import { Injectable } from "@angular/core";
import { Observable } from "rxjs/Observable";
import { Observer } from "rxjs/Observer";

declare let gapi: any;
declare let IN: any;
declare let FB: any;

export interface IProvider {
    clientId: string;
    apiVersion?: string;
}

export interface IProviders {
    [provider: string]: IProvider;
}

@Injectable()
export class AuthService {
    gauth: any;
    
    login(provider: string): Observable<Object>{
        return Observable.create(
            (observer: Observer<Object>) => {
                switch(provider){
                    case "google":
                                    if (typeof(this.gauth) == "undefined"){
                                        this.gauth = gapi.auth2.getAuthInstance();
                                    }
                                    if(!this.gauth.isSignedIn.get()){
                                        this.gauth.signIn().then(() => {
                                            localStorage.setItem('_login_provider', 'google');
                                            observer.next(this._fetchGoogleUserDetails());
                                            observer.complete();
                                        });
                                    }else{
                                        localStorage.setItem('_login_provider', 'google');
                                        observer.next(this._fetchGoogleUserDetails());
                                        observer.complete();
                                    }
                                    
                                    break;
                    case "facebook":
                                    FB.getLoginStatus((response: any) => {
                                        if(response.status === "connected"){
                                            FB.api('/me?fields=name,email,picture', (res: any) => {
                                                if(!res || res.error){
                                                    observer.error(res.error);
                                                }else{
                                                    let userDetails = {
                                                        name: res.name, 
                                                        email: res.email, 
                                                        uid: res.id, 
                                                        provider: "facebook", 
                                                        image: res.picture.data.url,
                                                        token: response.authResponse.accessToken
                                                    }
                                                    localStorage.setItem('_login_provider', 'facebook');
                                                    observer.next(userDetails);
                                                    observer.complete();
                                                }
                                            });
                                        }
                                        else{
                                            FB.login((response: any) => {
                                                if(response.status === "connected"){
                                                    FB.api('/me?fields=name,email,picture', (res: any) => {
                                                        if(!res || res.error){
                                                            observer.error(res.error);
                                                        }else{
                                                            let userDetails = {
                                                                name: res.name, 
                                                                email: res.email, 
                                                                uid: res.id, 
                                                                provider: "facebook", 
                                                                image: res.picture.data.url,
                                                                token: response.authResponse.accessToken
                                                            }
                                                            localStorage.setItem('_login_provider', 'facebook');
                                                            observer.next(userDetails);
                                                            observer.complete();
                                                        }
                                                    });
                                                }
                                            }, {scope: 'email'});
                                        }
                                    });
                                    break;
                    case "linkedin":
                                    IN.User.authorize(function(){
                                        IN.API.Raw("/people/~:(id,first-name,last-name,email-address,picture-url)").result(function(res: any){
                                            let userDetails = {name: res.firstName + " " + res.lastName, email: res.emailAddress, uid: res.id, provider: "linkedIN", image: res.pictureUrl};
                                            localStorage.setItem('_login_provider', 'linkedin');
                                            observer.next(userDetails);
                                            observer.complete();
                                        });
                                    });
                                    break;
                }
            }
        )
    }

    logout(): Observable<boolean>{
        let provider = localStorage.getItem("_login_provider");
        return Observable.create((observer: any) => {
            switch(provider){
                case "google":
                                let gElement = document.getElementById("gSignout");
                                if (typeof(gElement) != 'undefined' && gElement != null)
                                {
                                    gElement.remove();
                                }
                                let d = document, gSignout;
                                let ref: any = d.getElementsByTagName('script')[0];
                                gSignout = d.createElement('script');
                                gSignout.src = "https://accounts.google.com/Logout";
                                gSignout.type = "text/javascript";
                                gSignout.id = "gSignout";
                                localStorage.removeItem('_login_provider');
                                observer.next(true);
                                observer.complete();
                                ref.parentNode.insertBefore(gSignout, ref);
                                break;
                case "facebook":
                                FB.logout(function(res: any){
                                    localStorage.removeItem('_login_provider');
                                    observer.next(true);
                                    observer.complete();
                                });
                                break;
                case "linkedin":
                                IN.User.logout(function(){
                                    localStorage.removeItem('_login_provider');
                                    observer.next(true);
                                    observer.complete();
                  				}, {});
                                break;
            }
        })
    }

    private _fetchGoogleUserDetails(){
        let currentUser = this.gauth.currentUser.get();
        let profile = currentUser.getBasicProfile();
        let idToken = currentUser.getAuthResponse().id_token;
        let accessToken = currentUser.getAuthResponse().access_token;
        return {
            token: idToken,
            access_token: accessToken,
            uid: profile.getId(),
            name: profile.getName(),
            email: profile.getEmail(),
            image: profile.getImageUrl(),
            provider: "google"
        };
    }
}