package cgeo.geocaching.files;
import cgeo.geocaching.utils.Log;
import android.content.ContentResolver;
import android.net.Uri;
import android.support.annotation.NonNull;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.CharEncoding;
import org.apache.commons.lang3.StringUtils;
class FileTypeDetector {
private final ContentResolver contentResolver;
private final Uri uri;
FileTypeDetector(final Uri uri, final ContentResolver contentResolver) {
this.uri = uri;
this.contentResolver = contentResolver;
}
@NonNull
public FileType getFileType() {
InputStream is = null;
BufferedReader reader = null;
FileType type = FileType.UNKNOWN;
try {
is = contentResolver.openInputStream(uri);
if (is == null) {
return FileType.UNKNOWN;
}
reader = new BufferedReader(new InputStreamReader(is, CharEncoding.UTF_8));
type = detectHeader(reader);
} catch (final IOException e) {
if (!uri.toString().startsWith("http")) {
Log.e("FileTypeDetector", e);
}
} finally {
IOUtils.closeQuietly(reader);
IOUtils.closeQuietly(is);
}
return type;
}
private static FileType detectHeader(final BufferedReader reader)
throws IOException {
String line = reader.readLine();
if (isZip(line)) {
return FileType.ZIP;
}
// scan at most 5 lines of a GPX file
for (int i = 0; i < 5; i++) {
line = StringUtils.trim(line);
if (StringUtils.contains(line, "<loc")) {
return FileType.LOC;
}
if (StringUtils.contains(line, "<gpx")) {
return FileType.GPX;
}
line = reader.readLine();
}
return FileType.UNKNOWN;
}
private static boolean isZip(final String line) {
return StringUtils.length(line) >= 4
&& StringUtils.startsWith(line, "PK") && line.charAt(2) == 3
&& line.charAt(3) == 4;
}
}