//step 18
  const generateGameCode = () => {
    const letters = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'];
    let newGameCode = '';
    for (var x=0; x<4; x++) {
      newGameCode+= letters[Math.floor(Math.random() * (25 - 0 + 1) + 0)];
    }
    return checkGameCode(newGameCode);
  };


//setp 19
const checkGameCode = newGameCode => {
    return firestore().collection("ao-games").where("gameCode", "==", newGameCode)
      .get()
      .then(results => {
        if (results.size > 0) {
          return generateGameCode();
        } else {
          return saveGame(newGameCode);
        }
      })
      .catch(err => {
        return { hasError: true, value: err };
      });
  };


//step 20
const saveGame = newGameCode => {
    return firestore().collection("ao-games").add({
      gameCode: newGameCode,
      status: "waiting",
      players: [],
      owner: auth().currentUser.uid,
      answer: '',
      question: '',
    })
    .then(gameDoc => {
      return gameDoc.id;
    })
    .catch(err => {
      return { hasError: true, error: err };
    });
  };


//step 22
const joinGame = () => {
    if (gameCode.length === 4) {
      return firestore().collection("ao-games").where("gameCode", "==", gameCode.toUpperCase())
      .get()
      .then(results => {
        if (results.size > 0) {
          let thisGameDocID = null;
          results.forEach(game => {
            thisGameDocID = game.id;
          });
          setGameDocID(thisGameDocID);
          setCurrentStep('get-name');
        } else {
          setCurrentStep('error-game-not-found');
        }
      })
      .catch(err => {
        let friendlyError = { friendly: "Something has gone terribly wrong.", technical: err.toString() };
        setError(() => { throw friendlyError });
      });
    }
  };


//step 22
const createGame = () => {
    generateGameCode()
      .then(response => {
        if (!response.hasError) {
          setGameDocID(response);
          setCurrentStep('get-name');
        } else {
          let friendlyError = { friendly: "Something has gone terribly wrong.", technical: response.value !== undefined ? response.value.toString() : '' };
          setError(() => { throw friendlyError });
        }
      })
      .catch (err => {
        let friendlyError = { friendly: "Something has gone terribly wrong.", technical: err.toString() };
        setError(() => { throw friendlyError });
      });
  };


//step 25
  const updateName = () => {
    if (userName.length > 0) {
      return auth().currentUser.updateProfile({
        displayName: userName,
      })
      .then((r) => {
        props.joinGame(gameDocID);
      })
      .catch(err => {
        let friendlyError = { friendly: "Something has gone terribly wrong.", technical: err.toString() };
        setError(() => { throw friendlyError });
      });
    }
  };


//step 28
const startGame = () => {
    if ((props.GameData !== undefined) && (props.GameData.owner === props.auth.uid) && (props.GameData.players.length > 2)) {


        let questionAsker = { displayName: '', uid: '', avatar: '' };
        let answeringSpirit = { displayName: '', uid: '', avatar: '' };
        while (questionAsker.uid === answeringSpirit.uid) {
          questionAsker = getRandomPlayer(props.GameData.players);
          answeringSpirit = getRandomPlayer(props.GameData.players);
        }
        return setRoles(questionAsker, answeringSpirit)
          .then(response => {
            if (response.hasError) {
              let friendlyError = { friendly: "Something has gone terribly wrong.", technical: response.value.toString() };
              setError(() => { throw friendlyError });
            }
          });
    }
  };


//step 29
  const getRandomPlayer = players => {
    return players[Math.floor(Math.random() * players.length)];
  };



//step 30
  const setRoles = (questionAsker, answeringSpirit) => {
    return firestore().collection("ao-games").doc(props.GameID).update({
      status: "playing",
      questionAsker: questionAsker,
      answeringSpirit: answeringSpirit,
      question: '',
      answer: '',
    })
    .then(() => {
      return { hasError: false, value: null };
    })
    .catch(err => {
      return { hasError: true, value: err };
    });
  };