Initial commit

src/im/angry/openeuicc/bridge/LpaBridgeProvider.java

@@ -0,0 +1,253 @@
+package im.angry.openeuicc.bridge;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.MatrixCursor;
+import android.net.Uri;
+
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.HashMap;
+
+public class LpaBridgeProvider extends ContentProvider
+{
+    public static final String AUTHORITY = "lpa.bridge";
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)
+    {
+        MatrixCursor rows;
+
+        final String path = uri.getLastPathSegment();
+
+        if (path == null)
+        {
+            rows = error("no_path");
+        }
+        else
+        {
+            final Map<String, String> args = getArgsFromUri(uri);
+
+            switch (path)
+            {
+                case "test":
+                    rows = handleTest(args);
+                    break;
+                default:
+                    rows = error("unknown_path");
+                    break;
+            }
+        }
+
+        return projectColumns(rows, projection, new String[] { "error" });
+    }
+
+    // region Mandatory Overrides
+
+    @Override
+    public boolean onCreate() { return true; }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) { return null; }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { return 0; }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) { return 0; }
+
+    @Override
+    public String getType(Uri uri) { return null; }
+
+    // endregion
+
+    // region Handlers
+
+    private MatrixCursor handleTest(Map<String, String> args)
+    {
+        var slotId = new int[1];
+        var portId = new int[1];
+
+        var error = requireSlotAndPort(args, slotId, portId);
+        if (error != null) return error;
+
+        return row("ok", "true");
+    }
+
+    // endregion
+
+    // region Arg Helpers
+
+    private static Map<String, String> getArgsFromUri(Uri uri)
+    {
+        var out = new HashMap<String, String>();
+
+        for (String name : uri.getQueryParameterNames())
+        {
+            out.put(name, uri.getQueryParameter(name));
+        }
+    
+        return out;
+    }
+
+    private static boolean tryGet(Map<String, String> args, String key, String[] out)
+    {
+        String arg = args.get(key);
+
+        if (arg == null || arg.isEmpty())
+            return false;
+
+        out[0] = arg;
+        return true;
+    }
+
+    private static boolean tryGetInt(Map<String, String> args, String key, int[] out)
+    {
+        String[] tmp = new String[1];
+
+        if (!tryGet(args, key, tmp))
+            return false;
+
+        try
+        {
+            out[0] = Integer.parseInt(tmp[0]);
+            return true;
+        }
+        catch (NumberFormatException ex)
+        {
+            return false;
+        }
+    }
+
+    private MatrixCursor requireSlotAndPort(Map<String, String> args, int[] slotIdOut, int[] portIdOut)
+    {
+        final String slotIdArg = "slotId";
+        final String portIdArg = "portId";
+
+        if (!tryGetInt(args, slotIdArg, slotIdOut))
+            return error("missing_arg_" + slotIdArg);
+
+        if (!tryGetInt(args, portIdArg, portIdOut))
+            return error("missing_arg_" + portIdArg);
+
+        return null;
+    }
+
+    // endregion
+
+    // region Row Helpers
+
+    private static MatrixCursor empty()
+    {
+        return new MatrixCursor(new String[0]);
+    }
+
+    private static MatrixCursor error(String message)
+    {
+        return row("error", message);
+    }
+
+    private static MatrixCursor row(String key, String value)
+    {
+        return row(new String[] { key }, value);
+    }
+
+    private static MatrixCursor row(String[] columns, Object... values)
+    {
+        var rows = new MatrixCursor(columns);
+        rows.addRow(values);
+        return rows;
+    }
+
+    private static MatrixCursor projectColumns(MatrixCursor source, String[] projection)
+    {
+        return projectColumns(source, projection, null);
+    }
+
+    private static MatrixCursor projectColumns(MatrixCursor source, String[] projection, String[] preserve)
+    {
+        if (source == null)
+            return empty();
+
+        String[] sourceCols = source.getColumnNames();
+        var cols = new LinkedHashSet<String>();
+
+        if (projection != null && projection.length > 0)
+            Collections.addAll(cols, projection);
+        else
+            Collections.addAll(cols, sourceCols);
+
+        if (preserve != null && preserve.length > 0)
+        {
+            for (String col : preserve)
+            {
+                if (col == null)
+                    continue;
+
+                boolean exists = false;
+
+                for (String sourceCol : sourceCols)
+                {
+                    if (col.equals(sourceCol))
+                    {
+                        exists = true;
+                        break;
+                    }
+                }
+
+                if (exists)
+                    cols.add(col);
+            }
+        }
+
+        if (cols.isEmpty())
+            return source;
+
+        var outCols = cols.toArray(new String[0]);
+        var out = new MatrixCursor(outCols);
+
+        while (source.moveToNext())
+        {
+            var row = new Object[outCols.length];
+
+            for (int i = 0; i < outCols.length; i++)
+            {
+                int index = source.getColumnIndex(outCols[i]);
+
+                if (index < 0)
+                {
+                    row[i] = null;
+                    continue;
+                }
+
+                switch (source.getType(index))
+                {
+                    case Cursor.FIELD_TYPE_NULL:
+                        row[i] = null;
+                        break;
+                    case Cursor.FIELD_TYPE_INTEGER:
+                        row[i] = source.getLong(index);
+                        break;
+                    case Cursor.FIELD_TYPE_FLOAT:
+                        row[i] = source.getDouble(index);
+                        break;
+                    case Cursor.FIELD_TYPE_BLOB:
+                        row[i] = source.getBlob(index);
+                        break;
+                    case Cursor.FIELD_TYPE_STRING:
+                    default:
+                        row[i] = source.getString(index);
+                        break;
+                }
+            }
+
+            out.addRow(row);
+        }
+
+        return out;
+    }
+
+    // endregion
+}