import { Injectable } from '@angular/core';
import {Http, Request, RequestOptionsArgs, Response, Headers} from '@angular/http';
import { Observable } from 'rxjs';
import { CacheService } from "ionic-cache";
import { Helper } from '../pages/helper';
import { AuthService } from './auth.service';

@Injectable()
export class HttpService {
    constructor(private helper: Helper,
                private auth: AuthService,
                private http: Http,
                private cache: CacheService) {}

    request(url: string | Request, options?: RequestOptionsArgs): Observable<any> {
        return this.intercept(this.http.request(url, this.getRequestOptionArgs(options)));
    }

    get(url: string, options?: RequestOptionsArgs, cache?:object): Observable<any> {
        if (cache) {
            const groupKey = cache['groupKey'] || 'default';
            const ttl = cache['ttl'] || 60 * 60 * 24 * 7;
            const cacheKey = url;
            const request = this.intercept(this.http.get(url,this.getRequestOptionArgs(options)));
            return this.cache.loadFromObservable(cacheKey, request, groupKey, ttl);
        }
        return this.intercept(this.http.get(url, this.getRequestOptionArgs(options)));
    }

    post(url: string, body: any, options?: RequestOptionsArgs): Observable<any> {
        return this.intercept(this.http.post(url, body, this.getRequestOptionArgs(options)));
    }

    put(url: string, body: any, options?: RequestOptionsArgs): Observable<any> {
        return this.intercept(this.http.put(url, body, this.getRequestOptionArgs(options)));
    }

    delete(url: string, options?: RequestOptionsArgs): Observable<any> {
        return this.intercept(this.http.delete(url, this.getRequestOptionArgs(options)));
    }

    getRequestOptionArgs(options?: RequestOptionsArgs) : RequestOptionsArgs {
        if (!options) {
            options = {
                headers: new Headers()
            }
        }

        let token = this.auth.getToken();

        if (token) {
            options.headers.set("Authorization", "JWT " + token);
        }

        options.headers.set('Content-Type', 'application/json');

        return options;
    }

    intercept(observable: Observable<Response>): Observable<any> {
        return observable
            .map(response => response.text() ? response.json() : response.text())
            .catch((err, source) => {
                const errJson = err.json();

                if (errJson && errJson.message) {
                    this.helper.alertWarn(errJson.message);
                } else if (err.status != 401 && err.status != 403 && err.status != 404) {
                    this.helper.alertWarn("Um erro inesperado ocorreu.");
                }

                return Observable.throw(err);
            });
    }

    serialize(obj) {
        let str = [];

        for(let p in obj) {
            if (obj.hasOwnProperty(p) && obj[p]) {
                str.push(encodeURIComponent(p) + "=" + encodeURIComponent(obj[p]));
            }
        }

        return str.join("&");
    }
}