Horrific Minecraft protocol switch

            MouseButton button = MouseButton.LEFT;

            switch (packet102windowclick.shift) {
            case 0:
                // Shift key not held
                switch (packet102windowclick.button) {
                case 0:
                    button = MouseButton.LEFT;
                    break;
                case 1:
                    button = MouseButton.RIGHT;
                    break;
                default:
                    throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
                }
                break;
            case 1:
                // Shift key held
                switch (packet102windowclick.button) {
                case 0:
                    button = MouseButton.SHIFT_LEFT;
                    break;
                case 1:
                    button = MouseButton.SHIFT_RIGHT;
                    break;
                default:
                    throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
                }
            case 2:
                // Number press
                switch (packet102windowclick.button) {
                case 0:
                    button = MouseButton.NUMBER_1;
                    break;
                case 1:
                    button = MouseButton.NUMBER_2;
                    break;
                case 2:
                    button = MouseButton.NUMBER_3;
                    break;
                case 3:
                    button = MouseButton.NUMBER_4;
                    break;
                case 4:
                    button = MouseButton.NUMBER_5;
                    break;
                case 5:
                    button = MouseButton.NUMBER_6;
                    break;
                case 6:
                    button = MouseButton.NUMBER_7;
                    break;
                case 7:
                    button = MouseButton.NUMBER_8;
                    break;
                case 8:
                    button = MouseButton.NUMBER_9;
                    break;
                }
            case 3:
                // Middle click is always 3/3
                if (packet102windowclick.button != 3) {
                    throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
                }
                button = MouseButton.MIDDLE;
            case 5:
                // Painting
                if (packet102windowclick.slot == -999) {
                    // Start or stop
                    switch (packet102windowclick.button) {
                    case 0:
                        button = MouseButton.DRAG_START_LEFT;
                        break;
                    case 2:
                        button = MouseButton.DRAG_FINISH_LEFT;
                        break;
                    case 4:
                        button = MouseButton.DRAG_START_RIGHT;
                        break;
                    case 6:
                        button = MouseButton.DRAG_FINISH_RIGHT;
                        break;
                    default:
                        throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
                    }
                } else {
                    // Middle of stream
                    switch (packet102windowclick.button) {
                    case 0:
                        button = MouseButton.DRAG_LEFT;
                    case 1:
                        button = MouseButton.DRAG_RIGHT;
                    default:
                        throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
                    }
                }
                break;
            case 6:
                // Double click
                button = MouseButton.DOUBLE_CLICK;
                break;
            default:
                throw new AssertionError("Minecraft Packet 102 change! Shift=" + packet102windowclick.shift + " Button=" + packet102windowclick.button + " Slot=" + packet102windowclick.slot);
            }