package eu.siacs.conversations.utils;

import android.annotation.SuppressLint;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.provider.OpenableColumns;

import java.io.File;
import java.net.URL;
import java.util.List;

import de.thedevstack.conversationsplus.ConversationsPlusApplication;

import eu.siacs.conversations.entities.Transferable;

public final class FileUtils {

	/**
	 * Get a file path from a Uri. This will get the the path for Storage Access
	 * Framework Documents, as well as the _data field for the MediaStore and
	 * other file-based ContentProviders.
	 *
	 * @param uri     The Uri to query.
	 * @author paulburke
	 */
	@SuppressLint("NewApi")
	public static String getPath(final Uri uri) {
		if (uri == null) {
			return null;
		}

		final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        final Context context = ConversationsPlusApplication.getAppContext();
		// DocumentProvider
		if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
			// ExternalStorageProvider
			if (isExternalStorageDocument(uri)) {
				final String docId = DocumentsContract.getDocumentId(uri);
				final String[] split = docId.split(":");
				final String type = split[0];

				if ("primary".equalsIgnoreCase(type)) {
					return Environment.getExternalStorageDirectory() + "/" + split[1];
				}

				// TODO handle non-primary volumes
			}
			// DownloadsProvider
			else if (isDownloadsDocument(uri)) {

				final String id = DocumentsContract.getDocumentId(uri);
				final Uri contentUri = ContentUris.withAppendedId(
						Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

				return getDataColumn(context, contentUri, null, null);
			}
			// MediaProvider
			else if (isMediaDocument(uri)) {
				final String docId = DocumentsContract.getDocumentId(uri);
				final String[] split = docId.split(":");
				final String type = split[0];

				Uri contentUri = null;
				if ("image".equals(type)) {
					contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
				} else if ("video".equals(type)) {
					contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
				} else if ("audio".equals(type)) {
					contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
				}

				final String selection = "_id=?";
				final String[] selectionArgs = new String[]{
						split[1]
				};

				return getDataColumn(context, contentUri, selection, selectionArgs);
			}
		}
		// MediaStore (and general)
		else if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme())) {
			String path = getDataColumn(context, uri, null, null);
			if (path != null) {
				File file = new File(path);
				if (!file.canRead()) {
					return null;
				}
			}
			return path;
		}
		// File
		else if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
			return uri.getPath();
		}

		return null;
	}

	/**
	 * Get the value of the data column for this Uri. This is useful for
	 * MediaStore Uris, and other file-based ContentProviders.
	 *
	 * @param context       The context.
	 * @param uri           The Uri to query.
	 * @param selection     (Optional) Filter used in the query.
	 * @param selectionArgs (Optional) Selection arguments used in the query.
	 * @return The value of the _data column, which is typically a file path.
	 */
	private static String getDataColumn(Context context, Uri uri, String selection,
									   String[] selectionArgs) {

		Cursor cursor = null;
		final String column = "_data";
		final String[] projection = {
				column
		};

		try {
			cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,null);
			if (cursor != null && cursor.moveToFirst()) {
				final int column_index = cursor.getColumnIndexOrThrow(column);
				return cursor.getString(column_index);
			}
		} catch(Exception e) {
			return null;
		} finally {
			if (cursor != null) {
				cursor.close();
			}
		}
		return null;
	}


	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is ExternalStorageProvider.
	 */
	public static boolean isExternalStorageDocument(Uri uri) {
		return "com.android.externalstorage.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is DownloadsProvider.
	 */
	public static boolean isDownloadsDocument(Uri uri) {
		return "com.android.providers.downloads.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is MediaProvider.
	 */
	public static boolean isMediaDocument(Uri uri) {
		return "com.android.providers.media.documents".equals(uri.getAuthority());
	}

    public static String getRelevantExtension(URL url) {
        if (url == null) {
            return null;
        }
        String path = url.getPath();
        return getRelevantExtension(path);
    }

    public static String getRelevantExtension(String path) {
        if (path == null || path.isEmpty()) {
            return null;
        }

        String filename = path.substring(path.lastIndexOf('/') + 1).toLowerCase();

        final String lastPart = FileUtils.getLastExtension(filename);

        if (!lastPart.isEmpty()) {
            // we want the real file extension, not the crypto one
            final String secondToLastPart = FileUtils.getSecondToLastExtension(filename);
            if (!secondToLastPart.isEmpty() && Transferable.VALID_CRYPTO_EXTENSIONS.contains(lastPart)) {
                return secondToLastPart;
            } else {
                return lastPart;
            }
        }
        return null;
    }

	/**
	 * @param filename The filename to extract extension from
	 * @return last extension or empty string
	 */
	public static String getLastExtension(final String filename) {
		if (filename == null || filename.isEmpty()) {
			return "";
		}
		final int lastDotPosition = filename.lastIndexOf('.');
		final String lastPart = lastDotPosition != -1 ?
				filename.substring(lastDotPosition + 1) : "";
		return lastPart;
	}

	/**
	 * @param filename The filename to extract extension from
	 * @return second to last extension or empty string
	 */
	public static String getSecondToLastExtension(final String filename) {
		if (filename == null || filename.isEmpty()) {
			return "";
		}
		final int lastDotPosition = filename.lastIndexOf('.');
		final int secondToLastDotPosition = filename.lastIndexOf('.', lastDotPosition - 1);
		final String secondToLastPart = secondToLastDotPosition != -1 ?
				filename.substring(secondToLastDotPosition + 1, lastDotPosition) : "";
		return secondToLastPart;
	}

	/**
	 * Retrieve file size from given uri
	 * @param context actual Context
	 * @param uri uri to file
	 * @return file size or -1 in case of error
	 */
	private static long getFileSize(Context context, Uri uri) {
		Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
		if (cursor != null && cursor.moveToFirst()) {
			return cursor.getLong(cursor.getColumnIndex(OpenableColumns.SIZE));
		} else {
			return -1;
		}
	}

	/**
	 * Check for given list of uris if corresponding file sizes are all smaller than given maximum
	 * @param context actual Context
	 * @param uris list of uris
	 * @param max maximum file size
	 * @return true if all file sizes are smaller than max, false otherwise
	 */
	public static boolean allFilesUnderSize(Context context, List<Uri> uris, long max) {
		if (max <= 0) {
			return true; //exception to be compatible with HTTP Upload < v0.2
		}
		for(Uri uri : uris) {
			if (getFileSize(context, uri) > max) {
				return false;
			}
		}
		return true;
	}

	private FileUtils() {
		// Utility class - do not instantiate
	}
}