import * as uuidv4 from 'uuid/v4';
import moment = require("moment");

export class AuthService {
  private userStates: Array<any> = new Array<any>();

  constructor(private config) {

  }

  public createAuthUrl(userId: string) {
    this.userStates = new Array<any>();
    let state = {
      securityToken: uuidv4(),
      userId: userId
    };

    this.signOut(userId);
    this.userStates.push(state);

    return `${this.config.baseUrl}/html/auth-start.html?authorizationUrl=` + encodeURIComponent(`https://login.microsoftonline.com/common/oauth2/v2.0/authorize?client_id=${this.config.bot.appId}&response_type=code&response_mode=query&scope=offline_access%20User.ReadBasic.All%20People.Read&state=${JSON.stringify(state)}&redirect_uri=${this.config.baseUrl}/callback`);
  }

  public getUserState(userId: string) {
    return this.userStates.find(user => user.userId == userId);
  }

  public verifyToken(token: string, userId: string): boolean {
    const storedState = this.userStates.find(state => state.securityToken === token);
    const tokenVerified = storedState.userId === userId;
    if (tokenVerified) {
      storedState.verified = true;
    }
    return tokenVerified;

  }

  public async associateAuthKey(code: any, savedState: any) {
    const res = await fetch("https://login.microsoftonline.com/common/oauth2/v2.0/token",
      {
        method: 'POST',
      body: `client_secret=${this.config.bot.appPassword}&grant_type=authorization_code&client_id=${this.config.bot.appId}&scope=offline_access%20User.ReadBasic.All%20People.Read&code=${code}&redirect_uri=${encodeURIComponent(this.config.baseUrl + "/callback")}`,
        headers:
          {
            "Content-Type": "application/x-www-form-urlencoded"
          }
      });
    const json = await res.json();
    savedState.accessToken = json.access_token;
    savedState.refreshToken = json.refresh_token;
    savedState.expiresAt = moment().add(json.expires_in-60, "s");
  }

  public async getAuthKey(userId: string): Promise<string> {
    const state = this.getUserState(userId);

    if (state && state.verified) {
      if (moment().isBefore(state.expiresAt)) {
        return state.accessToken;
      } else {
        const res = await fetch("https://login.microsoftonline.com/common/oauth2/v2.0/token",
          {
            method: 'POST',
            body: `client_secret=${this.config.bot.appPassword}&grant_type=refresh_token&client_id=${this.config.bot.appId}&refresh_token=${state.refreshToken}`,
            headers:
              {
                "Content-Type": "application/x-www-form-urlencoded"
              }
          });
        const json  = await res.json();
        state.accessToken = json.access_token;
        state.refreshToken = json.refresh_token;
        state.expiresAt = moment().add(json.expires_in-60, "s");
        return state.accessToken;
      }
    }
  }

  public signedIn(userId: string): boolean {
    return this.userStates.some(state => state.userId == userId && state.verified);
  }

  public signOut(userId: string) {
    this.userStates = this.userStates.filter(state => state.userId !== userId);
  }
}