import React, { useState } from "react";
import { StyleSheet, SafeAreaView, Text, TextInput, View } from "react-native";
import { Button} from 'native-base';
import { useTheme } from '@react-navigation/native';

function Username({route, navigation}) {
    const { colors } = useTheme();
    const [username, setUsername] = useState('');
    function checkHandleUsername() {
        fetch(localhost+'/signup/'+username, {
            method: "GET",
            headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json',
            }
        })
        .then(
            function(response) {
                if (response.status === 200 || response.status === 201) {
                    console.log('good checkUsername');
                    response.json().then(function(data) {
                        if (data.length == 0) {
                            navigation.navigate("Password", {
                                firstName: route.params.firstName,
                                lastName: route.params.lastName,
                                email: route.params.email,
                                username: username
                            });
                        } else {
                            alert("Username already exists: Please enter a different username.")
                            setUsername('');
                        }
                    })
                } else {
                    // Examine the text in the response
                    console.log('issue in handleLogin. Status code: '+ response.status);
                    alert("Unsuccessful")
                }
            }
        )
        .catch(function(err) {
            console.log('Fetch Error :-S', err);
        });       
    }

    return (
        <SafeAreaView style={ [styles.screen, {flexDirection:"column"}] }>
            <Text style={ [styles.title, {color: colors.text}] }>Enter your username:</Text>
            <Text style={ [styles.subtitle, {color: colors.text}] }>This is how others will find your profile.</Text>
            <TextInput placeholder = "purduepete" style={ [styles.input, {color: colors.text}] } value={username} onChangeText={(username) => setUsername(username)} />
            
            <View style={{flexDirection: "row"}}>
                <Button style={ styles.nextButton } onPress={checkHandleUsername}>
                    <Text style={ styles.nextText } >Next</Text>
                </Button>
            </View>
        </SafeAreaView>
	
    );
}

const styles = StyleSheet.create({
    screen:{
        marginTop: "20%",
        paddingLeft: "5%",
        paddingRight: "5%",
        paddingBottom: "30%",
        marginLeft: "10%",
        marginRight: "10%"
    },
    title: {
        fontSize: 25,
        fontWeight: "bold",
        marginTop: "10%",
        paddingBottom: "20%",
        textAlign:"left"
    },
    subtitle: {
        fontSize: 16,
        textAlign:"left",
        fontWeight: "bold",
        color: '#5c5a55'
    },
    input: {
        width: "100%",
        height: 40,
        borderBottomWidth: 1
    },
    nextButton: {
        width: '100%',
        justifyContent: 'center',
        backgroundColor: "#d4911c",
        borderRadius: 10,
        alignItems: "center",
        marginBottom: 10,
        marginTop: 50
    },
    nextText: {
        fontSize: 16,
        fontWeight: "bold",
        color: "white"
    },
});

export default Username;