fix #3823: detect import file type by content

5 files changed, 209 insertions, 34 deletions

diff --git a/main/src/cgeo/geocaching/files/FileType.java b/main/src/cgeo/geocaching/files/FileType.java
new file mode 100644
index 0000000..ef62351
--- /dev/null
+++ b/main/src/cgeo/geocaching/files/FileType.java
@@ -0,0 +1,8 @@
+package cgeo.geocaching.files;
+
+public enum FileType {
+    UNKNOWN,
+    LOC,
+    GPX,
+    ZIP
+}
diff --git a/main/src/cgeo/geocaching/files/FileTypeDetector.java b/main/src/cgeo/geocaching/files/FileTypeDetector.java
new file mode 100644
index 0000000..389b83a
--- /dev/null
+++ b/main/src/cgeo/geocaching/files/FileTypeDetector.java
@@ -0,0 +1,77 @@
+package cgeo.geocaching.files;
+
+import cgeo.geocaching.utils.Log;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.eclipse.jdt.annotation.NonNull;
+
+import android.content.ContentResolver;
+import android.net.Uri;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class FileTypeDetector {
+
+    private final ContentResolver contentResolver;
+    private final Uri uri;
+
+    public FileTypeDetector(Uri uri, ContentResolver contentResolver) {
+        this.uri = uri;
+        this.contentResolver = contentResolver;
+    }
+
+	public @NonNull 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));
+			type = detectHeader(reader);
+            reader.close();
+        } catch (FileNotFoundException e) {
+			Log.e("FileTypeDetector", e);
+        } catch (IOException e) {
+			Log.e("FileTypeDetector", e);
+        } finally {
+            IOUtils.closeQuietly(reader);
+            IOUtils.closeQuietly(is);
+        }
+		return type;
+    }
+
+	private static FileType detectHeader(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(String line) {
+		return StringUtils.length(line) >= 4
+				&& StringUtils.startsWith(line, "PK") && line.charAt(2) == 3
+				&& line.charAt(3) == 4;
+	}
+
+}
diff --git a/main/src/cgeo/geocaching/files/GPXImporter.java b/main/src/cgeo/geocaching/files/GPXImporter.java
index cd2f445..f87e6b9 100644
--- a/main/src/cgeo/geocaching/files/GPXImporter.java
+++ b/main/src/cgeo/geocaching/files/GPXImporter.java
@@ -14,6 +14,7 @@ import cgeo.geocaching.utils.CancellableHandler;
 import cgeo.geocaching.utils.Log;
 
 import org.apache.commons.lang3.StringUtils;
+import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 
 import android.app.Activity;
@@ -93,46 +94,77 @@ public class GPXImporter {
      *
      * @param uri
      *            URI of the file to import
-     * @param knownMimeType
-     * @param knownPathName
+     * @param mimeType
+     * @param pathName
      */
-    public void importGPX(final Uri uri, final @Nullable String knownMimeType, final @Nullable String knownPathName) {
+    public void importGPX(final Uri uri, final @Nullable String mimeType, final @Nullable String pathName) {
         final ContentResolver contentResolver = fromActivity.getContentResolver();
-        String mimeType = knownMimeType;
-        final String pathName = knownPathName != null ? knownPathName : uri.getPath();
-
-        // if mimetype can't be determined (e.g. for emulators email app), derive it from uri file extension
-        // contentResolver.getType(uri) doesn't help but throws exception for emulators email app
-        //   Permission Denial: reading com.android.email.provider.EmailProvider uri
-        // Google search says: there is no solution for this problem
-        // Gmail doesn't work at all, see #967
-        if (mimeType == null) {
-            if (StringUtils.endsWithIgnoreCase(pathName, GPX_FILE_EXTENSION) || StringUtils.endsWithIgnoreCase(pathName, LOC_FILE_EXTENSION)) {
-                mimeType = "application/xml";
-            } else {
-                // if we can't determine a better type, default to zip import
-                // emulator email sends e.g. content://com.android.email.attachmentprovider/1/1/RAW, mimetype=null
-                mimeType = "application/zip";
-            }
-        }
 
         Log.i("importGPX: " + uri + ", mimetype=" + mimeType);
-        if (GPX_MIME_TYPES.contains(mimeType)) {
-            if (StringUtils.endsWithIgnoreCase(pathName, LOC_FILE_EXTENSION)) {
-                new ImportLocAttachmentThread(uri, contentResolver, listId, importStepHandler, progressHandler).start();
-            } else {
-                new ImportGpxAttachmentThread(uri, contentResolver, listId, importStepHandler, progressHandler).start();
-            }
-        } else if (ZIP_MIME_TYPES.contains(mimeType)) {
-            new ImportGpxZipAttachmentThread(uri, contentResolver, listId, importStepHandler, progressHandler).start();
-        } else {
-            importFinished();
+		@NonNull
+		FileType fileType = new FileTypeDetector(uri, contentResolver)
+				.getFileType();
+
+		if (fileType == FileType.UNKNOWN) {
+			fileType = getFileTypeFromPathName(pathName);
+		}
+		if (fileType == FileType.UNKNOWN) {
+			fileType = getFileTypeFromMimeType(mimeType);
+		}
+
+		ImportThread importer = getImporterFromFileType(uri, contentResolver,
+				fileType);
+
+		if (importer != null) {
+			importer.start();
+		} else {
+			importFinished();
+		}
+	}
+
+	private static @NonNull FileType getFileTypeFromPathName(
+			final String pathName) {
+        if (StringUtils.endsWithIgnoreCase(pathName, GPX_FILE_EXTENSION)) {
+        		return FileType.GPX;
         }
-    }
 
-    /**
-     * Import GPX provided via intent of activity that instantiated this GPXImporter.
-     */
+	if (StringUtils.endsWithIgnoreCase(pathName, LOC_FILE_EXTENSION)) {
+		return FileType.LOC;
+	}
+		return FileType.UNKNOWN;
+	}
+
+	private static @NonNull FileType getFileTypeFromMimeType(
+			final String mimeType) {
+        if (GPX_MIME_TYPES.contains(mimeType)) {
+			return FileType.GPX;
+        } else if (ZIP_MIME_TYPES.contains(mimeType)) {
+			return FileType.ZIP;
+		}
+		return FileType.UNKNOWN;
+	}
+
+	private ImportThread getImporterFromFileType(Uri uri,
+			ContentResolver contentResolver, FileType fileType) {
+		switch (fileType) {
+		case ZIP:
+			return new ImportGpxZipAttachmentThread(uri, contentResolver,
+					listId, importStepHandler, progressHandler);
+		case GPX:
+			return new ImportGpxAttachmentThread(uri, contentResolver, listId,
+					importStepHandler, progressHandler);
+		case LOC:
+			return new ImportLocAttachmentThread(uri, contentResolver, listId,
+					importStepHandler, progressHandler);
+		default:
+			return null;
+		}
+	}
+
+	/**
+	 * Import GPX provided via intent of activity that instantiated this
+	 * GPXImporter.
+	 */
     public void importGPX() {
         final Intent intent = fromActivity.getIntent();
         final Uri uri = intent.getData();
diff --git a/tests/src/cgeo/geocaching/files/FileTypeDetectorTest.java b/tests/src/cgeo/geocaching/files/FileTypeDetectorTest.java
new file mode 100644
index 0000000..ec7b3a8
--- /dev/null
+++ b/tests/src/cgeo/geocaching/files/FileTypeDetectorTest.java
@@ -0,0 +1,51 @@
+package cgeo.geocaching.files;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import cgeo.geocaching.test.AbstractResourceInstrumentationTestCase;
+import cgeo.geocaching.test.R;
+
+import org.eclipse.jdt.annotation.NonNull;
+
+import android.content.ContentResolver;
+import android.net.Uri;
+
+public class FileTypeDetectorTest extends AbstractResourceInstrumentationTestCase {
+
+    private static class FileContentProvider extends ContentResolver {
+
+        public FileContentProvider() {
+            super(null);
+        }
+
+    }
+
+    public void testUnknown() throws Exception {
+        assertFileType(R.raw.gc2cjpf_html, FileType.UNKNOWN);
+        assertFileType(R.raw.map1, FileType.UNKNOWN);
+    }
+
+    public void testLoc() throws Exception {
+        assertFileType(R.raw.gc1bkp3_loc, FileType.LOC);
+        assertFileType(R.raw.oc5952_loc, FileType.LOC);
+        assertFileType(R.raw.waymarking_loc, FileType.LOC);
+    }
+
+    public void testGpx() throws Exception {
+        assertFileType(R.raw.gc1bkp3_gpx100, FileType.GPX);
+        assertFileType(R.raw.gc1bkp3_gpx101, FileType.GPX);
+        assertFileType(R.raw.oc5952_gpx, FileType.GPX);
+        assertFileType(R.raw.renamed_waypoints_wpts, FileType.GPX);
+        assertFileType(R.raw.waymarking_gpx, FileType.GPX);
+    }
+
+    public void testZip() throws Exception {
+        assertFileType(R.raw.pq_error, FileType.ZIP);
+        assertFileType(R.raw.pq7545915, FileType.ZIP);
+    }
+
+    private void assertFileType(final int resourceId, final @NonNull FileType fileType) {
+        final Uri resourceURI = getResourceURI(resourceId);
+        assertThat(new FileTypeDetector(resourceURI, new FileContentProvider()).getFileType()).isEqualTo(fileType);
+    }
+}
diff --git a/tests/src/cgeo/geocaching/test/AbstractResourceInstrumentationTestCase.java b/tests/src/cgeo/geocaching/test/AbstractResourceInstrumentationTestCase.java
index df8dc1f..cbad794 100644
--- a/tests/src/cgeo/geocaching/test/AbstractResourceInstrumentationTestCase.java
+++ b/tests/src/cgeo/geocaching/test/AbstractResourceInstrumentationTestCase.java
@@ -12,7 +12,9 @@ import cgeo.geocaching.files.GPX10Parser;
 import cgeo.geocaching.files.ParserException;
 import cgeo.geocaching.list.StoredList;
 
+import android.content.ContentResolver;
 import android.content.res.Resources;
+import android.net.Uri;
 import android.test.InstrumentationTestCase;
 
 import java.io.File;
@@ -102,4 +104,9 @@ public abstract class AbstractResourceInstrumentationTestCase extends Instrument
             instream.close();
         }
     }
+
+    protected Uri getResourceURI(int resId) {
+        Resources resources = getInstrumentation().getContext().getResources();
+        return Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + resources.getResourcePackageName(resId) + '/' + resources.getResourceTypeName(resId) + '/' + resources.getResourceEntryName(resId));
+    }
 }