/**
 * React Native Example for Virtual Try-On API
 * 
 * Install required packages:
 * npm install expo-image-picker expo-file-system axios
 */

import React, { useState } from 'react';
import {
  View,
  Text,
  Image,
  TouchableOpacity,
  ActivityIndicator,
  StyleSheet,
  Alert,
} from 'react-native';
import * as ImagePicker from 'expo-image-picker';
import * as FileSystem from 'expo-file-system';
import axios from 'axios';

// Replace with your Hugging Face Space URL after deployment
const API_URL = 'https://your-username-virtual-tryon-api.hf.space';

const VirtualTryOnApp = () => {
  const [personImage, setPersonImage] = useState(null);
  const [clothingImage, setClothingImage] = useState(null);
  const [resultImage, setResultImage] = useState(null);
  const [loading, setLoading] = useState(false);
  const [processingTime, setProcessingTime] = useState(null);

  // Pick person image
  const pickPersonImage = async () => {
    const result = await ImagePicker.launchImageLibraryAsync({
      mediaTypes: ImagePicker.MediaTypeOptions.Images,
      allowsEditing: true,
      aspect: [1, 1],
      quality: 1,
    });

    if (!result.canceled) {
      setPersonImage(result.assets[0].uri);
    }
  };

  // Pick clothing image
  const pickClothingImage = async () => {
    const result = await ImagePicker.launchImageLibraryAsync({
      mediaTypes: ImagePicker.MediaTypeOptions.Images,
      allowsEditing: true,
      aspect: [1, 1],
      quality: 1,
    });

    if (!result.canceled) {
      setClothingImage(result.assets[0].uri);
    }
  };

  // Method 1: Using Base64 (Recommended for React Native)
  const generateTryOnBase64 = async () => {
    if (!personImage || !clothingImage) {
      Alert.alert('Error', 'Please select both person and clothing images');
      return;
    }

    setLoading(true);
    setResultImage(null);

    try {
      // Convert images to base64
      const personBase64 = await FileSystem.readAsStringAsync(personImage, {
        encoding: FileSystem.EncodingType.Base64,
      });

      const clothingBase64 = await FileSystem.readAsStringAsync(clothingImage, {
        encoding: FileSystem.EncodingType.Base64,
      });

      // Create form data
      const formData = new FormData();
      formData.append('person_image_base64', personBase64);
      formData.append('clothing_image_base64', clothingBase64);
      formData.append('num_steps', '40'); // Adjust for speed/quality trade-off

      // Make API request
      const response = await axios.post(`${API_URL}/tryon-base64`, formData, {
        headers: {
          'Content-Type': 'multipart/form-data',
        },
        timeout: 120000, // 2 minutes timeout
      });

      if (response.data.success) {
        const imageUri = `data:image/png;base64,${response.data.image}`;
        setResultImage(imageUri);
        setProcessingTime(response.data.processing_time);
        Alert.alert('Success', `Generated in ${response.data.processing_time.toFixed(1)}s`);
      }
    } catch (error) {
      console.error('Error:', error);
      Alert.alert('Error', error.message || 'Failed to generate try-on');
    } finally {
      setLoading(false);
    }
  };

  // Method 2: Using File Upload
  const generateTryOnFiles = async () => {
    if (!personImage || !clothingImage) {
      Alert.alert('Error', 'Please select both person and clothing images');
      return;
    }

    setLoading(true);
    setResultImage(null);

    try {
      // Create form data
      const formData = new FormData();

      formData.append('person_image', {
        uri: personImage,
        type: 'image/jpeg',
        name: 'person.jpg',
      });

      formData.append('clothing_image', {
        uri: clothingImage,
        type: 'image/jpeg',
        name: 'clothing.jpg',
      });

      formData.append('return_format', 'base64');
      formData.append('num_steps', '40');

      // Make API request
      const response = await axios.post(`${API_URL}/tryon`, formData, {
        headers: {
          'Content-Type': 'multipart/form-data',
        },
        timeout: 120000,
      });

      if (response.data.success) {
        const imageUri = `data:image/png;base64,${response.data.image}`;
        setResultImage(imageUri);
        setProcessingTime(response.data.processing_time);
        Alert.alert('Success', `Generated in ${response.data.processing_time.toFixed(1)}s`);
      }
    } catch (error) {
      console.error('Error:', error);
      Alert.alert('Error', error.message || 'Failed to generate try-on');
    } finally {
      setLoading(false);
    }
  };

  return (
    <View style={styles.container}>
      <Text style={styles.title}>Virtual Try-On</Text>

      <View style={styles.imageRow}>
        <TouchableOpacity style={styles.imageContainer} onPress={pickPersonImage}>
          {personImage ? (
            <Image source={{ uri: personImage }} style={styles.image} />
          ) : (
            <View style={styles.placeholder}>
              <Text>Select Person Image</Text>
            </View>
          )}
        </TouchableOpacity>

        <TouchableOpacity style={styles.imageContainer} onPress={pickClothingImage}>
          {clothingImage ? (
            <Image source={{ uri: clothingImage }} style={styles.image} />
          ) : (
            <View style={styles.placeholder}>
              <Text>Select Clothing Image</Text>
            </View>
          )}
        </TouchableOpacity>
      </View>

      <TouchableOpacity
        style={[styles.button, loading && styles.buttonDisabled]}
        onPress={generateTryOnBase64}
        disabled={loading}
      >
        {loading ? (
          <ActivityIndicator color="#fff" />
        ) : (
          <Text style={styles.buttonText}>Generate Try-On</Text>
        )}
      </TouchableOpacity>

      {processingTime && (
        <Text style={styles.info}>Processing time: {processingTime.toFixed(1)}s</Text>
      )}

      {resultImage && (
        <View style={styles.resultContainer}>
          <Text style={styles.subtitle}>Result:</Text>
          <Image source={{ uri: resultImage }} style={styles.resultImage} />
        </View>
      )}
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    padding: 20,
    backgroundColor: '#f5f5f5',
  },
  title: {
    fontSize: 24,
    fontWeight: 'bold',
    textAlign: 'center',
    marginVertical: 20,
  },
  imageRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    marginBottom: 20,
  },
  imageContainer: {
    width: '48%',
    aspectRatio: 1,
  },
  image: {
    width: '100%',
    height: '100%',
    borderRadius: 10,
  },
  placeholder: {
    width: '100%',
    height: '100%',
    backgroundColor: '#ddd',
    borderRadius: 10,
    justifyContent: 'center',
    alignItems: 'center',
  },
  button: {
    backgroundColor: '#007AFF',
    padding: 15,
    borderRadius: 10,
    alignItems: 'center',
    marginVertical: 10,
  },
  buttonDisabled: {
    backgroundColor: '#999',
  },
  buttonText: {
    color: '#fff',
    fontSize: 16,
    fontWeight: 'bold',
  },
  info: {
    textAlign: 'center',
    color: '#666',
    marginVertical: 10,
  },
  resultContainer: {
    marginTop: 20,
    alignItems: 'center',
  },
  subtitle: {
    fontSize: 18,
    fontWeight: 'bold',
    marginBottom: 10,
  },
  resultImage: {
    width: 300,
    height: 300,
    borderRadius: 10,
  },
});

export default VirtualTryOnApp;