package de.blinkt.openvpn.fragments;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.util.Base64;
import android.webkit.MimeTypeMap;

import java.io.*;
import java.util.TreeSet;
import java.util.Vector;

public class Utils {

    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static Intent getFilePickerIntent(FileType fileType) {
        Intent i = new Intent(Intent.ACTION_OPEN_DOCUMENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        TreeSet<String> supportedMimeTypes = new TreeSet<String>();
        Vector<String> extensions = new Vector<String>();

        switch (fileType) {
            case PKCS12:
                i.setType("application/x-pkcs12");
                supportedMimeTypes.add("application/x-pkcs12");
                extensions.add("p12");
                extensions.add("pfx");
                break;
            case CERTIFICATE:
                i.setType("application/x-pem-file");
                supportedMimeTypes.add("application/x-x509-ca-cert");
                supportedMimeTypes.add("application/x-x509-user-cert");
                supportedMimeTypes.add("application/x-pem-file");
                supportedMimeTypes.add("text/plain");

                extensions.add("pem");
                extensions.add("crt");
                break;
            case KEYFILE:
                i.setType("application/x-pem-file");
                supportedMimeTypes.add("application/x-pem-file");
                supportedMimeTypes.add("application/pkcs8");
                extensions.add("key");
                break;

            case OVPN_CONFIG:
                i.setType("application/x-openvpn-profile");
                supportedMimeTypes.add("application/x-openvpn-profile");
                supportedMimeTypes.add("application/openvpn-profile");
                supportedMimeTypes.add("application/ovpn");
                extensions.add("ovpn");
                extensions.add("conf");
                break;
            case TLS_AUTH_FILE:
                i.setType("text/plain");

                // Backup ....
                supportedMimeTypes.add("application/pkcs8");
                extensions.add("txt");
                extensions.add("key");
                break;
        }

        MimeTypeMap mtm = MimeTypeMap.getSingleton();

        for (String ext : extensions) {
            String mimeType = mtm.getMimeTypeFromExtension(ext);
            if (mimeType != null)
                supportedMimeTypes.add(mimeType);
            else
                supportedMimeTypes.add("application/octet-stream");
        }

        i.putExtra(Intent.EXTRA_MIME_TYPES, supportedMimeTypes.toArray(new String[supportedMimeTypes.size()]));
        return i;
    }

    public enum FileType {
        PKCS12,
        CERTIFICATE,
        OVPN_CONFIG,
        KEYFILE,
        TLS_AUTH_FILE
    }

    static private byte[] readBytesFromStream(InputStream input) throws IOException {

        ByteArrayOutputStream buffer = new ByteArrayOutputStream();

        int nRead;
        byte[] data = new byte[16384];

        while ((nRead = input.read(data, 0, data.length)) != -1) {
            buffer.write(data, 0, nRead);
        }

        buffer.flush();
        input.close();
        return buffer.toByteArray();
    }

    public static String getStringFromFilePickerResult(FileType ft, Intent result, Context c) throws IOException {

        Uri uri = result.getData();
        if (uri ==null)
            return null;

        byte[] fileData = readBytesFromStream(c.getContentResolver().openInputStream(uri));
        String newData = null;
        switch (ft) {
            case PKCS12:
                newData = Base64.encodeToString(fileData, Base64.DEFAULT);
                break;
            default:
                newData = new String(fileData, "UTF-8");
                break;
        }
        return newData;
    }
}