import React, { useState } from 'react';
import { View, StyleSheet, Alert } from 'react-native';
import { Button, Text, ProgressBar } from 'react-native-paper';
import { launchCamera } from 'react-native-image-picker';
import DocumentPicker from 'react-native-document-picker';
import axios from 'axios';

interface Props {
  onFileSelected: (fileName: string, s3Key: string) => void;
  getUploadUrl: (
    fileName: string,
  ) => Promise<{ uploadUrl: string; s3Key: string }>;
}

export function FilePickerButton({ onFileSelected, getUploadUrl }: Props) {
  const [uploading, setUploading] = useState(false);
  const [progress, setProgress] = useState(0);
  const [fileName, setFileName] = useState<string | null>(null);

  const uploadFile = async (uri: string, name: string, type: string) => {
    setUploading(true);
    setProgress(0);
    setFileName(name);

    try {
      const { uploadUrl, s3Key } = await getUploadUrl(name);

      const file = await fetch(uri);
      const blob = await file.blob();

      await axios.put(uploadUrl, blob, {
        headers: { 'Content-Type': type },
        onUploadProgress: (e) => {
          if (e.total) setProgress(e.loaded / e.total);
        },
      });

      onFileSelected(name, s3Key);
    } catch {
      Alert.alert(
        'Upload Failed',
        'Could not upload the file. Please try again.',
      );
      setFileName(null);
    } finally {
      setUploading(false);
    }
  };

  const pickDocument = async () => {
    try {
      const result = await DocumentPicker.pickSingle({
        type: [DocumentPicker.types.pdf],
      });
      if (result.uri && result.name) {
        await uploadFile(
          result.uri,
          result.name,
          result.type || 'application/pdf',
        );
      }
    } catch (err) {
      if (!DocumentPicker.isCancel(err)) {
        Alert.alert('Error', 'Could not pick document.');
      }
    }
  };

  const takePhoto = async () => {
    const result = await launchCamera({ mediaType: 'photo', quality: 0.8 });
    if (result.assets?.[0]?.uri) {
      const asset = result.assets[0];
      await uploadFile(
        asset.uri!,
        asset.fileName || 'vendor-proposal.jpg',
        asset.type || 'image/jpeg',
      );
    }
  };

  return (
    <View style={styles.container}>
      <View style={styles.buttons}>
        <Button
          mode="outlined"
          icon="file-pdf-box"
          onPress={pickDocument}
          disabled={uploading}
          style={styles.button}
        >
          Choose PDF
        </Button>
        <Button
          mode="outlined"
          icon="camera"
          onPress={takePhoto}
          disabled={uploading}
          style={styles.button}
        >
          Camera
        </Button>
      </View>
      {uploading && <ProgressBar progress={progress} style={styles.progress} />}
      {fileName && !uploading && (
        <Text variant="bodySmall" style={styles.fileName}>
          {fileName}
        </Text>
      )}
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    gap: 8,
  },
  buttons: {
    flexDirection: 'row',
    gap: 12,
  },
  button: {
    flex: 1,
  },
  progress: {
    marginTop: 4,
  },
  fileName: {
    color: '#2E7D32',
  },
});