import React from "react";
import { StyleSheet, SafeAreaView, ImageBackground, View, ScrollView, Alert, Image, Platform } from 'react-native';
import { Title, TextInput, Button, Text, Switch } from 'react-native-paper';
import API from "../API";
import * as ImagePicker from 'expo-image-picker';
import i18n from "../i18nMessages.js";

const DefaultPhoto = "https://social.emmint.com/uploads/e6f9be6d665dc43417701bf16a90122c.png";

const NewGroup = ({ navigation }) => {
    const [title, setTitle] = React.useState('');
    const [subtitle, setSubtitle] = React.useState('');
    const [description, setDescription] = React.useState('');
    const [isPrivate, setIsPrivate] = React.useState(false);
    const [isSubmitting, setIsSubmitting] = React.useState(false);
    const [selectedPhoto, setSelectedPhoto] = React.useState(null);

    const pickImage = async () => {
        if (isSubmitting) return;
        const result = await ImagePicker.launchImageLibraryAsync({
            mediaTypes: ImagePicker.MediaTypeOptions.Images,
            allowsEditing: true,
            aspect: [1, 1],
            quality: 0.6,
        });
        if (!result.canceled && result.assets?.[0]) {
            setSelectedPhoto(result.assets[0]);
        }
    };

    const handleUploadPhoto = async (photo) => {
        if (!photo) return '';
        const uri = Platform.OS === "android" ? photo.uri : photo.uri.replace("file://", "");
        const filename = photo.uri.split("/").pop() || "image.jpg";
        const match = /\.(\w+)$/.exec(filename);
        const ext = match?.[1] || "jpg";
        const type = match ? `image/${match[1]}` : "image/jpeg";
        const formData = new FormData();
        formData.append("banner", {
            uri,
            name: `image.${ext}`,
            type,
        });

        try {
            const uploaded = await fetch("https://social.emmint.com/upload.php", {
                method: "POST",
                body: formData,
                headers: { "Content-Type": "multipart/form-data" }
            })
                .then((res) => res.json())
                .then((data) => data?.fileName || '');
            return uploaded;
        } catch (error) {
            return '';
        }
    };

    const createGroup = async () => {
        const cleanTitle = title.trim();
        const cleanSubtitle = subtitle.trim();
        const cleanDescription = description.trim();

        if (!cleanTitle) {
            return Alert.alert("Missing name", "Please add a group name.");
        }
        if (!cleanDescription) {
            return Alert.alert("Missing description", "Please add a short group description.");
        }

        setIsSubmitting(true);
        try {
            const photoPath = selectedPhoto ? await handleUploadPhoto(selectedPhoto) : '';
            if (selectedPhoto && !photoPath) {
                return Alert.alert("Could not upload image", "Please try again.");
            }
            const data = await API.newGroup(cleanTitle, cleanSubtitle, cleanDescription, isPrivate, false, photoPath);
            if (data?.status !== "ok") {
                return Alert.alert("Could not create group", data?.status || "Please try again.");
            }

            setTitle('');
            setSubtitle('');
            setDescription('');
            setIsPrivate(false);
            setSelectedPhoto(null);

            if (data?._id) {
                return navigation.replace("Profile", { profileid: data._id });
            }

            Alert.alert(
                "Group created",
                "Your new group is ready. You can switch to it from the menu.",
                [{ text: "OK", onPress: () => navigation.goBack() }]
            );
        } catch (error) {
            Alert.alert("Could not create group", "Please try again.");
        } finally {
            setIsSubmitting(false);
        }
    };

    return (
        <SafeAreaView style={styles.safeArea}>
            <ImageBackground
                source={require("../assets/settings.png")}
                style={styles.background}
                imageStyle={styles.backgroundImage}
            >
                <ScrollView contentContainerStyle={styles.container}>
                    <Title style={styles.title}>{i18n.t("message.newGroup")}</Title>
                    <View style={styles.photoRow}>
                        <Image
                            source={{ uri: selectedPhoto?.uri || DefaultPhoto }}
                            style={styles.photoPreview}
                        />
                        <Button mode="outlined" icon="photo" onPress={pickImage} disabled={isSubmitting}>
                            {selectedPhoto ? i18n.t("message.changeImage") : i18n.t("message.addGroupImage")}
                        </Button>
                    </View>
                    <TextInput
                        mode="outlined"
                        label={i18n.t("message.groupName")}
                        value={title}
                        onChangeText={setTitle}
                        style={styles.input}
                    />
                    <TextInput
                        mode="outlined"
                        label={i18n.t("message.subtitleOptional")}
                        value={subtitle}
                        onChangeText={setSubtitle}
                        style={styles.input}
                    />
                    <TextInput
                        mode="outlined"
                        label={i18n.t("message.description")}
                        value={description}
                        onChangeText={setDescription}
                        multiline
                        numberOfLines={4}
                        style={styles.input}
                    />
                    <View style={styles.switchRow}>
                        <View style={styles.switchTextWrap}>
                            <Text style={styles.switchTitle}>{i18n.t("message.privateGroup")}</Text>
                            <Text style={styles.switchSubtitle}>{i18n.t("message.requireApprovalBeforeJoin")}</Text>
                        </View>
                        <Switch value={isPrivate} onValueChange={setIsPrivate} />
                    </View>
                    <Button
                        mode="contained"
                        onPress={createGroup}
                        loading={isSubmitting}
                        disabled={isSubmitting}
                        style={styles.button}
                    >
                        {i18n.t("message.createGroupAction")}
                    </Button>
                </ScrollView>
            </ImageBackground>
        </SafeAreaView>
    );
};

export default NewGroup;

const styles = StyleSheet.create({
    safeArea: {
        backgroundColor: "#edf2f7",
        flex: 1,
    },
    background: {
        flex: 1,
    },
    backgroundImage: {
        resizeMode: "contain",
        opacity: 0.05,
    },
    container: {
        padding: 14,
        paddingBottom: 24,
    },
    photoRow: {
        alignItems: "center",
        marginTop: 10,
        marginBottom: 4,
    },
    photoPreview: {
        width: 96,
        height: 96,
        borderRadius: 48,
        marginBottom: 10,
        backgroundColor: "#ddd",
    },
    title: {
        paddingBottom: 8,
        fontSize: 30,
        marginTop: 8,
        fontWeight: "bold",
        color: "#777",
    },
    input: {
        marginTop: 10,
        backgroundColor: "#fff",
    },
    switchRow: {
        marginTop: 16,
        flexDirection: "row",
        alignItems: "center",
        justifyContent: "space-between",
    },
    switchTextWrap: {
        flex: 1,
    },
    switchTitle: {
        fontSize: 16,
        fontWeight: "600",
    },
    switchSubtitle: {
        color: "#666",
        marginTop: 2,
    },
    button: {
        marginTop: 22,
    },
});