import { Injectable } from '@angular/core';
import axios, { AxiosInstance, AxiosResponse } from 'axios';
import { environment } from 'src/environments/environment';

import { Answer } from '../enums/answer.enum';
import { Poll } from '../models/poll.model';
import { HttpHeaders } from '@angular/common/http';

const apiVersion = environment.api.versionToUse;
const currentApiRoutes = environment.api.version[apiVersion];
const apiBaseHref = environment.api.version[apiVersion].baseHref;

const apiEndpoints = environment.api.endpoints;

@Injectable({
	providedIn: 'root',
})
export class ApiService {
	private axiosInstance: AxiosInstance;

	private readonly pollsEndpoint = apiEndpoints.polls.name;
	private readonly answersEndpoint = apiEndpoints.polls.answers.name;
	private readonly commentsEndpoint = apiEndpoints.polls.comments.name;
	private readonly slugsEndpoint = apiEndpoints.polls.slugs.name;
	private readonly usersEndpoint = apiEndpoints.users.name;
	private readonly usersPollsEndpoint = apiEndpoints.users.polls.name;
	private readonly usersPollsSendEmailEndpoint = apiEndpoints.users.polls.sendEmail.name;

	constructor() {
		this.axiosInstance = axios.create({ baseURL: apiBaseHref });
		this.axiosInstance.defaults.timeout = 2500;
		this.axiosInstance.defaults.headers.post['Content-Type'] = 'application/json';
		this.axiosInstance.defaults.headers.post['Accept'] = 'application/json';
		this.axiosInstance.defaults.headers.post['Charset'] = 'UTF-8';
		this.axiosInstance.defaults.headers.post['Access-Control-Allow-Methods'] = 'GET, POST, PUT, DELETE, OPTIONS';
		this.axiosInstance.defaults.headers.post['Access-Control-Allow-Origin'] = '*';
		console.log('this.axiosInstance.defaults.headers', this.axiosInstance.defaults.headers);
	}

	//////////////////////
	// CREATE OR UPDATE //
	//////////////////////
	public async createPoll(poll: any): Promise<string> {
		const dataToSend = poll;
		console.log('poll', poll);
		try {
			console.log('currentApiRoutes', currentApiRoutes);
			return await this.axiosInstance.post(`${apiBaseHref}${currentApiRoutes['api_new_poll']}`, {
				data: dataToSend,
			});
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async createParticipation(
		pollId: string,
		choiceLabel: string,
		pseudo: string,
		response: Answer
	): Promise<string> {
		try {
			return await this.axiosInstance.post(`${this.pollsEndpoint}/${pollId}${this.answersEndpoint}`, {
				choiceLabel,
				pseudo,
				response,
			});
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async createComment(slug: string, comment: string): Promise<string> {
		try {
			return await this.axiosInstance.post(`${this.pollsEndpoint}/${slug}${this.commentsEndpoint}`, comment);
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	//////////
	// READ //
	//////////
	public async getAllAvailablePolls(): Promise<Poll[]> {
		// TODO: used for facilities in DEV, should be removed in production
		try {
			const response: AxiosResponse<Poll[]> = await this.axiosInstance.get<Poll[]>(`${this.pollsEndpoint}`);
			return response?.data;
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async getPollBySlug(slug: string): Promise<Poll | undefined> {
		// TODO: identifier should be decided according to backend : Id || Slug ?
		try {
			// TODO: this interceptor should be avoided if backends returns the good object
			const adapterInterceptor: number = this.axiosInstance.interceptors.response.use(
				(response: AxiosResponse): AxiosResponse => {
					if (response.data['poll']) {
						// response from cipherbliss backend, actually used by oldstuffModule
						response.data = response.data['poll'];
					} else if (response.data[0] && response.data[0]['slug'] && response.data[0]['question']) {
						// response from local json-server
						response.data = Poll.adaptFromLocalJsonServer(response.data[0]);
					}
					return response;
				}
			);

			const response: AxiosResponse<Poll> = await this.axiosInstance.get<Poll>(`${this.pollsEndpoint}/${slug}`);
			console.log('fetch API : asking for poll with slug=' + slug, { response });

			axios.interceptors.request.eject(adapterInterceptor);

			return response && response.data && !Array.isArray(response.data) ? response.data : undefined;
		} catch (error) {
			if (error.response?.status === 404) {
				return undefined;
			} else {
				ApiService.handleError(error);
			}
		}
	}

	public async getSlug(slug: string): Promise<boolean> {
		try {
			// TODO: scenario should be : if we can get this slug, it exists. if not, it doesn't. It's just a GET.
			const response: AxiosResponse = await this.axiosInstance.get(
				`${this.pollsEndpoint}${this.slugsEndpoint}/${slug}`
			);
			if (response?.status !== 404) {
				return false;
			}
		} catch (error) {
			if (error.response?.status === 404) {
				return true;
			} else {
				ApiService.handleError(error);
			}
		}
	}

	public async sendEmailToUserOfItsPollsList(email: string): Promise<void> {
		// If user is not authenticated: the list of polls is send to user's email by the backend.
		try {
			await this.axiosInstance.get<Poll[]>(
				`${this.usersEndpoint}/${email}${this.usersPollsEndpoint}${this.usersPollsSendEmailEndpoint}`
			);
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async getPollsUrlsByUserEmail(email: string): Promise<Poll[]> {
		// If user is authenticated : retrieve polls & display directly in frontend.
		// TODO: Backend should handle this case. Actually the endpoint doesn't exist in backend.
		// Here, only the list of slugs is usefull. Maybe just handle the list of slugs.
		try {
			const response: AxiosResponse<Poll[]> = await this.axiosInstance.get<Poll[]>(
				`${this.usersEndpoint}/${email}${this.usersPollsEndpoint}`
			);
			return response?.data;
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	////////////
	// UPDATE //
	////////////
	public async updateAnswer(slug: string, choiceLabel: string, pseudo: string, answer: Answer): Promise<string> {
		try {
			return await this.axiosInstance.patch(`${this.pollsEndpoint}/${slug}${this.answersEndpoint}`, {
				choiceLabel,
				pseudo,
				answer,
			});
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	////////////
	// DELETE //
	////////////
	public async deletePoll(slug: string): Promise<boolean> {
		try {
			const response: AxiosResponse = await this.axiosInstance.delete(`${this.pollsEndpoint}/${slug}`);
			return response?.status === 204;
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async deletePollAnswers(slug: string): Promise<boolean> {
		try {
			const response: AxiosResponse = await this.axiosInstance.delete(
				`${this.pollsEndpoint}/${slug}${this.answersEndpoint}`
			);
			return response?.status === 204;
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	public async deletePollComments(slug: string): Promise<boolean> {
		try {
			const response: AxiosResponse = await this.axiosInstance.delete(
				`${this.pollsEndpoint}/${slug}${this.commentsEndpoint}`
			);
			return response?.status === 204;
		} catch (error) {
			ApiService.handleError(error);
		}
	}

	/////////////////////
	// PRIVATE METHODS //
	/////////////////////
	/**
	 * prepare headers like the charset and json type for any call to the backend
	 * @param bodyContent?
	 */
	private makeHeaders(bodyContent?: any) {
		const headerDict = {
			Charset: 'UTF-8',
			'Content-Type': 'application/json',
			Accept: 'application/json',
			'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS',
			'Access-Control-Allow-Origin': '*',
		};

		const requestOptions = {
			headers: new HttpHeaders(headerDict),
			body: bodyContent,
		};

		return requestOptions;
	}

	private static handleError(error): void {
		if (error.response) {
			// The request was made and the server responded with a status code
			// that falls out of the range of 2xx
			console.log(error.response.data);
			console.log(error.response.status);
			console.log(error.response.headers);
		} else if (error.request) {
			// The request was made but no response was received
			// `error.request` is an instance of XMLHttpRequest in the browser and an instance of
			// http.ClientRequest in node.js
			console.log(error.request);
		} else {
			// Something happened in setting up the request that triggered an Error
			console.log('Error', error.message);
		}
		console.log(error.config);
	}
}