poll): void {
		this._poll.next(poll);
	}

	public async getPollBySlug(slug: string): Promise<void> {
		const poll: Poll | undefined = await this.apiService.getPollBySlug(slug);
		this.updateCurrentPoll(poll);
	}

	public async saveCurrentPoll(): Promise<void> {
		const pollUrl: string = await this.apiService.createPoll(this._poll.getValue());
		// TODO: Maybe handle the url to update currentPoll according to backend response
		if (pollUrl) {
			this.toastService.display('Le sondage a été enregistré.');
		} else {
			this.toastService.display('Le sondage n’a été correctement enregistré, veuillez ré-essayer.');
		}
	}

	public saveParticipation(choice: Choice, user: User, response: Answer): void {
		const currentPoll = this._poll.getValue();
		currentPoll.choices.find((c) => c.label === choice.label)?.updateParticipation(user, response);
		this.updateCurrentPoll(currentPoll);
		this.apiService.createParticipation(currentPoll.slug, choice.label, user.pseudo, response);
		this.toastService.display(MessageSeverity.SUCCESS, 'Votre participation au sondage a été enregistrée.');
	}

	public async deleteAllAnswers(): Promise<void> {
		await this.apiService.deletePollAnswers(this._poll.getValue().slug);
		this.toastService.display(
			MessageSeverity.SUCCESS,
			'Les participations des votants à ce sondage ont été supprimées.'
		);
	}

	public async addComment(comment: string): Promise<void> {
		await this.apiService.createComment(this._poll.getValue().slug, comment);
		this.toastService.display('Votre commentaire a été enregistré.');
	}

	public async deleteComments(): Promise<void> {
		await this.apiService.deletePollComments(this._poll.getValue().slug);
		this.toastService.display('Les commentaires de ce sondage ont été supprimés.');
	}

	public buildAnswersByChoiceLabelByPseudo(poll: Poll): Map<string, Map<string, Answer>> {
		const pseudos: Set<string> = new Set();
		poll.choices.forEach((choice: Choice) => {
			choice.participants.forEach((users: Set<User>) => {
				users.forEach((user: User) => {
					pseudos.add(user.pseudo);
				});
			});
		});

		const list = new Map<string, Map<string, Answer>>();
		pseudos.forEach((pseudo: string) => {
			list.set(
				pseudo,
				new Map<string, Answer>(
					poll.choices.map((choice: Choice) => {
						return [choice.label, undefined];
					})
				)
			);
		});

		poll.choices.forEach((choice: Choice) => {
			choice.participants.forEach((users: Set<User>, answer: Answer) => {
				users.forEach((user: User) => {
					list.get(user.pseudo).set(choice.label, answer);
				});
			});
		});

		return list;
	}
}