text: import React, { useState } from 'react'
  import { Image, Text, TextInput, TouchableOpacity, View } from 'react-native'
  import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view';
  import styles from './styles';
  import { firebase } from '../../firebase/config'
  
  export default function LoginScreen({navigation}) {
      const [email, setEmail] = useState('')
      const [password, setPassword] = useState('')
  
      const onFooterLinkPress = () => {
          navigation.navigate('Registration')
      }
  
      const onLoginPress = () => {
          firebase
              .auth()
              .signInWithEmailAndPassword(email, password)
              .then((response) => {
                  const uid = response.user.uid
                  const usersRef = firebase.firestore().collection('users')
                  usersRef
                      .doc(uid)
                      .get()
                      .then(firestoreDocument => {
                          if (!firestoreDocument.exists) {
                              alert("User does not exist anymore.")
                              return;
                          }
                          const user = firestoreDocument.data()
                          navigation.navigate('Pokedex', {user: user})
                      })
                      .catch(error => {
                          alert(error)
                      });
              })
              .catch(error => {
                  alert(error)
              })
      }
  
      return (
          <View style={styles.container}>
              <KeyboardAwareScrollView
                  style={{ flex: 1, width: '100%' }}
                  keyboardShouldPersistTaps="always">
                  <Image
                      style={styles.logo}
                      source={require('../../../assets/icon.png')}
                  />
                  <TextInput
                      style={styles.input}
                      placeholder='E-mail'
                      placeholderTextColor="#aaaaaa"
                      onChangeText={(text) => setEmail(text)}
                      value={email}
                      underlineColorAndroid="transparent"
                      autoCapitalize="none"
                  />
                  <TextInput
                      style={styles.input}
                      placeholderTextColor="#aaaaaa"
                      secureTextEntry
                      placeholder='Password'
                      onChangeText={(text) => setPassword(text)}
                      value={password}
                      underlineColorAndroid="transparent"
                      autoCapitalize="none"
                  />
                  <TouchableOpacity
                      style={styles.button}
                      onPress={() => onLoginPress()}>
                      <Text style={styles.buttonTitle}>Log in</Text>
                  </TouchableOpacity>
                  <View style={styles.footerView}>
                      <Text style={styles.footerText}>Don't have an account? <Text onPress={onFooterLinkPress} style={styles.footerLink}>Sign up</Text></Text>
                  </View>
              </KeyboardAwareScrollView>
          </View>
      )
  }
  